Impact of Functional Versus Organic Baseline Mitral Regurgitation on Short- and Long-Term Outcomes After Transcatheter Aortic Valve Replacement.

The impact of the specific etiology of mitral regurgitation (MR) on outcomes in the transcatheter aortic valve replacement (TAVR) population is unknown. This study aimed to evaluate the longitudinal changes in functional versus organic MR after TAVR in addition to their impact on survival. Consecutive patients who underwent TAVR from May 2007 to May 2015 who had baseline significant (moderate or greater) MR were included. Transthoracic echocardiography was used to evaluate the cohort at baseline, post-procedure, 30-day, 6-month, and 1-year follow-up. The primary outcomes included mortality at 30 days and 1 year. Longitudinal, mixed-model regression analyses were performed to assess the differences in the magnitude of longitudinal changes of MR, left ventricular (LV) ejection fraction, and New York Heart Association functional class. Seventy patients (44% men, mean 83 years) with moderate or greater MR at baseline (30 functional vs 40 organic) were included, with the functional group having a statistically significant mean younger age and higher rates of previous coronary artery bypass grafting. Kaplan-Meier cumulative mortality rates were similar: 30 days (10% vs 17.5%, unadjusted log-ranked p = 0.413) and 1 year (29.4% vs 23.2%, unadjusted log-ranked p = 0.746) in the functional versus organic MR groups, respectively. There were greater degrees of short- and long-term improvement in MR severity (slope difference p = 0.0008), LV ejection fraction (slope difference p = 0.0009), and New York Heart Association class (slope difference p = 0.0054) in the functional versus organic group. In conclusion, patients with significant functional versus organic MR who underwent TAVR have similar short- and long-term survival; nevertheless, those with a functional origin are more likely to have significant improvements in MR severity, LV-positive remodeling, and functional class. These findings may help strategize therapies for MR in patients with combined aortic and mitral valve disease who are undergoing TAVR.
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