Early drop in systolic blood pressure, heart rate at admission, and their effects on worsening renal function in elderly patients with acute heart failure

BACKGROUND: Regardless of patients’ baseline renal function, worsening renal function (WRF) during hospitalization is associated with poor outcomes. In individuals with acute heart failure (AHF), one predictor of WRF is an early drop in systolic blood pressure (SBP). Few studies have investigated WRF in elderly AHF patients or the influence of these patients’ heart rate (HR) at admission on the relationship between an early SBP drop SBP and the AHF. METHODS: We measured the SBP and HR of 245 elderly AHF inpatients (83 ± 6.0 years old, females 51%) at admission and another six times over the next 48 h. We defined ‘WRF’ as a serum creatinine increase ≥0.3 mg/dL by Day 5 post-admission. We calculated the ‘early SBP drop’ as the difference between the admission SBP value and the lowest value during the first 48 h of hospitalization. RESULTS: There were significant differences between the 36 patients with WRF and the 209 patients without WRF: early SBP drop (51 vs. 33 mmHg, p < 0.01) and HR at admission (79 vs. 90 bpm, p < 0.05), respectively. In the multiple logistic regression analysis adjusted for the confounders, higher early SBP drop (p < 0.04) and lower HR at admission (p < 0.01) were significantly associated with WRF. No significant association was shown for the interaction term of early SBP drop × HR at admission with WRF. CONCLUSIONS: In these elderly AHF patients, exaggerated early SBP drop and lower HR at admission were significant independent predictors of WRF, and these factors were additively associated with WRF.