Development of a Reproducible Swine Model of Chronic Ischemic Mitral Regurgitation: Lessons Learned.

Abstract Introduction Durability of mitral valve (MV) repair for ischemic mitral regurgitation (IMR) remains poor. We established a swine model of chronic IMR, and describe the methods and lessons learned from this model. Methods Thirty-five swine underwent percutaneous myocardial infarction (MI) with ethanol ablation of the circumflex or obtuse marginal (OM) arteries. Swine were followed with routine echocardiography for the development of severe IMR. Once severe IMR was established, swine underwent mitral valve operations on cardiopulmonary bypass. After operation, swine were survived up to 7 weeks. Angiographic and echocardiographic features of swine who developed severe IMR (IMR swine) and those who did not (non-IMR swine) were compared. Results The median number of OM arteries was 3, with 2 OM arteries infarcted. Acute survival after the MI was 74% (26/35) with 3 (9%) early, postoperative deaths. Among the 23 swine with follow-up to determine IMR status, 14/23 (61%) developed >moderate IMR. Among IMR pigs, LVEF decreased from 65% pre-MI to 45% pre-mitral valve intervention (p Conclusion A reproducible percutaneous model of severe IMR in swine is feasible with a guided anesthetic and peri-operative approach. This model can serve as a platform to better understand the mechanism of IMR and subsequently to test novel repair techniques.