220 - Worsening Blood Urea Nitrogen and Creatinine levels Can Predict Length of Hospital Stay and 30-day Readmission Rate Among Patients with Heart Failure and Reduced Ejection Fraction Admitted for Acute Heart Failure Syndrome

Background: Baseline renal dysfunction is a well-known risk factor that has been shown to result in unfavorable outcomes among heart failure patients. However, the value of worsening blood urea nitrogen (BUN) and Creatinine (Cr) levels as determinants of prognostic outcomes among hospitalized patients with acute heart failure syndrome and normal baseline kidney function is not well elucidated. Methods: A retrospective analysis was performed on all patients admitted to our hospital for acute heart failure syndrome from January 2005 to December 2015. Serum BUN and Cr levels were obtained from the admission laboratory panel. Patients with known chronic kidney disease or abnormal BUN/Cr within 2 years prior to admission were excluded. Patients were organized into groups according to their serum BUN and Cr levels. A comparison was made between patients with BUN <22 mg/dL versus those with BUN ≥22 mg/dL, and patients with Cr <1.5 mg/dL versus those with Cr ≥1.5 mg/dL regarding their 30-day readmission rate, length of stay (LOS) and mortality rate. Results: Of 1,031 patients with heart failure with reduced ejection fraction (HFrEF) admitted for acute heart failure syndrome and met the study criteria, 520 patients (49.5%) had BUN ≥22 and 511 patients (50.5%) had BUN <22 mg/dL. After standardizing medications and confounding factors, the 30-day readmission rate was 18% in patients with BUN ≥22 mg/dL versus 17% in patients with BUN <22 mg/dL (P = .8). The LOS was 6.7 days in patients with BUN ≥22 mg/dL versus 5 days in those with BUN <22 mg/dL (P < .0001). The mortality rate did not differ between the two groups. Similarly, 355 patients (34.4%) had Cr ≥1.5 mg/dL and 676 (65.6%) had Cr <1.5 mg/dL. After standardizing medications and confounding factors, the 30-day readmission rate in patients with Cr ≥1.5 was 21.1% versus 16% in those with Cr <1.5 mg/dL (OR: 1.4, 95% CI: 1.1–2, P = .04). The LOS was 7 days in patients with Cr ≥1.5 mg/dL versus 5.5 days in those with Cr <1.5 mg/dL (P = .04). The mortality rate was 3% in patients with Cr<1.5 mg/dL versus 2.9% in those with Cr ≥1.5 mg/dL (P = .8). Conclusions: Worsening BUN ≥22 mg/dL and Cr ≥1.5 mg/dL can aid in predicting the length of stay and 30-day readmission rate, respectively, among patients with heart failure and reduced ejection fraction admitted for acute heart failure syndrome. Further studies are warranted to assess their significance among heart failure patients with preserved ejection fraction.