66009_FMXX_final.indd i
Intravascular Ultrasound Pocket Guide
Seventh Edition
Robert J. Russo, MD, PhD Director, Intravascular Imaging Program Director, Cardiac MRI Program Scripps Clinic La Jolla, CA
1/15/10 2:57:34 PM
World Headquarters Jones and Bartlett Publishers 40 Tall Pine Drive Sudbury, MA 01776 978-443-5000
[email protected] www.jbpub.com
Jones and Bartlett Publishers Canada 6339 Ormindale Way Mississauga, Ontario L5V 1J2 Canada
Jones and Bartlett Publishers International Barb House, Barb Mews London W6 7PA United Kingdom
Jones and Bartlett’s books and products are available through most bookstores and online booksellers. To contact Jones and Bartlett Publishers directly, call 800-832-0034, fax 978-443-8000, or visit our website, www.jbpub.com. Substantial discounts on bulk quantities of Jones and Bartlett’s publications are available to corporations, professional associations, and other qualified organizations. For details and specific discount information, contact the special sales department at Jones and Bartlett via the above contact information or send an email to
[email protected]. Copyright © 2011 by Jones and Bartlett Publishers, LLC All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from the copyright owner. The authors, editor, and publisher have made every effort to provide accurate information. However, they are not responsible for errors, omissions, or for any outcomes related to the use of the contents of this book and take no responsibility for the use of the products and procedures described. Treatments and side effects described in this book may not be applicable to all people; likewise, some people may require a dose or experience a side effect that is not described herein. Drugs and medical devices are discussed that may have limited availability controlled by the Food and Drug Administration (FDA) for use only in a research study or clinical trial. Research, clinical practice, and government regulations often change the accepted standard in this field. When consideration is being given to use of any drug in the clinical setting, the healthcare provider or reader is responsible for determining FDA status of the drug, reading the package insert, and reviewing prescribing information for the most up-to-date recommendations on dose, precautions, and contraindications, and determining the appropriate usage for the product. This is especially important in the case of drugs that are new or seldom used. It is our purpose to promote an understanding of intravascular ultrasound and to review examples where IVUS imaging may be helpful in diagnostic and interventional applications. Production Credits Senior Acquisitions Editor: Alison Hankey Senior Editorial Assistant: Jessica Acox Production Director: Amy Rose Associate Production Editor: Laura Almozara Senior Marketing Manager: Barb Bartoszek V.P., Manufacturing and Inventory Control: Therese Connell
Composition: Cape Cod Compositors, Inc. Interior Design: Anne Spencer Printing and Binding: Transcontinental Metrolitho Cover Printing: Transcontinental Metrolitho Cover Design: Scott Moden
Library of Congress Cataloging-in-Publication Data Russo, Robert J. Intravascular ultrasound pocket guide / Robert J. Russo. — 7th ed. p. ; cm. Includes bibliographical references and index. ISBN-13: 978-0-7637-6600-9 ISBN-10: 0-7637-6600-3 1. Blood-vessels—Ultrasonic imaging—Handbooks, manuals, etc. 2. Intravascular ultrasonography—Handbooks, manuals, etc. I. Title. [DNLM: 1. Vascular Diseases—ultrasonography—Handbooks. 2. Image Processing, Computer-Assisted—methods—Handbooks. WG 39 R969i 2011] RC691.6.U47R87 2011 616.1´307543—dc22 2009045695 6048 Printed in Canada
14 13 12 11 10
66009_FMXX_final.indd ii
10 9 8 7 6 5 4 3 2 1
1/15/10 2:57:35 PM
66009_FMXX_final.indd iii
Dedication To Sophia Grace and Isabella Rose
1/15/10 2:57:35 PM
66009_FMXX_final.indd iv
1/15/10 2:57:35 PM
66009_FMXX_final.indd v
Table of Contents Acknowledgments ................................................ vii Part I: Imaging Anatomy ............................................................................... 1 Pathology............................................................................ 15 Calcium .............................................................................. 31 Stent................................................................................... 41 Complications ..................................................................... 56 Peripheral Images ............................................................... 69 Artifacts .............................................................................. 74
Part II: Application Guideline Update ................................................................ 81 IVUS Coding ....................................................................... 83 IVUS Coding—Outpatient .............................................. 83 IVUS Coding—Physician Payment................................. 84 IVUS Catheters ................................................................... 85 IVUS Catheters—Coronary Imaging ............................... 85 IVUS Catheters—Peripheral Imaging ............................. 86 Clinical Trials....................................................................... 87 Clinical Trial—RESIST ................................................... 87 Clinical Trial—CRUISE .................................................. 88 Clinical Trial—OPTICUS ................................................ 89 Clinical Trial—TULIP ..................................................... 90 Clinical Trial—AVID ....................................................... 91 IVUS Criteria ....................................................................... 92 IVUS Criteria Bare-Metal Stent Placement—MUSIC ....... 92 IVUS Criteria Bare-Metal Stent Placement—AVID........... 93 IVUS Criteria Drug-Eluting Stent—PRAVIO/AVIO ............ 94 IVUS Criteria—Left Main Stenosis—Abizaid AS, et al. ..... 95 IVUS Criteria—Left Main Stenosis—Fassa AA, et al. ....... 96 IVUS Criteria—Left Main Stenosis—Russo RJ, et al. ....... 97 IVUS Criteria—Left Main Stenosis—Sano K, et al. .......... 98 IVUS Criteria—Non-Left Main Stenosis —Abizaid AS, et al..................................................... 99 IVUS Criteria—Non-Left Main Stenosis —Nishioka T, et al. .................................................. 100
Index................................................................. 101
1/19/10 9:38:51 AM
66009_FMXX_final.indd vi
1/15/10 2:57:35 PM
66009_FMXX_final.indd vii
Acknowledgments I would like to express my sincere gratitude to the many people at Scripps Clinic who assisted me with this handbook: Jennifer Lucisano for the seminal idea and the inspiration to publish a reference work of images in a handbook format; Heather Costa for her endless enthusiasm in the preparation of the present edition; Patricia Silva for her unequaled editing skills; Richard Schatz, Paul Teirstein, Dave Kanzari, Curtiss Stinis, and Matt Price, in addition to countless fellows in Interventional Cardiology at Scripps Clinic over the past decade who have tolerated my many requests for IVUS evaluation; and the very benevolent and patient editors at Jones and Bartlett.
1/15/10 2:57:35 PM
66009_FMXX_final.indd viii
Part I: Imaging
1/15/10 2:57:35 PM
ANATOMY
66009_PT01_final.indd 1
IVUS Sampler Guidewire
Calcium
Intima
Calcium Shadow Media
Plaque Guidewire Artifact
Adventitia
Septal Branch
Example of intravascular ultrasound imaging with a 30-MHz catheter in the mid portion of the LAD. Note blood artifact within the lumen and the crescent-shaped eccentric fibrocalcific plaque in the right upper quadrant of the artery.
Anatomy
1
1/15/10 3:01:56 PM
Three-Layer Appearance ANATOMY
IVUS of an angiographically normal segment of the distal left main coronary artery shows all three layers of a muscular artery. Moderate, circumferential intimal thickening of intermediate echogenicity is consistent with fibrous plaque. The medial layer (internal elastic lamina, smooth muscle, and external elastic lamina) is seen as a distinct, circumferential, echolucent (black) zone or structure. The outermost layer, the adventitia (comprised of collagen and elastic fibers), is seen as a circumferential, echo-bright layer surrounding the vessel and separating it from myocardium. (Note: In the absence of calcium, the adventitia represents the brightest vascular structure within the image.)
2
66009_PT01_final.indd 2
PART I Imaging
1/15/10 3:01:58 PM
ANATOMY
66009_PT01_final.indd 3
Measurements
Vessel cross-sectional area (CSA) is obtained by tracing the border between the hypoechoic media and hyperechoic adventitia (dashed line). Lumen area is measured by tracing the lumen-intima interface (dotted line). The lumen diameter is obtained by determining the smallest diameter that passes through the geometric center of the lumen (vertical line with arrows). Note that all IVUS diameter measurements have both a minimal and maximal value. The proximal and distal reference segments are defined as the most normal appearing vessel within a 10-mm segment proximal or distal to the lesion. Diameter stenosis is calculated as (reference lumen diameter – minimum lumen diameter) divided by reference lumen diameter. Plaque area is plaque+media CSA, which can be calculated by subtracting the vessel lumen CSA from the arterial CSA.
Anatomy
3
1/15/10 3:28:30 PM
Pericardium ANATOMY
Diagnostic IVUS imaging was performed in the distal portion of a large-caliber ramus intermedius. The vessel measures 1.75 mm (media-to-media) with minimal intimal thickening. In the lower left quadrant the echolucent ventricular cavity is seen. A band of myocardium (~1.5 mm) extends from the upper left to lower right portion of the image and contains the arterial lumen. On the superior edge of myocardium, the epicardial surface and visceral pericardium are identified. The echolucent pericardial space separates the visceral and parietal pericardial layers.
4
66009_PT01_final.indd 4
PART I Imaging
1/15/10 3:01:59 PM
ANATOMY
66009_PT01_final.indd 5
Normal SVG
IVUS imaging in an angiographically normal segment of a saphenous vein graft (SVG) shows minimal circumferential intimal thickening of a fibrous quality. Mediastinal fibrous tissue has engulfed the vessel as a result of wound healing. A horizontal, echolucent interface most likely represents a pericardial reflection or epicardial surface. (Note: Although a three-layer appearance may be appreciated, a saphenous vein does not contain a true adventitial layer, and, when compared to a muscular epicardial coronary artery, elastic and smooth muscle layers of the medial are significantly less prominent.)
Anatomy
5
1/15/10 3:02:01 PM
Vein Graft Anastomosis ANATOMY
Angiographic views failed to adequately visualize a lesion at the anastomosis of an SVG to the distal RCA. Ultrasound was performed within the anastomosis. On the left, the lumen of the vein graft can be seen, with modest thickening of the intimal layer. Blood echoes fill the lumen. On the right, the threelayer appearance of the native artery can be seen. Significant plaque is noted, with an intermediate or fibrous to fibrocalcific echoreflective quality. Due to the unusual plane of the imaging catheter, both vessels are viewed tangentially.
6
66009_PT01_final.indd 6
PART I Imaging
1/15/10 3:02:02 PM
ANATOMY
66009_PT01_final.indd 7
Vein Graft Valve
By angiography, a discrete, eccentric, 50% stenosis was noted in the mid-portion of an SVG. Differential angiographic diagnosis included eccentric plaque, dissection, and vein graft valve. IVUS imaging revealed mildly calcified, immobile leaflets of a vein graft valve, resulting in a 50% cross-sectional area stenosis. No other vascular pathology was visualized.
Anatomy
7
1/15/10 3:02:02 PM
Epicardial Vein ANATOMY
Pre-procedure IVUS imaging was performed in an angiographically normal portion of the mid-RCA. An eccentric vessel lumen measures 2.2 x 2.5 mm. A guidewire artifact with far-field shadowing is noted in the inferior portion of the image. The lumen of a branch vessel, septal, is also seen in the bottom of the image. Coursing over the artery in a circumferential path on the epicardial side is a cardiac vein. The vein is a thin-walled structure of 1-mm diameter. Unlike arteries, cardiac veins do not demonstrate a three-layer appearance. The identity of the vein can be confirmed by following its course to be assured that it does not communicate with the adjacent artery.
8
66009_PT01_final.indd 8
PART I Imaging
1/15/10 3:02:03 PM
ANATOMY
66009_PT01_final.indd 9
Cardiac Vein
Diagnostic IVUS was performed in the proximal portion of a medium-caliber left circumflex coronary artery. The vessel measures 3.1 mm (media-to-media) with minimal circumferential intimal thickening. In the upper left portion of the image, adjacent to the artery, a thin-walled, echolucent cardiac vein is noted. This venous structure (coronary sinus) lacks the three-layer appearance of the epicardial muscular artery.
