Renal impairment and outcomes in heart failure: systematic review and meta-analysis.

Objectives: We estimated the prevalence of renal impairment in heart failure (HF) patients and the magnitude of associated mortality risk using a systematic review of published studies.
Background: Renal impairment in HF patients is associated with excess mortality, although precise risk estimates are unclear.
Methods: A systematic search of MEDLINE (through May 2005) identified 16 studies characterizing the association between renal impairment and mortality in 80,098 hospitalized and non-hospitalized HF patients. All-cause mortality risks associated with any renal impairment (creatinine >1.0 mg/dl, creatinine clearance [CrCl] or estimated glomerular filtration rate [eGFR] <90 ml/min, or cystatin-C >1.03 mg/dl) and moderate to severe impairment (creatinine > or =1.5, CrCl or eGFR <53, or cystatin-C > or =1.56) were estimated using fixed-effects meta-analysis.
Results: A total of 63% of patients had any renal impairment, and 29% had moderate to severe impairment. After follow-up > or =1 year, 38% of patients with any renal impairment and 51% with moderate to severe impairment died versus 24% without impairment. Adjusted all-cause mortality was increased for patients with any impairment (hazard ratio [HR] = 1.56; 95% confidence interval [CI] 1.53 to 1.60, p < 0.001) and moderate to severe impairment (HR = 2.31; 95% CI 2.18 to 2.44, p < 0.001). Mortality worsened incrementally across the range of renal function, with 15% (95% CI 14% to 17%) increased risk for every 0.5 mg/dl increase in creatinine and 7% (95% CI 4% to 10%) increased risk for every 10 ml/min decrease in eGFR.
Conclusions: Renal impairment is common among HF patients and confers excess mortality. Renal function should be considered in risk stratification and evaluation of therapeutic strategies for HF patients.