High sensitive cardiac troponin I level useful prognostic marker in chronic HF
MedWire News: High sensitive cardiac troponin I (hs-cTnI) level is an independent and useful prognostic predictor of mortality in patients with chronic heart failure (HF), a study suggests.
Researchers studied the prognostic value of cardiac troponin T (cTnT) using a conventional assay and that of hs-cTnI using a recently developed sensitive commercial assay.
Given that very low plasma levels of hs-cTnT have previously been shown to be of prognostic value in stable chronic HF, “sensitive cardiac troponin assays may be useful to predict severity and prognosis in patients with chronic HF,” say the authors.
Takayoshi Tsutamoto (Shiga University, Otsu, Japan) and colleagues measured hemodynamic parameters and serum levels of cTnT, hs-cTnI, and N-terminal pro-brain natriuretic peptide (NT-proBNP) in 258 chronic HF patients with low left ventricular ejection fraction (LVEF; <45%), and then followed them up for an average of 2.6 years.
Defining both elevated cTnT and cTnI as ≥0.03 ng/ml, as this was the lowest concentration at which the coefficient of variation was <10% in both assays, the researchers found that 32 (12%) patients had elevated serum cTnT, and 112 (43%) had elevated hs-cTnI levels.
Log cTnT and log hs-cTnI levels showed significant, positive correlation in the patients with elevated cTnT, while log hs-cTnI levels significantly and positively correlated with log NT-proBNP levels in patients with elevated hs-cTnI.
Stepwise multivariate analysis showed that elevated plasma NT-proBNP (≥627 pg/ml, p=0.0063) and hs-cTnI (p=0.016), but not cTnT, were independent predictors of cardiac death.
The hazard ratio for mortality associated with both elevated NT-proBNP and hs-cTnI levels compared with lower levels was 5.74 (p<0.0001).
The findings suggest that “the assay for hs-cTnI is more sensitive than the conventional commercial assay for cTnT, and the sensitive assay system for cTnI or cTnT provides useful information on the prognosis of chronic HF with low LVEF,” write Tustamoto et al in the American Heart Journal.
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By Caroline Price