Anatomy
9
1/15/10 3:02:03 PM
Coronary Sinus ANATOMY
Diagnostic IVUS was performed using automatic pullback in a medium- to small-caliber, non-dominant left circumflex coronary artery. Imaging was obtained from the distal vessel to the ostium. The vessel measures 2.5 mm (media-to-media) with eccentric calcified plaque noted at 12 o’clock. Superficial calcium is noted within the lesion with far-field shadowing. In the bottom portion of the image, a large echolucent space of 3 x 7 mm is noted, which represents the coronary sinus. This venous structure (coronary sinus) lacks the three-layer appearance of the epicardial muscular artery.
10 PART I Imaging
66009_PT01_final.indd 10
1/15/10 3:02:04 PM
ANATOMY
66009_PT01_final.indd 11
Extra-Vascular Space
Diagnostic IVUS was performed to assess an inconclusive lesion in a medium-caliber left main coronary artery. In the proximal portion of the vessel, prior to the left main-aortic junction, an echo-free space is noted. This non-vascular structure is a space bounded by the visceral and parietal pericardial layers and is often seen during assessment of the left main coronary artery.
Anatomy 11
1/15/10 3:02:05 PM
Coronary Spasm ANATOMY
Diagnostic IVUS was performed to assess an intermediateto high-grade lesion in the mid-portion of the left anterior descending coronary artery. The vessel lumen measures 1.9 x 2.1 mm without significant intimal pathology (plaque). In addition, very prominent medial and adventitial layers are noted. When intracoronary nitroglycerin was administered, the lumen diameter increased and the angiographic stenosis resolved. The combination of a prominent, thickened media with minimal plaque is characteristic of a vessel segment where spontaneous coronary artery spasm may occur.
12 PART I Imaging
66009_PT01_final.indd 12
1/15/10 3:29:18 PM
ANATOMY
66009_PT01_final.indd 13
Branch Vessels
Diagnostic IVUS was performed in the mid-portion of a medium caliber left anterior descending coronary artery to assess a lesion adjacent to the origin of a diagonal branch. The LAD measures 3.0 mm from media to media and contains mild superficial calcification. A diagonal branch is seen at 10 o’clock, and a septal branch is noted at 5 o’clock. The echolucent space in the lower left-hand portion of the image is the pericardial space. Although the branch vessels can be visualized, great care should be taken when evaluating for ostial disease.
Anatomy 13
1/15/10 3:02:06 PM
Contrast Flush ANATOMY
Diagnostic IVUS was performed in the distal portion of the left main coronary artery prior to elective stent placement. Superficial calcification was noted, however, the luminal dimensions could not be accurately measured. To clear the blood echoes and accurately define the luminal border, a small bolus of contrast was administered through the guide catheter. When the blood signal is removed from the image in a contrast-filled vessel, the lumen border is easily identified and accurate measurements can be made. Nonagitated saline can also be used, but contrast yields a more consistent image.
14 PART I Imaging
66009_PT01_final.indd 14
1/15/10 3:57:28 PM
PATHOLOGY
66009_PT01_final.indd 15
Transplant Atherosclerosis
Diagnostic IVUS was performed in the proximal LAD in a patient with a history of cardiac transplantation 8 years prior. IVUS imaging reveals a vessel diameter (media-to-media) of 6.0 mm (probably the result of positive compensatory remodeling). The lumen diameter measures 2.25 mm with a lumen area of 4.0 mm2. Circumferential, bulky intimal thickening is noted (1.0 to 1.75 mm) with a fibrous appearance with microcalcification that is typical of transplant vasculopathy. Diffuse microcalcification is seen in the mid-portion of the plaque layer, between 12 and 3 o’clock.
Pathology 15
1/15/10 3:02:08 PM
Lipid-Laden Plaque
PATHOLOGY
This patient was a well-trained aerobic athlete. One week after a non-Q-wave MI, a 50% angiographic stenosis was seen in the mid-portion of the LAD. Diagnostic ultrasound demonstrated an 80% relative cross-sectional area stenosis when compared to the distal reference vessel lumen. The media-to-media distance of 5.5 mm may appear to represent the early stage of vascular remodeling. However, the distal vessel was of similar size without plaque. This large plaque mass has a heterogenous appearance. Intermediate echogenecity at 5 o’clock resembles necrotic or lipid-rich plaque. Guidewire artifact is seen at 3 o’clock.
16 PART I Imaging
66009_PT01_final.indd 16
1/15/10 3:02:08 PM
PATHOLOGY
66009_PT01_final.indd 17
Ulcerated Plaque
Diagnostic IVUS was performed in the left main coronary artery after an acute myocardial infarction and primary balloon angioplasty. In this image the distal portion of the left main measures 5.0 x 5.6 mm (media-to-media). The lumen measures 2.2 x 4.0 mm. A large amount of plaque is noted with dense, superficial calcium (and far-field shadowing) in the right lower quadrant. At one o’clock, a disruption is noted in the luminal contour with ulceration extending deep into the plaque layer. This ulcerated plaque may have been the culprit triggering the anterior infarction.
Pathology 17
1/15/10 3:30:03 PM
Blood Stasis
PATHOLOGY
A stent was placed in the distal portion of a large-caliber right coronary artery. By angiography, a distal, contraststaining dissection was noted. Ultrasound reveals a bright echo-reflective area in the right lower quadrant of the vessel, representing acute blood stasis. Thrombus may appear as either an echolucent or mildly echoreflective structure with an irregular border within the lumen. Static blood, however, has a highly reflective appearance, similar in intensity to calcium or a metallic stent.
18 PART I Imaging
66009_PT01_final.indd 18
1/15/10 3:02:10 PM
PATHOLOGY
66009_PT01_final.indd 19
Complicated Left Main Plaque
Due to a hazy appearance of the left main ostium, diagnostic intravascular ultrasound was performed. IVUS shows the superior portion of the left main ostium at the top of the image, while aortic blood is seen at the bottom. Moderate superficial calcification is noted. Because the imaging catheter exits the left main with a cranially-directed, non-coaxial path, the tomographic ultrasound plane includes the superior wall of the left main coronary ostium, but not the inferior wall. For the appropriate measurement of ostial left main stenosis, the catheter must be placed in a coaxial position and images obtained that include a circumferential appearance of the lumen.
Pathology 19
1/15/10 3:02:11 PM
Pericardium and Eccentric Plaque
PATHOLOGY
Diagnostic IVUS was performed in the mid-portion of the left anterior descending coronary artery to evaluate an inconclusive lesion by angiography. The vessel measured 4 mm from media to media, with a lumen diameter of 2.0 x 3.0 mm. Minimum cross-sectional area at the lesion was 4.9 mm2, which represented a relative 60% area stenosis when compared to a distal reference segment without significant plaque. The pericardial space is noted in the lower right-hand quadrant of the image. Superficial calcium is noted with significant far-field shadowing in the upper lefthand quadrant. Plaque deposit is eccentric with pericardial accumulation greater than myocardial.
20 PART I Imaging
66009_PT01_final.indd 20
1/15/10 3:02:11 PM
PATHOLOGY
66009_PT01_final.indd 21
Thrombus 1
Diagnostic IVUS was performed within the left circumflex coronary artery to assess the results of circumflex coronary stent placement. IVUS demonstrated a large mobile structure (left-hand side of the image extending from 7 to 11 o’clock) with intermediate and homogeneous echo intensity. This angiographically occult finding by IVUS represents dissection at the proximal stent edge with discontinuity noted at 11 o’clock. In addition, deep calcification is noted on the left side of the image. The stiff, calcified wall may have provided resistance to stent balloon expansion compared to the more compliant adjacent vessel wall. Thus the interface between calcium and compliant vessel is a point of dissection.
Pathology 21
1/15/10 3:02:12 PM
Heterogenous Plaque
PATHOLOGY
Diagnostic IVUS was performed in the mid to distal portion of the left anterior descending coronary artery to assess an inconclusive lesion. The vessel measures 3.5 mm from media to media. The lumen measures 1.8 x 2.0 mm with a cross-sectional area of 2.8 mm2 and a relative cross-sectional area of stenosis of 71%. The intermediate echo intensity of the plaque is consistent with fibrocalcific disease with micro-calcification noted throughout the lesion. A collection of dense, deep calcification is noted at 8 o’clock with minimal far-field shadowing.
22 PART I Imaging
66009_PT01_final.indd 22
1/15/10 3:02:12 PM
PATHOLOGY
66009_PT01_final.indd 23
Circumferential Calcification
Penetration of the ultrasound beam at 40 MHz is dependent upon the presence of calcification, previous stent placement, vessel size, and volume of plaque burden. All decrease the penetration of ultrasound. Diagnostic IVUS was performed to assess an intermediate eccentric lesion by angiography. The IVUS image demonstrates a lumen 1.6 x 2.4 mm with a cross-sectional area of 3.0 mm2. Significant diffuse microcalcification is noted with far-field shadowing. The smallest plaque burden is noted between 7–9 o’clock with identification of the media and acceptable far-field penetration. However, this image does not allow for identification of the media or measurement of vessel area.
Pathology 23
1/15/10 3:02:13 PM
Complex Thrombus
PATHOLOGY
This patient experienced an acute inferior wall infarction treated with thrombectomy and placement of a bare metal stent. Two days later, the patient experienced reocclusion of the RCA. After infusion of a IIb/IIIa inhibitor and repeat thrombectomy, IVUS was performed. The image shows a vessel diameter (media to media) of 5.0 mm, a lumen diameter of 2.3 x 2.8 mm with an irregular luminal surface. A guidewire artifact is noted at 1 o’clock. The vessel lumen is filled with a homogeneous ultrasound signal of intermediate echogenicity which cleared after further thrombectomy and is consistent with interluminal thrombus. Note channels within the thrombus at 6 and 8 o’clock.
24 PART I Imaging
66009_PT01_final.indd 24
1/15/10 3:02:14 PM
PATHOLOGY
66009_PT01_final.indd 25
Protruding Plaque
Pre-stent placement IVUS was performed to assess an area of angiographic “haziness” in the mid-portion of the left main. IVUS reveals a lumen diameter of 3.4 mm and a vessel diameter of 4.0 mm. Guidewire artifact is seen at 10 o’clock. A very eccentric plaque with a dense superficial calcification is noted protruding into the vessel lumen at 9 o’clock. The proximity of the calcified plaque to the imaging catheter creates a large far-field shadow obscuring most of the vessel anatomy on the left side of the image. This type of plaque appearance is worrisome as guiding catheters and balloons/stents may create a dissection plane at this location.
Pathology 25
1/15/10 3:02:15 PM
High-Grade Lesion
PATHOLOGY
Diagnostic IVUS was performed within the mid-portion of the left anterior descending coronary artery to assess an inconclusive angiographic lesion. The vessel measures 3.6 mm (media-to-media). The vessel lumen measures 1.5 x 1.5 mm with a cross-sectional area of 1.8 mm2. This represents an 84% cross-sectional area stenosis. Cross-sectional area lesion severity of greater than 75% is unusual by IVUS and requires a residual lumen not much larger than the imaging catheter and a distal reference vessel of 3.5 mm or greater. The echolucent zone at 11 o’clock represents a guidewire shadow.
26 PART I Imaging
66009_PT01_final.indd 26
1/15/10 3:02:16 PM
PATHOLOGY
66009_PT01_final.indd 27
Thrombus 2
This patient with acute anterior wall myocardial infarction underwent IVUS to identify the culprit lesion within a diffusely diseased LAD. This image shows a vessel diameter of 4.3 x 4.9 mm (CSA of 16.5 mm2). The lumen measures 1.5 x 2.0 mm (CSA exclusive of thrombus 2.3 mm2; inclusive of thrombus 4.7 mm2). Thick circumferential fibrous plaque is seen. In the lumen surrounding the imaging catheter, a low intensity is noted consistent with luminal thrombus. At 4–5 o’clock a channel is noted in the thrombus, which is laminated upon superficial calcification. IVUS was used not only to identify the culprit lesion but also to determine the appropriate size of balloon and stent.
