Longitudinal change in renal function in patients with idiopathic dilated cardiomyopathy without renal insufficiency at initial diagnosis

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) >= 60ml/min at the first diagnosis. Cumulative event proportions and renal insufficiency defined as eCcr < 60ml/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 ss-blocker therapy were associated with a poor prognosis in renal function.