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(BQ) It contains 900 questions in the same proportion as the actual exam to ensure highly targeted, high-yield preparation. Answers with brief explanations and references are included. Indications for particular procedures—a major focus of the board exam—are integrated throughout the text, particularly in the context of ACC/AHA guidelines.
900 Questions: An Interventional Cardiology Board Review 900 Questions: An Interventional Cardiology Board Review EDITORS Debabrata Mukherjee, MD Associate Professor of Medicine Director, Cardiac Catheterization Laboratories Gill Foundation Professor of Interventional Cardiology Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Leslie Cho, MD Director, Women’s Cardiovascular Center Medical Director, Preventive Cardiology and Rehabilitation Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio David J Moliterno, MD Professor and Vice-Chairman of Medicine Chief, Cardiovascular Medicine Jefferson Morris Gill Professor of Cardiology Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Donna A Gilbreath Managing Editor Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Acquisitions Editor: Frances R DeStefano Managing Editor: Nicole Dernoski Project Manager: Jennifer Harper Senior Manufacturing Manager: Benjamin Rivera Marketing Manager: Angela Panetta Art Director: Risa Clow Production Services: Laserwords Private Limited, Chennai, India Printer: Victor Graphics, Inc © 2007 by LIPPINCOTT WILLIAMS & WILKINS, a Wolters Kluwer business 530 Walnut Street Philadelphia, PA 19106 USA LWW.com All rights reserved This book is protected by copyright No part of this book may be reproduced in any form or by any means, including photocopying, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews Materials appearing in this book prepared by individuals as part of their official duties as U.S government employees are not covered by the above-mentioned copyright We appreciate that even with the best of efforts from the authors, editors, and publishers that some of the questions or answers in this textbook may need refinement So, too, while the object was to carefully design each question with a single best answer, some questions may be more controversial than intended or may have more than one reasonable response With these points in mind and with our hopes to continually improve this book with future editions, comments regarding this first edition are welcomed and can be sent to Dr Debabrata Mukherjee (Mukherjee@uky.edu) or Dr David Moliterno (Moliterno@uky.edu) Printed in the USA Library of Congress Cataloging-in-Publication Data 900 questions : an interventional cardiology board review / editors, Debabrata Mukherjee [et al.] p ; cm ISBN-13: 978-0-7817-7349-2 ISBN-10: 0-7817-7349-0 Heart—Diseases—Treatment—Examinations, questions, etc Cardiovascular system—Diseases—Treatment—Examinations, questions, etc I Mukherjee, Debabrata II Title: Nine hundred questions [DNLM: Cardiovascular Diseases—Examination Questions Cardiovascular Diseases—therapy—Examination Questions WG 18.2 Z9991 2007] RC683.8.N564 2007 616.1 20076—dc22 2006027893 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication Application of this information in a particular situation remains the professional responsibility of the practitioner The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of publication However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions This is particularly important when the recommended agent is a new or infrequently employed drug Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in their clinical practice To purchase additional copies of this book, call our customer service department at (800) 638-3030 or fax orders to (301) 223-2320 International customers should call (301) 223-2300 Visit Lippincott Williams & Wilkins on the Internet: at LWW.com Lippincott Williams & Wilkins customer service representatives are available from 8:30 am to pm, EST 10 ‘‘To my parents, for their infinite patience, love, and understanding, who continue to be my source of inspiration, and to my wonderful wife, Suchandra, for her love and support’’ Debabrata Mukherjee ‘‘To Nathaniel and Benjamin, my sons and suppliers of life’s important questions, and to Judith, my wife and partner in finding the answers’’ David J Moliterno Preface Insightful questions have been used through the ages as a metric to assess one’s knowledge, but when coupled with carefully delivered answers they can become a powerful teaching tool This book of questions and annotated answers covering the field of interventional cardiology is meant to serve as a helpful resource for individuals preparing for the interventional cardiovascular medicine