Pathology 27
1/15/10 3:02:16 PM
Ulcerated Plaque 2
PATHOLOGY
Diagnostic IVUS was performed within the mid-portion of the right coronary artery to assess an inconclusive angiographic lesion. This image shows a vessel diameter of 4.5 mm (media-to-media). The eccentric lumen measures 2.2 x 3.3 mm in diameter. A superficial defect or ulceration is noted in the fibrocalcific eccentric plaque at 9 o’clock. Guidewire artifact is seen at 2 o’clock.
28 PART I Imaging
66009_PT01_final.indd 28
1/15/10 3:02:17 PM
PATHOLOGY
66009_PT01_final.indd 29
Eccentric Complicated Plaque
A patient with unstable coronary symptoms underwent diagnostic angiography. IVUS was performed to evaluate an eccentric lesion in the proximal part of the LAD. The image demonstrates very eccentric plaque deposition. A small superficial ulcer is seen at 9 o’clock. The vessel measures 3.2 x 4.3 mm in diameter with a cross-sectional area of 11.2 mm2. The residual lumen measures 1.8 x 2.4 mm2 with a crosssectional area of 3.3 mm2 and an absolute cross-sectional area stenosis of 71%. Two areas of low image intensity are noted at 8 and 10 o’clock in the mid-portion of the plaque, and most likely represent lipid deposition. Thus, this image is consistent with unstable coronary syndrome.
Pathology 29
1/15/10 3:02:18 PM
Vulnerable Plaque
PATHOLOGY
After an inconclusive angiogram, this patient with crescendo symptoms and an abnormal CT angiogram underwent IVUS evaluation of the LAD. This image of the left main demonstrates a vessel diameter of 4.0 x 4.8 mm (CSA of 14.5 mm2). The lumen measures 2.7 x 3.7 mm (CSA of 8.4 mm2). Heterogenous, eccentric fibrocalcific plaque is noted between 3 and 7 o’clock. At 4 o’clock a thin cap of superficial calcium is noted superficial to a deeper echolucent area consistent with a lipid-rich or necrotic core. This has the appearance of a vulnerable plaque. However, the definition of a thin-cap fibroatheroma (TCFA) or vulnerable plaque is superficial calcium of <100 µm covering a necrotic core. With a resolution of 0.1 mm, IVUS cannot be used to reliably identify vulnerable or rupture-prone plaque elements or lesions.
30 PART I Imaging
66009_PT01_final.indd 30
1/15/10 3:02:18 PM
CALCIUM
66009_PT01_final.indd 31
Left Main Calcium
Diagnostic intravascular ultrasound imaging was performed in the left main coronary artery due to clinical suspicion of significant coronary calcium (without angiographic evidence of obstruction). At 4 o’clock an ulcerated plaque with superficial calcium in noted. At 3 o’clock a calcified edge of the ulcer protrudes into the lumen. In the superior portion of the lumen, plaque of intermediate to low echogenicity, which may represent mature thrombus, is seen with a dissection plane at 10 o’clock that extends behind the plaque mass.
Calcium 31
1/15/10 3:02:19 PM
Calcium with Shadowing
CALCIUM
A hazy appearance in the mid-portion of the LAD was noted on angiography. IVUS imaging reveals a complicated, calcific plaque. Spontaneous dissection behind a layer of calcium is noted in the left-hand portion of the image. Superficial and deep, dense, complicated calcium is seen superiorly, with significant far-field shadowing in the upper right-hand quadrant.
32 PART I Imaging
66009_PT01_final.indd 32
1/15/10 3:02:20 PM
CALCIUM
66009_PT01_final.indd 33
Calcium After Rotablator™
IVUS imaging was performed after rotational atherectomy. Sequential 1.75- and 2.25-mm Rotablator™ burrs were used prior to adjunct balloon angioplasty. IVUS revealed a dual or “double barrel” lumen created by sequential passes of the Rotablator burrs. The “figure of eight” appearance of the lumen represents preferential, rather than concentric, calcium ablation. The Rotablator burr appears to avoid previously treated portions of the artery that have a smooth surface. As a result of this preferential cutting of contralateral surfaces, the major axis diameter of the lumen by IVUS of 2.70 mm is 0.45 mm greater than the diameter of the largest burr used. The calcific collar of the lesion appears to have been reduced or “debulked.” However, significant calcium remains in a radial or circumferential pattern and may subsequently resist adequate stent inflation without further debulking.
Calcium 33
1/15/10 3:02:21 PM
Complex Plaque 1
CALCIUM
By angiography, a 50% lesion was noted in the mid-portion of a left main coronary artery. Ultrasound reveals a marked decrease in lumen caliber with very complex eccentric plaque. A deep layer of calcified mature plaque is noted in the superior portion of this image. Complicated plaque with spontaneous fissure planes and an intermediate echodensity occupies the luminal aspect of the large, eccentric plaque mass, consistent with mature thrombus without calcification.
34 PART I Imaging
66009_PT01_final.indd 34
1/15/10 3:02:22 PM
CALCIUM
66009_PT01_final.indd 35
Complex Plaque 2
Diagnostic IVUS of the left main was performed due to a hazy angiographic image. By IVUS, the vessel measures 3.5 x 4.1 mm (media-to-media). The vessel lumen has a bi-lobed appearance. In the right portion of the lumen, dense superficial calcification is seen that identifies this as the chronic true lumen (note far-field shadowing in the upper right). However, on the left, a non-calcified ulcer with fibrous plaque is separated from the true lumen by a calcified septum. This pattern is consistent with recent plaque rupture.
Calcium 35
1/15/10 3:02:22 PM
Superficial Calcium
CALCIUM
A 68-year-old patient with an LAD electron beam CT coronary calcium score of 2000 units and an abnormal exercise Cardiolite examination underwent diagnostic coronary angiography. An inconclusive lesion was noted in the mid LAD. IVUS imaging demonstrated a single quadrant of superficial intimal calcification with far-field shadowing (noted in the lower right). This degree of calcium by IVUS may mimic the appearance of thrombus, dissection, or an eccentric lesion by angiography. No significant obstructive lesion was noted by IVUS.
36 PART I Imaging
66009_PT01_final.indd 36
1/15/10 3:02:23 PM
CALCIUM
66009_PT01_final.indd 37
Calcified Lesion with Thrombus
This patient presented with symptoms of unstable coronary syndrome one week after RCA stent placement. An intermediate lesion was noted in the mid-distal LAD. IVUS demonstrated a vessel diameter (media-to-media) of 4.0 x 4.5 mm. The lumen diameter (inclusive of thrombus) is 2.6 x 2.9 mm with a lumen cross-sectional area of 5.8 mm2. Circumferential intimal thickening is noted measuring 0.5–1.2 mm. A rim of superficial calcification is noted extending from 4–11 o’clock. The calcified rim results in moderate beam attenuation (far-field shadowing) in the left lower quadrant. Within the lumen, layered upon the calcific rim between 5–9 o’clock, is an intermediate echodensity. In this clinical setting, the intraluminal pathology is most consistent with layered luminal thrombus. This finding resolved after the administration of a GP IIb/IIIa inhibitor.
Calcium 37
1/15/10 3:02:23 PM
Eccentric Superficial
CALCIUM
This patient with crescendo anginal symptoms underwent diagnostic coronary angiography with an inconclusive lesion within the LAD. IVUS imaging in the mid-portion of the LAD demonstrated a lumen diameter of 2.5 x 3.1 mm with a CSA of 5.6 mm2. Dense contiguous superficial calcification is noted with significant far-field shadowing of the ultrasound beam. The vessel media can be easily identified at 2–3 o’clock. However, the media, and thus the true vessel size, cannot be identified due to calcium shadowing. Caution should be used in vessel sizing in this circumstance. In addition, this appearance of contiguous, dense, superficial calcium adjacent to a normal vessel predicts dissection at the junction after balloon angioplasty alone.
38 PART I Imaging
66009_PT01_final.indd 38
1/15/10 3:02:24 PM
CALCIUM
66009_PT01_final.indd 39
Heavy Calcium
Moderate calcification was noted in the mid-portion of a medium-caliper LAD with an inconclusive lesion by angiography. IVUS demonstrated three quadrants of dense, superficial calcification with significant far-field shadowing. The lumen measures 1.5 x 3.7 mm. However, the media cannot be seen and thus the vessel diameter and lumen cannot be measured. It appears from this image that the true vessel is 4.75 mm (by visual estimate). When the non-calcified distal reference vessel is analyzed, the diameter is 3.5 x 4.7 mm (media to media), vessel area is 13.1 mm2 and the lumen area is 9.1 mm2.
Calcium 39
1/15/10 3:02:25 PM
Thin Calcific Cap
CALCIUM
After LAD stent placement, IVUS was performed to assess adjacent pathology in the distal vessel. The vessel measures 3.2 x 3.9 mm (media-to-media) with a vessel cross-sectional area of 9.8 mm2. The lumen has been cleared by contrast flush and measures 2.4 x 2.5 mm with a lumen area of 5.1 mm2. A very thin rim of dense, superficial calcification is noted between 3 and 9 o’clock without far-field shadowing. Remember that the limit of resolution of IVUS at 40–45 MHz is 0.10–0.15 mm. Thus, the diagnosis of a thin-capped fibroatheroma (TFCA) cannot be made with this imaging modality. At the present time, OCT (optical coherence tomography) would be required if the operator is concerned with “unstable” or “vulnerable” plaque.
40 PART 1 Imaging
66009_PT01_final.indd 40
1/15/10 3:02:25 PM
STENT
66009_PT01_final.indd 41
Stent Placement
A self-expanding bare-metal stent was placed within the midportion of an RCA and post-dilated with a 3.5 mm balloon. An excellent angiographic appearance was obtained. This IVUS image demonstrates the three fundamentals of stent placement: apposition of stent struts to the vessel wall, full expansion, and lack of sign dissection.
Stent 41
1/15/10 3:02:26 PM
Stent in a Stent
STENT
Overlapping bare-metal stents were previously placed in the mid-LAD. Subsequently, the patient required placement of an additional bare-metal stent for symptomatic in-stent restenosis. Six months later, diagnostic IVUS was performed. Moderate neointimal hyperplasia is noted within the stent (with reduction of the lumen to 1.9 mm). All three concentric stent layers are seen as discrete, echobright structures. However, in the far-field (best appreciated in the left-upper quadrant) echobright stent artifacts (stent ghosts) are noted at multiples of the catheter-to-stent distance.
42 PART I Imaging
66009_PT01_final.indd 42
1/15/10 3:02:27 PM
STENT
66009_PT01_final.indd 43
Coil Stent Signature
Diagnostic intravascular ultrasound was performed to assess an intermediate lesion in the mid-portion of the left circumflex coronary artery. An unexpected finding in the restenotic lesion was the ultrasound signature of a bare-metal redundant coil wire stent. Unlike a tubular stent, only a portion of the redundant coil can be visualized in a single imaging plane. The echoreflective 90-degree arc on the luminal surface at 9 o’clock is a portion of the coil stent.
Stent 43
1/15/10 3:02:28 PM
Stent Non-Apposition
STENT
A 4.0-mm stent was placed within the ostium of a largecaliber, dominant RCA, with an excellent angiographic result. However, intravascular ultrasound revealed stent expansion of 4.0 mm within a 5.0-mm vessel at the distal stent margin. Stent non-apposition in the lower right-hand quadrant of the image was confirmed by coronary contrast injection through the guiding catheter to clear the blood and improve visualization of the space between the stent and the vessel wall.
