Improving Mitral Repair for Functional Mitral Regurgitation

The investigators are interested in determining the best surgical technique to correct functional mitral regurgitation, as there is currently not one technique that is established to work better than the other. The technique used in current clinical practice is undersizing mitral annuloplasty (UMA), in which a prosthetic ring is implanted onto the mitral valve to correct the leakage. Though widely adopted, durability of the repair is less, as 58% of the patients present with recurrent FMR within 2 years. There are no specific algorithms to predict who might have UMA failure, but research indicates that some geometric indices might be strong predictors. The investigators are interested in testing the hypothesis that, elevated lateral inter-papillary muscle separation (IPMS) is a predictor of post-UMA recurrence of FMR at 12 months. In the first part of this study, the study team will measure lateral IPMS before surgery and relate to post-surgery FMR severity at discharge/30 days, 6 months and 12 months. A relatively newer technique is papillary muscle approximation (PMA), in which a suture draws together the two muscles that connect the mitral valve to the heart muscle prior to performing UMA. This reduces the lateral inter-papillary muscle separation (IPMS) and is expected to improve the durability of UMA. In the second part of this study, the investigators will perform PMA and UMA together and determine if FMR severity is reduced at discharge/30 days, 6 months and 12 months.