Abstract 14460: Impact of Carotid Artery Plaque Detection on Cardiovascular Disease Risk and the Importance of Age in the Multi-Ethnic Study of Atherosclerosis

Abstract

Background Carotid artery plaque (CAP) predicts future atherosclerotic cardiovascular disease (ASCVD) events; however, its prevalence increases with age and differs by sex and race/ethnicity, so how its presence influences ASCVD risk in clinical settings is uncertain. Hypothesis: We hypothesized that the impact of CAP detection on relative ASCVD risk declines with age. Methods: CAP was detected and quantified by ultrasound in adults free of clinical ASCVD at Exam 1 of the Multi-Ethnic Study of Atherosclerosis who were followed longitudinally for coronary death, myocardial infarction, angina, stroke, and ASCVD death. Cox proportional hazards models investigated associations of CAP and incident ASCVD events in subsets defined by age categories. These models were adjusted for confounders and an age*CAP interaction. Results: The 5198 participants were a mean (standard deviation) 61.8 (10.1) years old (53% female, 27% Black, 22% Hispanic, 12% Chinese) and experienced 880 ASCVD events over 14.3 (5.7) years. Prevalence of CAP and the age at which 50% of participants had detectable CAP differed by age, sex, and race/ethnicity, ranging from 13% in Chinese women <50 years old to 97% in Non-Hispanic White men 80-84 years old (Figure). CAP presence independently predicted ASCVD events (hazard ratio, 1.35, [95% confidence interval 1.17-1.57], p<0.001), however the strength of this association declined with increasing age (p interaction =0.029, Figure). CAP detection in younger individuals conferred higher relative ASCVD risk than in older participants who had higher absolute risk, regardless of CAP. Conclusions: Prevalence of CAP varies by sex and race/ethnicity. CAP becomes very common with increasing age and its relative association with future ASCVD events declines. These data can assist in guiding ASCVD risk assessment in younger adults and provide perspective for incidentally detected CAP on clinical imaging studies in older adults who have higher absolute ASCVD risk.