Estimated glomerular filtration rate is an independent predictor for mortality of patients with acute heart failure

Background: Heart failure is a major public health problem in developed countries including Japan, therefore it is important to estimate the future risk in patients with heart failure. Recently, it has been reported that chronic kidney disease (CKD) is an independent predictor for mortality in chronic heart failure. However, it is unknown whether CKD is an independent predictor for mortality in acute heart failure. We retrospectively investigated the relationship between estimated glomerular filtration rate (eGFR) on admission for acute heart failure and long-term mortality. Methods: We analyzed 194 patients who were admitted for acute heart failure from January, 2002 to February, 2005. Patients were divided into two groups, high-eGFR group (eGFR <60 ml/min, n=75) and low-eGFR group (eGFR >= 60 ml/min, n=119). eGFR was calculated by equation of MDRD (modification of the diet in renal disease) study. eGFR level <60 ml/min/1.73 m(2) is impaired renal function according to the guidelines of the Japanese Society of Nephrology and of the National Kidney Foundation. Serum B-type natriuretic peptide (BNP) level and left ventricular ejection fraction (LVEF), anemia, age, gender, and etiology of heart failure were also evaluated. Median observation period was 609 days (range: 30-1627). Mean age was 69 years and 138 patients were male. Results: Median eGFR on admission was 74.2 ml/min (range: 5.48-238.7), median BNP level was 840 pg/ml (range: 200-4800), and median LVEF was 36% (range: 11-81%). Forty-two percent of patients had eGFR <60 ml/min of eGFR at the time of coronary care unit admission. Patients with low-eGFR had a significantly lower mortality rate by Kaplan-Meier analysis (log rank test, p=0013). By Cox's proportional-hazard analysis, eGFR was an independent factor for long-term mortality of acute heart failure (p=0.039). Conclusions: Lower eGFR at the time of admission could be an independent predictor for mortality of acute heart failure. (C) 2010 Japanese College of Cardiology. Published by Elsevier Ireland Ltd. All rights reserved.