Objective: This article reviews the benefits and risks of coronary artery bypass grafting and angioplasty for patients with moderate or severe left ventricular systolic dysfunction and summarizes the recommendations of the expert panel for the Agency for Health Care Policy and Research Heart Failure Guideline.
Data sources: Data were obtained from studies published in English and referenced in MEDLINE or EMBASE between 1966 and 1993. We used the search terms heart failure, congestive; congestive heart failure; heart failure; cardiac failure; and dilated cardiomyopathy in conjunction with the terms coronary artery bypass grafting and angioplasty.
Study selection: All cohort studies and case series that provided separate outcomes data on a subgroup of patients with a left ventricular ejection fraction less than 0.40 were reviewed.
Data extraction and synthesis: Studies were reviewed for inclusion and exclusion criteria, survival, and functional status measures using a standardized form. Cohort studies were assessed on eight aspects of study quality using a defined list of study flaws.
Conclusion: Coronary artery bypass grafting improves 3-year survival by approximately 30% to 50% and physical functioning by approximately one New York Heart Association class in patients with moderate to severe left ventricular dysfunction and limiting angina. However, the operative mortality ranges from 5% to 30% depending on patients' ejection fractions and comorbidity. It is not clear whether patients whose predominant symptom is heart failure rather than angina benefit from bypass surgery or how much ischemia is required to justify surgical intervention. Clinical outcomes after angioplasty have not been adequately studied to determine the relative risks and benefits compared with bypass grafting.