Effect of renal function on prognosis in chronic heart failure.

Renal dysfunction (RD) is associated with increased mortality in heart failure (HF). The aim of this study was to identify whether worsened or improved renal function during mid-term follow-up is associated with worsened outcomes in patients with chronic HF. A total of 892 participants from a multicenter cohort study of chronic HF were followed over 3.1 ± 1.9 years of enrollment. Worsened and improved renal functions were tested with multivariate models as independent predictors of HF hospitalization and mortality. Although 12% of subjects experienced a ≥25% decrease in estimated glomerular filtration rate (eGFR), 17% experienced a ≥25% increase in eGFR, and there was stability of kidney function observed in the cohort as a whole. The quartile with the worst RD at any point in time had increased risk of HF hospitalization and mortality. Worsened eGFR was associated with HF outcomes in the unadjusted (hazard ratio = 1.71, 95% confidence interval 1.04 to 2.81, p = 0.035), but not the adjusted analysis. Improvement in eGFR was not associated with outcome (p = 0.453). In chronic HF, the severity of RD predicts risk of poor outcome better than changes in renal function during mid-term follow-up. This suggests that in patients with appropriately treated chronic HF, worsening renal function in itself does not yield useful prognostic information and may not reflect poor outcome.