Temporal Trends in the Distribution of Extracranial Carotid and Intracranial Artery Disease Among South Korean Stroke Patients

Background and Purpose To examine 16-year temporal trends in the distribution of symptomatic extracranial carotid artery disease (ECAD) versus intracranial artery disease (IAD) among South Korean patients with anterior-circulation steno-occlusive ischemic stroke, and to explore how evolving vascular risk profiles and their management may have influenced these patterns.Methods Using the CRCS-K-NIH (Clinical Research Collaboration for Stroke in Korea-National Institute of Health) registry, we retrospectively included first-ever ischemic stroke patients admitted to 9 South Korean hospitals from April 2008 to December 2023. Patients with symptomatic ≥50% stenosis or occlusion in the anterior circulation were selected, while those with high-risk cardioembolic sources or rare stroke etiologies were excluded. Temporal trends in the proportions of symptomatic ECAD and IAD were evaluated across four time periods (2008–2011, 2012–2015, 2016–2019, and 2020–2023), and logistic regression was used to assess associations of periods and risk factors with ECAD and IAD.Results Among 7,978 eligible patients, the unadjusted proportion with ECAD decreased linearly, whereas the unadjusted proportion with IAD remained stably predominant. Over the same period, age, diabetes and obesity prevalence, and pre-stroke use of antihypertensive, antidiabetic medications, and statins increased, while current smoking declined. Temporal trends in ECAD persisted after adjustment for baseline factors. Use of antihypertensive and antidiabetic medications and current smoking was not associated with the presence of ECAD, while statin use was associated with the presence of ECAD after adjusting for possible confounders.Conclusions In South Korean patients with anterior-circulation steno-occlusive ischemic stroke, symptomatic ECAD has declined over 16 years, contrasting with the persistently high burden of IAD. Further research is needed to clarify what caused these trends.