The FAST-FURO study: effect of very early administration of intravenous furosemide in the prehospital setting to patients with acute heart failure attending the emergency department.

Aims: The effect of early administration of intravenous (IV) furosemide in the emergency department (ED) on short-term outcomes of acute heart failure (AHF) patients remains controversial, with one recent Japanese study reporting a decrease of in-hospital mortality and one Korean study reporting a lack of clinical benefit. Both studies excluded patients receiving prehospital IV furosemide and only included patients requiring hospitalization. To assess the impact on short-term outcomes of early IV furosemide administration by emergency medical services (EMS) before patient arrival to the ED.

Methods And Results: In a secondary analysis of the Epidemiology of Acute Heart Failure in Emergency Departments (EAHFE) registry of consecutive AHF patients admitted to Spanish EDs, patients treated with IV furosemide at the ED were classified according to whether they received IV furosemide from the EMS (FAST-FURO group) or not (CONTROL group). In-hospital all-cause mortality, 30-day all-cause mortality, and prolonged hospitalization (>10 days) were assessed. We included 12 595 patients (FAST-FURO = 683; CONTROL = 11 912): 968 died during index hospitalization [7.7%; FAST-FURO = 10.3% vs. CONTROL = 7.5%; odds ratio (OR) = 1.403, 95% confidence interval (95% CI) = 1.085-1.813; P = 0.009], 1269 died during the first 30 days (10.2%; FAST-FURO = 13.4% vs. CONTROL = 9.9%; OR = 1.403, 95% CI = 1.146-1.764; P = 0.004), and 2844 had prolonged hospitalization (22.8%; FAST-FURO = 25.8% vs. CONTROL = 22.6%; OR = 1.189, 95% CI = 0.995-1.419; P = 0.056). FAST-FURO group patients had more diabetes mellitus, ischaemic cardiomyopathy, peripheral artery disease, left ventricular systolic dysfunction, and severe decompensations, and had a better New York Heart Association class and had less atrial fibrillation. After adjusting for these significant differences, early IV furosemide resulted in no impact on short-term outcomes: OR = 1.080 (95% CI = 0.817-1.427) for in-hospital mortality, OR = 1.086 (95% CI = 0.845-1.396) for 30-day mortality, and OR = 1.095 (95% CI = 0.915-1.312) for prolonged hospitalization. Several sensitivity analyses, including analysis of 599 pairs of patients matched by propensity score, showed consistent findings.

Conclusion: Early IV furosemide during the prehospital phase was administered to the sickest patients, was not associated with changes in short-term mortality or length of hospitalization after adjustment for several confounders.