Weight loss as a marker of successful decongestion during acute heart failure hospitalisation

BACKGROUND: Effective decongestion is a key therapeutic goal during hospitalisation for acute heart failure (HF), but the clinical significance of intravenous loop diuretic-induced weight loss and its relationship with biomarker changes remain uncertain. METHODS: We included patients hospitalised for HF in the nationwide Swedish Heart Failure Registry (2017-2021) who received intravenous loop diuretics, survived to discharge and had body weight recorded at admission and discharge. Weight loss was defined as ≥2 kg between admission and discharge. Associations between weight loss, changes in biomarkers (estimated glomerular filtration rate (eGFR), N-terminal pro-B-type natriuretic peptides (NT-proBNP), haemoglobin, sodium and potassium) and outcomes were evaluated. The primary outcome was rehospitalisation for HF (re-HHF); the secondary outcome was the composite of cardiovascular death or re-HHF at 30 days and 1 year. RESULTS: Among 4979 patients (median age 80 years; 57% male), median weight change during hospitalisation was -2.5 kg and 2949 (59%) achieved weight loss ≥2 kg. Male sex, atrial fibrillation, obesity, higher admission NT-proBNP and mineralocorticoid receptor antagonist use were independently associated with weight loss. Weight change showed no meaningful association with change in eGFR. Weight loss was independently associated with a lower risk of re-HHF (HR 0.59, 95% CI 0.53 to 0.67) and the composite of cardiovascular death or re-HHF (HR 0.76, 95% CI 0.69 to 0.84) within 30 days but not thereafter. These associations were consistent irrespective of biomarker changes, including worsening renal function. CONCLUSIONS: In this nationwide cohort of patients hospitalised for HF and treated with intravenous loop diuretics, diuretic-induced weight loss, a pragmatic marker of decongestion, was associated with improved short-term clinical outcomes without an accompanying decline in renal function and irrespective of biomarker changes, including worsening renal function.