Effect of empagliflozin on epicardial adipose tissue volume in patients with type 2 diabetes, or prediabetes, and heart failure with reduced ejection fraction (SUGAR-DM-HF)

Background Epicardial adipose tissue (EAT) is postulated to be linked to the pathophysiology of heart failure with reduced ejection fraction (HFrEF), acting both as a biomarker and a potential therapeutic target. Investigating changes in EAT volume following treatment with sodium-glucose cotransporter 2 (SGLT2) inhibitor could provide valuable mechanistic insights. Purpose This posthoc substudy of the SUGAR-DM-HF trial aimed to assess the effect of the SGLT2 inhibitor empagliflozin on EAT volume. Methods Within a multicentre, randomised, double-blind, placebo-controlled trial, the effects of empagliflozin were evaluated in patients with HFrEF (New York Heart Association functional class II-IV, left ventricular ejection fraction (LVEF) ≤40%), and type 2 diabetes or prediabetes. Patients with atrial fibrillation/flutter were excluded to avoid image degradation. Patients were randomly assigned 1:1 to empagliflozin 10mg daily or placebo. EAT volume was quantified using cardiovascular magnetic resonance (CMR) cine imaging at baseline and week 36, and reported as: (a) total EAT volume (mL); (b) EAT volume indexed to body surface area (mL/m2); (c) % change from baseline. Observers were blinded to subject identification, scan date, clinical data, and randomization arm. Scans with major artefacts were not analysed. Results One hundred five patients were randomly assigned: mean age 68.7 (SD, 11.1) years, 77 (73.3%) male, 82 (78.1%) diabetes and 23 (21.9%) prediabetes, mean LVEF 32.5% (9.8%). Baseline EAT volume was available in 101 patients (median [IQR] 85 [67-104] mL and 41 [34-52] mL/m2). Paired baseline and 36-week EAT volume was available in 90 patients. Higher baseline total EAT volume was associated with male gender, higher body mass index, coronary artery disease, elevated serum creatinine, higher left ventricular end-diastolic volume, and higher left ventricular mass (TABLE). EAT volume changed by -2.7 mL / -1.3 mL/m2 / -3.1% in the empagliflozin group versus 0.3 mL / 0.3 mL/m2 / 1.5% in the placebo group (between-group difference -3.4 mL, 95% CI -6.7 to -0.1; p=0.045 and -1.7 mL/m2, 95% CI -3.4 to -0.04; p=0.045) at 36 weeks (FIGURE). The beneficial reduction in left ventricular end-systolic volume indexed to body surface area observed with empagliflozin treatment was not modified by baseline total or indexed EAT volumes (p interaction=0.31 and 0.45, respectively). Conclusion Empagliflozin treatment significantly reduced EAT volume. This may represent an additional benefit of SGLT2 inhibition in HFrEF.