Worsening renal function and prognosis in heart failure: systematic review and meta-analysis.

BACKGROUND Renal impairment is associated with increased mortality in heart failure (HF). Recently, reports suggest that worsening renal function (WRF) is another predictor of clinical outcome in HF. The present study was designed to establish the proportion of patients with HF that exhibits (WRF) and the associated risk for mortality and hospitalization by conducting a systematic review and meta-analysis. METHODS AND RESULTS A systematic search of MEDLINE revealed 8 studies on the relationship between WRF and mortality in 18,634 patients with HF. The mortality risk associated with WRF was estimated using random-effects meta-analysis. WRF was defined as an increase in serum creatinine > or = 0.2 mg/dL or a corresponding decrease in estimated glomerular filtration rate > or = 5 mL x min x 1.73 m2. Subgroup analysis included differentiation between in- and out-hospital patients, degree of WRF and time until end point occurrence. WRF developed in 4,734 (25%) patients and was associated with a higher risk for mortality (odds ratio [OR] = 1.62; 95% confidence interval [CI] 1.45-1.82, P < .001) and hospitalization (OR = 1.30, 95% CI 1.04-1.62, P = .022). The severity of WRF was also associated with greater mortality. Patients with impaired renal function at baseline were more prone to progressive renal function loss. CONCLUSIONS WRF predicts substantially higher rates of mortality and hospitalization in patients with HF.