One-Year Mortality, Causes of Death, and Cardiac Interventions in Patients with Postoperative Myocardial Injury

Abstract

Background: To evaluate the role of routine troponin surveillance in patients undergoing major noncardiac surgery, unblinded screening with cardiac consultation per protocol was implemented at a tertiary care center. In this study, we evaluated 1-year mortality, causes of death, and consequences of cardiac consultation of this protocol.

Methods: This observational cohort included 3224 patients ≥60 years old undergoing major noncardiac surgery. Troponin I was measured routinely on the first 3 postoperative days. Myocardial injury was defined as troponin I >0.06 μg/L. Regression analysis was used to determine the association between myocardial injury and 1-year mortality. The causes of death, the diagnoses of the cardiologists, and interventions were determined for different levels of troponin elevation.

Results: Postoperative myocardial injury was detected in 715 patients (22%) and was associated with 1-year all-cause mortality (relative risk [RR] 1.4, P = 0.004; RR 1.6, P < 0.001; and RR 2.2, P < 0.001 for minor, moderate, and major troponin elevation, respectively). Cardiac death within 1 year occurred in 3%, 5%, and 11% of patients, respectively, in comparison with 3% of the patients without myocardial injury (P = 0.059). A cardiac consultation was obtained in 290 of the 715 patients (41%). In 119 (41%) of these patients, the myocardial injury was considered to be attributable to a predisposing cardiac condition, and in 111 patients (38%), an intervention was initiated.

Conclusions: Postoperative myocardial injury was associated with an increased risk of 1-year all-cause but not cardiac mortality. A cardiac consultation with intervention was performed in less than half of these patients. The small number of interventions may be explained by a low suspicion of a cardiac etiology in most patients and lack of consensus for standardized treatment in these patients.