44 PART I Imaging
66009_PT01_final.indd 44
1/15/10 3:02:28 PM
STENT
66009_PT01_final.indd 45
Crushed Stent
Six months after stent replacement at an anastamosis of an SVG to the RCA, PTCA was performed for in-stent restenosis. The procedure was complicated by difficult balloon passage. IVUS was performed to assess the procedural complication. IVUS shows the echobright struts of a compressed stent on the right side of the vein graft lumen. The guidewire had been passed between the unapposed stent and the wall of the vein graft and then through a stent strut. When the balloon was inflated, the proximal stent was partially compressed. IVUS was subsequently used to direct guidewire passage through the stent lumen, and appropriate stent expansion was accomplished.
Stent 45
1/15/10 3:02:29 PM
Neointimal Hyperplasia
STENT
IVUS imaging performed for in-stent restenosis within a highgrade angiographic lesion reveals discrete stent struts and an eccentric lumen (major axis 2.6 mm). An intermediate echodensity within the circumference of the stent represents neointimal growth. The image was obtained one year after stent placement. The time interval between stent placement and IVUS assessment accounts for the intermediate echogenicity of the neointimal layer. Neointimal hyperplasia usually has a near-translucent appearance when IVUS images are obtained within six months after stent placement.
46 PART I Imaging
66009_PT01_final.indd 46
1/15/10 3:02:29 PM
STENT
66009_PT01_final.indd 47
Side-Branch Stent
A bare-metal stent was placed in the ostium of a first diagonal branch. IVUS was performed to assess angiographic haziness within the LAD at the diagonal origin after stent placement. In the upper-right quadrant of this image, the echobright proximal edge of the stent can be seen extending into the lumen of the LAD. Note the elliptical configuration of the stent edge as the struts enter the imaging plane from an oblique angle formed by the origin of the diagonal branch.
Stent 47
1/15/10 3:02:30 PM
Stented Side Branch
STENT
Drug-eluting stent placement was performed 3.5 years prior to repeat coronary angiography. During the initial procedure, bifurcation stent placement was performed delivering a 3.0-mm drug-eluting stent within the LAD and a 2.5-mm drug-eluting stent in a diagonal branch vessel. Diagnostic IVUS within the LAD demonstrates a well-apposed stent without significant in-stent restenosis and a stent lumen diameter of 2.8 mm. At 8 o’clock, in the left lower quadrant, a stent is seen in cross-section within the proximal portion of a diagonal branch. Although the branch vessel stent is well seen, caution should be used when evaluating the lumen. If the ostium of the branch vessel is in question then the vessel should be wired and IVUS performed.
48 PART I Imaging
66009_PT01_final.indd 48
1/15/10 3:02:31 PM
STENT
66009_PT01_final.indd 49
Crushed Stent
Diagnostic IVUS was performed in the left main coronary artery to assess a previously placed bare-metal stent and proximal left anterior descending coronary artery. Angiography showed a widely patent left main and an inconclusive stenosis within the proximal LAD. IVUS demonstrates two contiguous stent layers in the lower left-hand quadrant of the image. Previously, overlapping stents had been placed and post-dilated to 4.5 mm. IVUS imaging suggests that during the procedure, guidewire position was lost and reestablished between the stent and vessel wall. Then, when the stent was post-dilated, it was crushed leaving a circular imprint on the surface of the stent (between 6–10 o’clock). If necessary, the IVUS catheter could be left in its present position to facilitate wire reintroduction into the lumen of the crushed stent.
Stent 49
1/15/10 3:02:32 PM
Left Main Stent
STENT
The patient underwent left main coronary stent placement. A 3.0-mm drug-eluting stent was placed within the LAD and a 2.75-mm drug-eluting stent within the left circumflex in a side-by-side fashion. IVUS was performed from the mid-left circumflex for post-procedural assessment. The IVUS catheter is within the circumflex stent, which measures 1.6 x 2.3 mm. Below the circumflex stent is the “D” shaped LAD stent, which measures 1.8 x 3.2 mm.
50 PART I Imaging
66009_PT01_final.indd 50
1/15/10 3:02:32 PM
STENT
66009_PT01_final.indd 51
In-Stent Restenosis
The patient underwent bare-metal stent placement in the right coronary artery receiving a 3.5-mm bare-metal stent 4 months prior to repeat percutaneous coronary intervention. Diagnostic angiography showed a high-grade lesion within the proximal RCA. Diagnostic IVUS was performed to differentiate stent underexpansion from in-stent restenosis. IVUS demonstrates a well-apposed stent with a diameter of 3.4 mm. However, the stent lumen is filled with a homogeneous tissue consistent with neointimal hyperplasia. The intermediate echogenicity and the lack of calcification suggests that the tissue ingrowth is less than one year old. The residual lumen measures 1.9 x 1.9 mm in diameter, with a cross-sectional area of 2.8 mm and a relative crosssectional area of stenosis of 69%.
Stent 51
1/15/10 3:02:33 PM
Stent Non-Apposition
STENT
Sequential 3.5-mm drug-eluting stents were placed within a saphenous vein graft to an obtuse marginal branch of the left circumflex. After stent placement, IVUS was performed to confirm adequate stent apposition and to exclude dissection. The stent has been expanded to 3.5 mm. However, at this position the vessel diameter measures 4.9 mm. Half of the stent struts are unapposed to the vessel wall from 4–12 o’clock in a clockwise direction. Although non-apposition is clearly visualized, contrast or saline injection through the guide catheter would flush the blood echoes from the lumen and clearly demonstrate nonapposition of the stent.
52 PART I Imaging
66009_PT01_final.indd 52
1/15/10 3:02:34 PM
STENT
66009_PT01_final.indd 53
Three-Layer Stent
A patient with a longstanding history of coronary artery disease underwent diagnostic coronary angiography for symptoms of unstable coronary syndrome. Over the preceding decade, the patient had undergone multiple percutaneous coronary revascularization procedures, receiving a total of 12 stents (both bare-metal and drug-eluting stents). IVUS shows a lumen diameter of 2.0 x 2.3 mm with a cross-sectional area of 3.6 mm2. Three stent layers can be easily identified. Ultrasound penetration can be seen between stent layers extending into the left lower quadrant of the image. Clinically, this represents an area of stent overlap at the time of the initial procedure (two layers). Subsequently in-stent restenosis was treated with an additional stent (the third layer). Distinct far-field reverberation artifacts (ghosts) are not seen in this image.
Stent 53
1/15/10 3:02:35 PM
Thrombus 3
STENT
A patient underwent percutaneous coronary intervention for a symptomatic chronically-occluded right coronary artery. After the total occlusion was crossed, and three drug-eluting stents were placed, intravascular ultrasound was performed. This image at the distal stent edge shows an eccentric stent lumen 2.5 x 2.9 mm after treatment with a 3.0-mm balloon. Protruding into the vessel lumen at 11 o’clock, a mobile structure of intermediate echogenicity is noted. Because the image was obtained immediately after stent placement at the stent edge, the interluminal pathology most likely represents atheroma secondary to dissection plus thrombus.
54 PART I Imaging
66009_PT01_final.indd 54
1/15/10 3:02:37 PM
STENT
66009_PT01_final.indd 55
Under-Expanded Small Stent
A patient underwent percutaneous coronary intervention for an acute anterior wall myocardial infarction. Diagnostic angiography revealed an occluded LAD treated with aspiration for intraluminal thrombus followed by coronary stent placement. A 2.5-mm drug-eluting stent was placed in the mid-portion of the vessel with an adequate angiographic appearance. However, IVUS demonstrated an underdilated stent measuring 2.0 x 2.0 mm, a cross-sectional area of 3.1 mm2, and a distal reference vessel area of 6.5 mm2 (52% CSA stenosis). The stent was then postdilated with a 3.0-mm balloon.
Stent 55
1/15/10 3:02:38 PM
Left Main Dissection
COMPLICATIONS
During elective stent placement in the proximal LCx, a filling defect was noted in the distal left main. Diagnostic IVUS revealed a 4.0 x 4.5-mm vessel (media-to-media), with circumferential, fibrocalcific plaque. In the inferior portion of the lumen, a heterogenous atheroma is noted with discontinuity of the vessel wall at 6 o’clock. On the superior surface of the atheroma is a thin, echoreflective filament (mobile in dynamic images). This probably represents an acute-upon-chronic thrombus after plaque dissection.
56 PART I Imaging
66009_PT01_final.indd 56
1/15/10 3:02:38 PM
A stent was placed in a large-caliber, dominant RCA. Six hours after the procedure the patient experienced symptoms of an acute inferior wall myocardial infarction. By angiography, TIMI grade 1 flow was documented with suggestion of a spiral dissection. IVUS demonstrates a circumferential intramural hematoma. The central portion of the image shows the true vessel lumen and media. The echobright region surrounding the true lumen represents an intramural hematoma that has acutely expanded the vessel to 8 mm in diameter (adventitia-to-adventitia).
COMPLICATIONS
66009_PT01_final.indd 57
Intramural Hematoma 1
Complications 57
1/15/10 3:02:39 PM
Intramural Hematoma 2
COMPLICATIONS
Balloon angioplasty was performed in the proximal left anterior descending coronary artery. By angiography, a small, linear dissection was noted at the site of balloon inflation. IVUS demonstrated an intermediate echodensity representing an intramural hematoma in the left-hand portion of the image. The hematoma displaces the easily identified true lumen and media (circumferential echolucent zone) to the right.
58 PART I Imaging
66009_PT01_final.indd 58
1/15/10 3:02:40 PM
A stent was placed within the mid-RCA with an excellent angiographic result. No dissection was visible. However, IVUS imaging showed a significant dissection with superficial intimal tear proximal to the stent. In addition, a significant Type C dissection is noted in the upper left-hand quadrant, which represents a full-thickness tear of the intima, extending into the medial layer and behind the layer of plaque. (Type C is a dissection behind the plaque that subtends an arc of up to 180 degrees around the circumference of the vessel.)
COMPLICATIONS
66009_PT01_final.indd 59
Dissection of Native Vessel
Complications 59
1/15/10 3:02:41 PM
SVG Dissection
COMPLICATIONS
A mobile, Type B dissection of significant size is noted. The point of intimal disruption at 10 o’clock can be easily visualized. In addition, dissection has exposed the deep elements of the vein graft wall noted in the left lower quadrant. Although this dissection appears highly significant, it was occult to angiographic detection. (Type B is defined by a split in the plaque that extends to the media.)
60 PART I Imaging
66009_PT01_final.indd 60
1/15/10 3:02:41 PM
Diagnostic IVUS of an SVG was performed to assess lesion severity with a mechanical imaging catheter. During the first imaging sequence, eccentric fibrous plaque was noted without calcification. However, on the second sequence, a poor image was obtained. Degradation in the image quality was thought to be due to a bubble trapped on the surface of the transducer. As a result, the imaging catheter was flushed. Subsequently, multiple, discrete, echobright areas were seen (left side of the image) with dense far-field shadowing. This most likely represents the appearance of microbubbles embedded into the surface of the soft plaque when the imaging catheter was flushed.
COMPLICATIONS
66009_PT01_final.indd 61
Embedded Microbubbles
Complications 61
1/15/10 3:02:42 PM
False Lumen 1
COMPLICATIONS
Angiography of an RCA two years after laser angioplasty demonstrated a “double barrel” appearance with equal lumen calibers. Diagnostic intravascular ultrasound was performed prior to stent placement to differentiate the true from the false lumen. The side-branch vessel at 6 o’clock identifies the lumen on the left side as the true lumen. The vessel wall of the false lumen, seen on the right, lacks a three-layer appearance.
62 PART I Imaging
66009_PT01_final.indd 62
1/15/10 3:02:43 PM
The patient underwent PCI for a chronic total occlusion of a dominant RCA, which filled via right-to-right collateral flow. The lesion was crossed easily with a guidewire, however, an extensive dissection was noted after a drug-eluting 4.0-mm stent placement. Diagnostic IVUS was performed to differentiate true from false lumen. Two lumens are noted on IVUS. The larger blood-filled lumen (on the right) is circular with “septum” or dissection flap bowing toward the smaller lumen. The imaging catheter is in the smaller of the two lumens, which has an intact wall (between 7 and 11 o’clock) with a three-layered appearance. This is the true lumen. A side branch could also be used to identify the true lumen.
