Elevated blood urea nitrogen-to-creatinine ratio increased the risk of hospitalization and all-cause death in patients with chronic heart failure.

Objectives: To examine the relationship between blood urea nitrogen (BUN)-to-creatinine ratio and the prognosis of chronic heart failure (HF).

Methods: We analyzed the data from the cohort of 243 adult patients with chronic HF followed at the HF clinic in a tertiary medical center between December 2003 and June 2006. Primary endpoints were the events of all-cause death and first hospitalization for HF.

Results: During a median follow-up of 1.2 years, 72 events were recorded with an event rate of 25.7 events per 100 person-years. In multivariate-adjusted Cox regression models, elevated BUN-to-creatinine ratio was associated with a heightened risk of hospitalization and all-cause death [hazard ratio (HR), 1.24; 95% confidence interval (CI), 1.02-1.51]. The relationship remained after adjusting for glomerular filtration rate (GFR) (HR, 1.23; 95% CI, 1.01-1.51). There was a linear trend toward increasing risks of adverse outcomes across the tertiles of BUN-to-creatinine ratio (P = 0.02). The coexisting presence of the third tertile of BUN-to-creatinine ratio and GFR < 60 ml/min/1.73 m(2) tended to pose a synergistic risk for hospitalization and all-cause death (relative risk, 2.29), relative to those at the first and second tertiles who had GFR > or = 60 ml/min/1.73 m(2).

Conclusions: An elevated BUN-to-creatinine ratio, independent of GFR, confers an increased risk of hospitalization and all-cause death in patients with chronic HF.