Abstract P226: Higher Calcium Density in Abdominal Aortic Calcium (AAC) and Coronary Artery Calcium (CAC) Does Not Increase Risk for Cardiovascular Disease (CVD) Events: The Multi-Ethnic Study of Atherosclerosis (MESA)
Background: AAC and CAC independently and similarly predict CVD events, but only AAC independently predicts all-cause mortality (ACM). The standard calcified plaque score, the Agatston method, up-weights for greater calcium density, thus modeling higher calcium density associated with increased CVD risk. We evaluated this model by comparing associations of density and volume separately of AAC and CAC for incident coronary heart disease (CHD, defined as myocardial infarction, and resuscitated cardiac arrest), CVD (defined as CHD plus stroke and stroke death), and ACM.
Methods: Cox-proportional hazard model was used to compare independent associations of AAC and CAC density and volume to CHD, CVD, and ACM, with adjustments for the General Framingham Risk Score (composite of CVD risk factors, predicts 10 year CVD risk), ethnicity and statin therapy. Density was calculated as:
Density = Agatston / (volume, mm3 / CT scan slice thickness, mm). Agatston = area, mm2 X density.
Results: In 997 participants with prevalent AAC and CAC, mean age was 66 ± 9 years, mean AAC density 3.10 ± 0.58, and mean CAC density was 2.75 ± 0.72, 58% were men, 46% were European-, 24% were Hispanic-, 16% were African-, and 13% were Chinese-Americans. Over a mean follow-up of 9 years, there were 77 CHD, 118 CVD, and 169 ACM. Compared to the 0-50th, the >75th percentile of AAC density was non-significantly associated with lower ACM but not CHD or CVD (Table). Also, the >75th percentile of CAC density was non-significantly associated with lower CHD and CVD, but not ACM. In contrast, compared to the 0-50th, the >75th percentile of AAC volume was significantly associated with higher CHD, CVD, ACM, and the >75th percentile of CAC volume was significantly associated with higher CHD, CVD, but not ACM.
Conclusion: In mutually adjusted models, although volume of AAC and CAC increased CVD risk, density of AAC and CAC did not. Thus, the Agatston method of up-weighting calcium scores for greater density, in CVD risk prediction, may be inappropriate for the aorta and coronary arteries.
Author Disclosures: N.I. Forbang: None. J. Ix: None. R. Remigo-Baker: None. M. Allison: None. R. McClelland: None. V. Sandfort: None. E. Michos: None.
- © 2016 by American Heart Association, Inc.