board examination as well as for clinicians who wish to perform an in-depth self-assessment on individual topics or the full spectrum The book has many key features, which we believe will make the reader successful in passing the boards and improving clinical practice Of foremost importance, the areas covered are relevant not only to the day-to-day practice of interventional cardiology, but have also been patterned in scope and content to the actual board examination The book begins with several chapters dedicated to the anatomy and physiology associated with interventional cardiology and the pathobiology of atherosclerosis and inflammation This corresponds to the 15% of the board examination targeting material in basic science The subsequent chapters focus on the essential interventional pharmacotherapy of antiplatelets, anticoagulants, and other commonly used medications in the catheterization laboratory and outpatient setting for patients with atherosclerosis These chapters correspond to the next 15% of the boards centering on pharmacology A similar-sized 15% of the board examination is directed toward imaging, and the book includes specific chapters on radiation safety, catheterization laboratory equipment and technique, contrast agents, and intravascular ultrasound The two largest areas of the examination, each covering 25% of the content, include case selection–management and procedural techniques The review book dedicates 25 chapters to comprehensively cover these areas Finally, we have included chapters for the miscellaneous remaining areas covered by the board examination, including peripheral vascular disease, ethics, statistics, and epidemiology, as well as a chapter directed at improving test-taking skills Also essential to the quality and appropriateness of the questions and annotated answers is the expertise of the chapter authors We are fortunate to have assembled the ‘‘who’s who of academic interventional cardiology’’ The 59 contributing authors from leading medical centers around the world have over 4,600 articles cited in PubMed We are greatly indebted to these authors who are recognized both for their interventional expertise and for their teaching skills In the end, the true value of this textbook is not only the relevance of the questions, the outstanding quality of the authors, but also the value of the annotated answers The text includes 910 questions and 254 figures and tables The corresponding answers have been appropriately detailed to provide relevant facts and information as well as up-to-date journal citations The practice of interventional cardiology is exciting, rewarding, and a privilege each of us enjoys Likewise, it has been our privilege to work with the superb contributors, our colleagues in interventional cardiology, as well as the editorial team at the University of Kentucky and Lippincott Williams and Wilkins It is our personal hope that you will enjoy this book and that it will be a valuable resource to you in passing the board examination and providing the highest quality care possible to your patients DEBABRATA MUKHERJEE, MD LESLIE CHO, MD DAVID J MOLITERNO, MD vii Contributors Robert J Applegate, MD Director, Cardiovascular Training Program Wake Forest University School of Medicine Winston-Salem, North Carolina Joseph Babb, MD Professor of Medicine Department of Internal Medicine, Cardiology Division Brody School of Medicine East Carolina University; Director, Cardiac Catheterization Laboratories Pitt County Memorial Hospital Greenville, North Carolina Thomas M Bashore, MD Professor of Medicine Division of Cardiovascular Medicine; Director, Fellowship Training Program and Adult Congenital and Valvular Disease Program Duke University Medical Center Durham, North Carolina Matthew C Becker, MD Fellow in Cardiovascular Disease Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio Deepak L Bhatt, MD Associate Professor of Medicine Staff, Cardiac, Peripheral, and Carotid Intervention Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio David C Booth, MD Endowed Professor Medicine Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky; Chief of Cardiology Lexington VA Medical Center Lexington, Kentucky Sorin J Brener, MD Associate Professor of Medicine Department of Medicine Case Western Reserve University; Staff Physician Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio Ivan P Casserly, MD Assistant Professor of Medicine Cardiology Division University of Colorado; Director of Interventional Cardiology Denver VA Medical Center Denver, Colorado Leslie Cho, MD Director, Women’s Cardiovascular Center Medical Director, Preventive Cardiology and Rehabilitation Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio Antonio