The MITRA-HR study: design and rationale of a randomised study of MitraClip transcatheter mitral valve repair in patients with severe primary mitral regurgitation eligible for high-risk surgery

Aims: Percutaneous mitral valve repair has become an alternative to conventional surgery in patients suffering primary mitral regurgitation (MR) with a contraindication to surgery and could benefit patients at high surgical risk. The aim of the MITRA-HR study is to raise the level of evidence supporting the use of the MitraClip device in primary MR patients with a predefined high risk for surgery. Methods and results: MITRA-HR is a prospective, multicentre, randomised study designed to compare mitral valve repair using the MitraClip with conventional surgery in patients with severe primary mitral regurgitation at high risk for surgery. The surgical risk is defined by age, Society of Thoracic Surgeons (STS) risk estimate score, frailty, major organ system dysfunction, and procedure-specific impediments. The study will enrol 330 patients randomised between conventional surgery and MitraClip with a 1:1 ratio. The composite primary endpoint includes all-cause mortality, unplanned rehospitalisation for cardiovascular reasons, and mitral valve reintervention at 12 months. The main secondary safety endpoint is a major adverse event composite assessment evaluated 30 days after the procedure. Conclusions: The randomised MITRA-HR study is designed to provide additional supportive evidence of non-inferiority in efficacy and superiority in safety for percutaneous mitral valve repair using the MitraClip compared to conventional surgery in high surgical risk patients.