Impact of Blood Urea Nitrogen on In-Hospital Mortality in Patients with Acute Heart Failure

Abstract

Backgrounds: In heart failure (HF), several studies have demonstrated that elevated blood urea nitrogen (BUN) is associated with adverse outcomes. This purpose is to assess the relationship between BUN and in-hospital outcomes in patients with HF. Methods: Objectives were 281 cases with HF admitted in ICU (77610 years, Male 155) from April 2007 through September 2008, in which IHD, valve disease, cardiomyopathy, tachycardia, hypertension, bradycardia, acute coronary syndrome and others were 111, 42, 36, 31, 18, 11, 8 and 24 cases. The relationships between in-hospital outcomes and hemodynamics, anemia, renal function, serum electrolytes, neurohormonal factors at admission, pre-hospital medication were evaluated retrospectively. Results: Systolic blood pressure (SBP), uric acid, BUN were 150637mmHg, 7.162.5mg/dl, 28.4618.3mg/dl (median 23.0). Median of plasma aldosterone concentration (PAC) and plasma rennin activity (PRA) were 5.3pg/ml and 1.7ng/ml/h. Death in hospital was 27 cases (9.6%). Non-survivors have significantly lower SBP, higher PAC, higher PRA, higher uric acid and higher BUN than survivors in-hospital (p!0.05). In Cox’s proportional hazards analysis, BUNO23mg/dl was an independent predictive factor of in-hospital death (HR 1.181, 95%CI 0.067-0.488, p!0.01). Age, SBP, uric acid, PACO5.3, PRAO1.7, renin-angiotensin blockers before admission were not independent predictive factor of in-hospital death. Conclusion: These results may suggest that higher BUN is the risk factor of short-term mortality in acute HF patients.