Colombo, MD Chief of Invasive Cardiology Universit`a Vita-Salute and San Raffaele Scientific Institute and Columbus Hospitals Milan, Italy Harold L Dauerman, MD Professor of Medicine University of Vermont; Director, Cardiovascular Catheterization Laboratories Fletcher Allen Health Care Burlington, Vermont Steven R Daugherty, PhD Assistant Professor of Psychology Assistant Professor of Preventive Medicine Rush Medical College Chicago, Illinois ix x Contributors Stephen G Ellis, MD Professor of Medicine Department of Cardiovascular Medicine Cleveland Clinic Lerner College of Medicine Case Western Reserve University; Director, Cardiac Catheterization Laboratories Cleveland Clinic Foundation Cleveland, Ohio Nezar Falluji, MD, MPH Clinical Instructor Gill Heart Institute Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Hussam Hamdalla, MD Assistant Professor of Medicine Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Robert A Harrington, MD Professor of Medicine Director, Cardiovascular Clinical Trials Co-Director, Cardiovascular Research Duke Clinical Research Institute Department of Medicine, Division of Cardiology Duke University Medical Center Durham, North Carolina Howard C Herrmann, MD David P Faxon, MD Director of Strategic Planning Department of Medicine Brigham and Women’s Hospital; Professor of Medicine Department of Medicine Harvard Medical School Boston, Massachusetts Joel A Garcia, MD Interventional Cardiology and Research Fellow Department of Cardiology University of Colorado Denver, Colorado Thomas Gehrig, MD Cardiology Fellow Division of Cardiovascular Medicine Duke University Medical Center Durham, North Carolina Professor of Medicine Cardiovascular Division University of Pennsylvania School of Medicine; Director, Interventional Cardiology and Cardiac Catheterization Laboratories Hospital of the University of Pennsylvania Philadelphia, Pennsylvania L David Hillis, MD Professor and Vice Chair Department of Internal Medicine University of Texas Southwestern Medical Center Dallas, Texas Alice K Jacobs, MD Professor of Medicine Department of Medicine, Section of Cardiology Boston University School of Medicine; Director, Cardiac Catheterization Laboratories and Interventional Cardiology Boston Medical Center Boston, Massachusetts John Lynn Jefferies, MD, MPH Bernard Gersh, MB, ChB, DPhil Professor of Medicine Cardiology Diseases Mayo Clinic College of Medicine Rochester, Minnesota John C Gurley, MD, MBA Professor of Medicine Director, Interventional Cardiology Fellowship Gill Heart Institute Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Assistant Professor Adult and Pediatric Cardiology Baylor College of Medicine Divisions of Adult Cardiovascular Diseases and Pediatric Cardiology Texas Children’s Hospital Texas Heart Institute at St Luke’s Episcopal Hospital Houston, Texas Hani Jneid, MD Division of Cardiology Massachusetts General Hospital and Harvard Medical School Boston, Massachusetts Contributors Dominique Joyal, MD Interventional Cardiology Fellow Cardiology Division Loyola University Medical Center Maywood, Illinois David E Kandzari, MD John B Simpson Assistant Professor of Interventional Cardiology and Genomic Sciences Division of Cardiology Department of Medicine Duke University Medical Center Durham, North Carolina Samir Kapadia, MD Associate Professor of Medicine Cleveland Clinic Lerner College of Medicine of Case Western Reserve University; Director, Interventional Cardiology Fellowship Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio Juhana Karha, MD Fellow, Cardiovascular Medicine Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio Morton J Kern, MD Clinical Professor of Medicine Associate Chief of Cardiology Department of Cardiology University of California Irvine Orange, California Richard A Lange, MD Professor of Medicine Chief of Clinical Cardiology Johns Hopkins University Baltimore, Maryland Bruce E Lewis, MD Professor of Medicine Associate Director, Interventional Cardiology Loyola University Medical Center Maywood, Illinois; Chief, Cardiology Division St Joseph Hospital Chicago, Illinois Ferdinand Leya, MD Cardiology Department Loyola University Medical Center Maywood, Illinois Andrew O Maree, MD Interventional Cardiology Fellow Division of Cardiology Massachusetts General Hospital; Instructor, Department of Medicine Harvard Medical School Boston, Massachusetts J Jeffery Marshall, MD Medical Director Cardiac Catheterization Laboratory Northeast Georgia Heart Center Gainesville, Florida Telly A Meadows, MD Cardiology Fellow Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio Bernhard Meier, MD Professor of Medicine Chairman, Department of Cardiology University Hospital Bern Bern, Switzerland David J Moliterno, MD