Abstract P373: Higher Plaque Volume but Not Density of Coronary Artery Calcium is Associated With Left Ventricular Mass

Abstract

Coronary artery calcium (CAC) predicts future cardiovascular disease (CVD) events, including heart failure (HF), improves risk stratification beyond traditional CVD risk factors, and is associated with a higher left ventricular mass (LVM), a HF risk factor. Recent findings from the MESA have shown that for a given CAC volume, higher CAC density was inversely associated with incident CVD. It remains uncertain whether CAC volume and density associate differently with LVM. In a multi-ethnic cohort of community dwelling individuals free from clinical CVD at recruitment, we determined the independent cross-sectional associations of baseline CAC volume and density, measured by non-contrast cardiac CT, with LVM, measured by MRI. In 2432 participants with prevalent CAC (density can only be assessed in those with CAC > 0), the mean age was 66 ± 10 years, 59% were men, 50% were European-, 22% were African-, 20% were Hispanic-, and 13% were Chinese-Americans. Median (25-75 th ) CAC volume was 78 (23-259) mm 3 , mean CAC density was 2.7 ± 0.7, and mean LVM was 151 ± 41 grams. CAC density and natural log ( ln ) CAC volume were correlated (correlation coefficient=0.60, P-value < 0.01). Multivariable linear regression models investigated associations of ln (CAC volume) and CAC density with LVM. Model 1 adjusted for demographics (age, sex, and ethnicity) and body surface area. Model 2 included Model 1 plus CVD risk factors (smoking status, fasting glucose, total and HDL cholesterol, systolic blood pressure, and use of medications for hypertension, diabetes, and abnormal lipids). In fully adjusted models one log unit increase in CAC volume as associated with 1.7 gram increase in LVM (Beta = 1.7, 95% CI: 0.7 to 2.6, P < 0.01). In contrast, a unit increase in CAC density was associated with 1.9 gram decrease in LVM (Beta = -1.9, 95% CI: -3.9 to 0.1, P = 0.07). Higher CAC volume, but not CAC density, was cross-sectionally associated with higher LVM; a risk factor for HF. Higher calcium density of coronary artery plaques may not be a hazard for ischemic heart disease mediated increase in LVM. Future studies should determine independent associations of CAC volume and density with incident HF.