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

      Pasrija, Chetan; Quinn, Rachael W; Alkhatib, Hani; Tran, Douglas; Bernstein, Daniel; Rice, MaryJoe; Kotloff, Ethan; Morales, David; D'Ambra, Michael N; Vesely, Mark R; et al. (Elsevier Inc., 2020-06-15)
      Background: Durability of mitral valve 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 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 myocardial infarction was 74% (26 of 35) with 3 (9%) early, postoperative deaths. Among the 23 swine with follow-up to determine IMR status, 14 of 23 (61%) developed significant IMR. Among IMR pigs, left ventricular (LV) ejection fraction decreased from 65% pre-myocardial infarction to 45% pre-mitral valve intervention (P < .001). Among non-IMR swine, LV ejection fraction decreased nonsignificantly from baseline (60%) to latest follow-up (55%) (P = .443). LV end-diastolic dimension (P = .039), wall motion score (P = .027), global circumferential strain (P = .014), and global longitudinal strain (P = .023) were significantly worse in IMR compared with non-IMR swine. Conclusions: A reproducible percutaneous model of severe IMR in swine is feasible with a guided anesthetic and perioperative approach. This model can serve as a platform to better understand the mechanism of IMR and subsequently to test novel repair techniques.
    • Intensive care and anesthesia management for HARPOON beating heart mitral valve repair.

      Diprose, Paul; Fogg, Katheryn J; Pittarello, Demetrio; Gammie, James S; D'Ambra, Michael N (Wolters Kluwer Health, 2020-07-01)
      Patients with severe mitral valve regurgitation secondary to degenerative disease are known to benefit from mitral valve repair surgery. Novel techniques for achieving mitral valve repair on the beating heart have been developed and are being introduced into clinical practice. The HARPOON Beating Heart Mitral Valve Repair System (MVRS) in recent studies has demonstrated efficacy and safety for the repair of degenerative mitral valve disease on the beating heart. The device uses transoesophageal echocardiographic guidance to implant artificial expanded polytetrafluoroethylene (ePTFE) cords on prolapsed mitral valve leaflets in the beating heart. It requires general anaesthesia and there are specific intensive care and anaesthesia considerations for the safe management of these cases. This article describes the general principles of intensive care and anaesthesia management employed for the initial patients treated with the HARPOON Beating Heart MVRS, the outcomes for these patients, and the potential challenges for the future management of these cases.