Implications of Mitral Annular Calcification on Outcomes Following Mitral Transcatheter Edge-to-Edge Repair

Limited data exist regarding the impact of mitral annular calcification (MAC) on outcomes of transcatheter edge-to-edge repair for mitral regurgitation (MR).

We retrospectively analyzed 968 individuals (median age, 79 [interquartile range, 70-86] years; 60.0% males; 51.8% with functional MR) who underwent an isolated, first-time intervention. Stratified by MAC extent per baseline transthoracic echocardiogram, the cohort was assessed for residual MR, functional status, all-cause mortality, heart failure hospitalizations, and mitral reinterventions post-procedure.

Patients with above-mild MAC (n=101; 10.4%) were older and more likely to be female, exhibited a greater burden of comorbidities, and presented more often with severe, primary MR. Procedural aspects and technical success rate were unaffected by MAC magnitude, as was the significant improvement from baseline in MR severity and functional status along the first postprocedural year. However, the persistence of above-moderate MR or functional classes III and IV at 1 year and the cumulative incidence of reinterventions at 2 years were overall more pronounced within the above-mild MAC group (significant MR or functional impairment, 44.7% versus 29.9%, P=0.060; reinterventions, 11.9% versus 6.2%, P=0.033; log-rank P=0.035). No link was demonstrated between MAC degree and the cumulative incidence or risk of mortality and mortality or heart failure hospitalizations. Differences in outcomes frequencies were mostly confined to the primary MR subgroup, in which patients with above-mild MAC also experienced earlier, more frequent 2-year heart failure hospitalizations (20.8% versus 9.6%; P=0.016; log-rank P=0.020).

Mitral transcatheter edge-to-edge repair in patients with and without above-mild MAC is equally feasible and safe; however, its postprocedural course is less favorable among those with primary MR.