Cardiac troponin T (cTnT) is a highly sensitive and specific marker of acute myocardial infarction. Serum cTnT is also slightly elevated in patients with severe heart failure and is associated with left ventricular hypertrophy (LVH) in patients treated with haemodialysis. In this study serum cTnT concentrations and echocardiographic findings were investigated in heart failure patients without acute coronary syndrome. cTnT was also compared with other cardiac markers and plasma levels of brain natriuretic peptide (BNP).
Twenty-six patients hospitalized with heart failure were included in the study. Echocardiographic measurements and blood sampling were carried out 12-36 h after admission. Serum cTnT (3rd generation assay), cardiac troponin I (cTnI), creatine kinase MB (CKMB) and CK were measured. Plasma BNP was analysed using the Shionoria assay. LVH was defined as left ventricular mass index (LVMI) > 125 g/m for males and > 110 g/m for females. Left ventricular systolic function was estimated from the mitral annulus motion (AV-mean LV).
Median cTnT was 0.012 (< 0.010-0.032) microg/L. Sixty-two percent of the patients (16 of 26) had elevated serum cTnT >or= 0.010 micro/L. cTnT was positively correlated with CKMB (rho = 0.40, p = 0.04) and BNP (rho = 0.43, p = 0.03), but not with cTnI and CK. A negative correlation was found between cTnT and AV-mean LV (rho = -0.58, p = 0.007), and there was a positive correlation between cTnT and LVMI (rho = 0.44, p = 0.03). No other analyte was correlated to LVMI.
Serum cTnT but not cTnI was associated with left ventricular dysfunction and LVH in patients hospitalized with heart failure. This explains why cTnT tends to be slightly elevated in patients with heart failure without symptoms of acute myocardial ischaemia.