Incomplete Revascularization and Cardiac Events in Noncardiac Surgery

Study Questions:

Is there an association between incomplete revascularization and the risk of major adverse cardiovascular events (MACE) and myocardial infarction (MI) among patients undergoing noncardiac surgery?

Methods:

Using the Veterans Affairs (VA) Clinical Assessment, Reporting and Tracking system, the VA Surgical Quality Improvement Program database, and Centers for Medicare and Medicaid Services database, the authors performed a retrospective cohort study of patients who underwent noncardiac surgery within 2 years after coronary artery stent placement between 2005 and 2010. Incomplete revascularization was defined as the presence of a ≥50% lesion in the left main coronary artery or a ≥70% stenosis in another major epicardial coronary vessel. Noncardiac surgery performed during the same hospitalization as stent placement or after cardiac surgery and minor procedures were excluded. The primary outcome was a composite of MACE within 30 days after noncardiac surgery, defined as the first occurrence of all-cause death, MI, or need for coronary revascularization. A logistic regression model adjusting for age, history of MI within 6 months of surgery, revised cardiac risk index, procedure type, percutaneous coronary intervention (PCI) risk, and time from surgery to PCI was used to test the association of incomplete revascularization with the primary endpoint.

Results:

During the study period, 12,486 patients without coronary artery bypass grafting were identified who underwent PCI and subsequent noncardiac surgery. Among these, 4,332 patients (34.7%) had incomplete revascularization. Patients with incomplete revascularization were more likely to have had MIs in the prior 6 months (13.9% vs. 10.5%, p < 0.001), were more likely to have heart failure (39.1% vs. 32.8%, p < 0.001), and were more likely to have diabetes (57.9% vs. 52.8%, p < 0.001). The adjusted odds ratio for the primary outcome at or before 6 weeks was 1.22 (95% confidence interval [CI], 0.76-1.95). After adjustment, incomplete revascularization was associated with a significantly increased risk for postoperative MI if surgery occurred within 6 weeks after stent placement (adjusted odds ratio, 1.84; 95% CI, 1.04-2.38). Treating incomplete revascularization as a continuous variable showed a 17% increase in the odds of postoperative MI for every additional vessel with residual stenosis (p < 0.001).

Conclusions:

In this retrospective cohort study, incomplete revascularization among patients with coronary artery disease was associated with an increased risk of MI following noncardiac surgery. The risk appeared highest if surgery occurred within 6 weeks following PCI.

Perspective:

This study shows an association between incomplete revascularization and recent PCI and postoperative complications after noncardiac surgery, particularly for postoperative MI. As the study is retrospective, it does not prove a causal association between complete revascularization and a reduction in MACE or MI. Prospective studies are required to investigate the role of complete or incomplete revascularization in patients with coronary artery disease in the perioperative period. Trials such as the ISCHEMIA trial (International Study of Comparative Healthy Effectiveness With Medical and Invasive Approaches), while not directly focused on patients undergoing noncardiac surgery, may shed light on the best management strategy for patients with stable ischemic heart disease and known ischemia.


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