Different loop diuretic dosing and administration in acute heart failure (DIUR-AHF): a multicenter prospective observational open-label study.

Background Although Loop diuretics (LD) represent the milestone treatment in acute heart failure (AHF), relevant concerns exist about the best administration modality. We aim to investigate the effects of different LD regimen and dosage in patients with AHF. Methods In this multicenter prospective observational open-label study, patients were assigned to receive twice-daily intravenous injections (Bolus infusion, BiV) or continuous intravenous infusion (CiV) of furosemide for a period of 72-120 hours. High dose (HD) was defined as furosemide dose >120 mg/day. Patients were eligible if they showed clinical signs of congestion associated with N-terminal pro-B-type natriuretic peptide (NT-proBNP) >500 pg/ml. Combined of rehospitalisation or death for cardiovascular causes were evaluated as primary endpoint during a 6-months follow-up. Results 402 AHF patients were included, 197 treated with CiV and 205 with BiV. CiV showed higher rate of NTproBNP decrease >30 % (63 % vs 45 %, p < 0.001), associated with significantly weight loss (-4.3 ± 2.6 vs -3.2 ± 2.4 Kg, <0.001) and daily mean urine output (2181 ± 845 ml vs 2019 ± 696 ml, p = 0.036) compared to BiV. Conversely, BiV patients experienced a shorter hospital stay (11.5 ± 4.5 vs 12.7 ± 4.5 days, p = 0.006) and lower adverse events rate (29 % vs 45 %, p = 0.001). HD administration was associated with prolonged hospital stay and poor outcome (55 % vs 18 %). Multivariable analysis confirmed CiV (HR 1.51, 1.02-2.23) and HD infusion (HR 2.50,1.64-3.83) were both associated with the primary endpoints. Conclusions CiV was associated with higher NTproBNP decrease and weight loss but it demonstrates a poorer outcome. Similarly, HD was associated with an increased risk.