Renal impairment, worsening renal function, and outcome in patients with heart failure: an updated meta-analysis.

AIMS Chronic kidney disease (CKD) and worsening renal function (WRF) have been associated with poor outcome in heart failure (HF). METHODS AND RESULTS Articles were identified by literature search of MEDLINE (from inception to 1 July 2012) and Cochrane. We included studies on HF patients and mortality risk with CKD and/or WRF. In a secondary analysis, we selected studies investigating predictors of WRF. We retrieved 57 studies (1,076,104 patients) that investigated CKD and 28 studies (49,890 patients) that investigated WRF. The prevalence of CKD was 32% and associated with all-cause mortality: odds ratio (OR) 2.34, 95% confidence interval (CI) 2.20-2.50, P < 0.001). Worsening renal function was present in 23% and associated with unfavourable outcome (OR 1.81, 95% CI 1.55-2.12, P < 0.001). In multivariate analysis, moderate renal impairment: hazard ratio (HR) 1.59, 95% CI 1.49-1.69, P < 0.001, severe renal impairment, HR 2.17, 95% CI 1.95-2.40, P < 0.001, and WRF, HR 1.95, 95% CI 1.45-2.62, P < 0.001 were all independent predictors of mortality. Across studies, baseline CKD, history of hypertension and diabetes, age, and diuretic use were significant predictors for the occurrence of WRF. CONCLUSION Across all subgroups of patients with HF, CKD, and WRF are prevalent and associated with a strongly increased mortality risk, especially CKD. Specific conditions may predict the occurrence of WRF and thereby poor prognosis.