Change in Diuretic Dose After Initiation of a SGLT2 Inhibitor in Patients with Heart Failure with Reduced Ejection Fraction

Abstract

<h3>Purpose</h3> This study was designed to evaluate the change in loop diuretic dose at three months post-initiation of a sodium-glucose cotransporter-2 inhibitor (SGLT2i) in patients with heart failure with reduced ejection fraction (HFrEF). <h3>Methods</h3> This was a retrospective cohort study including 69 patients from January 2020 to September 2021. Patients were included if they were ≥ 18 years old, had an ejection fraction (EF) of ≤ 40%, were prescribed a loop diuretic, and were initiated on a SGLT2i as an outpatient. Patients were excluded if the SGLT2i was discontinued prior to follow-up or if there was insufficient data available in the patient's chart such as missing loop diuretic dose or lack of follow-up visit after SGLT2i initiation. The primary outcome was the change in loop diuretic dose from baseline to 3 months after SGLT2i initiation. Secondary outcomes included change in other diuretic medications, change in the patient's heart failure status based on the New York Heart Association (NYHA) classification, and the incidence of adverse effects at 3 months after SGLT2i. The primary outcome was analyzed using the Wilcoxon signed-rank test with a p-value <0.05 considered significant. <h3>Results</h3> This cohort was primarily male (69.6%) with a median age of 64 years, a median EF of 20%, and a median loop diuretic dose of 40 mg (22.8-80.0) of furosemide equivalents at baseline. The majority of patients had NYHA class II or III at baseline (79.7%). Most patients were on guideline directed medical therapy at baseline with 63 patients (91.3%) on a renin-angiotensin inhibitor, 67 patients (97.1%) on a beta blocker, and 45 patients (65.2%) on a mineralocorticoid receptor antagonist. At a median of 94 days after initiation of a SGLT2i, 26 patients (37.7%) required a reduction in their loop diuretic dose. The median loop diuretic dose at 94 days was 40 mg (20.0-60.0) of furosemide equivalents which is a significant change from baseline (p = 0.001). No significant differences were noted in the secondary outcomes (p >0.05). <h3>Conclusion</h3> While the median loop diuretic dose was similar before and after SGLT2i initiation there was a statistically significant number of patients who had their loop diuretic dose reduced. This study provides a real-world experience on the additional diuresis obtained with a SGLT2i and a potential guide to loop diuretic dose adjustments in HFrEF patients.