Acute heart failure is the leading cause of hospitalization in older adults and carries a high risk of short-term death or readmission. Initial treatment involves intravenous loop diuretics, often combined with vasodilators, despite limited evidence. The individual and combined effects of loop diuretics and vasodilators have never been directly compared during the initial emergency phase, as previous studies have included patients after early stabilization, leaving the optimal first-line treatment unknown.

DECONGEST-AHF is a pragmatic, multicenter, randomized, double-blinded, placebo-controlled trial evaluating early treatment strategies in patients with suspected acute heart failure. Patients are included no later than 3 hours after emergency department arrival. Inclusion criteria are acute dyspnea, clinical signs of congestion, oxygen saturation <94% or need for oxygen therapy, and systolic blood pressure ≥100 mmHg. Patients are randomized (1:1:1) to receive intravenous furosemide, intravenous isosorbide dinitrate, or both as initial in-hospital treatment.

The primary outcome is days alive and outside of the hospital at 30 days. The trial will enroll 1,041 patients across 5 Danish hospitals.

By initiating treatment during the hyperacute phase and applying a blinded and placebo-controlled design, we aim to clarify the individual and combined effects of 2 widely used therapies. The use of emergency consent procedures enables the inclusion of a real-world patient population, including patients who are often excluded from clinical trials. This approach ensures broad generalizability and reflects routine emergency care. Findings from DECONGEST-AHF may improve early management of patients with acute heart failure.

ClinicalTrials.gov identifier: www.NCT05276219 .