Mitral annular calcification in interventional cardiology: address all fears

Mitral annular calcification (MAC) is a particularly challenging pathological condition that can prove difficult to address. It consists of calcium depositions in the mitral valve ring, secondary to chronic inflammation and complex molecular pathogenetic mechanisms of injury and cellular response. MAC has been associated with worse survival in patients with valvulopathies compared to individuals without MAC, as well as with an enhanced risk for cardiovascular events and all-cause mortality. MAC also complicates interventions in the aortic and mitral valves, with several reports showcasing suboptimal results after transcatheter aortic valve implantation (TAVI). For mitral interventions, it is currently being evaluated whether transcatheter edge-to-edge repair (TEER) or transcatheter mitral valve replacement (TVMR) would best suit these patients, in the presence of severe mitral regurgitation (MR), with both procedures showing benefit in early study results. However, the limitations of each procedure for certain phenotypes and anatomies necessitate more extensive research, aiming to identify the most suitable candidates for each intervention. The purpose of this review is, thus, to present a summary of the factors that affect MAC, explore available diagnostic and therapeutic approaches, and provide a framework to anticipate and overcome the potential challenges that may arise during MAC-associated mitral valve disease treatment.