Prediction of perioperative myocardial infarction/injury in high-risk patients after noncardiac surgery.

Abstract

Perioperative myocardial infarction/injury (PMI) is a surprisingly common, yet difficult to predict cardiac complication in patients undergoing non-cardiac surgery. We aimed to assess the incremental value of preoperative cardiac troponin (cTn) concentration in the prediction of PMI. Among prospectively recruited patients at high cardiovascular risk (age >65 years OR >45 years with pre-existing cardiovascular disease), PMI was defined as an absolute increase in high-sensitivity cTnT (hs-cTnT) concentration of ≥14ng/L (the 99th percentile) above the preoperative concentration. PMI was centrally adjudicated by two independent cardiologists using serial measurements of hs-cTnT. Using logistic regression, three models were derived: Model 1 included patient- and procedure-related information, Model 2 adding routinely available laboratory values, and Model 3 further adding preoperative hs-cTnT concentration. Models were compared also versus preoperative hs-cTnT alone. Findings were validated in two independent cohorts. Among 6'944 patients, PMI occurred in 1058 patients (15.2%). The predictive accuracy as quantified by the area under the receiver-operating characteristic curve was 0.73 (95%CI 0.71-0.74) for Model 1, 0.75 (95%CI 0.74-0.77) for Model 2, 0.79 (95%CI 0.77-0.80) for Model 3, and 0.74 for hs-cTnT alone. Model 3 included 10 preoperative variables: age, body-mass-index, known coronary artery disease, metabolic equivalent >4, risk of surgery, emergency surgery, planned duration of surgery, haemoglobin, platelet count and hs-cTnT. These findings were confirmed in both independent validation cohorts (n=722, n=966). Preoperative cTn adds incremental value above patient- and procedure-related variables as well as routine laboratory in the prediction of PMI.