Evaluation of the efficacy of empagliflozin in patients with preserved left ventricular ejection fraction undergoing transcatheter aortic valve implantation for aortic stenosis: protocol for a randomised, open-label, controlled study

INTRODUCTION: Heart failure occasionally develops after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS), despite procedural success. Most cases present with mildly reduced or preserved left ventricular ejection fraction (LVEF), underscoring the role of diastolic dysfunction. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown benefits across the heart failure spectrum, independent of LVEF. The purpose of this randomised controlled trial is to determine whether adding a SGLT2 inhibitor to conventional medications improves LV diastolic function in patients with preserved LVEF after TAVI. METHODS AND ANALYSIS: This study is a prospective, single-centre, open-label, randomised, parallel-group, two-arm trial enrolling patients with mildly reduced or preserved LVEF (≥40%) undergoing TAVI for severe AS. Participants will be randomised in a 1:1 ratio to receive either conventional medications plus empagliflozin or conventional medications alone. In the empagliflozin group, participants will receive conventional medical therapy plus empagliflozin 10 mg orally once daily, initiated 4 weeks after TAVI. Empagliflozin treatment will continue throughout the study period. Participants in the control group will receive conventional medications without empagliflozin. The primary endpoint is the change in E/e', assessed by echocardiography from treatment initiation at 4 weeks post TAVI (day 1) to day 168 (week 24). Each group will include 50 patients, totalling 100 patients. ETHICS AND DISSEMINATION: Ethical approval for this study has been obtained from the Chiba University Hospital Certified Clinical Research Review Board (CRB0111-25). TRIAL REGISTRATION NUMBER: jRCT1031250190.