Prognosis of persistent mitral regurgitation in patients undergoing transcatheter aortic valve replacement.

Objective: The objective of this study was to assess imaging predictors of mitral regurgitation (MR) improvement and to evaluate the impact of MR regression on long-term outcome in patients undergoing transcatheter aortic valve replacement (TAVR).
Background: Concomitant MR is a frequent finding in patients with severe aortic stenosis but usually left untreated at the time of TAVR.
Methods: Mitral regurgitation was graded by transthoracic echocardiography before and after TAVR in 677 consecutive patients with severe aortic stenosis. 2-year mortality was related to the degree of baseline and discharge MR. Morphological echo analysis was performed to determine predictors of MR improvement.
Results: 15.2% of patients presented with baseline MR ≥ 3 +, which was associated with a significantly decreased 2-year survival (57.7% vs. 74.4%, P < 0.001). MR improved in 50% of patients following TAVR, with 44% regressing to MR ≤ 2 +. MR improvement to ≤ 2 + was associated with significantly better survival compared to patients with persistent MR ≥ 3 +. Baseline parameters including non-severe baseline MR, the extent of mitral annular calcification and large annular dimension (≥ 32 mm) predicted the likelihood of an improvement to MR ≤ 2 +. A score based on these parameters selected groups with differing probability of MR ≤ 2 + post TAVR ranging from 10.5 to 94.4% (AUC 0.816; P < 0.001), and was predictive for 2-year mortality.
Conclusion: Unresolved severe MR is a critical determinant of long term mortality following TAVR. Persistence of severe MR following TAVR can be predicted using selected parameters derived from TTE-imaging. These data call for close follow up and additional mitral valve treatment in this subgroup. Factors associated with MR persistence or regression after TAVR.