Association between hospital postoperative troponin use and patient outcomes after vascular surgery

Background — Acute myocardial injury after noncardiac surgery, which is most often symptomatically silent, is associated with increased mortality and morbidity. However, it is not known if routine postoperative troponin testing will affect patient outcomes.

Methods — We assembled a cohort of patients who underwent carotid endarterectomy or abdominal aortic aneurysm repair in Ontario, Canada, from 2010 to 2017. Hospitals were categorized into high, medium, and low troponin testing intensity based on the proportion of patients who received postoperative troponin testing. Cox proportional hazards modeling was used to assess the association between hospital-specific testing intensity and 30-day and 1-year major adverse cardiovascular events (MACEs) while adjusting for patient-, surgery-, and hospital-level factors.

Results — The cohort consisted of 18,467 patients from 17 hospitals. Mean age was 72 years, and 74.0% were men. Rates of postoperative troponin testing were 77.5%, 35.8%, and 21.6% in the high-, medium-, and low-testing intensity hospitals, respectively. At 30 days, 5.3%, 5.3%, and 6.5% of patients in high-, medium-, and low-testing intensity hospitals experienced MACE, respectively. Higher troponin testing rate was associated with lower adjusted hazard ratios (HRs) for MACE at 30 days (0.94; 95% confidence interval [CI], 0.89-0.98) and at 1 year (0.97; 95% CI, 0.94-0.99) for each 10% increase in hospital troponin rate. Hospitals with high-testing intensity had higher rates of postoperative cardiology referrals, cardiovascular testing, and rates of new cardiovascular prescriptions.

Conclusions — Patients undergoing vascular surgery at hospitals with higher postoperative troponin testing intensity experienced fewer adverse outcomes than patients who had surgery at hospitals with lower testing intensity.