Abstract 18980: Aortic Distensibility May Be Associated With the Characteristics of Coronary Atherosclerosis Plaque

Abstract

Purpose: Aortic distensibility (AD) has been shown to be inversely proportional to disease severity and presence of cardiovascular risk factors. MDCT can simultaneously characterize coronary and thoracic aortic atherosclerotic plaque morphology by delineating between calcified, mixed, non-calcified lesions. This study aimed to access relation between the characteristics of coronary plaque and AD in cardiac MDCT. Methods: The study was a retrospective analysis of the findings in 69 patients who performed cardiac MDCT for evaluation of chest pain symptoms. The 69 subjects was performed 64 channel cardiac MDCT and Scan data were reconstructed at 20 phases between 0% and 95% of the R-R intervals with an increment of 5%. Pixel-based measurements of arterial dimensions were performed at 1 cross-section of the descending aorta in a transverse plane at the aortic valve level. End diastole area was measured at 95% of R-R interval and end systolic area was measured at 35% of R-R interval. Aortic distensibility was calculated as follows: AD= (end systolic area - end diastolic area)/ (end diastolic area х pulse pressure). Coronary plaques in cardiac MDCT were categorized as calcified, mixed, or non-calcified. Results: Descending AD were lower in patients with any coronary plaque, calcified or mixed plaque than those without (mixed: p<0.001, calcified: p=0.041) but not with non-calcified coronary plaque (p=0.497). In multivariate logistic regression analysis, descending AD (p = 0.011, HR 6.446) is independently associated with mixed coronary plaque after adjustment of age, sex, body mass index. The cutoff value of descending AD for prediction of mixed plaque in cardiac MDCT was 1.6 X 10 -3 mmHg with 69.2% of sensitivity and 69.2% of specificity (Fig). Conculsions: Descending AD may be associated with the mixed or calcified plaque in by MDCT. Especially, Descending AD might be associated with mixed coronary plaque.