COMPLICATIONS
66009_PT01_final.indd 63
False Lumen 2
Complications 63
1/15/10 3:02:43 PM
Dissection Distal LM
COMPLICATIONS
Stent placement was performed within a long LAD lesion. However, after stent deployment, vessel perforation was noted requiring balloon occlusion and subsequent placement of a covered-stent. IVUS was performed to determine the extent of dissection within the left anterior descending and left main coronary arteries. By IVUS, the plane of dissection begins at 10 o’clock and extends inferiorly into the complicated calcified plaque at 3–4 o’clock. The point of vessel discontinuity is at 8 o’clock with a large 0.5–0.75-mm dissection plane. Significant far-field shadowing is noted on the right side of the image behind the calcified plaque.
64 PART I Imaging
66009_PT01_final.indd 64
1/15/10 3:02:44 PM
The patient underwent drug-eluting stent placement within a free radial artery bypass graft to the left anterior descending coronary artery. IVUS was performed to confirm optimal stent deployment and to exclude arterial graft dissection. The radial artery measures 2.9 mm in diameter (media-to-media). Two equal, contrast-filled lumens are noted. The imaging catheter is within the true lumen on the left side of the image. The lumen on the left is filled with contrast and has a multilayered appearance. The lumen on the right is the false lumen. The epicardial surface of the heart is seen in the superior portion of the image.
COMPLICATIONS
66009_PT01_final.indd 65
Dissection 1
Complications 65
1/15/10 3:02:45 PM
Dissection 2
COMPLICATIONS
This patient underwent stent placement within a free radial artery bypass graft to the LAD. After non-overlapping 2.5 x 13-mm stents were placed, a dissection by angiography was noted between stented segments. This image shows the IVUS catheter within a lumen that measures 2.1 x 2.2 mm (CSA of 3.54 mm2). A second lumen on the right side of the vessel is without blood (filled with contrast) and does not have an identifiable medial layer. As a free arterial graft, the adventitia is not usually seen. The second lumen is the false lumen and is slightly smaller with a CSA of 2.58 mm2.
66 PART I Imaging
66009_PT01_final.indd 66
1/15/10 3:02:45 PM
This patient with multivessel coronary artery disease underwent 3-vessel stent placement. IVUS was performed to assess the results of left main-to-proximal LAD stent placement due to concerns regarding intraluminal thrombus. This IVUS image obtained within the mid portion of the stented area shows a stent with eccentric deployment. The stent measures 3.4 x 3.9 mm (CSA 10.3 mm2). An intermediate and mobile echodensity is noted extending from the upper-right quadrant and adherent to the imaging catheter. The heterogenous speckled appearance with amorphous shape, luminal mobility, and location are consistent with the acute formation of thrombus. In this setting, an injection of contrast or saline may also be helpful for identification of thrombus.
COMPLICATIONS
66009_PT01_final.indd 67
Thrombus 4
Complications 67
1/15/10 3:02:46 PM
False Lumen 3
COMPLICATIONS
This patient underwent PCI for a chronically occluded RCA. The vessel was wired, then dilated with 1.5- and 2.5-mm balloons. Angiography showed a significant dissection, which was treated with two stents (total length 56 mm). IVUS was performed to evaluate the results of stent placement. This image shows the IVUS catheter in a lumen with a diameter of 1.5 mm (CSA of 1.84 mm2). A second lumen is noted on the right side of the image without a three-layered appearance (intima/plaque, media, and adventitia). Thus, the imaging catheter appears to be in the true lumen. Other helpful clues would be a side branch (usually a branch of the true lumen) and sequestration of contrast in the false lumen with clearance of blood.
68 PART I Imaging
66009_PT01_final.indd 68
1/15/10 3:02:47 PM
Pullback of a 6.2F, 20 MHz intravascular ultrasound imaging catheter was performed from the left ventricle through the aortic valve plane. A 0.035˝ wire is seen at 12 o’clock with far-field shadowing. The image includes two of the three leaflets of a normal aortic valve in this patient (3 o’clock and 6 o’clock). No significant valvular calcification is noted. PERIPHERAL IMAGES
66009_PT01_final.indd 69
Aortic Valve
Peripheral Images 69
1/15/10 3:02:48 PM
Aortic Stenosis
PERIPHERAL IMAGES
The IVUS catheter was placed in the left ventricle, and slow pullback was performed to the level of the aortic valve to obtain this image of a heavily calcified and severely stenotic aortic valve. The IVUS catheter is in the center of the image, with the calcified valve leaflets surrounding it. (Each grid marker represents 4.0 mm.) Using IVUS measurement software, the diameter of the aortic valve orifice measures 5.6 x 8.0 mm with an area of 0.36 cm2 in mid-systole.
70 PART I Imaging
66009_PT01_final.indd 70
1/15/10 3:02:48 PM
Intravascular ultrasound of the aorta was performed with a 6.2F, 20-MHz imaging catheter. Images were obtained distal to the origin of the left subclavan artery. A three-layer appearance is noted without significant intimal thickening or calcification. The vessel lumen measures 2.6 cm in diameter. (Each grid marker represents 8.0 mm.) PERIPHERAL IMAGES
66009_PT01_final.indd 71
Normal Aorta
Peripheral Images 71
1/15/10 3:02:49 PM
Great Vessels
PERIPHERAL IMAGES
Intravascular ultrasound of the aorta at the level of the arch demonstrates the takeoff of the right subclavian artery at one o’clock. At 2 o’clock, the 0.035” wire shadow is noted with far-field shadowing. The aorta has a three-layer appearance, best seen at 12 o’clock. A thin, echobright intima with adjacent echolucent media is surrounded by a thick, echobright adventitial layer. The subclavian vein measures 1.1 cm in diameter, while the aorta at this level measures 3.3 cm. (Each grid marker represents 8.0 mm.)
72 PART I Imaging
66009_PT01_final.indd 72
1/15/10 3:02:49 PM
Diagnostic intravascular ultrasound was performed in a patient with an abdominal aortic aneurysm with a 6.2F, 20-MHz imaging catheter. Images of the aorta were obtained proximal to the aortic bifurcation and distal to the maximum diameter of the aneurysm to assess the patient’s candidacy for aortic stent graft placement. At this level, the lumen measures 1.8 x 3.3 cm. (Each grid marker represents 8.0 mm.) Moderate superficial calcium is noted. The luminal surface is irregular with ulceration noted at 2 and 6 o’clock. Note the significant amount of plaque at 4 o’clock.
PERIPHERAL IMAGES
66009_PT01_final.indd 73
AAA with Calcium
Peripheral Images 73
1/15/10 3:02:50 PM
ARTIFACTS
NURD
IVUS was performed in the mid-portion of the RCA for recurrent chest pain. A significant imaging artifact was noted due to non-unifom rotational distortion (NURD). Non-uniform rotation of a mechanical imaging catheter results in either expansion or compression of the two-dimensional representation. This artifact, which is the result of image expansion, can be seen as a wedge-shaped smearing at 1 o’clock. In addition, vessel distortion, noted at 11 o’clock, is the result of image compression and a non-centered catheter position. NURD may be the result of vessel tortuosity, non-coaxial catheter position, acute primary curvature of the guide catheter, excessive pressure of the hemostatic valve, or kinking of the imaging catheter.
74 PART I Imaging
66009_PT01_final.indd 74
1/15/10 3:02:50 PM
ARTIFACTS
66009_PT01_final.indd 75
Severe NURD
The quality of this image is severely affected by non-uniform rotational distortion (NURD) and cannot be used for diagnostic purposes. Bending of the imaging catheter either outside of the body or within the coronary artery can produce this artifact. Bending creates an area of local friction and causes non-uniform rotation of the imaging core within the imaging sheath. The post-processing imaging presentation algorithm anticipates uniform rotation of the imaging core and then presents the imaging data with equal radial distribution. Non-uniform catheter rotation causes the imaging core to “slow down” and “speed up” as the catheter spins. Areas of slow rotation are over-represented in the image and result in streaking as seen between 10 and 12 o’clock.
Artifacts 75
1/15/10 3:02:51 PM
ARTIFACTS
Background Interference
Imaging was performed in the mid-portion of the right coronary artery prior to stent placement. Vessel diameter (media-to-media) measured 3.3 x 3.9 mm. Lumen diameter measured 2.3 x 2.6 mm with a cross-sectional area of 4.9 mm2. Eccentric fibrous plaque is noted between 12 and 6 o’clock with mild superficial calcification. The image quality is affected by a “starry sky” artifact easily noted in the far field against the black background. This electrical artifact is usually the result of an ungrounded system in the catheterization laboratory environment. This may also be due to a defective imaging catheter.
76 PART I Imaging
66009_PT01_final.indd 76
1/15/10 3:02:51 PM
ARTIFACTS
66009_PT01_final.indd 77
Contrast Layering
Post-stent placement imaging was performed in the proximal and mid-left anterior descending coronary artery after 3.5-mm drug-eluting stent placement. The stent was postdilated to 4 mm. IVUS imaging demonstrates excellent stent apposition to the vessel wall with a stent lumen diameter of 4.25 mm (measured from leading edge to leading edge). At 4 o’clock, a stent “ghost” is seen in the far field and represents a reflection of ultrasound from the imaging catheter resulting in a duplicate image. In addition, the dark crescentshaped region extending from 3–6 o’clock is the result of contrast layering within this large caliber vessel.
Artifacts 77
1/15/10 3:02:52 PM
ARTIFACTS
Dual Guidewires
Diagnostic IVUS was performed prior to elective bifurcation drug-eluting stent placement in a left anterior descending/ diagonal lesion. This image demonstrates the appearance of multiple 0.014˝ guidewires. The guidewire at 4 o’clock is within the LAD and was used for passage of the IVUS catheter. Two additional guidewires are noted at 1 and 2 o’clock and have been placed within the first and second diagonal branches of the LAD. The diagonal origin is seen at 3 o’clock.
78 PART I Imaging
66009_PT01_final.indd 78
1/15/10 3:02:53 PM
ARTIFACTS
66009_PT01_final.indd 79
Air Artifact
Imaging was performed within the distal left anterior descending coronary artery. The epicardial surface is on the right-hand side of the image, while the left ventricular cavity is seen in the left lower quadrant. Eccentric superficial calcification is noted on the left side of the vessel without shadowing. The right side of the image is obscured by a bright speckled artifact. This type of imaging artifact is usually the result of microbubbles trapped between the transducer and the imaging catheter sheath. The catheter must be removed from the coronary artery and flushed properly with saline to remove the microbubbles.
Artifacts 79
1/15/10 3:02:53 PM
66009_PT01_final.indd 80
Part II: Application
1/19/10 9:32:36 AM
5.6.1 Intravascular Ultrasound Imaging (IVUS) Class IIa: IVUS is reasonable for the following: a. Assessment of the adequacy of deployment of coronary stents, including the extent of stent apposition and determination of the minimum luminal diameter within the stent. (Level of Evidence: B) b. Determination of the mechanism of stent restenosis (inadequate expansion versus neointimal proliferation) and to enable selection of appropriate therapy (vascular brachytherapy versus repeat balloon expansion). (Level of Evidence: B) c. Evaluation of coronary obstruction at a location difficult to image by angiography in a patient with a suspected flow-limiting stenosis. (Level of Evidence: C) d. Assessment of a suboptimal angiographic result after PCI. (Level of Evidence: C) e. Establishment of the presence and distribution of coronary calcium in patients for whom adjunctive rotational atherectomy is contemplated. (Level of Evidence: C) f. Determination of plaque location and circumferential distribution for guidance of directional coronary atherectomy. (Level of Evidence: B)
GUIDELINE UPDATE
66009_PT02_final.indd 81
Guideline Update for Percutaneous Coronary Intervention ACC/AHA/SCAI 2005
Smith SC Jr, Feldman TE, Hirshfeld JW Jr, et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). Circulation. 2006;113:e166–e286. American Heart Association Web Site. Available at: http://www.americanheart.org.
