Determinants of diuresis/natriuresis following ambulatory intravenous loop diuretics for worsening heart failure

Abstract

Background The use of intravenous (IV) diuretics in an outpatient setting may represent an alternative to conventional hospitalization. Our objective was to identify factors associated with diuretic response during ambulatory IV diuretic sessions in a population of advanced heart failure with no therapeutic project and a frequent flyer profile. Method All patients with 4-h IV diuretic sessions were analysed. An initial bolus followed a tailored protocol for continuous infusion based on the patient's baseline diuretic dose. Variables associated with diuresis and natriuresis following furosemide infusion were evaluated using mixed linear models. Results Seventy-six patients (mean age 75.4 years; LVEF 42.7%; eGFR 40.7 mL/min/1.73 m2) totalling 175 IV diuretic sessions were included. Mean diuresis was 1.0 L, natriuresis 92.6 mmol/L, and weight loss 610 grams. Baseline use of ACE inhibitors (+302 mL, P = 0.0005), eGFR (+160 mL per 10 mL/min/1.73 m2 increase, P < 0.0001), and addition of thiazide during the diuretic session (+238 mL, P = 0.0001) were associated with higher diuresis. Prior percutaneous mitral valve repair or chronic thiazide treatment was associated with lower diuresis. Baseline use of ACE inhibitors (+10.83 mmol/L, P = 0.018) was associated with higher natriuresis. Worsening renal function (>3 mg/L increase from baseline) and dyskalaemia 48 h after these sessions were uncommon (respectively 11% and 15%). Conclusions Ambulatory 4-h IV loop diuretic sessions induced a diuresis of approximately 1000 mL with a substantial sodium content, without causing significant complications. Addition of thiazide during the session increased diuresis and/or natriuresis, and could potentially be implemented to maximize the efficacy of ambulatory IV diuretic therapy.