Prognostic value of cardiac troponin T after noncardiac surgery: 6-Month follow-up data

Objectives. We sought to evaluate the prognostic significance of cardiac troponin T (TnT) serum levels after noncardiac surgery. Background. Cardiac TnT has been found to be a marker for myocardial injury, but elevations of TnT are common in patients undergoing noncardiac surgery without clinical evidence of severe ischemia. Methods. We studied 772 patients who underwent major noncardiac procedures and did not have major cardiovascular complications during their inpatient course. Total serum creatine kinase (CK) and cardiac TnT were measured according to a protocol that included sampling in the recovery room and during the next 2 days. A 6-month follow-up interview was performed for 722 (94%) of the patients. Results. Elevated cardiac TnT and CK-MB results were detected for 92 (12%) and 211 (27%) patients, respectively. During the follow-up period, there were 19 (2.5%) major cardiac complications, including 14 cardiac deaths, 3 nonfatal myocardial infarctions and 2 admissions for unstable angina. Compared with patients with cardiac TnT values <0.1 ng/ml, patients with elevated TnT had a relative risk for cardiac events of 5.4 (95% confidence interval: 2.2 to 13, p = 0.001), whereas CK-MB was not correlated with postdischarge cardiac events. In multivariate logistic regression analysis adjusting for preoperative clinical and CK-MB data, a cardiac TnT value >0.1 ng/ml was an independent correlate of cardiac events (adjusted odds ratio 4.6, p < 0.05). This correlation was a function of the relation of elevated TnT levels with postoperative in-hospital congestive heart failure and new sustained arrhythmias, suggesting that elevated postoperative TnT levels detected myocardial ischemia during these clinical events. Conclusions. We conclude that an abnormal TnT level in patients undergoing noncardiac surgery may be a useful marker of ischemic disease and a predictor of 6-month prognosis.