ABSTRACT NUMBER: ESOC2026A1445 PROGRESSION AND REGRESSION OF ASYMPTOMATIC CAROTID STENOSIS IN A MULTICENTER KOREAN REGISTRY (K-ACAS)

Abstract Background and aims The natural history of asymptomatic carotid stenosis (ACS) under contemporary medical therapy remains incompletely defined, particularly regarding ultrasonographic progression and regression. This study aimed to quantify the rates and determinants of carotid stenosis progression and regression in patients with ACS and to explore their association with short-term vascular events. Methods The Korean Asymptomatic Carotid Artery Stenosis (K-ACAS) registry is a prospective observational study at 14 Korean centers enrolling patients with ≥50% asymptomatic internal carotid artery stenosis on duplex ultrasound using predefined velocity criteria. Baseline and annual ultrasound examinations graded stenosis severity, and numeric change defined progression or regression. Clinical variables, Framingham stroke risk, ASCVD risk, and medical therapy were recorded, and factors associated with 1-year progression or regression were assessed. Results Of 350 enrolled patients, 294 (84.0%) completed 1-year ultrasound follow-up. At 1 year, 29.9% showed progression and 22.4% regression; among those with longer follow-up, progression and regression were 34.7% and 26.6% at 2 years and 52.5% and 24.6% at 3 years. Progression was associated with older age, peripheral artery disease, and higher Framingham stroke risk and ASCVD risk scores. Regression was associated with lower triglycerides and higher atorvastatin-equivalent statin doses. One-year stroke incidence was 1.4%, and major adverse cardiovascular events were rare and did not differ by progression status. Conclusions In ACS, carotid stenosis severity on ultrasound is dynamic, with substantial progression and regression despite low event rates. Higher global vascular risk favor progression, whereas intensive lipid-lowering is linked to regression. Conflict of interest Han-Yeong Jeong: nothing to disclose, Hyung-Min Kwon: nothing to disclose, Keun-Hwa Jung: nothing to disclose, Sungwook Yu: nothing to disclose, KyuSik Gang: nothing to disclose, Ji Man Hong: nothing to disclose, Sang Beom Kim: nothing to disclose, Yang-Ha Hwang: nothing to disclose, Jun Hong Lee: nothing to disclose, Eung-Gyu Kim: nothing to disclose, Jay Chol Choi: nothing to disclose, Seung-Jae Lee: nothing to disclose, Jong-Ho Park: nothing to disclose, Yong-Jae Kim: nothing to disclose, Yong-Seok Lee: nothing to disclose