Background: Impaired renal function is associated with poor outcomes among patients with chronic heart failure (CHF). However, the long-term changes in renal function in CHF patients without renal insufficiency at initial diagnosis remain unclear.
Methods and results: Retrospective analysis of patients presenting with idiopathic dilated cardiomyopathy (IDCM) from 1984 to 2003 and who had normal renal function defined as estimated creatinine clearance (eCcr)>or=60 ml/min at the first diagnosis. Cumulative event proportions and renal insufficiency defined as eCcr<60 ml/min were calculated by the Kaplan-Meier method. The predictors of renal insufficiency were evaluated by logistic regression analysis. Impaired renal function developed in 20% during an 8-year follow-up and in 50% during a 20-year follow-up. Advanced age at the first diagnosis, high frequency of admissions, and hypotension during the clinical course were associated with the occurrence of impaired renal function. Beta-blocker therapy was a negative predictor of renal insufficiency.
Conclusions: In patients with IDCM without renal insufficiency at initial diagnosis, worsening renal function occurred during the follow-up period. Frequent admissions, hypotension, and lacking beta-blocker therapy were associated with a poor prognosis in renal function.