Timing of Worsening Renal Function in Patients Hospitalized for Heart Failure Exacerbation Who Were Being Treated With Intravenous Diuretic Therapy

Background: This retrospective observational study investigated the incidence of worsening renal function (WRF) in patients hospitalized for heart failure (HF) and treated with intravenous diuretics in Japan. Methods and Results: Associations between WRF at any point and HF treatments, and the effects of WRF on outcomes were evaluated (Diagnosis Procedure Combination database). Of 1,788 patients analyzed (mean [ +/- SD] age 80.5 +/- 10.2 years; 54.4% male), 641 (35.9%) had WRF during a course of hospitalization for worsening HF: 208 (32.4%) presented with WRF before admission (BAWRF; estimated glomerular filtration rate decreased by >= 25% from baseline at least once between 30 days prior to admission and admission); 44 (6.9%) had WRF that persisted before and after admission (P-WRF); and 389 (60.7%) had WRF develop after admission (AA-WRF). Delayed initial diuretic administration, higher maximum doses of intravenous diuretics during hospitalization, and diuretic readministration during hospitalization were associated with a significantly higher incidence of AA-WRF. Patients with WRF at any time point were at higher risk of death during hospitalization compared with patients without WRF, with adjusted hazard ratios of 3.56 (95% confidence interval [CI] 2.23-5.69) for BA-WRF, 3.23 (95% CI 2.21-4.71) for AA-WRF, and 13.16 (95% CI 8.19-21.15) for P-WRF (all P<0.0001). Conclusions: Forty percent of WRF occurred before admission for acute HF; there was no difference in mortality between patients with BA-WRF and AA-WRF.