Worsening renal function in acute heart failure in the context of diuretic response

BACKGROUND: For patients with acute heart failure (AHF), substantial diuresis after administration of loop diuretics is generally associated with better clinical outcomes but may cause creatinine to rise, suggesting renal function decline. We investigated the interaction between diuretic response and worsening renal function (WRF) on clinical outcomes in patients with AHF. METHODS AND RESULTS: In two AHF cohorts (PROTECT, n = 1698 and RELAX‐AHF‐2, n = 5586 in current analysis), the prognostic impact of WRF (creatinine ≥0.3 mg/dl increase baseline—day 4; sensitivity analyses incorporated baseline renal function) by diuretic response (kg weight loss/40 mg furosemide equivalent baseline—day 4) was investigated with regard to (cardiovascular) death or cardiovascular/renal hospitalization using subpopulation treatment effect pattern plots (STEPP) and survival analyses. WRF occurred in 286 (16.8%) and 1031 (18.5%) patients in PROTECT and RELAX‐AHF‐2, respectively. Patients with WRF had higher left ventricular ejection fraction and lower estimated glomerular filtration rate at baseline (p < 0.05), and received higher doses of loop diuretics and had a worse diuretic response (p < 0.001). In patients with a poor diuretic response (≤0.35 kg weight loss/40 mg furosemide equivalent as identified by STEPP), WRF was associated with higher risk of (cardiovascular) death or cardiovascular/renal hospitalization (p < 0.001 both cohorts), but this was not the case for patients with a good diuretic response (p = 0.900 both cohorts). CONCLUSION: In two large cohorts of patients with AHF, WRF in the first 4 days was not associated with worse outcomes when patients had a good diuretic response. The occurrence of WRF in patients with AHF should therefore be considered in the context of diuretic response.