Difference in long-term prognostic value of renal function between ischemic and non-ischemic mild heart failure

Renal function is one of the strongest prognostic markers in patients with chronic heart failure, but it has been suggested that this might be due to (local, i.e. renal) vascular atherosclerosis. The aim of the present study is to evaluate the prognostic value of renal function in both ischemic and non-ischemic mild chronic heart failure. From 161 patients with early chronic heart failure and NYHA class II, who had been enrolled in a multicenter trial, ischemic chronic heart failure was present in 120 patients and non-ischemic chronic heart failure in 41 patients. Estimated glomerular filtration rate was calculated by the Cockcroft–Gault equation (GFRc). Follow-up duration was 13 years (mean 11.7 years). Mean age was 60.5±8.0 years, 86% was male and mean left ventricular ejection fraction was 0.29±0.08. Baseline characteristics were not statistically different between the groups. Multivariate Cox regression analysis revealed that in non-ischemic chronic heart failure, renal function was an important predictor of all-cause mortality (Relative Risk; 1.65 (1.05–2.58); p = 0.029). In contrast, in ischemic chronic heart failure, renal function was not related to all-cause mortality (Relative Risk; 1.07 (0.92–1.23); p = 0.40). In mild chronic heart failure, renal function is a prognostic risk marker for long-term mortality in non-ischemic chronic heart failure, but not in patients with coronary artery disease. These data suggest that renal vascular abnormalities are not primarily responsible for the prognostic value of renal function in patients with mild chronic heart failure.