Abstract 12611: Moderate to Severe Acute Kidney Injury Provides the Additional Long-Term Prognostic Information to the Blood Urea Nitrogen to Creatinine Ratio in Patients Admitted With Acute Decompensated Heart Failure

Abstract

Backgrounds: Elevated blood urea nitrogen to creatinine ratio (BUN/Cr), a surrogate for renal neurohumoral activation, is a marker of mortality in patients with heart failure. Acute kidney injury (AKI) during heart failure treatment is also associated with poor outcome in patients admitted with acute decompensated heart failure (ADHF). However, there is little information available on the long-term prognostic significance of AKI, relating to BUN/Cr in ADHF patients. Methods and Results: We studied 305 consecutive ADHF patients discharged with survival. We defined high BUN/Cr as top tertile at the admission (>24.0). AKI during ADHF treatment was defined according to AKI Network criteria (stage 1, ≥0.3mg/dl absolute or 1.5- to 2.0-fold relative increase in serum creatinine level (s-Cr); stage 2, >2- to 3-fold increase in s-Cr; stage 3, >3-fold increase in s-Cr or s-Cr≥4.0mg/dl with an acute rise of ≥0.5mg/dl). During a follow-up period of 4.2±3.2 yrs, 69 patients had cardiovascular death (CVD). At multivariate Cox analysis, BUN/Cr (p=0.01) and AKI (p=0.0005) were significantly associated with CVD, independently of age, systolic blood pressure, serum sodium and hemoglobin levels and estimated glomerular filtration rate. Irrespective of high or low BUN/Cr, patients with stage 2 or 3 AKI (adjusted hazard ratio(HR): 6.9 (95%CI 1.5 to 30.4) in high BUN/Cr group, 2.9 (95%CI 1.1 to 7.7) in low BUN/Cr group) had the significant increased CVD risk, compared to patients with no AKI. On the other hand, although patients with stage 1 AKI had the significant increased CVD risk (adjusted HR: 3.8 (95%CI 1.5 to 9.7) in high BUN/Cr group, there was no significant difference in CVD risk between patients with stage 1 AKI (adjusted HR: 0.6 (95%CI 0.3 to 1.2) and no AKI in low BUN/Cr group. Conclusion: Moderate to severe AKI during heart failure treatment would provide the additional long-term prognostic information to BUN/Cr in ADHF patients.