Prevalence and Natural History of Mitral Annulus Calcification and Related Valve Dysfunction

Objective: To evaluate the prevalence and natural history of mitral annulus calcification (MAC) and associated mitral valve dysfunction (MVD) in patients undergoing clinically indicated echocardiography. Methods: A retrospective review was conducted of all adults who underwent echocardiography in 2015. Mitral valve dysfunction was defined as mitral regurgitation or mitral stenosis (MS) of moderate or greater severity. All-cause mortality during 3.0 (0.4 to 4.2) years of follow-up was compared between groups stratified according to the presence of MAC or MVD. Results: Of 24,414 evaluated patients, 5502 (23%) had MAC. Patients with MAC were older (75 +/- 10 years vs 60 +/- 16 years; P<.001) and more frequently had MVD (MS: 6.6% vs 0.5% [P<.001]; mitral regurgitation without MS: 9.5% vs 6.1% [P<.001]). Associated with MS in patients with MAC were aortic valve dysfunction, female sex, chest irradiation, renal dysfunction, and coronary artery disease. Kaplan-Meier 1-year survival was 76% in MAC+/MVD+, 87% in MAC+/MVD-, 86% in MAC-/MVD vertical bar, and 92% in MAC/MVD . Adjusted for age, diabetes, renal dysfunction, cancer, chest irradiation, ejection fraction below 50%, aortic stenosis, tricuspid regurgitation, and pulmonary hypertension, MAC was associated with higher mortality during follow-up (adjusted hazard ratio, 1.40; 95% CI, 1.31 to 1.49; P<.001); MVD was associated with even higher mortality in patients with MAC (adjusted hazard ratio, 1.79; 95% CI, 1.58 to 2.01; P<.001). There was no significant interaction between MAC and MVD for mortality (P=.10). Conclusion: In a large cohort of adults undergoing echocardiography, the prevalence of MAC was 23%. Mitral valve dysfunction was more than twice as prevalent in patients with MAC. Adjusted mortality was increased in patients with MAC and worse with both MAC and MVD. (C) 2021 Mayo Foundation for Medical Education and Research