901-83 Troponin T and Perioperative Ischemia in Noncardiac Surgery

Abstract

To evaluate troponin T (TnT) as a marker for perioperative ischemia, we prospectively studied 1028 patients (PTS) undergoing major noncardiac procedures. Clinical data 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 data in 29 (3%) of PTS, including acute myocardial infarction (AMI). pulmonary edema, cardiac arrest, complete heart block, and sustained ventricular tachycardia or fibrillation. AMI was diagnosed using CK-MB criteria 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 criteria for AMI but normal TnT levels. Among the 1014 PTS without CK-MB criteria 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:ProcedureTnT < 0.10.1-0.2 > 0.2Abdom. Aortic Aneur.39 (66%)13 (22%)7 (12%)Other vascular160 (79%)20 (10%)23 (11%)Thoracic75 (64%)30 (26%)12( 10%)Abdominal99 (89%)8 (7%)4 (4%)Orthopedic304 (92%)16 (5%)12 (4%)Other180 (87%)16 (8%)10 (5%) 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 a 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.