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.     

Left Ventricular Dilation and Incident Congestive Heart Failure in Asymptomatic Adults Without Cardiovascular Disease: Multi-Ethnic Study of Atherosclerosis (MESA)

BackgroundLimited data exist on the association between left ventricular (LV) dilation/remodeling and incident heart failure (HF), especially in adults without prior myocardial infarction (MI) and valvular heart disease. We assessed the association between LV dilation and remodeling and incident HF in a multiethnic cohort.Methods and ResultsA total of 4,974 of 6,814 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) had cardiac magnetic resonance imaging and complete data. Kaplan-Meier and Cox proportional hazard analyses were used to assess the association between LV end-diastolic diameter (LVEDD) and adjudicated HF. During the 12 years of follow-up (mean 9.4 y), 177 (3.6%) HF events occurred, 126 (71.2%) in HF with reduced ejection fraction (EF) and 51 (28.8%) in HF with preserved EF. LV dilation (LVEDD >52 mm or >95th percentile) was associated with HF in univariate (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.08–1.46; P = .007) and multivariable Cox models (HR 1.28, 95% CI 1.09–1.57; P = .01) adjusting for traditional risk factors, medication use, LV EF, and interim MI. We found a significant multiplicative interaction between LVEDD and LV EF in our full multivariable models. Participants with dilated LV and preserved EF had increased risk [HR 2.22, 95% CI 1.46–3.37; P = .006) and those with dilated LV and reduced EF had worse prognosis (HR 7.35, 95% CI 2.36–22.85; P = .0006) compared with normal-size LV and preserved EF. A high proportion of participants with LV dilation had eccentric remodeling, a risk factor for HF. Concentric hypertrophy, also a risk factor for HF, was common in the normal-size LV group.ConclusionsLV dilation predicts incident HF independently from risk factors, LV EF, and interim MI.     

Relation of aortic wall thickness and distensibility to cardiovascular risk factors (from the Multi-Ethnic Study of Atherosclerosis [MESA])

To determine the relation between aortic wall thickness (WT) and aortic distensibility (AD) with traditional cardiovascular risk factors in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort, 1,053 participants in MESA who underwent cardiac magnetic resonance imaging were consecutively selected for the measurement of aortic WT and AD. Double inversion-recovery fast spin-echo images of the thoracic aorta were obtained to measure average and maximum WT. AD was measured at the same level using a gradient-echo cine sequence. Average and maximum WT were positively correlated with increasing age, and AD was inversely related to age (p <0.01). Compared with normotensive participants, those with hypertension had significantly greater mean average WT (2.45 vs 2.23 mm, p <0.01) and maximum WT (3.61 vs 3.41 mm, p <0.01) and lower AD (0.15 vs 0.2 mm Hg(-1), p <0.01). In multiple regression analysis, older age and hypertension were significantly associated with higher mean average WT, while older age, male gender, and higher blood pressure were associated with higher mean maximum WT. AD was inversely related to older age, hypertension, current smoking, African American ethnicity, and lower high-density lipoprotein cholesterol level. In conclusion, in the MESA cohort, older age and higher blood pressure were associated with higher aortic WT and lower AD. Decreased AD was further associated with current smoking, African American ethnicity, and higher high-density lipoprotein cholesterol level.     

Use of Novel Markers for the Prediction of Cardiovascular Disease: Updates from the Multi-Ethnic Study of Atherosclerosis (MESA)

The development of technology has led to evolution in the risk assessment for cardiovascular disease (CVD). Current preventive guidelines for CVD recommend that management decisions should be based on risk assessment, which prototypically involves calculation of estimated risk using tools such as the Framingham risk score. This review will discuss some improved methods of risk stratification for CVD including the use of novel risk markers studied in the Multi-Ethnic Study of Atherosclerosis (MESA). Compared to several novel serum biomarkers, coronary artery calcium (CAC) offered a significantly higher improvement in discrimination and reclassification over both Framingham risk score and Reynolds risk score for individuals identified as having intermediate risk for CVD.     

Age modification of the association of lipoprotein, lipid, and lipoprotein ratio with carotid intima-media thickness (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Multiple studies have demonstrated an age-related attenuation in risk associations of lipoproteins and lipoprotein ratios with cardiovascular disease events. We recently reported a similar age-related attenuation in risk associations of lipoproteins and lipoprotein ratios with coronary artery calcium. We assessed risk associations of lipoproteins and lipoprotein ratios with carotid intima-media thickness (CIMT), which has not been reported previously. We performed multivariable linear regression using data from the Multi-Ethnic Study of Atherosclerosis (MESA). MESA participants were community-dwelling adults 45 to 84 years of age without clinically apparent cardiovascular disease at baseline, and 4,961 met inclusion criteria for these analyses. In fully adjusted models, differences in CIMT were similar across the MESA age spectrum, with differences in internal CIMT per SD increase in low-density lipoprotein of 0.037 mm (95% confidence interval 0.018 to 0.055) for those 45 to 54 years old and 0.087 mm (95% confidence interval 0.027 to 0.146) for those 75 to 84 years old (p for interaction = 0.2). Similarly, the difference in internal CIMT per SD increase in the total/high-density lipoprotein cholesterol ratio was 0.029 mm (95% confidence interval 0.009 to 0.049) for those 45 to 54 years old and 0.101 mm (95% confidence interval 0.033, 0.169) for those 75 to 84 years old (p for interaction = 0.03). In general, risk associations of lipoproteins and lipoprotein ratios were associated with similar differences in CIMT across all age categories. In conclusion, abnormal lipoproteins and lipoprotein ratios in middle-aged and older patients are powerful risk factors for early atherosclerosis as manifested by an increased CIMT.