Serum troponin (cTnT) levels, a commonly measured biomarker of myocardial injury, has rarely been considered in risk models after cardiac surgery.Materials and methods:
Retrospective study of patients undergoing any cardiac surgery between 2004 and 2012. Patients with a history of recent myocardial injury (<21 days) were excluded. The minimum P value approach was used to determine categories of peak cTnT associated with in-hospital death. A multivariable analysis was performed to identify independent predictors of mortality.Results:
A total of 5318 patients without evidence of preoperative ischemia underwent a number of cardiac surgical interventions ranging from isolated coronary revascularization to combined valve coronary artery bypass grafting. The unadjusted in-hospital mortality rate was 3.3% (n = 175 patients). Four categories of peak cTnT were identified using the minimum P value approach: less than or equal to 0.6 ng/mL, 0.7 to 1.9 ng/mL, 2.0 to 3.1 ng/mL, and greater than 3.1 ng/mL with unadjusted mortality rates of 1.0%, 3.6%, 10.1%, and 33.1%, respectively. Multivariate logistic regression demonstrated that all peak cTnT levels greater than 0.6 ng/mL were independent predictors of in-hospital mortality in a dose-dependent manner.Conclusions:
We demonstrate that in patients without preoperative myocardial ischemia, the demonstration of myocardial injury (>0.6 ng/mL) in the postoperative period is highly predictive of in-hospital death.