Background: Mitral annular calcification (MAC) has been suggested as a reliable, time-averaged marker of atherosclerosis and is associated with coronary artery disease, heart failure, ischemic stroke, and increased mortality. Data on the relationship between MAC and cardiovascular morbidity and mortality in atrial fibrillation (AF) are sparse, with the exception of the relationship between MAC and stroke. We investigated the association of MAC with cardiovascular morbidity, stroke, cardiovascular mortality, and all-cause death in a cohort of middle-aged patients with AF with a mean 10-year follow-up.
Methods: This was an observational study of patients with nonvalvular AF between 1992 and 2007.
Results: Of 1,056 patients, 33 (3.1%) had MAC; they were more likely to be older and female and to have a dilated left atrium, reduced left ventricular ejection fraction, permanent AF, hypertension, and/or diabetes mellitus (all P < .05). Total follow-up was 10,418.5 years (mean, 9.9 ± 5.9 years), and the mean age was 52.7 ± 12.2 years. In univariate analysis, MAC was associated with all-cause death, cardiovascular death, stroke, new cardiac morbidity (all P < .05), and the composite end point of ischemic stroke, myocardial infarction (MI), and all-cause death (P < .001). In multivariate analyses, MAC was related to all-cause death (hazard ratio [HR], 4.3; 95% CI, 1.8-10.0; P < .001), cardiovascular death (HR, 3.5; 95% CI, 1.2-10.4; P = .025), the composite end point (HR, 2.1; 95% CI, 1.0-4.3; P = .048), and new cardiac morbidity (HR, 2.4; 95% CI, 1.3-4.5; P = .005). There was no significant relationship between MAC and stroke or MI in the multivariate analyses.
Conclusions: MAC is associated with increased cardiovascular morbidity, cardiovascular mortality, and all-cause mortality of patients with AF. MAC should be acknowledged as a marker of increased cardiovascular risk in middle-aged patients with AF.