Usefulness of postoperative high-sensitive troponin T measurement and implications for defining type 5 infarction

Abstract

Background and aim of the study: Guidelines indicate for type 5 myocardial infarction (MI) that postoperative troponin need not be exclusively ischemic but may also be caused by epicardial injury. Complexity arises from the introduction of high-sensitive troponin. This study attempts to contribute to the understanding of postoperative high-sensitive cardiac troponin T (hs-cTnT) increase. Methods: The median enzyme increase of different cardiac operations was compared. Linear regression analyses were used to determine correlations between enzyme rise and independent parameters. Receiver-operating characteristics (ROC) served to evaluate the discriminatory power of enzyme rise in detecting ischemia and to determine possible thresholds. Results: Among 400 patients, 2.8% had intervention-related ischemia analogous to type 5 MI definition. The median postoperative hs-cTnT/creatine kinase myocardial band (CK-MB) increase varied according to types of surgery, with highest increase after mitral valve and lowest after off-pump coronary surgery. After ruling out patients with preoperatively elevated hs-cTnT, regression analysis confirmed Maze procedure (p