A Nationwide Survey of Surgical Treatment for Severe Ischemic Mitral Regurgitation

Objective: Mitral subvalvular procedures in addition to restrictive annuloplasty are promising for ischemic mitral regurgitation (IMR). However, the prevalence and efficacy of specific subvalvular repair in severe IMR have not been elucidated. This is the first nationwide survey regarding surgeons’ attitudes toward IMR in Japan. Methods: A questionnaire was sent to 543 institutions. From 2015 to 2019, numbers of elective first-time mitral valve replacement (MVR) with/without complete chordal preservation (CCP)/papillary muscle approximation (PMA) and mitral valvuloplasty (MVP) with/without papillary muscle relocation (PMR)/PMA in patients with severe IMR were collected. Concomitant procedures for coronary artery, tricuspid valve, and arrhythmia could be included but left ventricular reconstruction was excluded. Results: Completed questionnaires were received from 286 institutions (52.7%). The majority (90%) had less than 20 cases within 5 years. The number of MVP (1413, 61.5%) surpassed MVR (886, 38.5%). CCP was performed in half of MVR (50.0%), while PMA was included in only 1.9% of MVR. PMA and PMR were also performed infrequently, in only 7.7% and 10.9% of MVP, respectively. Conclusion: Japanese surgeons aggressively perform MVP for severe IMR. Subvalvular repair was also aggressively performed in addition to MVR, but not to MVP. A multicenter registry study is in progress.