Preoperative empagliflozin and ventricular remodeling after coronary artery bypass grafting in type 2 diabetes: a prespecified analysis of the POST-CABGDM randomized trial

Background Type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD) are associated with adverse ventricular remodeling. Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) may further contribute to myocardial injury through inflammatory and ischemia–reperfusion mechanisms. Sodium–glucose cotransporter 2 inhibitors (SGLT2i) have demonstrated cardioprotective effects, including reduction in left ventricular mass, but their impact in the perioperative setting of cardiac surgery remains unclear. Methods This study is a prespecified secondary analysis of the open-label randomized POST-CABGDM trial (NCT04523064). Patients with T2DM and multivessel CAD undergoing CABG with CPB were randomized to receive empagliflozin 25 mg once daily or standard antidiabetic therapy. SGLT2i were discontinued 3 days before surgery and were not protocol-mandated postoperatively. Transthoracic echocardiography was performed preoperatively and at 1–6 months postoperatively. The primary endpoint was the change in left ventricular mass index (ΔLVMI). Secondary endpoints included changes in left ventricular ejection fraction (ΔLVEF) and ventricular dimensions. Results A total of 118 patients were included (53 in the intervention group and 65 in the control group). Baseline characteristics were well balanced. No significant difference was observed in ΔLVMI between groups (− 1.39 ± 18.7 vs. −4.55 ± 16.8 g/m²; p = 0.337), and this finding remained unchanged after adjustment for baseline LVMI. Similarly, no differences were found in ΔLVEF or ventricular dimensions. Surgical characteristics and postoperative complications were comparable. In a separate exploratory, non-randomized multivariable analysis, continued use of SGLT2i during follow-up was associated with a higher likelihood of LVMI reduction (OR 4.69; 95% CI 1.20–18.40; p = 0.03). Conclusions Preoperative empagliflozin use was not associated with significant short-term changes in LVMI, LVEF, or ventricular dimensions after CABG with CPB. Exploratory, non-randomized analyses suggested an association between continued SGLT2i use during follow-up and LVMI reduction, but these findings should be considered hypothesis-generating and require confirmation in prospective studies designed to evaluate sustained perioperative and postoperative therapy. Trial registration ClinicalTrials.gov NCT04523064.