Excerpt

Atherosclerosis develops in a patchy, discontinuous fashion within coronary arteries. Therefore, it is possible to treat the discrete areas of obstruction that most impede coronary blood flow to the myocardium. The mechanical approaches to coronary revascularization fall broadly into two categories: coronary artery bypass grafting surgery (CABG) and catheter-based percutaneous coronary interventions (PCI). Together, these coronary revascularization methods are among the most common major medical procedures performed in North America and Europe.

Coronary bypass surgery and coronary angioplasty (with or without stents) are alternative approaches to mechanical coronary revascularization, so their comparative effectiveness in terms of patient outcomes has been of great interest. The comparative effectiveness of bypass surgery and angioplasty is an open question primarily for those patients for whom either procedure would be technically feasible and whose coronary disease is neither too limited nor too extensive.

CABG is generally preferred for patients with left main coronary artery disease or severe triple-vessel disease with reduced left ventricular function because it has been previously shown in randomized trials to improve survival compared with medical therapy. In contrast, PCI is generally preferred for patients with most forms of single-vessel disease when symptoms warrant coronary revascularization, in light of its lower procedural risk and the evidence that PCI reduces angina and myocardial ischemia in this subset of patients.

The choice between PCI and CABG is most relevant for patients whose coronary artery disease (CAD) lies in between these extremes, namely patients with single-vessel disease of the proximal left anterior descending artery (LAD), most forms of double-vessel CAD, and less extensive forms of triple-vessel CAD. Most randomized controlled clinical trials (RCTs) of angioplasty and surgery have been conducted in this middle segment of the patient population with CAD.

The purpose of this report is to evaluate the evidence for the comparative effectiveness of PCI and CABG in this population of patients with CAD.

Contents

• Preface
• Acknowledgments
• Executive Summary
• 1. Introduction
  • Background
  • Scope and Key Questions
• 2. Methods
  • Topic Development
  • Search Strategy
  • Study Selection
  • Data Extraction
  • Quality Assessment of Individual Studies
  • Grading the Body of Evidence for Each Key Question
  • Data Synthesis
  • Peer Review and Public Commentary
• 3. Results
  • General Description of Included Studies
  • Key Question 1a. In patients with ischemic heart disease, and angiographically-proven single or multi-vessel disease, what is the comparative effectiveness of PCI compared to CABG, in reducing the occurrence of adverse objective outcomes and improving subjective outcomes?
  • Key Question 1b. Over what period of time are the comparative benefits of PCI and CABG sustained?
  • Key Question 2. Is there evidence that the comparative effectiveness of PCI and CABG varies based on
• 4. Summary and Discussion
  • Outcomes Overall
  • Outcomes in Subgroups
  • Generalizability of Randomized Trials of PCI Versus CABG
  • Evolving Revascularization Methods
  • Future Research
• Abbreviations
• Appendixes
  • Appendix A Search Strategies
  • Appendix B List of Excluded Studies
  • Appendix C Additional Analyses and Evidence Tables
  • Appendix D Peer Reviewers
  • Appendix E Abstraction Forms
• References

Prepared for: Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services.¹ Contract No. 290-02-0017. Prepared by: Stanford-UCSF Evidence-based Practice Center.

Suggested citation:

Bravata DM, McDonald KM, Gienger AL, Sundaram V, Perez MV, Varghese R, Kapoor JR, Ardehali R, McKinnon MC, Stave CD, Owens DK, Hlatky MA. Comparative Effectiveness of Percutaneous Coronary Interventions and Coronary Artery Bypass Grafting for Coronary Artery Disease. Comparative Effectiveness Review No. 9. (Prepared by Stanford-UCSF Evidence-based Practice Center under Contract No. 290-02-0017.) Rockville, MD: Agency for Healthcare Research and Quality. October 2007. Available at: http://effectivehealthcare.ahrq.gov/healthInfo.cfm?infotype=all&reptype=allfinal.

This report is based on research conducted by the Stanford-UCSF Evidence-based Practice Center (EPC) under contract to the Agency for Healthcare Research and Quality (AHRQ), Rockville, MD (Contract No. 290-02-0017). The findings and conclusions in this document are those of the author(s), who are responsible for its contents; the findings and conclusions do not necessarily represent the views of AHRQ. Therefore, no statement in this report should be construed as an official position of the Agency for Healthcare Research and Quality or of the U.S. Department of Health and Human Services.

This report is intended as a reference and not as a substitute for clinical judgment. Anyone who makes decisions concerning the provision of clinical care should consider this report in the same way as any medical reference and in conjunction with all other pertinent information.

This report may be used, in whole or in part, as the basis for development of clinical practice guidelines and other quality enhancement tools, or as a basis for reimbursement and coverage policies. AHRQ or U.S. Department of Health and Human Services endorsement of such derivative products may not be stated or implied.

Dr. Hlatky received grant support from the National Heart, Lung, and Blood Institute and the Robert Wood Johnson Foundation as an investigator in the Bypass Angioplasty Revascularization Investigation (BARI) trial. He also served as a consultant to the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) trial, which was sponsored by the Cooperative Studies Program of the U.S. Department of Veterans Affairs and by the National Heart, Lung, and Blood Institute. None of the other investigators has any affiliations or financial involvement that conflicts with the material presented in this report.

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