Changes of cardiac troponin I and operative mortality of coronary artery bypass

Abstract

Recently, cardiac troponin I has been used to detect myocardial injury because of its superior cardiac specificity. However, there has been debate about the appropriate timing and cutoff level of cardiac troponin I to detect perioperative myocardial injury after coronary artery bypass grafting. The objective of this study was to define the relationship between operative mortality and changes in cardiac troponin I after isolated coronary artery bypass. A retrospective analysis was carried out on data of 218 isolated coronary artery bypass patients who were operated on between June 2009 and February 2012. All patients followed an institutional perioperative management protocol that included 6 cardiac troponin I measurements (preoperatively and 0, 12, 24, 36, and 48 h after coronary artery bypass). According to the patterns of cardiac troponin I, the patient cohort was divided into 2 groups. Group 1 was patients in whom cardiac troponin I levels decreased 24 h after the operation, and group 2 comprised the patients with cardiac troponin I levels that did not decrease or even increased after 24 h. The operative mortality was 4.1% (9/218). Group 2 showed significantly higher mortality (5/25, 20%) than group 1 (4/193, 2.1%). An elevated cardiac troponin I level is common after coronary artery bypass. A persistently high level of cardiac troponin I after 24 h is an important predictor of operative mortality after coronary artery bypass surgery.