Professor and Vice-Chairman of Medicine Chief, Cardiovascular Medicine Jefferson Morris Gill Professor of Cardiology Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Pedro R Moreno, MD Director, Interventional Cardiology Research Mount Sinai Hospital; Associate Professor Department of Medicine Mount Sinai School of Medicine New York, New York Douglass A Morrison, MD Cardiology Department University of Arizona Tucson, Arizona xi xii Contributors Debabrata Mukherjee, MD Associate Professor of Medicine Director, Cardiac Catheterization Laboratories Gill Foundation Professor of Interventional Cardiology Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Brahmajee K Nallamothu, MD, MPH Assistant Professor of Medicine Interventional Cardiologist Department of Internal Medicine University of Michigan Health System Ann Arbor, Michigan Craig R Narins, MD Assistant Professor of Medicine Division of Cardiology University of Rochester School of Medicine Rochester, New York Zoran S Nedeljkovic, MD Assistant Professor of Medicine Department of Medicine, Section of Cardiology Boston University School of Medicine; Interventional Cardiologist Boston Medical Center Boston, Massachusetts Michael R Nihill, MBBS Professor of Clinical Pediatrics Department of Pediatrics Baylor College of Medicine; Associate in Pediatric Cardiology Department of Cardiology Texas Children’s Hospital Houston, Texas Alan W Nugent, MBBS Assistant Professor of Pediatrics Baylor College of Medicine; Pediatric Cardiologist Texas Children’s Heart Center Texas Children’s Hospital Houston, Texas Igor F Palacios, MD Physician Cardiac Unit Massachusetts General Hospital Boston, Massachusetts Karen S Pieper, MS Senior Statistician Duke Clinical Research Institute Department of Medicine, Division of Cardiology Duke University Medical Center Durham, North Carolina Marco Roffi, MD Lecturer in Cardiology Zurich Medical School; Staff Cardiologist University Hospital Zurich, Switzerland Christopher L Sarnoski, MD Cardiology Fellow Division of Cardiovascular Medicine University of Vermont Burlington, Vermont Paul Sorajja, MD Assistant Professor of Medicine Mayo Clinic College of Medicine Rochester, Minnesota Amy L Seidel, MD Interventional Cardiology Fellow Division of Cardiovascular Medicine Emory University School of Medicine Atlanta, Georgia Steven R Steinhubl, MD Associate Professor of Medicine Director of CV Education and Clinical Research Gill Heart Institute and Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Ann O’Connor, MD Instructor in Medicine Section of Cardiology Department of Medicine University of Chicago Chicago, Illnois Eric J Topol, MD Professor of Genetics Department of Genetics Case Western Reserve University Cleveland, Ohio Contributors Thomas T Tsai, MD Cardiology Fellow Department of Internal Medicine University of Michigan Ann Arbor, Michigan E Murat Tuzcu, MD Professor of Medicine Department of Cardiovascular Medicine Cleveland Clinic Lerner College of Medicine Case Western Reserve University; Vice Chairman Department of Cardiovascular Medicine Cleveland Clinic Foundation Cleveland, Ohio Christopher Walters, MD Cardiology Fellow Gill Heart Institute Division of Cardiovascular Medicine University of Kentucky Lexington, Kentucky Peter Wenaweser, MD Attending Physician Department of Cardiology University Hospital Bern Bern, Switzerland Christophe A Wyss, MD Cardiology Fellow University Hospital Zurich, Switzerland Khaled M Ziada, MD Assistant Professor of Medicine Gill Heart Institute Division of Cardiovascular Medicine University of Kentucky; Director, Cardiac Catheterization Laboratories Lexington VA Medical Center Lexington, Kentucky xiii 19 Drug-Eluting Stents and Local Drug Delivery for the Prevention of Restenosis Peter Wenaweser and Bernhard Meier Questions Stents coated with drugs like sirolimus and paclitaxel reduce the incidence of in-stent restenosis The main effect of the drugs is on: (A) (B) (C) (D) Elastic recoil Arterial remodeling Smooth muscle cell proliferation/migration Extracellular matrix production Which of the following is true regarding sirolimus? (D) Sirolimus influences regulator genes that control the cell cycle (E) A, B, C, and D are correct Which of the following statements concerning paclitaxel (Taxus) is wrong? (A) Paclitaxel induces disassembly of microtubules (B) Paclitaxel was discovered in a crude extract from the bark of a Pacific yew (C) Paclitaxel is an antimicrotubule drug (D) Paclitaxel was first evaluated as an antitumor drug Which of the following statements regarding drugeluting stent platforms is not correct? (A) Sirolimus is a macrolide (B) Sirolimus is the metabolic substrate of the fungus Streptomyces hygroscopicus (C) Sirolimus was at an early stage