Cardiac computed tomography-based assessment of mitral annular calcification in patients undergoing mitral transcatheter edge-to-edge repair

Background: The role of assessment of mitral annular calcification (MAC) using cardiac computed tomography (CCT) in mitral transcatheter edge-to-edge repair (TEER) remains unclear. The aim of this study was to investigate the association of MAC assessed by CCT with procedural and clinical outcomes in patients undergoing TEER. Methods: We retrospectively analyzed 275 patients who underwent pre-procedural CCT prior TEER. Mitral calcium volume (MCV) and MAC score were measured by CCT. Functional procedural success was defined as residual mitral regurgitation of ≤2+ with mean transmitral gradient of <5 ​mmHg at discharge. All-cause mortality within two years after TEER was collected. Results: MAC was present in 115 of 275 patients (41.8 %). The median MCV was 198 ​mm³ (interquartile range [IQR]: 84 to 863 ​mm³), and the median MAC score was 3 (IQR: 2 to 4). Higher MCV and MAC score were inversely related to the rate of functional procedural success, independently of anatomical features of mitral valve. Patients with moderate/severe MAC, defined as MAC score of ≥4, had a lower rate of functional procedural success than those without MAC (56.1 ​% vs. 81.3 ​%; p ​= ​0.002). Moreover, higher MCV and MAC score were associated with a higher risk of all-cause mortality within two years, irrespective of baseline characteristics and functional procedural success. Conclusions: The presence and burden of MAC assessed by CCT were associated with procedural and clinical outcomes in patients undergoing TEER. The CCT-based assessment of MAC may improve patient selection for TEER.