Mitral Annular Calcification: Understanding the Disease and Treatment Options

Abstract

Mitral annular calcification (MAC) is a degenerative process that causes calcium deposits along the mitral annulus. The pathophysiological mechanisms contributing to the development of MAC are not fully understood. The main risk factors for MAC are advanced age, female gender, chronic kidney disease, and conditions predisposing to left ventricular hypertrophy, which increases mitral annulus tension and subsequent annular degeneration. The prevalence of MAC varies widely among studies, from 5% to 42%, depending on the characteristics of the study population and the imaging modality used to make the diagnosis, and it is increasing over time. MAC is independently associated with all-cause mortality, cardiovascular mortality, and the occurrence of cardiovascular disease such as atrial fibrillation, conduction abnormalities, or stroke. MAC can progress and involve the mitral valve leaflets, causing mitral stenosis, mitral regurgitation, or both. Patients who develop symptomatic mitral valve dysfunction associated with significant MAC have lower survival when mitral valve intervention is not performed. However, the surgical risk of these patients is often high, precluding surgery in many. Therefore, transcatheter mitral valve implantation is emerging as an alternative in patients with severe MAC and associated symptomatic mitral valve dysfunction. This manuscript summarizes a description of the disease process in MAC and its treatment options.