targeted as rapamycin for use in renal transplantation (A) The sirolimus-eluting (Cypher) stent is composed of a stainless steel stent coated with a nonerodable polymer (B) Paclitaxel can only be used in combination with a polymer-based stent platform (C) Polymers are long-chain molecules, which form a reservoir, and facilitate controlled and prolonged drug delivery (D) A conceptually ideal drug-eluting stent should have a large surface area, minimal gaps between cells, and no strut deformation after deployment Polymeric materials coated on stents: (A) Allow a controlled and sustained release of agents 149 150 900 Questions: An Interventional Cardiology Board Review (B) Minimize the potential of underdosing or overdosing of drug levels (C) Serve as drug reservoir (D) Are potentially toxic (E) A to D are true The first randomized comparison of a sirolimuseluting stent with a standard bare-metal stent reduced the rate of in-stent restenosis after months to: (A) (B) (C) (D) 20% 15% 10% 1 year) stent thrombosis after drug-eluting stent implantation: (A) May be associated with chronic inflammation of the arterial wall (B) May be due to a hypersensitivity reaction to the polymer (C) Can be avoided by prescribing prolonged dual antiplatelet therapy (D) Carries a high morbidity and mortality 10 Which of the following antiproliferative agents is under clinical investigation as new drug-eluting stent systems? (A) (B) (C) (D) (E) Tacrolimus Everolimus Biolimus Zotarolimus All of the above 11 The SIRTAX trial, a randomized, controlled, singleblind study comparing sirolimus-eluting stents with paclitaxel-eluting stents in approximately 1,000 allcomer patients favors a treatment with a sirolimuseluting stent because of: (A) Balloon angioplasty is always the treatment of choice (B) A treatment with a sirolimus- or paclitaxeleluting stent appears to be superior to balloon angioplasty (C) A treatment with β-radiation has shown to be inferior to balloon angioplasty (D) Paclitaxel-eluting stent implantation appears to be superior to sirolimus-eluting stent implantation Experimental models of stent implantation in human coronary arteries show: (A) A complete healing after bare-metal stent implantation within to months (B) That the deployment of sirolimus-eluting or paclitaxel-eluting stents is associated with an increase in neointimal thickness at 28 days in comparison with bare-metal stents (C) A delayed healing with persistence of fibrin and incomplete endothelialization after drugeluting stent implantation (D) Always a greater inflammatory reaction after drug-eluting stent implantation in comparison with bare-metal stent within 28 days (A) Lower incidence of cardiac death (B) Lower incidence of stent thrombosis (C) Fewer major adverse cardiac events, primarily by decreasing rates of clinical and angiographic restenosis (D) Better acute gain and higher success of stent implantation (E) B and C 12 A meta-analysis of randomized trials by Kastrati et al comparing sirolimus-eluting with paclitaxeleluting stents in patients with coronary artery disease reported all except: (A) Target lesion revascularization is less frequently performed in patients treated with a sirolimuseluting stent (B) Rate of death is comparable (C) Angiographic restenosis is more frequently observed in patients treated with a paclitaxeleluting stent (D) Rates of myocardial infarction and stent thrombosis are lower in sirolimus-eluting stent treated patients 13 A 58-year-old man underwent coronary angiography due to angina pectoris CCS The invasive evaluation showed a subtotal proximal left anterior descending (LAD) lesion The result after balloon dilatation Drug-Eluting Stents and Local Drug Delivery for the Prevention of Restenosis and stent implantation is good (see the figure on the left) Six months later the patient suffered from acute, ongoing chest pain with anterior STsegment elevation in the electrocardiogram (EKG) The coronary angiography at this point of time is depicted in the figure on the right What is your diagnosis and treatment? (A) Complete in-stent restenosis with plaque rupture (B) Late stent thrombosis with a large amount of visible thrombus (C) Balloon angioplasty and additional stent implantation (D) Balloon angioplasty, possible thrombus aspiration/removal, and use of abciximab (E) A and C (F) B and D 14 Evaluation of the cost-effectiveness of drug-eluting stents in an unselected patient population in the year 2003 to 2004 (Lancet 2005;366:921–929) shows that: (A) The use of drug-eluting stents in all patients is less effective than in studies with selected patients (B) A restriction to patients in high-risk groups should be evaluated in further trials (C) With respect to the current prices