Natural History of Mitral Annular Calcification and Calcific Mitral Valve Disease

Abstract

The natural history of mitral annular calcification (MAC) and risk for developing calcific mitral valve disease (CMVD) have been poorly defined. The aim of this study was to evaluate the progression rate of MAC and of the development of CMVD. Patients with MAC and paired echocardiograms ≥1year apart between 2005 and 2019 were included. Progression rates from mild or moderate to severe MAC and to CMVD (defined as severe MAC and significant mitral stenosis and/or regurgitation) were assessed, along with potential association with sex. A total of 11,605 patients (mean age, 73±10years; 51% men) with MAC (78% mild, 17% moderate, 5% severe) were included and underwent follow-up echocardiography at 4.2±2.7years. Among patients with mild or moderate MAC, 33% presented with severe MAC at 10years. The rate of severe MAC was higher in women than in men (41% vs 24% [P<.001]; hazard ratio, 1.3; P<.001) and in patients with moderate versus mild MAC (71% vs 22% [P<.001]; hazard ratio, 6.1; P<.001). At 10years, 10% presented with CMVD (4%, 23%, and 60% in patients with mild, moderate, and severe MAC, respectively), which was predicted by female sex (15% vs 5%; P<.0001), even after adjustment for MAC severity (hazard ratio, 1.9; P<.001). In this large cohort of patients with MAC, progression to severe MAC was common and frequently resulted in CMVD. Female sex was associated with higher progression rates. MAC and CMVD are expected to dramatically increase as the population ages, highlighting the importance of a better understanding of the pathophysiology of MAC to develop effective preventive medical therapies.