Troponin T and Perioperative Ischemi in Noncardiac Surgery

To evaluate troponin T (TnT) as marker for perioperative ischemia, we prospectively studied 1028 patients (PTS) undergoing major noncardiac procedures. Clinical dat included preoperative examinations, daily clinical follow-up, and serial electrocardiograms, CK/CK-MB, and TnT levels. Major cardiac complications (COMPS) were classified by reviewers blinded to TnT dat in 29 (3%) of PTS, including acute myocardial infarction (AMI), pulmonary edema, cardiac arrest, complete heart block, and sustained ventricular tachycardi or fibrillation. AMI was diagnosed using CK-MB criteri in 14 (1.4%) PTS, for whom peak TnT levels were >0.1 mcg/l in 86% and >0.2 mcg/l in 62%. No postoperative clinical complications occurred to the two PTS with CK-MB criteri for AMI but normal TnT levels. Among the 1014 PTS without CK-MB criteri for AMI, COMPS occurred in 5 (0.6%) of 855 PTS with TnT ≤ 0.1 mcg/l versus 10 (6%) of 159 with higher peak TnT levels (p < 0.0001). This table shows the distribution of peak TnT levels by procedure type: We conclude that Tnt correlates with rates of COMP after major noncardiac surgery even among PTS without AMI by CK-MB criteria. In this cohort, elevated TnT levels were more common with procedures generally associated with higher risk of COMPS. Long term follow-up is needed to determine whether elevated TnT levels in patients without COMPS were false positive results or subclinical ischemic events.