Epidemiology of mitral annular calcification and its predictive value for coronary events in African Americans: the Jackson Cohort of the Atherosclerotic Risk in Communities Study.

BACKGROUND: Despite the potential link between mitral annular calcification (MAC) and atherosclerosis, there is limited data regarding the prevalence of MAC in African Americans and its relationship with coronary heart disease (CHD)events in this high-risk population.

METHODS: The study population included 2409 African American participants of the Artherosclerotic Risk in Communities study (ARIC) undergoing echo examinations between 1993-1996. The primary outcome was incident CHD events [defined as fatal coronary event, hospitalized myocardial infarction or cardiac procedure]. MAC was considered a binary variable (yes/no). The Cox proportional hazard model was used for the analysis and the model was adjusted for gender, age, body mass index, hypertension, diabetes, smoking status, renal function (based on serum creatinine), high LDL and low HDL.

RESULTS: Of the 2409 in the study population, 1549 (64%) were women and the mean age was 59.2 +/- 5.8 years (range 49-75). MAC was positively associated with age and renal function. The overall prevalence of MAC was 4.6% for women and 5.6% for men. In participants aged >or= 70, the prevalence of MAC was 10% in women and 15.2% in men. During a median follow-up of 4.8 years, there were 237 total incident CHD events recorded. After adjustment, the hazard ratio for CHD events among the MAC subgroup was 2.32 (95% CI, 1.11-4.87).

CONCLUSIONS: In this relatively young population of middle-aged African Americans, the prevalence of MAC is low; however, the presence of MAC incurs a significant risk for coronary events.