Risk of Major Adverse Cardiac Events Following Noncardiac Surgery in Patients With Coronary Stents

Study Questions:

What are the risk factors for adverse cardiac events in patients undergoing noncardiac surgery following coronary stent implantation?

Methods:

This was a national, retrospective cohort study of 41,989 Veterans Affairs (VA) and non-VA operations occurring in the 24 months after a coronary stent implantation between 2000 and 2010. Nonlinear generalized additive models examined the association between timing of surgery and stent type with major adverse cardiac events (MACE), adjusting for patient, surgery, and cardiac risk factors. A nested case-control study assessed the association between perioperative antiplatelet cessation and MACE. The main outcomes measure was a composite 30-day MACE rate of all-cause mortality, myocardial infarction, and cardiac revascularization.

Results:

Within 24 months of 124,844 coronary stent implantations (47.6% drug-eluting stent [DES], 52.4% bare-metal stent [BMS]), 28,029 patients (22.5%; 95% confidence interval [CI], 22.2%-22.7%) underwent noncardiac operations, resulting in 1,980 MACE (4.7%; 95% CI, 4.5%-4.9%). Time between stent and surgery was associated with MACE (<6 weeks, 11.6%; 6 weeks to <6 months, 6.4%; 6-12 months, 4.2%; >12-24 months, 3.5%; p < 0.001). MACE rate by stent type was 5.1% for BMS and 4.3% for DES (p < 0.001). After adjustment, the three factors most strongly associated with MACE were nonelective surgical admission (adjusted odds ratio [AOR], 4.77; 95% CI, 4.07-5.59), history of myocardial infarction in the 6 months preceding surgery (AOR, 2.63; 95% CI, 2.32-2.98), and revised cardiac risk index >2 (AOR, 2.13; 95% CI, 1.85-2.44). Of the 12 variables in the model, timing of surgery ranked fifth in explanatory importance, measured by partial effects analysis. Stent type ranked last, and DES was not significantly associated with MACE (AOR, 0.91; 95% CI, 0.83-1.01). After both BMS and DES placement, the risk of MACE was stable at 6 months. A case-control analysis of 284 matched pairs found no association between antiplatelet cessation and MACE (OR, 0.86; 95% CI, 0.57-1.29).

Conclusions:

The authors concluded that among patients undergoing noncardiac surgery within 2 years of coronary stent placement, MACE were associated with emergency surgery and advanced cardiac disease, but not stent type or timing of surgery beyond 6 months after stent implantation.

Perspective:

This retrospective study assessing the risk MACE after noncardiac surgery in patients with recent coronary stenting identified several risk factors, principally acuity of clinical presentation for surgery and several markers of advanced cardiac disease as predictors of MACE. Although the time from stent placement to surgery was associated with MACE, this was primarily observed for surgery in the first 6 months after the stent procedure, whereas timing of surgery more than 6 months after the stent procedure was not significantly associated with MACE. Although the data suggest that the risk of surgery after DES placement may stabilize earlier, the potential confounding and nonrandomized nature of this observational study does not allow for direct comparison of outcomes by stent type. Given multiple limitations of the analysis, these findings should suggest need for additional research, ideally with randomized trials, to improve the evidence base supporting current guideline recommendations.

Keywords: Myocardial Infarction, Case-Control Studies, Coronary Angiography, Benzimidazoles, Drug-Eluting Stents, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Cardiovascular Diseases, Risk Factors, Homeodomain Proteins, Angioplasty, Balloon, Coronary, POU Domain Factors


< Back to Listings