Abstract. 
Objective: We quantified the magnitude of systolic blood pressure (SBP) adverse effects associated with intravenous furosemide (IVFu), compared to other factors, during treatment for acute decompensated heart failure (ADHF).
Methods: Continuous BP monitoring (598.2 person-hours, 91,210 observations) before and after IVFu was performed in a prospective multicenter ADHF cohort (n = 253). Multivariable-adjusted mixed effects regression was used to determine the amount of SBP reduction and the risk of hypotension attributable to IVFu administration, as opposed to confounders (e.g., non-IVFu treatments and baseline patient characteristics).
Results: Median SBP was 124 mmHg (IQR: 105-149) at baseline. Hypotension occurred in 5515 observations (6.0%). The multivariable models explained 79.6% and 58.1% of variance in SBP and risk of hypotension, respectively. Only 1.4% of variance in SBP and 1.7% of hypotension risk were related to IVFu, with the remainder accounted for by confounders. After multivariable adjustment, SBP dropped -11.9 mmHg on average after 80 mg IVFu, reaching a nadir at 147 min (-15.2 mmHg) and partial return to baseline by 6 h (-8.5 mmHg). IVFu-related risk of hypotension after multivariable adjustment depended predominantly on baseline SBP and dose. Risk of hypotension associated with 80 mg IVFu was ≤ 2% with baseline SBP ≥ 120 mmHg. For 40 mg, IVFu-associated hypotensive risk was ≤ 2% with SBPs of 90-100 mmHg, and < 1% with SBP ≥ 110 mmHg. IVFu-associated risk of hypotension returned to zero at 6 h after administration, regardless of dose.
Conclusions: Blood pressure reductions after IVFu during ADHF treatment are modest, and hypotension is rare and transient. Most variance in SBP during ADHF treatment is due to other factors.
© 2025 The Author(s). Academic Emergency Medicine published by Wiley Periodicals LLC on behalf of Society for Academic Emergency Medicine.