Abstract
BACKGROUND: Increased baseline heart rate is associated with cardiovascular risk and all-cause mortality in the general population. We hypothesized that elevated preoperative heart rate increases the risk of myocardial injury after non-cardiac surgery (MINS). METHODS: We performed a secondary analysis of a prospective international cohort study of patients aged ≥45 yr undergoing non-cardiac surgery. Preoperative heart rate was defined as the last measurement before induction of anaesthesia. The sample was divided into deciles by heart rate. Multivariable logistic regression models were used to determine relationships between preoperative heart rate and MINS (determined by serum troponin concentration), myocardial infarction (MI), and death within 30 days of surgery. Separate models were used to test the relationship between these outcomes and predefined binary heart rate thresholds. RESULTS: Patients with missing outcomes or heart rate data were excluded from respective analyses. Of 15 087 patients, 1197 (7.9%) sustained MINS, 454 of 16 007 patients (2.8%) sustained MI, and 315 of 16 037 patients (2.0%) died. The highest heart rate decile (>96 beats min(-1)) was independently associated with MINS {odds ratio (OR) 1.48 [1.23-1.77]; P<0.01}, MI (OR 1.71 [1.34-2.18]; P<0.01), and mortality (OR 3.16 [2.45-4.07]; P<0.01). The lowest decile (<60 beats min(-1)) was independently associated with reduced mortality (OR 0.50 [0.29-0.88]; P=0.02), but not MINS or MI. The predefined binary thresholds were also associated with MINS, but more weakly than the highest heart rate decile. CONCLUSIONS: Preoperative heart rate >96 beats min(-1) is associated with MINS, MI, and mortality after non-cardiac surgery. This association persists after accounting for potential confounding factors. CLINICAL TRIAL REGISTRATION: NCT00512109.