The prognostic use of serum concentrations of cardiac troponin-I, CK-MB and myoglobin in patients with idiopathic dilated cardiomyopathy

ObjectiveTo examine the association between survival and serum concentrations of cTnI, CK-MB, and myoglobin in patients with idiopathic dilated cardiomyopathy (IDC).BackgroundIt has been suggested that elevated circulating biomarkers of myocardial damage such as cardiac troponin-I (cTnI), creatine kinase MB (CK-MB) and myoglobin are independent risk factors for mortality in patients with heart failure, and recent studies, although limited, showed that there was a potential association between cTnI and the prognosis of patients with dilated cardiomyopathy (DCM).MethodsA cohort study was undertaken in 310 patients with IDC. Standard demographic information, transthoracic echocardiography, and routine blood tests were obtained shortly after hospital admission. Outcome was assessed with all-cause mortality.ResultsAmong the 310 patients studied, 61 (19.7%) died during a mean follow-up of 2.2 years. There was a significant difference in the all-cause mortality rate between patients with serum cTnI >0.05 ng/mL and with cTnI ≤0.05 ng/mL (37.5% vs 15%, log-rank χ2 = 18.423, P < 0.001). After adjustment for other factors associated with prognosis at baseline, serum cTnI >0.05 ng/mL, QRS duration, NYHA functional class and systolic blood pressure predicted all-cause mortality in patients with IDC. There was no association between circulating CK-MB and myoglobin levels and all-cause mortality in the studied IDC patients.ConclusionSerum concentrations of cTnI but not CK-MB or myoglobin are an independent predictor of all-cause mortality in patients with IDC.