Simultaneous Measurement of Cardiac Troponin I, B-type Natriuretic Peptide, and C-reactive Protein for the Prediction of Long-term Cardiac Outcome after Cardiac Surgery

Abstract

Background Simultaneous assessment of cardiac troponin I, B-type natriuretic peptide, and C-reactive protein has been found to provide unique prognostic information in acute coronary syndromes. The current study addressed the prognostic implication of a multiple-marker approach in cardiac surgery. Methods Two hundred twenty-four patients undergoing cardiac surgery were included and followed up within 12 months after surgery. Serial blood samples were drawn in all patients the day before surgery, at the end of surgery, and 6, 24, and 120 h after surgery. Major adverse cardiac events within 12 months after surgery were chosen as study endpoints and were defined as malignant ventricular arrhythmia, myocardial infarction, congestive heart failure, the need for myocardial revascularization, and/or death from cardiac cause. Predictive ability of each cardiac biomarker was assessed using logistic regression. Results Accuracies of C-reactive protein, cardiac troponin I, and B-type natriuretic peptide, considered as continuous variables, to predict the occurrence of major adverse cardiac events were limited (area under receiver operating characteristic curve: 0.54 [0.47-0.60], P = 0.42; 0.62 [0.55-0.68], P = 0.01; and 0.68 [0.61-0.74], P < 0.001, respectively). When biomarkers were considered as 75% specificity dichotomized variables, elevated C-reactive protein (> 180 mg/l), cardiac troponin I (> 3.5 ng/ml), and B-type natriuretic peptide (> 880 pg/ml) were independent predictors of major adverse cardiac events (odds ratio: 2.14 [1.03-4.49], P = 0.043; 2.37 [1.25-5.64], P = 0.011; and 2.65 [1.16-4.85], P = 0.018, respectively) in a multivariate model including the European System for Cardiac Operative Risk Evaluation score. Conclusions Simultaneous measurement of cardiac troponin I, B-type natriuretic peptide, and C-reactive protein improves the risk assessment of long-term adverse cardiac outcome after cardiac surgery.