BackgroundThe management of patients with mitral regurgitation (MR) undergoing transcatheter aortic valve replacement (TAVR) is challenging. We sought to investigate the evolution and long-term prognostic impact of residual post-TAVR MR. MethodsThe severity of MR was assessed at baseline and at 30 days and six months post-TAVR. Left ventricular mass and volumes were assessed by magnetic resonance imaging at two weeks and six months post-TAVR. ResultsThe study included 970 patients (age, 80.6 ± 6.2 years; female, 53.2%; Society of Thoracic Surgeons score, 5.2 ± 4.6). Moderate-severe MR at baseline improved at 30-day post-TAVR in 60% of cases, and TAVR with the Medtronic CoreValve (OR: 0.44 [0.23–0.86]) was associated with a lower likelihood of improvement. Further MR improvement continued beyond 30 days post-TAVR especially in patients with a significant improvement of left ventricular volume and mass.Stratified by the severity of MR at 30 days post-TAVR, the 5-year cumulative incidence of the composite of cardiovascular mortality or heart failure hospitalization was 37.5%, 40.0%, and 58.2% in patients with none-mild, moderate, and severe MR, respectively (log rank p < .001; adjusted hazard ratio of severe vs. none-mild MR: 4.83 [2.49–9.38]. ConclusionsMR improves in a majority of patients early after TAVR, and its evolution continues thereafter in line with reverse cardiac remodeling. Residual post-TAVR severe MR is associated with adverse long-term outcome. Therefore, intervention to treat severe MR persisting after TAVR should be considered by the heart team.