Guideline Update 81
1/15/10 3:00:43 PM
Class IIb: IVUS may be considered for the following:
GUIDELINE UPDATE
a. Determination of the extent of atherosclerosis in patients with characteristic anginal symptoms and a positive functional study with no focal stenoses or mild CAD on angiography. (Level of Evidence: C) b. Preinterventional assessment of lesional characteristics and vessel dimensions as a means to select an optimal revascularization device. (Level of Evidence: C) c. Diagnosis of coronary disease after cardiac transplantation. (Level of Evidence: C) Class III: IVUS is not recommended when the angiographic diagnosis is clear and no interventional treatment is planned. (Level of Evidence: C)
Level of Evidence A: Data derived from multiple randomized clinical trials or meta-analyses. Level of Evidence B: Data derived from a single randomized trial or nonrandomized studies. Level of Evidence C: Only consensus opinion of experts, case studies, or standard-of-care.
82 PART II Application
66009_PT02_final.indd 82
1/15/10 3:00:43 PM
IVUS Coding Medicare Hospital Outpatient
CPT® Code
Coronary IVUS
92978
IVUS (coronary vessel or graft) during diagnostic evaluation and/or therapeutic intervention, including imaging supervision, interpretation and report; initial vessel (List separately in addition to code for primary procedure)
92979
Each additional vessel (List separately in addition to code for primary procedure)
CPT® Code
Peripheral IVUS
37250
IVUS (noncoronary vessel) during diagnostic evaluation and/or therapeutic intervention, including imaging supervision, interpretation and report; initial vessel (List separately in addition to code for primary procedure)
37251
Each additional vessel (List separately in addition to code for primary procedure)
75945
IVUS (non-coronary vessel), radiologic supervision and interpretation; initial vessel
75946
IVUS (noncoronary vessel), radiologic supervision and interpretation; each additional vessel (List separately in addition to code for primary procedure)
IVUS CODING
66009_PT02_final.indd 83
TABLE 1
CPT copyright 2008 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.
IVUS Coding 83
1/15/10 3:00:43 PM
TABLE 2
IVUS Coding Physician Payment
IVUS CODING
CPT® Code
Coronary IVUS
92978-26
IVUS (coronary vessel or graft) during diagnostic evaluation and/or therapeutic intervention, including imaging supervision, interpretation and report; initial vessel (List separately in addition to code for primary procedure)
92979-26
Each additional vessel (List separately in addition to code for primary procedure)
CPT® Code
Peripheral IVUS
+37250
IVUS (noncoronary vessel) during diagnostic evaluation and/or therapeutic intervention, including imaging supervision, interpretation and report; initial vessel (List separately in addition to code for primary procedure)
37251
Each additional vessel (List separately in addition to code for primary procedure)
75945-26
IVUS (noncoronary vessel), radiologic supervision and interpretation; initial vessel
75946-26
IVUS (noncoronary vessel), radiologic supervision and interpretation; each additional vessel (List separately in addition to code for primary procedure)
CPT copyright 2008 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.
84 PART II Application
66009_PT02_final.indd 84
1/15/10 3:00:44 PM
IVUS Catheters Coronary Imaging Freq. (MHz)
Length (cm)
Profile: 3.2F Transducer: Rotational Min. Guide Catheter: 6F Max. Guide Wire: 0.014˝
40
135
Profile: 3.2F Transducer: Rotational Min. Guide Catheter: 6F Max. Guide Wire: 0.014˝ Hydrophilic Coating
40
135
Eagle Eye™ Gold Profile: 2.9F Volcano Therapeutics, Inc. Transducer: Solid State Min. Guide Catheter: 5F Max. Guide Wire: 0.014˝
20
150
Revolution™ Profile: 3.2F Volcano Therapeutics, Inc. Transducer: Rotational Min Guide Catheter: 6F Max. Guide Wire: 0.014˝
45
135
Name
Size
Atlantis® SR Pro Boston Scientific Corp.
iCross® Boston Scientific Corp.
IVUS CATHETERS
66009_PT02_final.indd 85
TABLE 3
IVUS Catheters 85
1/15/10 3:00:44 PM
TABLE 4
IVUS Catheters Peripheral Imaging
IVUS CATHETERS
Freq. (MHz)
Length (cm)
Profile: 3.2F Transducer: Rotational Min. Sheath: 6F Max. Guide Wire: 0.018˝
40
135
Atlantis® PV Boston Scientific Corp.
Profile: 8F Transducer: Rotational Min. Sheath: 8F Max. Guide Wire: 0.035˝
15
95
Sonicath™ Ultra 9 Boston Scientific Corp.
Profile: 9F Transducer: Rotational Min. Sheath: 8.5F Max. Guide Wire: N/A
9
110
Visions® PV .018 Volcano Therapeutics, Inc.
Profile: 3.4F Transducer: Solid State Min. Sheath: 6F Max. Guide Wire: 0.018˝
20
135
Visions® PV 8.2F Volcano Therapeutics, Inc.
Profile: 8.2F Transducer: Solid State Min. Sheath: 9F Max. Guide Wire: 0.038˝
10
90
Name
Size
Atlantis® 018 Boston Scientific Corp.
86 PART II Application
66009_PT02_final.indd 86
1/15/10 3:00:44 PM
Clinical Trial: RESIST (Restenosis after IVUS guided stenting) Patients (n=155) underwent PTCA (percutaneous transluminal coronary angioplasty) followed by stent placement prior to being randomized to either IVUS-directed or IVUSdocumented therapy. Stents were placed as a primary planned procedure, or after a suboptimal PTCA result. The primary endpoint was angiographic restenosis at 6 months, which showed no significant difference between the two treatment strategies (IVUS 22.5% vs. angiography 28.8%; P=0.25). The IVUS-directed group had a significantly larger stent cross-sectional area (CSA) by IVUS immediately post-procedure and at 6-month follow-up. The rate of target lesion revascularization (TLR) was not reported in this trial. The authors concluded that a nonsignificant reduction was observed in the angiographic restentosis rate and the angiographic stent MLD at 6-month follow-up. However, they could not rule out a beneficial effect of IVUS guidance owing to a lack of statistical power.
CLINICAL TRIALS
66009_PT02_final.indd 87
Clinical Trials
Schiele F, Meneveau N, Vuillemenot A, et al. Impact of intravascular ultrasound guidance in stent deployment on 6-month restenosis rate: A multicenter, randomized study comparing two strategies—with and without intravascular ultrasound guidance. RESIST Study Group. REStenosis after Ivus guided STenting. J Am Coll Cardiol. 1998;32(2):320–328.
Clinical Trials 87
1/15/10 3:00:45 PM
Clinical Trial: CRUISE (Can routine ultrasound influence stent expansion) A multicenter, prospective study comparing IVUS-guided and IVUS-documented stent placement in a nonrandomized study of 525 patients. Treatment assignment was determined by institutional preference; patients were not randomized to a treatment group. IVUS criteria for optimal stent placement were not specified. Post-procedure minimal stent dimensions were measured by angiography and IVUS, and clinical outcome (major cardiac events) was determined at 9-month follow-up. The IVUS-guided group had a larger minimal stent area by quantitative coronary ultrasound compared to the angiography-guided group (7.78 vs. 7.06 mm2, P<0.001). A significant improvement in the rate of target lesion revascularization (TLR) was observed. This difference was associated with a significantly lower rate of target vessel revascularization in the IVUS-guided group compared to the angiography-guided group at 9-month follow-up (8.5 vs. 15.3%; P<0.05), but no difference was observed in mortality or myocardial infarction. The authors suggest that IVUS guidance of stent placement may result in more effective expansion. CLINICAL TRIALS
Fitzgerald PJ, Oshima A, Hayase M, et al. Final results of the Can Routine Ultrasound Influence Stent Expansion (CRUISE) study. Circulation. 2000;102(5):523–530.
88 PART II Application
66009_PT02_final.indd 88
1/15/10 3:00:45 PM
A multicenter randomized trial of 550 patients that compared an angiography-guided to an IVUS-guided stent placement procedure using MUSIC criteria for optimum stent placement by IVUS. The primary end points were angiographic dichotomous restenosis rate, minimal lumen diameter, and percent diameter stenosis after 6 months as determined by quantitative coronary angiography. Secondary endpoints were the occurrence rates of major adverse cardiac events (death, myocardial infarction, coronary bypass surgery, and repeat PCI) after 6 and 12 months of follow-up. At 6-month follow-up there was no difference in the dichotomous angiographic rate of restenosis when the IVUSguided group was compared to the angiography-guided group (24.5 vs. 22.8%; P=0.68), and at 12-months no difference in the rate of repeat intervention (11.0 vs. 8.7%; P=0.87). IVUS was not performed at the conclusion of the procedure in the angiography-guided group. This study does not support the routine use of IVUS guidance for stent placement.
CLINICAL TRIALS
66009_PT02_final.indd 89
Clinical Trial: OPTICUS (Optimization with ICUS to reduce stent restenosis)
Mudra H, di Mario C, de Jaegere P, et al. Randomized comparison of coronary stent implantation under ultrasound or angiographic guidance to reduce stent restenosis (OPTICUS Study). Circulation. 2001;104 (12):1343–1349.
Clinical Trials 89
1/15/10 3:00:45 PM
Clinical Trial: TULIP (Thrombocyte activity evaluation and effects of ultrasound guidance in long intracoronary stent placement)
CLINICAL TRIALS
A single-center, randomized trial that evaluated the benefit of IVUS-guided stent placement in long lesions (>20 mm). Patients (n=144) were randomized to intravascular ultrasound or angiography-guided stent placement. IVUS was not performed in the angiography-directed group. In patients assigned to IVUS-guided stent placement, final balloon diameter and additional stent size were determined by ultrasound measurements. Balloon dilations were performed until the following IVUS criteria were fulfilled: (1) complete stent apposition; (2) in-stent minimal lumen diameter (MLD) ≥ 80% of the mean of proximal and distal reference diameters; and (3) in-stent minimal lumen area (MLA) greater than or equal to distal reference lumen area. The primary endpoint was angiographic diameter within the stent at 6 months. Significant clinical and angiographic benefits were noted in the IVUS-directed group at 6-month follow-up. At 6-month follow-up, both TLR and angiographic restenosis (>50%) were significantly lower in the IVUSguided group compared to the angiography-guided group (4 vs. 14%; P=0.037 and 23 vs. 45%; P=0.008 respectively). The authors conclude that long stent placement guided by IVUS is superior to guidance by angiography alone.
Oemrawsingh PV, Mintz GS, Schalij MJ, Zwinderman AH, Jukema JW, v.d. Wall EE. Intravascular ultrasound guidance improves angiographic and clinical outcome of stent implantation for long coronary artery stenoses. Final results of a randomized comparison with angiographic guidance (TULIP Study). Circulation 2003;107:62–67.
90 PART II Application
66009_PT02_final.indd 90
1/15/10 3:00:45 PM
This is a multicenter, randomized trial designed to assess the effect of intravascular ultrasound (IVUS)-directed stent placement on the 12-month rate of target lesion revascularization (TLR). A total of 800 patients were randomized to angiographyor IVUS-directed therapy. In the IVUS-guided group AVID critera for optimal stent placement were applied. In the angiography group, blinded IVUS was performed without further therapy. Compared to angiography-directed stent placement, IVUS-directed stent placement resulted in larger acute stent dimensions (6.90 vs. 7.55 mm2; P=0.001) without an increase in complications and a significantly lower 12-month TLR rate for vessels ≥2.5 mm by angiography (10.1 vs. 4.3%; P=0.01) and for vessels with high-grade prestent stenosis (14.2 vs. 3.1%; P=0.002). However, for the entire sample (intention to treat) IVUS-directed bare metal stent placement did not reduce the 12-month TLR rate when compared to stent placement guided by angiography alone (8.1 vs. 12.0%, P=0.08).
