Decisions in Diuretic Resistance: Oral or Subcutaneous Furosemide in Advanced Ambulatory Heart Failure?

Objectives

The objective of this study was to explore differences in short-term clinical response, renal outcomes, and healthcare resource utilization between two non-equivalent outpatient furosemide strategies: high-dose oral solution and subcutaneous administration.

Methods

This retrospective observational study included 108 consecutive outpatients with advanced heart failure (HF) and diuretic resistance treated between January 2018 and December 2024. Patients received furosemide for 5 days as oral solution (250 mg/day; n = 81) or subcutaneous infusion via elastomeric pump (100 mg/day; n = 27). Primary endpoints were changes in functional status (NYHA [New York Heart Association] class), body weight, and renal function, assessed by changes in serum creatinine and estimated glomerular filtration rate and by clinically relevant worsening renal function criteria. Secondary endpoints included NT-proBNP changes and unplanned healthcare utilization at 30 days.

Results

Both strategies were associated with short-term decongestion. Weight decreased similarly in both groups, with no difference in the proportion of patients achieving weight loss (oral 90% vs. subcutaneous 89%; p = 0.854). Functional improvement was more frequently observed in the oral-solution group (99% vs. 89%; p = 0.019). Renal outcomes were comparable between strategies, with no significant changes in eGFR and a similar proportion of patients experiencing a serum creatinine increase ≥0.3 mg/dL (25.9% vs. 22.2%; p = 0.85). No significant differences were observed in NT-proBNP changes. HF-related healthcare encounters decreased during the 30 days following treatment compared with the preceding 30-day period in the oral-solution group, whereas no significant within-group change was observed in the subcutaneous group.

Conclusions

In this exploratory real-world cohort of patients with advanced HF and refractory congestion, both outpatient strategies were associated with short-term decongestion, with differences observed in symptomatic response. These findings are hypothesis-generating and warrant confirmation in prospective studies using comparable dosing strategies.