Abstract 18964: Long-Term Prognostication of Atherosclerotic Cardiovascular Disease Risk Based on the Discordance Between Coronary Artery Calcium Area and Density

Abstract

Introduction and Hypothesis: Coronary artery calcium scoring is used to quantify the burden of atherosclerotic plaque in coronary arteries in patients with coronary artery disease. It is measured as a product of two variables: plaque area and density. Our study sought to evaluate the long-term prognosis of atherosclerotic cardiovascular disease (CVD) based on the discordance between these two variables. Methods: 1750 patients with a CAC score greater than 0 were enrolled in this retrospective, multicenter study. Agatston CAC score was used to quantify a lesion as the product of plaque area and a 4-level categorical peak calcium density factor. COX proportional hazards were performed for atherosclerotic CVD mortality over a median period of 5.2 years while adjusting the Agatston CAC score and other classic risk factors. Results: The mean age was 61.2 years, and 19% were female. The prevalence of plaque discordance was 23% (12% high calcium area/low calcium density, 11% low calcium area/high calcium density). Compared to those with low calcium area/low calcium density, patients with low calcium area/high calcium density had a 65% lower risk of ASCVD death (HR: 0.27 [95% CI: 0.08-0.95]). Female sex ([95% CI: 1.25-1.76]) and body mass index ([95% CI: 1.16-1.32], per 5 kg/m2 higher) were significantly associated with high calcium density discordance. Conclusions: Our study concluded that high calcium density relative to plaque area confers lower long-term ASCVD risk, likely as an imaging marker for lesion severity. Additional studies are needed to define a robust definition of calcium area/density discordance for real-life clinical risk prediction.