Prevalence, predictors and prognostic value of acute impairment in renal function during intensive unloading therapy in a community population hospitalized for decompensated heart failure

Abstract

Background and methods: Chronic heart failure (CHF) is often associated with impaired renal function. Diuretics and vasodilators may lead to aggravated renal dysfunction (ARD), particularly among patients with decompensated CHF. Although the prevalence of ARD has been evaluated in patients awaiting heart transplantation, little is known about ARD in the community sample of CHF patients. Accordingly, we prospectively assessed the prevalence, predictors and prognostic value of ARD in 79 consecutive patients admitted to our general community hospital for decompensated CHF undergoing intensive unloading therapy (intravenous nitroprusside and furosemide). ARD was defined as a >or= 25% increase in serum creatinine between admission and maximal value of >or= 2 mg/dl.

Results: Sixteen patients (20%) developed ARD with a mean increase in serum creatinine of 31% (from 1.74 +/- 0.6 to 2.27 +/- 0.9 mg/dl). ARD persisted at 8-day evaluation in seven of 16 subjects (44%) whereas it was reversible in nine (56%). Lower creatinine clearance at baseline [exp beta = 0.93, 95% confidence interval (CI)=0.87-0.99] and the higher dose of furosemide (exp beta=1.02, 95% CI=1.01-1.03) emerged as independent predictors of ARD. During a follow-up of 11 +/- 8 months, death and hospitalization for worsening CHF occurred more frequently in ARD than non-ARD patients (69% versus 17%, P=0.0001; 69% versus 29%, P=0.003, respectively). Persistent ARD was a powerful independent predictor of long-term adverse outcome (odds ratio=11.1; 95% CI=1.12-36.1; P=0.04).

Conclusions: Intensive unloading therapy is associated with the development of ARD in one-fifth of the community population hospitalized for decompensated CHF. The magnitude of this phenomenon is not greater than that observed in younger selected populations with advanced CHF, and depends on baseline renal function and increased diuretic dosage. ARD persisting after 8 days from starting intensive unloading is a powerful predictor of subsequent worsened clinical outcome.