CLINICAL TRIALS
66009_PT02_final.indd 91
Clinical Trial: AVID (Angiography versus intravascular ultrasound-directed stent placement)
Russo RJ, Silva PD, Teirstein PS, et al. A randomized controlled trial of angiography versus intravascular ultrasound-directed bare-metal coronary stent placement (The AVID Trial). Circ Cardiovasc Intervent. 2009;2: 113–123.
Clinical Trials 91
1/15/10 3:00:46 PM
IVUS Criteria Bare-Metal Stent Placement
MUSIC (Multicenter ultrasound stenting in coronaries) IVUS criteria of optimal stent expansion 1. Complete apposition of the stent over its entire length against the vessel wall. 2a. In-stent minimal lumen area ≥90% of the average reference lumen area or ≥100% of lumen area of the reference segment with the lowest lumen area. In-stent lumen area of proximal stent entrance ≥90% of proximal reference lumen area. 2b. In case the in-stent luminal area >9.0 mm2. In-stent minimal lumen area ≥80% of the average reference lumen area or ≥90% of lumen area of the reference segment with the lowest lumen area. In-stent lumen area of proximal stent entrance ≥90% of proximal reference lumen area. 3. Symmetric stent expansion defined by minimum lumen diameter/maximum lumen diameter (LDmin/LDmax) ≥0.7.
IVUS CRITERIA
de Jaegere P, Mudra H, Figulla H, et al. Intravascular ultrasound-guided optimized stent deployment. Immediate and 6-month clinical and angiographic results from the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study). Eur Heart J. 1998;19(8):1214–1223.
92 PART II Application
66009_PT02_final.indd 92
1/15/10 3:00:46 PM
Bare-Metal Stent Placement
AVID (Angiography versus intravascular ultrasound-directed stent placement) IVUS criteria for optimal stent expansion a. The smallest cross-sectional area (minimal stent area) within the stent should be 90% of the distal reference lumen cross-sectional area. b. Full apposition of the stent to vessel wall must be observed. c. Dissections involving exposure of the media or deep wall elements of an SVG must be covered by subsequent stent placement. The distal reference vessel selected for comparison of CSA should be a normal section of vessel within 5 mm of the distal stent edge.
Russo RJ, Silva PD, Teirstein PS, et al. A randomized controlled trial of angiography versus intravascular ultrasound-directed bare-metal coronary stent placement (The AVID Trial). Circ Cardiovasc Intervent. 2009;2: 113–123.
IVUS CRITERIA
66009_PT02_final.indd 93
IVUS Criteria
IVUS Criteria 93
1/15/10 3:00:46 PM
IVUS Criteria Drug-Eluting Stent (DES)
PRAVIO/AVIO (Preliminary investigation to the angiographic versus IVUS optimization) IVUS criteria for optimal DES expansion Based upon a single center study of 113 complex lesions. a. IVUS is performed after DES implantation. b. Minimum and maximum media-to-media diameters of the vessel are measured at the proximal, mid, and distal portion of the stented lesion. c. The media-to-media diameters are averaged to determine the diameter of the post-dilating balloon (rounded to the nearest 0.5 mm). d. The cross-sectional area (CSA) of the post-dilating noncompliant balloon is calculated (CSA=πr2) and no overexpansion is assumed. e. Optimal stent expansion is defined as a minimal stent CSA >70% of the CSA of the post-dilating balloon.
IVUS CRITERIA
Gerber RT, Latib A, Ielasi A, et al. Defining a new standard for IVUS optimized drug eluting stent implantation: The PRAVIO study. Catheter Cardiovasc Interv. 2009;74:348-356.
94 PART II Application
66009_PT02_final.indd 94
1/15/10 3:00:46 PM
Left Main Stenosis (Abizaid AS, et al., 1999) The purpose of this study was to correlate angiographic and intravascular ultrasound (IVUS) findings in left main coronary artery (LMCA) disease and identify the predictors of coronary events at one year in patients with LMCA stenoses. One hundred twenty-two patients who underwent angiographic and IVUS assessment of the severity of LMCA disease and who did not have subsequent catheter or surgical intervention were followed for one year. Standard clinical, angiographic and IVUS parameters were collected. There was a poor correlation between QCA and IVUS in the assessment of reference segment and lesion site lumen dimensions. Core laboratory measurement of angiographic stenosis in the patients with an adverse event during the first year was 44% and 42% in the patients with and without an adverse event, respectively. Univariate predictors (P<0.05) of adverse clinical events (cardiac death, myocardial infarction, LM-PCI, CABG) were diabetes, presence of another lesion whether treated with catheter-based intervention or untreated with diameter stenosis (DS)>50%. In addition, IVUS predictors of patients (n=18) who experienced an adverse event within one-year included reference plaque burden, lesion lumen area (6.8 mm2), MLD (2.3 mm), plaque area (15.7 mm2) and relative (70%) and absolute area stenosis (52%).
Abizaid AS, Mintz GS, Abizaid A, et al. One-year follow-up after intravascular ultrasound assessment of moderate left main coronary artery disease in patients with ambiguous angiograms. J Am Coll Cardiol. 1999;34(3): 707–715.
IVUS CRITERIA
66009_PT02_final.indd 95
IVUS Criteria
IVUS Criteria 95
1/15/10 3:00:47 PM
IVUS Criteria Left Main Stenosis (Fassa AA, et al., 2005) The purpose of this study was to evaluate the efficacy of an IVUS-guided assessment strategy for patients with angiographically indeterminate left main coronary artery (LMCA) disease. IVUS was performed on 121 patients with angiographically normal left main coronary arteries, and the lower range of normal minimum lumen area (MLA) determined to be 7.5 mm2. Of 214 patients with angiographically indeterminate LMCAs, 38.8% had MLA <7.5 mm2 and 61.2% and MLA ≥7.5 mm2. LMCA revascularization was performed on 85.5% of the patients with MLA <7.5 mm2, and deferred in 86.9% of patients with MLA ≥7.5 mm2. Long-term follow-up showed no significant difference in major adverse cardiac events between patients with MLA <7.5 mm2 who underwent revascularization (freedom from major adverse cardiac events [MACE] 79.2%), and those with an MLA ≥7.5 mm2 deferred for revascularization (freedom from MACE 88.4%). Significant predictors of adverse events identified by multivariate analysis were age, smoking status, and number of diseased non-LMCA vessels. The authors conclude that IVUS is an accurate method to assess an angiographically indeterminate left main lesion and the deferred revascularization with a minimal left main lumen MLA ≥7.5 mm2 appears to be safe.
IVUS CRITERIA
Fassa AA, Wagatsuma K, Higano ST, et al. Intravascular ultrasoundguided treatment for angiographically indeterminate left main coronary artery disease: A long-term follow up study. J Am Coll Cardiol. 2005; 45(2):204–211.
96 PART II Application
66009_PT02_final.indd 96
1/15/10 3:00:47 PM
Left Main Stenosis (Russo RJ, et al., 2006) The Left Main IVUS Registry is a multicenter study designed to determine the value of diagnostic IVUS for an inconclusive left main stenosis by angiography. IVUS criteria for a significant left main stenosis requiring revascularization (CABG or PCI) were >60% relative cross-sectional area (CSA) lumen stenosis or an absolute lumen CSA of <6.0 mm2 when no distal reference vessel could be identified. A total of 252 patients with an inconclusive left main angiogram underwent clinically indicated IVUS. A significant left main stenosis was identfied by IVUS in 48% of patients who were then candidates for the LM-PCI or CABG, while 52% did not have a significant stenosis and were candidates for medical therapy. Mean angiographic lesions stenosis was 33% in the CABG/PCI group and 31% in the medical therapy group. When an inconclusive lesion was identified by angiography in the proximal portion of the left main, 15% of patients met IVUS criteria for CABG, in the mid vessel 40%, and in the distal vessel and bifurcation 57% (P<.001). In patients with an inconclusive left main angiogram, IVUS is superior to angiography for clinical decision-making. Distal lesion location is associated with a significantly greater need for revascularization.
Russo RJ, Wong SC, Marchant D, et al. Abstract 2467: Is left main angiographic lesion location predictive of a significant stenosis by intravascular ultrasound and the need for revascularization? Observations from the left main IVUS registry. Circulation 2006;114:II_508.
IVUS CRITERIA
66009_PT02_final.indd 97
IVUS Criteria
IVUS Criteria 97
1/15/10 3:00:47 PM
IVUS Criteria Left Main Stenosis (Sano K, et al., 2007) The aim of this study was to evaluate the severity of ambiguous left main coronary artery stenosis (LMCS) by IVUS, and to clarify how frequently significant stenosis occurs. Significant LMCS was defined as a diameter stenosis > 50% by QCA and a minimal lumen area <6.0 mm2 by IVUS. A retrospective review of 115 patients with angiographically ambiguous, intermediate LMCS who underwent IVUS evaluation found the following: 1. Less than half (44%) of intermediate LMCSs were significant by IVUS assessment. 2. Intermediate LMCSs had different qualitative and quantitative characteristics varying by lesion location. 3. Minimal lumen diameter (MLD) by QCA was less well correlated with MLD by IVUS in ostial lesions than in other lesion locations. IVUS minimal lumen area and plaque burden measured 6.8 mm2 and 63% in these intermediate angiographic left main lesions. A significant LMCS was seen in 44% of lesions by IVUS but in only 13% of lesions by QCA. IVUS assessment showed only 36% of angiographically inconclusive ostial lesions had significant stenosis and 41% had <50% plaque burden. The authors concluded that patients with an intermediate left main stenosis by angiography deserve IVUS assessment before proceeding to revascularization.
IVUS CRITERIA
Sano K, Mintz GS, Carlier SG, et al. Assessing intermediate left main coronary lesions using intravascular ultrasound. Am Heart J. 2007;154(5): 983–988.
98 PART II Application
66009_PT02_final.indd 98
1/15/10 3:00:47 PM
Non-Left Main Stenosis (Abizaid AS, et al., 1999) The purposes of this study were (1) to determine the event rate in patients with chest pain and angiographically intermediate de novo native coronary artery lesions after intervention was deferred on the basis of IVUS findings and (2) to identify the clinical, angiographic, and IVUS predictors of late cardiac events in these patients. Three hundred patients, in whom intervention was deferred based on IVUS findings, were followed for >1 year. Events occurred in 24 patients (8%). In lesions with a minimum lumen area ≥4.0 mm2, the event rate was 4.4%, and TLR rate was 2.8%. In patients with no adverse clinical events at 12 months (328 patients) the MLA was 6.2 mm2. Variables tested as possible predictors of cardiac events included diabetes mellitus, IVUS lesion-site lumen crosssectional area (CSA), MLD, plaque and media CSA, crosssectional narrowing, and area stenosis (AS) at the lesion site, without comparison with a reference vessel. Of those, IVUS lesion-site CSA and AS were the only independent predictors of cardiac events at follow-up. Predictors for target lesion revascularization were diabetes mellitus, IVUS lesion-site lumen CSA, and IVUS AS. The only independent predictor of death and MI was IVUS MLD. The authors concluded that deferred revascularization with a de novo lesion minimum lesion area ≥4.0 mm2 was associated with a low adverse event rate.
Abizaid AS, Mintz GS, Mehran R, et al. Long-term follow-up after percutaneous transluminal coronary angioplasty was not performed based on intravascular ultrasound findings: Importance of lumen dimensions. Circulation 1999;100(3):256–261.
