Elevations in coronary artery calcification (CAC) scores detected by electron beam computed tomography (EBCT) correlate with the extent of atherosclerosis. EBCT can also be used to assess calcification in the ascending aorta (AoC), another marker of vascular atherosclerosis. We measured CAC and AoC as part of a comprehensive analysis of vascular structure and function in perimenopausal women in the Study of Women’s Health Across the Nation (SWAN Heart study).
213 women underwent EBCT for CAC and AoC. Brachial flow-mediated dilation (FMD), carotid average intimal-medial thickness (IMT), and pulse wave velocity (PWV) were measured using ultrasound. Studies were done fasting and off medications and tobacco. CAC scores were stratified by presence or absence of significant calcium (<10 or ≥10).
Mean age was 49.9, mean arterial pressure (MAP) 95.0 mmHg, and mean body mass index (BMI) of 29.1; 5% were smokers. Mean CAC was 8.1, AoC 78.3, and FMD 6.1%. CAC correlated significantly with AoC (r=0.30, p<0.001). Subjects with CAC ≥ or <10 differed significantly in FMD (6.5 ±3.9 vs 4.9 ±3.5, p=0.03), average IMT (0.68 vs 0.63, p=0.01), maximum IMT (0.88 vs 0.82, p=0.03), log PWV (6.85 vs 6.60, p<0.01), BMI (34.4 vs 27.4, p<0.001), age, and HDL. Subjects with AoC ≥ or <10 differed significantly only in age and BMI (32.9 ±5.7 vs 25.7 ±3.6, p<0.001).
The determinants of coronary and aortic calcification differed in this population of asymptomatic perimenopausal women. This suggests that mechanisms contributing to calcification differ between conduit vessels and coronary arteries. BMI was a strong predictor of both CAC and AoC.
As a result of these findings, early preventive strategies in this population may be undertaken.
V.K. Verma, None.