Study Examines Risk Factors for Adverse Cardiac Events after non-Cardiac Surgery in Veterans with Coronary Stents
BACKGROUND:
Approximately 600,000 percutaneous coronary stent procedures are performed annually in the U.S., and the incidence of non-cardiac surgery within two years of a cardiac stent is 12% to 23%. While early research suggested a high rate of major adverse cardiac events (MACE) following non-cardiac surgery in patients with drug-eluting stents (DES), subsequent larger multi-center studies reported rates consistent with those observed in patients with bare metal stents (BMS). Further, there is little evidence that continued dual antiplatelet therapy (APT) in the perioperative period mitigates the risk for MACE, despite guidelines recommending continued APT for all patients at least one year following DES implantation. This retrospective cohort study examined the risk factors for MACE in Veterans undergoing non-cardiac surgery following coronary stent implantation, including the relationship between stent type and time from stent to surgery. The main outcome was a composite 30-day MACE rate of all-cause mortality, myocardial infarction (MI), and/or cardiac revascularization. Between 2000 and 2010, a total of 28,029 Veterans met study inclusion criteria and underwent 41,989 surgical procedures in the 24 months following stenting. For Veterans with multiple percutaneous coronary intervention (PCI) episodes of care, the timing between stent and surgery was measured from the most recent PCI care episode prior to surgery.
FINDINGS:
- The three most significant risk factors associated with MACE following non-cardiac surgery in Veterans with recent coronary stent implantation were non-elective surgical admission, history of MI in the six months preceding surgery, and a revised cardiac risk index greater than 2.
- Stent type and timing of surgery beyond 6 months following stent implantation were not associated with MACE. Also, no association between APT cessation and MACE was observed.
LIMITATIONS:
- The clinical decision-making factors that influenced stent selection were largely unavailable.
- Many Veterans underwent more than one PCI procedure during the study period, which could have resulted in misclassification bias for time from stent to surgery. The investigators also relied on administrative data to determine their end-points, which also could result in misclassification bias.
IMPLICATIONS:
- Investigators suggest that a more comprehensive approach to perioperative risk assessment and management among Veterans with coronary stents that emphasizes cardiac and surgical risk factors, rather than stent type, may be warranted.
AUTHOR/FUNDING INFORMATION:
This study was funded by HSR&D (IIR 09-347). Drs. Richman and Maddox also were supported by HSR&D Career Development Awards. Dr. Maddox is part of HSR&D's Center for Innovation for Veteran-Centered and Value-Driven Care in Denver.
Hawn M, Graham L, Richman J, Itani K, Henderson W, and Maddox T. Risk of Major Adverse Cardiac Events Following Non-Cardiac Surgery in Patients with Coronary Stents. JAMA October 9, 2013;310(14):1462-72.