IVUS CRITERIA
66009_PT02_final.indd 99
IVUS Criteria
IVUS Criteria 99
1/15/10 3:00:48 PM
IVUS Criteria Non-Left Main Stenosis (Nishioka T, et al., 1999) The objective of this investigation was to validate intravascular ultrasound (IVUS) measurements for differentiating functionally significant from nonsignificant coronary stenosis. Preinterventional IVUS imaging (30-MHz imaging catheter) of 70 de novo coronary lesions was performed. The lesion lumen area and three IVUS-derived stenosis indexes comparing lesion lumen area with the lesion external elastic lamina (EEL) area, the mean reference lumen area, and the mean reference EEL area were compared with the results of stress myocardial perfusion imaging. The lesion lumen area and three IVUS-derived stenosis indexes showed sensitivities and specificities ranging between 80% and 90% using stress myocardial perfusion imaging as the gold standard. The lesion lumen area <4 mm2 is a simple and highly accurate criterion for significant coronary narrowing. The authors concluded that quantitative IVUS indices (<4 mm2) can be reliably used for identifying significant epicardial coronary artery stenoses.
IVUS CRITERIA
Nishioka T, Amanullah AM, Luo H, et al. Clinical validation of intravascular ultrasound imaging for assessment of coronary stenosis severity: Comparison with stress myocardial perfusion imaging. J Am Coll Cardiol. 1999;33(7):1870–1878.
100 PART II Application
66009_PT02_final.indd 100
1/15/10 3:00:48 PM
66009_INDX_final.indd 101
Index Note: Italicized page locators indicate a photo; tables are noted with a t.
A AAA, with calcium, 73 Abdominal aortic aneurysm, 73 Abizaid study IVUS criteria for left main stenosis, 95 IVUS criteria for non-left main stenosis, 99 Acute anterior wall myocardial infarction, thrombus 2 in patient with, 27 Acute inferior wall myocardial infarction, 57 Acute-upon-chronic thrombus, after plaque dissection, 56 Adventitia, 2 Air artifact, 79 Angiographic lesion, inconclusive, assessing, 26 Aorta normal, 71 three-layer appearance of, 72 Aortic stenosis, 70 Aortic valve, 69 Aortic valve orifice, measuring, 70 Atherosclerosis, transplantrelated, 15 Atlantis® O18, 86t Atlantis® PV, 86t Atlantis® SR Pro, 85t AVID clinical trial, 91
B Background interference, 76 Balloon, thrombus 2 and appropriate size of, 27 Bare-metal redundant stent, ultrasound signature of, 43 Bare-metal stent placement, 42 self-expanding, 41 Bare-metal stents in ostium of first diagonal branch, 47 Bending, of imaging catheter, severe NURD and, 75 Blood stasis, 18 Branch vessels, 13, 13
C Calcification, circumferential, 23 Calcium AAA with, 73 heavy, 39 left main, 31 within lesion with far-field shadowing, 10 Rotablator™ treatment and, 33 with shadowing, 32 superficial, 36 Cardiac vein, 9 Circumferential calcification, 23 Circumflex coronary stent placement, diagnostic IVUS assessment of, 21 Clinical trials AVID, 91 CRUISE, 88 OPTICUS, 89 RESIST, 87 TULIP, 90
INDEX 101
1/15/10 2:59:39 PM
Coil stent signature, 43 Complex eccentric plaque, 34 Complex plaque 1, 34 Complex plaque 2, 35 Complex thrombus, 24 Complicated left main plaque, 19 Contrast layering, 77 Contrast use, for clearing blood echoes and defining luminal border, 14 Coronary IVUS coding for, 83t physician payment coding for, 84t Coronary sinus, 10 Coronary spasm, 12 Cross-sectional area, 87, 94, 97 vessel, obtaining, 3 Cross-sectional narrowing, predictor of cardiac events and, 99 CRUISE clinical trial, 88 Crushed stent, 45, 49 CSA. See Cross-sectional area
“Double barrel” lumen, sequential passes of Rotablator™ burrs and, 33 Drug-eluting stents contrasting layering, 77 dissection 1 and, 65 nonapposition of, 52 placement of, 48, 55 PRAVIO/AVIO, 94 Dual guidewires, 78
E Eagle Eye™ Gold, 85t Eccentric complicated plaque, 29 Eccentric superficial calcium, 38 EEL. See External elastic lamina Embedded microbubbles, 61 Epicardial vein, 8 Exercise Cardiolite examination, abnormal, 36 External elastic lamina, 100 Extra-vascular space, 11
D DES expansion, optimal, IVUS criteria for, 94 Diabetes mellitus, predictor of cardiac events and, 99 Diameter stenosis, calculating, 3 Dissection 1, 65 Dissection 2, 66 Dissection distal LM, 64 Dissection of native vessel, 59 “Double barrel” appearance, with false lumen 1, 62
F False lumen, 68 dissection 2 and, 66 False lumen 1, 62 False lumen 2, 63 False lumen 3, 68 Fassa study, IVUS criteria for left main stenosis, 96 Fibrocalcific disease, intermediate echo intensity of plaque consistent with, 22
102 INDEX
66009_INDX_final.indd 102
1/15/10 2:59:40 PM
66009_INDX_final.indd 103
G Great vessels, 72 Guide catheter, acute primary curvature of, 74 Guidewire artifact, 1 complex thrombus and, 24 lipid-laden plaque and, 16 protruding plaque and, 25 ulcerated plaque 2 and, 28 Guidewire shadow, echolucent zone showing, 26 Guidewires, dual, 78
H Heavy calcium, 39 Heterogenous plaque, 22 High-grade lesion, 26 Hyperplasia, neointimal, 46
I iCross®, 85t Imaging catheters mechanical, non-uniform rotation of, 74 severe NURD and bending of, 75 Inconclusive lesion, assessing, diagnostic IVUS performed for, 11 In-stent restenosis, 51 Intima, 1 Intramural hematoma 1, 57 Intramural hematoma 2, 58 IVUS catheters coronary imaging, 85t peripheral imaging, 86t
IVUS coding Medicare hospital outpatient, 83t physician payment, 84t IVUS criteria drug-eluting stent, PRAVIO/ AVIO, optimal DES expansion, 94 left main stenosis Abizaid study, 95 Fassa study, 96 Russo study, 97 Sano study, 98 non-left main stenosis Abizaid study, 99 Nishioka study, 100 stent placement AVID, optimal stent expansion, 93 MUSIC, optimal stent expansion, 92 IVUS (intravascular ultrasound imaging) of angiographically normal segment of distal left main coronary artery, three-layer appearance, 2 of calcium with shadowing, 32 example, with 30-MHz catheter in mid portion of LAD, 1 pre-procedure, in angiographically normal portion of mid-RCA, 8 in proximal portion of medium-caliber left circumflex coronary artery, 9 sampler, 1
INDEX 103
1/15/10 2:59:40 PM
IVUS (Continued) within six months after stent placement, neointimal hyperplasia and, 46 of stent placement, 41 using automatic pullback in medium to smallcaliber, non-dominant left circumflex coronary artery, 10
K Kinking, of imaging catheter, 74
L LAD lesion, long, stent placement performed within, 64 Large-caliber ramus intermedius, diagnostic IVUS imaging performed in distal portion of, 4 Layered luminal thrombus, intraluminal pathology consistent with, 37 Left main calcium, 31 Left main coronary artery disease, 95 Left main coronary artery stenosis, 98 Left main coronary stent placement, 50 Left main dissection, 56 Left Main IVUS Registry, 97 Left main stenosis IVUS criteria for Abizaid study, 95 Fassa study, 96
Russo study, 97 Sano study, 98 Lesions calcified, with thrombus, 37 high-grade, 26 Lipid-laden plaque, 16 LMCA disease. See Left main coronary artery disease LMCS. See Left main coronary artery stenosis Lumen diameter, measuring, 3
M Medicare hospital outpatient, IVUS coding, 83t Microbubble trapping, air artifact and, 79 Microbubbles, embedded, 61 Microcalcification, significant diffuse, noting with farfield shadowing, 23
N Neointimal hyperplasia, in-stent restenosis and, 46, 51 Nishioka study, IVUS criteria for non-left main stenosis, 100 Nonapposition, of stent, 52 Non-coaxial catheter position, 74 Non-left main stenosis IVUS criteria for Abizaid study, 99 Nishioka study, 100
104 INDEX
66009_INDX_final.indd 104
1/15/10 2:59:40 PM
66009_INDX_final.indd 105
Non-uniform rotational distortion severe, 75 significant imaging artifact due to, 74 Normal aorta, 71 NURD. See Non-uniform rotational distortion
O Optical coherence tomography (OCT), 40 OPTICUS clinical trial, 89 Optimal stent expansion, defined, 94 Ostial left main stenosis, appropriate measurement of, 19 Overlapping stents, 42
P Percutaneous coronary intervention guideline update for, 81–82 Class IIa: IVUS reasonable for, 81 Class IIb: IVUS considerations for, 82 Class III: IVUS not recommended for, 82 Percutaneous transluminal coronary angioplasty performing, for in-stent restenosis, 45 RESIST clinical trial and, 87
Pericardial space, 13 Pericardium, 4 eccentric plaque and, 20 Peripheral IVUS coding for, 83t physician payment coding for, 84t Physician payment, IVUS coding for, 84t Plaque complicated, left main, 19 eccentric complicated, 29 pericardium and, 20 heterogenous, 22 lipid-laden, 16 protruding, 25 significant, vein graft anastomosis and, 6 ulcerated, 17 vulnerable, 30 Plaque rupture, recent, complex plaque 2 and, 35 Protruding plaque, 25 PTCA. See Percutaneous transluminal coronary angioplasty
R RESIST clinical trial, 87 Revolution™ catheter, 85t Rotablator™, calcium after, 33 Rotational atherectomy, 33 Russo study, IVUS criteria for left main stenosis, 97
INDEX 105
1/15/10 2:59:41 PM
S Sano study, IVUS criteria for left main stenosis, 98 Saphenous vein graft dissection, 60 IVUS imaging in angiographically normal segment of, 5 Shadowing, calcium with, 32 Side-branch stent, 47 Sonicath™ Ultra 9, 86t “Starry sky” artifact, background interference and, 76 Stenosis 50%, in mid-portion of SVG, 7 aortic, 70 Stent expansion, optimal AVID, IVUS criteria for, 93 MUSIC, IVUS criteria of, 92 Stent “ghost,” 77 Stent non-apposition, 44, 52 Stent placement, 41 AVID, IVUS criteria for optimal stent expansion, 93 Stented side branch, 48 Stents coil stent signature, 43 crushed, 45, 49 in distal portion of largecaliber right coronary artery, 18 left main, 40 overlapping, 42 side-branch, 47 three-layer, 53
thrombus 2 and determining appropriate size of, 27 under-expanded, 55 Superficial calcium, 36 SVG. See Saphenous vein graft
T Target lesion revascularization, AVID clinical trial and, 91 TCFA. See Thin cap fibroatheroma Thickened media, with minimal plaque, coronary artery spasm and, 12 Thin calcific cap, 40 Thin cap fibroatheroma definition of, 30 diagnostic issues with, 40 Three-layer stents, 53 Thrombectomy, 24 Thrombus blood stasis and appearance of, 18 calcified lesion with, 37 complex, 24 identification of, 67 Thrombus 1, 21 Thrombus 2, 27 Thrombus 3, 54 Thrombus 4, 67 TLR. See Target lesion revascularization Transplant atherosclerosis, 15 Transplant vasculopathy, typical bulky intimal thickening with fibrous appearance and microcalcification, 15
106 INDEX
66009_INDX_final.indd 106
1/15/10 2:59:41 PM
66009_INDX_final.indd 107
True lumen false lumen differentiated from, 62 false lumen 3 and, 68 TULIP clinical trial, 90 Type B dissection, 60 Type C dissection, 59
Unstable coronary syndrome calcified lesion with thrombus and, 37 eccentric complicated plaque and, 29 three-layer stent and, 53
U
V
Ulcerated plaque anterior infarction and, 17 with superficial calcium, 31 Ulcerated plaque 2, 28 Under-expanded small stent, 55
Vein graft anastomosis, 6 Vein graft valve, 7 Vessel cross-sectional area, obtaining, 3 Visions® PV .018, 86t Visions® PV 8.2F, 86t Vulnerable plaque, 30
INDEX 107
1/15/10 2:59:41 PM
