One of the challenges in treating patients with heart failure (HF) is achieving clinical stability and reducing the hospital readmission rate. A diuretic dose adjustment algorithm developed in the United States (Diuretic Treatment Algorithm, DTA) and later validated for use in Brazil (as the Algoritmo de Ajuste de Diurético, AAD) has proved feasible and readily applicable, but its effect on clinical outcomes has yet to be assessed. This report aims to describe a randomized clinical trial protocol designed to assess the effectiveness of the AAD and of nonpharmacologic management in improving clinical stability and reducing the readmission rate at 90 days in patients with HF.

A PROBE (prospective randomized open blinded endpoint) parallel-group design will be used. Adult patients with a diagnosis of reduced ejection fraction HF, who are being treated at a specialized HF clinic are being recruited. Those with indications for loop diuretic dose adjustment during routine clinic visits will be randomized to take part in the trial. Participants in the intervention group (IG) shall have their diuretic doses adjusted in accordance with the AAD and receive four telephone calls (one per week) over 30 days to reinforce guidance on nonpharmacological management (fluid and sodium restriction). Participants in the control group (CG) shall have their diuretic doses adjusted by a physician during the first trial visit and shall not receive any telephone calls. Patients in both groups shall return at 1 month for face-to-face reassessment. The study endpoints shall comprise readmission and/or emergency department visits due to HF decompensation within 90 days and clinical instability. All participants shall be required to have a scale at home (or easy access to one), a telephone number, agree to telephone-based follow-up, and be available to return for a 1-month trial visit. Overall, 135 patients are expected to be enrolled in each group.

Inclusion Criteria:

• Patients of both genders
• Age ≥ 18 years
• Diagnosed with systolic HF
• Able to monitor body weight at home
• Using furosemide

Exclusion Criteria:

• Those who are not able to make return visits or participate in telephone contact, and those on renal replacement therapy.