Comparative efficacy of continuous versus intermittent administration of furosemide in acute heart failure: an updated systematic review and meta-analysis of 22 RCTs.

INTRODUCTION

Acute heart failure is defined as the rapid or gradual onset of signs and/or symptoms of heart failure severe enough to warrant unplanned hospital or emergency department care. As of 2019, an estimated 56.2 million individuals across 204 countries and territories were living with heart failure; data gaps suggest the true burden is likely higher. The global number of HF cases doubled from 27.2 million in 1990 to 56.2 million in 2019, with a parallel doubling observed in both sexes. Intravenous loop diuretics-predominantly furosemide-constitute the cornerstone of decongestive therapy, yet the optimal dosing strategy is still debated. Previous studies have established the framework for this field but yielded conflicting conclusions. In addition, those studies had some limitations. Therefore, we conducted an updated systematic review and meta-analysis that identified and included all RCTs comparing continuous infusion with intermittent bolus furosemide in adult patients with acute heart failure or NYHA class III-IV symptoms.

METHODS

We conducted a systematic literature search in PubMed, Embase, the Cochrane Library, CNKI, Wan Fang, and VIP databases for relevant studies published up to 1 October 2025. RCTs comparing continuous infusion with intermittent bolus furosemide in adult patients with acute heart failure or NYHA class III-IV symptoms were included. Primary endpoints were all-cause mortality and freedom from congestion. Secondary endpoints were weight loss, 24-h urine volume, length of hospital stay, 72-h urine volume, post-treatment BNP, edema resolution time, time to dyspnea improvement, post-treatment LVEF, and post-treatment LVEDD.

RESULTS

A total of 22 RCTs with 2,633 participants were included. The intermittent intravenous (iIV) arm showed a numerical trend toward all-cause mortality without reaching statistical significance (low evidence quality) compared with the continuous intravenous (cIV) arm (RR: 1.36, 95% CI: 0.96-1.94, p =  0.08). The cIV arm demonstrated significant improvements in freedom from congestion (moderate evidence quality) compared with the iIV arm (RR: 1.42, 95% CI: 1.06-1.91, p = 0.02). In addition, the cIV arm showed significant improvements in weight loss (moderate evidence quality), 24-h urine volume (low evidence quality), length of hospital stay (low evidence quality), edema resolution time (low evidence quality), time to dyspnea improvement (low evidence quality), post-treatment LVEF (low evidence quality), post-treatment LVEDD (low evidence quality), and post-treatment BNP level (moderate evidence quality).

DISCUSSION: Compared with intravenous bolus furosemide, continuous infusion was associated with faster relief of congestion, greater weight loss, and greater reduction in post-treatment BNP levels (moderate evidence quality). However, no significant advantage was demonstrated for the remaining outcomes or long-term survival, as judged by the quality of evidence and effect estimates.

SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD420260223267, identifier CRD420260223267.