of drugeluting stent, an unrestricted use of these stents is not justified (D) A to C are correct 15 A large prospective observational cohort study evaluated the incidence and predictors for stent thrombosis following drug-eluting stent implantation The overall incidence amounted to 1.3% in a 9-month follow-up Which of the following parameters was the strongest predictor? (A) Premature antiplatelet therapy discontinuation (B) Renal failure (C) Bifurcation lesions (D) Diabetes (E) Low ejection fraction 151 16 The assessment of coronary endothelial function months after comparing sirolimus-eluting stent implantation with bare-metal stent implantation, assessed with bicycle exercise as a physiologic stimulus (see following figure), revealed that: (A) Implantation of a bare-metal stent does effect physiologic response to exercise proximal and distal to the stent (B) Implantation of a bare-metal stent does not effect physiologic response to exercise proximal and distal to the stent (C) Implantation of a sirolimus-eluting stent does not effect physiologic response to exercise proximal and distal to the stent (D) Implantation of a sirolimus-eluting stent does effect physiologic response to exercise proximal and distal to the stent (E) B and D (F) B and C 17 What are possible pitfalls of drug-eluting stents? (A) Prolonged dual antiplatelet treatment after stent implantation (B) Severe allergic reactions (C) Hypersensitivity reactions caused by polymerbased stent platforms (D) Loss of radial force of the stent after complete drug-release (E) A, B, and C (F) A and C 18 For the treatment of patients with multivessel disease: (A) Coronary artery bypass grafting (CABG) is obsolete and inferior to multivessel stenting with drug-eluting stents (B) CABG is still superior to multivessel percutaneous coronary intervention (PCI) (C) Drug-eluting stents may provide a comparable long-term outcome to CABG, but there is a lack of conclusive data 152 900 Questions: An Interventional Cardiology Board Review (D) Not more than three stents or 50 mm total drug-eluting stent length should be implanted in the same patient 19 The sirolimus-eluting (Cypher) and paclitaxeleluting (Taxus) stent platform share the following characteristics, except: (A) (B) (C) (D) Stainless steel stent Nonbiodegradable polymer Strut thickness 130 to 140 µm Equal release rate of the drug (sirolimus or paclitaxel) 20 A meta-analysis of all published, randomized trials comparing the clinical outcome of drug-eluting stents (sirolimus and paclitaxel) with bare-metal stents until 2004 favors the use of drug-eluting stents because of: (A) Significant reduction of myocardial infarction (B) Significant reduction of mortality (C) Significant reduction of restenosis and major adverse cardiac events (D) Significant reduction of stent thrombosis Answers and Explanations Answer E Although developed as an antibiotic, it was found more useful as an immunosuppressant Answer A Paclitaxel promotes the polymerization of tubulin and does not induce the disassembly of microtubules like other antimicrotubule agents such as vinca alkaloids (N Engl J Med 1995;332:1004– 1014) Answer B Some drugs can be loaded directly onto metallic surfaces (e.g., prostacyclin, paclitaxel) (Circulation 2003;107:2274–2279) Answer E (Pharmacol Ther 2004;102:1–15) Answer D None of the patients in the sirolimusstent group, as compared with 26.6% of those in the standard stent group, had restenosis of 50% or more of the luminal diameter (p 3 years after surgery) Morphologically, vein graft lesions tend to be diffuse, concentric, and friable with a poorly developed or absent fibrous cap and little evidence of calcification (Circulation 1998;97:916–931) Answer E Optimal graft flow as assessed at the end of surgery has a protective effect against graft occlusion Good flow conditions are observed in patients with larger target vessels, lack of significant disease distally to the anastomosis, and several runoff branches Significant predictors of SVG occlusion or disease at months after surgery include congestive heart failure, grafting to diagonal arteries, larger vein graft size, and poor runoff Traditional cardiovascular risk factors, such as hypertension, sex, diabetes mellitus, and previous MI, not seem to affect early graft patency (J Thorac Cardiovasc Surg 2005;129: 496–503) Answer E Vein graft thrombosis is the principal underlying mechanism of early vein graft occlusion Vein graft thrombosis is caused by alterations in the vessel wall, altered flow dynamics, or changes in blood rheology (Virchow’s Triad) Bypass surgery has a systemic effect on circulating levels of factors influencing hemostasis, creating a prothrombotic state Focal endothelial cell loss and