A combined index of cardiac biomarkers as a risk factor for early cardiovascular mortality in hemodialysis patients

Background: Cardiac biomarkers, including cardiac troponin-I (cTn-I) and N-terminal pro brain natriuretic peptide (NT-proBNP) have been associated with poor outcome in hemodialysis (HD) patients. The present study was designed to evaluate these biomarkers as biological risk factors for early and late mortality in HD patients. In addition, a multimarker approach including inflammatory index was performed in order to improve the cardiovascular risk assessment of these patients. Methods: cTnI, NT-proBNP and C-reactive protein (CRP) were measured at baseline (October through November 2002) in 130 HD patients [median age 69.0 (23.4 – 87.7) years old, 76 females, 54 males]. Patients were followed during 8 years. Adjusted hazard ratios (HRs) of death and 95% confidence intervals (CIs) were estimated using Cox proportional hazard models. Results: During the follow-up, 82 patients died, mainly from cardiac cause (63.4%). Elevated cTnI, NT-proBNP or CRP were all associated with increased early (death within 2 years of follow-up) but not late mortality. Moreover, the combination of all parameters (CRP ≥ 10.51 mg/L and cTnI ≥ 0.037 µ g/L and NT-proBNP ≥ 10,204 pg/mL) dramatically increased the short-term mortality especially the cardiovascular mortality (HR 8.58, 95% CI 1.59 – 46.2; p = 0.0007). Conclusions: A combined index of cardiovascular risk factors could provide supplementary risk stratification in HD patients for early cardiovascular mortality, strongly supporting the annual routine determination of these biomarkers.