Door-to-furosemide time and clinical outcomes in acute heart failure

Background and importance: Acute heart failure (AHF) is one of the main causes of unplanned hospitalization in patients >65 years of age and is associated with adverse outcomes in this population. Observational studies suggest that intravenous diuretic therapy given in the first hour of presentation for AHF was associated with favorable outcomes.

Objectives: To study the short-term prognostic associations of the timing of intravenous diuretic therapy in patients admitted to the emergency department (ED) for acute AHF.

Design, settings and participants: Patients treated in the ED with intravenous diuretics were selected from the Estratificação de Doentes com InsuFIciência Cardíaca Aguda (EDIFICA) registry, a prospective study including AHF hospitalized patients. Early and non-early furosemide treatment groups were considered using the 1-h cutoff: door-to-furosemide ≤1 h and >1 h.

Outcomes measure and analysis: Primary outcomes were a composite of heart failure re-hospitalizations or cardiovascular death at 30- and 90-days.

Main results: Four-hundred ninety-three patients were included in the analysis. The median (interquartile range) door-to-furosemide time was 85 (41-220) min, and 210 (43%) patients had diuretics in the first hour. Patients in the ≤1 h group had higher evaluation priority according to the Manchester Triage System, presented more often with acute pulmonary edema, warm-wet clinical profile, higher blood pressure, and signs of left-side heart failure, while >1 h group had higher Get With the Guidelines-heart failure risk score, more frequent signs of right-side heart failure, higher circulating B-type natriuretic peptides and lower albumin. Door-to-furosemide ≤ 1 h was independently associated with lower 30-day heart failure hospitalizations and composite of heart failure hospitalizations or cardiovascular death (adjusted analysis Heart Failure Hospitalizations: odds ratios (OR) 3.65; 95% confidence interval (CI), 1.22-10.9; P = 0.020; heart failure hospitalizations or cardiovascular death: OR 3.15; 95% CI, 1.49-6.64; P < 0.001). These independent associations lost significance at 90 days.

Conclusion: Door-to-furosemide ≤1 h was associated with a lower short-term risk of heart failure hospitalizations or cardiovascular death in AHF patients. Our findings add to the existing evidence that early identification and intravenous diuretic therapy of AHF patients may improve outcomes.