Functional and circulatory renal changes in advanced heart failure

The aim of the study was to describe the relations between heart and renal functions and to investigate whether reduced glomerular filtration rate is influenced more by reduced perfusion or venous congestion.

A prospective cohort study of 101 patients (69 men, 32 women) with chronic heart failure aged 52 (49-54) (median, 95 % confidence interval) years. We analyzed the blood samples, parameters of echocardiography and right heart catheterization.

Left ventricular ejection fraction correlated with the estimated glomerular filtration rate eGFR (r = 0.214, p = 0.036) in the whole sample of patients. We found a correlation between cardiac output and renal perfusion pressure in the whole sample (r = 0.232, p = 0.0225) and in patients with chronic heart failure (r = 0.254, p = 0.0278).In the whole sample the mean pulmonary artery pressure (PAP) correlated with the variables determining renal function: PAP and renal perfusion pressure (r = -0.345, p = 0.002),PAP and eGFR (r = -0.299, p = 0.009). In the other two studied groups these correlations were not significant.

In the group of heart failure patients left and right ventricular functions were the main determinants for renal function. Current cardiac output or right atrial pressure as markers of renal perfusion were not associated with renal functions in advanced but stable heart failure patients with low burden of extracardiac comorbidities (Tab. 1, Fig. 4, Ref. 13).