Coronary revascularization prior to elective vascular surgery: does it reduce cardiac risk?

Atherosclerosis is a generalized process, and patients with peripheral vascular disease often have coexistent coronary artery disease (CAD). Ashton et al and others have shown that patients who require vascular surgery appear to have an increased risk for cardiac complications because many of the risk factors contributing to peripheral vascular disease (eg, diabetes mellitus, tobacco use, hyperlipidemia) are also risk factors for CAD. Another factor leading to increased complications with vascular surgery is that major arterial operations are time-consuming and may be associated with substantial fluctuations in extravascular fluid volumes, cardiac filling pressures, systemic blood pressure, heart rate, and thrombogenicity. In a selective review of several thousand vascular surgical procedures (carotid endarterectomy, aortic aneurysm resection, and lower-extremity revascularization) reported in the literature from 1970 to 1987, Hertzer found that cardiac complications were responsible for about half of all perioperative deaths and that fatal events were nearly five times more likely to occur in the presence of standard preoperative indicators of CAD. No randomized trials of preoperative coronary revascularization for the purpose of lowering perioperative risk of noncardiac surgery have been performed, but reports of several retrospective cohort studies have been published. One study used an administrative database of patients who were undergoing noncardiac surgery in the state of Washington. As compared with patients who did not undergo percutaneous coronary intervention (PCI) preoperatively, those who did undergo the procedure had a lower incidence of perioperative cardiac complications. Evidence of a potential protective effect of preoperative coronary artery bypass grafting (CABG) comes from follow-up studies of randomized trials and/or registries that compare medical and surgical therapy for coronary artery disease. In a prospective cohort of 246 patients with abdominal aortic aneurysm (AAA), Hertzer et al demonstrated that the cumulative 5-year survival rate (75%) and cardiac mortality rate (5%) after CABG was significantly better than the cumulative survival (29%) and cardiac mortality rates (34%) in patients with severe, uncorrected coronary involvement (P .0001). The investigators concluded that in selected patients who require elective resection of AAA also warranted is myocardial revascularization to enhance perioperative outcomes and late survival. The largest study to date included 3368 noncardiac operations performed within a 10-year period among patients assigned to medical therapy or CABG in the Coronary Artery Surgery Study. Prior successful CABG had a cardioprotective effect among patients who underwent high-risk noncardiac surgery (abdominal, thoracic, vascular, or orthopedic surgery). The perioperative mortality rate was nearly 50% lower in the group of patients who had undergone CABG than in those who received medical therapy (3.3% vs 1.7%, P .05). There was no difference in the outcome of patients undergoing low-risk procedures such as breast and urologic surgery. Fleisher et al used Medicare claims’ data to assess 30-day and 1-year mortality after noncardiac surgery according to the use of cardiac testing and coronary interventions such as CABG and PCI within the year before noncardiac surgery. Preoperative revascularization significantly reduced the 1-year mortality rate for patients undergoing aortic surgery but had no effect on the mortality rate for those undergoing infrainguinal surgery. Finally, an analysis of the Bypass Angioplasty Revascularization Investigation (BARI) evaluated the incidence of postoperative cardiac complications after noncardiac surgery among patients with multivessel coronary disease who were randomly assigned to undergo PCI or CABG for severe angina. At an average of 29 months after coronary revascularization, both groups had similar, low rates of postoperative myocardial infarction or death from cardiac causes (1.6% in each group). These data suggest that prior successful coronary revascularization, when accompanied by careful follow-up, is associated with a low rate of cardiac events after noncardiac surgery. In this issue of the Journal, Back et al evaluate the cardiac protective effect of previous coronary revascularizaFrom the Division of Cardiology, University of Michigan Health System, Ann Arbor. Competition of interest: nil. Reprint requests: Kim A Eagle, MD, Division of Cardiology, University of Michigan Health System, 3910 Taubman Center, 1500 E Medical Center Drive, Ann Arbor, MI 48103 (e-mail: keagle@umich.edu). J Vasc Surg 2002;36:644-5. Copyright © 2002 by The Society for Vascular Surgery and The American Association for Vascular Surgery. 0741-5214/2002/$35.00 0 24/9/126559 doi:10.1067/mva.2002.126559