Short- and long-term prognostic value of postoperative cardiac troponin I concentration in patients undergoing coronary artery bypass grafting

Background: The value of postoperative cardiac troponin I (cTnI) has been shown to indicate a higher risk of in-hospital death after cardiac surgery. The authors therefore assessed the long-term prognostic value of cTnI in patients undergoing elective coronary artery bypass grafting. Methods: Consecutive patients (n = 202) were included and divided into two groups according to the postoperative value of cTnI (< or greater than or equal to 13 ng/ml). In-hospital mortality and nonfatal cardiac events (delayed extubation > 24 h; postoperative requirement of inotropic agent; ventricular and supraventricular arrhythmia; postoperative myocardial infarction) were recorded. Survivors were then followed up over a 2-yr period. Data are median and odds ratio (95% confidence interval). Results: Of all patients, 174 (86%) had a low cTnI (4.1 ng/ml; range, 1.1-12.6) and 28 (14%) had a high cTnI (23.8 ng/ml; range, 13.4-174.6). in-hospital mortality was not significantly different (4 vs. 2%), whereas long-term mortality (18 vs. 3%, P = 0.006) and mortality from cardiac cause (18 vs. 1%, P < 0.001) was greater in patients with a high cTnI. A high cTnI was a significant factor predicting death (odds ratio, 7.3 [2.027-1]) or death from cardiac causes (odds ratio, 37.4 [4.2-334.4]). Nonfatal cardiac events were also more frequent in the hospital (64 vs. 41%, P = 0.02) and within the 2-yr follow-up period (39% vs. 16%, P = 0.03) in patients with high cTnI. Conclusion: A high postoperative peak of cTnI is associated with increased risk of death, death from cardiac causes, and nonfatal cardiac events within 2 yr after coronary artery bypass grafting.