Spot Analysis of Natriuresis to Guide up- or Down-titration of Diuretic Therapy in Ambulatory Patients With Chronic Heart Failure

Heart failure is commonly associated with sodium retention and congestion. Loop diuretics are used to relieve congestion but are typically adjusted based on symptoms and clinical judgment. Spot urine sodium concentration is an objective measure of diuretic response that may help personalize treatment. A point-of-care urine sodium sensor provides rapid results and may support effective decongestion or safe reduction of diuretics when appropriate. This prospective, two-center pilot study includes three clinical groups: Group 1: Up-titration cohort Patients with clinical congestion or objective evidence of congestion. These participants will be randomized 1:1 to natriuresis-guided up-titration or standard care. Group 2: Down-titration cohort Stable, euvolemic patients who may safely reduce diuretic therapy. These participants will be randomized 1:1 to natriuresis-guided down-titration or standard care. Group 3: Observational cohort The first 100 screened patients who do not meet criteria for Groups 1 or 2. These participants will undergo baseline assessments and routine follow-up without intervention. Urine sodium will be measured at baseline and follow-up visits. Randomized participants will have diuretic doses adjusted based on predefined algorithms. Standard care participants will receive usual clinical management. The primary aim is to assess feasibility, including recruitment, retention, adherence to sampling procedures, and workflow implementation. Secondary analyses will describe clinical, laboratory, and symptom-based outcomes to inform development of a larger definitive trial.