Randomized Trial of Empagliflozin in Nondiabetic Patients With Heart Failure and Reduced Ejection Fraction

Background: Large clinical trials established the benefits of sodium-glucose cotransporter 2 inhibitors in patients with diabetes and with heart failure with reduced ejection fraction (HFrEF). The early and significant improvement in clinical outcomes is likely explained by effects beyond a reduction in hyperglycemia. Objectives: The purpose of this study was to assess the effect of empagliflozin on left ventricular (LV) function and volumes, functional capacity, and quality of life (QoL) in nondiabetic HFrEF patients. Methods: In this double-blind, placebo-controlled trial, nondiabetic HFrEF patients (n = 84) were randomized to empagliflozin 10 mg daily or placebo for 6 months. The primary endpoint was change in LV end-diastolic and -systolic volume assessed by cardiac magnetic resonance. Secondary endpoints included changes in LV mass, LV ejection fraction, peak oxygen consumption in the cardiopulmonary exercise test, 6-min walk test, and quality of life. Results: Empagliflozin was associated with a significant reduction of LV end-diastolic volume (−25.1 ± 26.0 ml vs. −1.5 ± 25.4 ml for empagliflozin vs. placebo, respectively; p < 0.001) and LV end-systolic volume (−26.6 ± 20.5 ml vs. −0.5 ± 21.9 ml for empagliflozin vs. placebo; p < 0.001). Empagliflozin was associated with reductions in LV mass (−17.8 ± 31.9 g vs. 4.1 ± 13.4 g, for empagliflozin vs. placebo, respectively; p < 0.001) and LV sphericity, and improvements in LV ejection fraction (6.0 ± 4.2 vs. −0.1 ± 3.9; p < 0.001). Patients who received empagliflozin had significant improvements in peak O₂ consumption (1.1 ± 2.6 ml/min/kg vs. −0.5 ± 1.9 ml/min/kg for empagliflozin vs. placebo, respectively; p = 0.017), oxygen uptake efficiency slope (111 ± 267 vs. −145 ± 318; p < 0.001), as well as in 6-min walk test (81 ± 64 m vs. −35 ± 68 m; p < 0.001) and quality of life (Kansas City Cardiomyopathy Questionnaire-12: 21 ± 18 vs. 2 ± 15; p < 0.001). Conclusions: Empagliflozin administration to nondiabetic HFrEF patients significantly improves LV volumes, LV mass, LV systolic function, functional capacity, and quality of life when compared with placebo. Our observations strongly support a role for sodium-glucose cotransporter 2 inhibitors in the treatment of HFrEF patients independently of their glycemic status.