damage is associated with high-pressure distension of the venous conduits due to harvesting Reduction of graft flow due to implantation proximal to an atherosclerotic segment or a stricture at the anastomosis is a predisposing factor for occlusion by thrombosis Several comparative antithrombotic trials have shown that oral anticoagulants are equivalent to aspirin in terms of 1-year vein graft patency rates (Circulation 1998;97:916–931) 159 160 900 Questions: An Interventional Cardiology Board Review Answer E Although within the first month of surgery thrombosis is the main mechanism of vein graft disease, from month to year, ischemia in territory supplied by an SVG is most often due to lesions at the distal perianastomotic site or midgraft stenosis caused by neointimal hyperplasia Neointimal hyperplasia, defined as the proliferation of smooth muscle cells and accumulation of extracellular matrix in the intimal compartment, is the characteristic adaptive mechanism of venous conduits to systemic blood pressures This process represents the foundation for later development of graft atherosclerosis Graft occlusion due to subacute thrombosis is a more rare cause of ischemia between month and year after CABG 10 Answer A Although the fundamental processes of atherosclerosis in native coronary vessels and in vein grafts are similar, there are several temporal, histologic, and metabolic differences Lipid handling of SVG endothelium is characterized by slow lipolysis, more active lipid synthesis, and high lipid uptake than in the native coronary arteries In addition, SVG atherosclerosis is more rapidly progressive From a histologic point of view, SVG atherosclerosis is characterized by more foam and inflammatory cells SVG atherosclerotic involvement is diffuse and lesions are friable with a poorly developed fibrous cap and little evidence of calcification (Circulation 1998;97:916–931) 11 Answer E A number of morphologic factors have been associated with reduced vein graft patency It has been observed that 1-year vein graft patency was significantly lower if the grafted vessel was 1.5 mm (Ann Thorac Surg 1979;28:176–183) Severity of native vessel atherosclerosis proximal to the anastomotic site influences the flow in the vein graft Sustained competitive flow through mild stenotic native vessels has been described as a predisposing factor for vein graft occlusion However, this mechanistic view remains a source of debate because the available data is conflicting (J Thorac Cardiovasc Surg 1981;82:520–530, Ann Thorac Surg 1979;28:176–183) Cigarette smoking is an important predictor of recurrent angina during the first year after surgery and of poor longterm clinical outcome The evidence implicating hyperlipidemia as a key risk factor in the development of vein graft atherosclerosis is as consistent and strong as it is for native coronary disease 12 Answer E Aspirin has been shown to increase short- and midterm vein graft patency Cessation of smoking is a highly effective strategy in preventing atherosclerosis Accordingly, it has been shown that persistent smokers had more than twice the risk of suffering MI or required redo surgery at year following CABG compared with patients who quit smoking at the time of surgery (Circulation 1996;93:42–47) Several trials have shown a clear-cut benefit for aggressive lipid-lowering therapy in the post-CABG setting Similarly, the use of arterial grafts has been a major breakthrough in bypass surgery owing to the better long-term patency compared with SVG 13 Answer A For patients undergoing CABG, addition of dipyridamole to aspirin therapy is not recommended (BMJ 1994;308:159–168) According to the American College of Chest Physicians (ACCP) guidelines, for patients intolerant to aspirin, an oral loading dose of 300 mg clopidogrel hours after surgery followed by 75 mg per day is recommended Patients undergoing CABG who require oral anticoagulation at the same time (e.g., for atrial fibrillation or mechanical valve replacement) also qualify for aspirin (Chest 2004;126:600S–608S) In patients who undergo CABG for non–ST-segment elevation ACS, the Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) study has demonstrated that the combination of aspirin and clopidogrel, 75 mg per day for to 12 months, is superior to aspirin alone (N Engl J Med 2001;345:494–502) 14 Answer A Suture line rupture is of concern only in the early phase after surgery Characteristic Event’s rates in SVG-PCI (compared with PCI in native vessels) 30-d events (%) Death MI Urgent revascularization Death/MI Death/MI/urgent revascularization 6-mo events (%) Death MI Revascularization Death/MI Death/MI/ revascularization Grafts PCI n = 627 Native PCI n = 13, 158 2.1 13.1 1.0 7.7 0.006