Relation between mitral annular calcium and complex intraaortic debris

Relation of mitral annular calcium and coronary calcium (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Atherosclerosis is a complex diffuse disorder. The close correlation between coronary artery calcium (CAC) score on computed tomogram and extent and severity of coronary atherosclerosis is well established. It has been suggested that mitral annular calcification (MAC) may be a manifestation of generalized atherosclerosis. The MESA population included a population-based sample of 4 ethnic groups (12% Chinese, 38% white, 22% Hispanic, and 28% black) of 6,814 women and men 45 to 84 years of age. Computed tomographic scans were performed for all participants. The calcium score of each lesion was calculated by multiplying lesion area by a density factor derived from maximal Hounsfield units. A total calcium score was determined by summing individual lesion scores at each anatomic site. Relative risk regression was used to model the probability of MAC as a function of CAC >0 and CAC categories (0, 1 to 99, 100 to 399, and ≥400) with the referent group being CAC 0. The final study population consisted of 6,814 subjects (mean age 62 ± 10 years, 47% men). Overall 9% and 50% had detectable MAC and CAC, respectively. Of those with absent CAC, only 4% had MAC, whereas 9%, 19%, and 15% had MAC scores with increasing CAC scores of 1 to 99, 100 to 399, and ≥400, respectively (p<0.0001 for trend). After taking into account demographics and other risk factors, the prevalence ratio of MAC in those with mild CAC (1 to 99) was 2.13 (95% confidence interval 1.69 to 2.69) and increased to 7.57 (95% confidence interval 5.95 to 9.62) for CAC ≥400. Similar statistically significant increased risk of MAC was found when CAC was assessed as a continuous variable. In conclusion, we observed a strong association between MAC and increasing burden of CAC. This association weakened but persisted after adjustment for age, gender, and other traditional cardiovascular risk factors. These findings suggest that presence of MAC is an indicator of atherosclerotic burden rather than just a degenerative change of the mitral valve.

Is Carotid Atherosclerosis More Important in Patients With Mitral Annular Calcification Than in Those Without?

It has been suggested that mitral annular calcification (MAC) may be a manifestation of generalized atherosclerosis. However, how the incidence and extent of coronary artery disease (CAD) are affected by the coexistence of carotid atherosclerosis (CAS) in patients with versus without MAC have not yet been studied. We studied 101 patients with echocardiographic MAC and 52 controls without MAC to investigate the clinical impact of CAS on the frequency and severity (defined as the number of obstructed vessels) of CAD in patients with MAC. Carotid Doppler ultrasonographic examination was performed on all patients before coronary angiography. In patients with both MAC and CAS, the incidences of CAD and multivessel disease (> or = 2 vessel or left main coronary artery disease) were significantly higher than in the control group with CAS alone (91% versus 68%, P = 0.008 and 76% versus 44%, P = 0.004, respectively). On the other hand, among study and control patients without CAS, although the frequencies of CAD and multivessel disease were higher in patients with MAC, interestingly, the differences were not statistically significant (37% versus 58% and 15% versus 26%, respectively, P > 0.05 for both). Stepwise multiple logistic regression analysis revealed that CAS (P < 0.001), MAC (P < 0.01) and, to a limited extent hypertension (P = 0.054), were independent predictors for the presence of CAD. In conclusion, the coexistence of CAS is more important in patients with MAC than in those without as it provides valuable information about the incidence and severity of underlying CAD. In cases with MAC but without CAS, MAC could be caused by factors other than atherosclerosis.