Effect of enhanced external counterpulsation on coronary microcirculation dysfunction (CMD) in patients with coronary artery disease (EECP-CMD II): study protocol of a single-centre, open-label, parallel group, randomised controlled trial

INTRODUCTION: Coronary microcirculation dysfunction (CMD) is prevalent in patients with coronary artery disease (CAD). Current therapies for CMD are focused on pharmacotherapy, non-pharmacological treatments such as enhanced external counterpulsation (EECP) have shown favourable results in patients with CAD. However, whether EECP can improve CMD remains unknown. This study is designed to evaluate the effectiveness of EECP on CMD in patients with CAD, and to assess the feasibility of conducting a multicentre randomised controlled trial. METHODS AND ANALYSIS: This study is a single-centre, outcome-assessor-blinded, parallel randomised controlled trial. A total of 110 participants with CAD will be included and randomly assigned to either the intervention group (EECP plus optimal medical therapy (OMT)) or the control group (OMT alone). EECP will be administered by operators for 60 min, 5 times per week for 7 weeks (35 times in total). Outcomes include patients' retention rates, the primary outcome and secondary outcomes. The primary outcome is the change in Myocardial Perfusion Reserve Index with cardiac MRI from baseline to the end of follow-up. The planned study duration is from 2024 to 2026. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Ethics Committee of the Eighth Affiliated Hospital, Sun Yat-sen University (ID: 2023-045-03). The findings will be disseminated in peer-reviewed publications. TRIAL REGISTRATION NUMBER: ChiCTR2300076231.