Abstract A045: High Early Recurrence of Ischemic Stroke After Cranio-Cervical Artery Dissection: A Nationwide Cohort Study

Introduction: Cranio-cervical artery dissection (CAD) is a major cause of ischemic stroke in young and middle-aged adults. Although the overall prognosis is often favorable, a substantial proportion of patients experience recurrent ischemic events, particularly in the early period. The incidence and predictors of ischemic stroke recurrence after CAD remain poorly defined, particularly in patients presenting with acute ischemic stroke or transient ischemic attack (TIA). Methods: We conducted a multicenter, prospective cohort study using data from the Clinical Research Collaboration for Stroke in Korea–National Institute of Health (CRCS-K-NIH), a nationwide web-based stroke registry. The study included consecutive patients aged ≥18 years who were admitted with acute ischemic stroke or TIA to one of 17 participating academic centers between January 2011 and April 2021. CAD was diagnosed within 7 days of symptom onset. Recurrent ischemic stroke events were assessed over a 1-year follow-up. Analyses were stratified by dissection location (intracranial vs. extracranial), and by angiographic patterns (occlusion, stenosis without dilatation, dilatation without stenosis, and the pearl-and-string sign), and other vascular imaging features (intramural hematoma, intimal flap, and double lumen). Results: Among the 711 patients (mean [SD] age, 49.0 [12.5] years; 73.0% men), 541 (76.1%) had intracranial dissections. Recurrent ischemic stroke occurred in 243 patients (27.9%), and 74.5% of events occurred within 7 days of symptom onset. In time-specific analysis, recurrence incidence was highest on day 1 (131.8 per 1,000 person-days) and declined sharply thereafter. Dissection location was not significantly associated with recurrence risk after adjustment. In contrast, vascular morphologic features were strongly associated with recurrence timing and risk: occlusion was linked to recurrence on day 1 (adjusted IRR, 2.18; 95% CI, 1.03–4.61), double lumen to recurrence at 4–7 days (IRR, 2.83; 95% CI, 1.41–5.68), and dilatation without stenosis beyond 7 days (IRR, 2.86; 95% CI, 1.00–8.17). Conclusion: Recurrent ischemic stroke after CAD is common and occurs predominantly within the first week. Vascular morphologic features—not dissection location—are the most powerful and time-sensitive predictors of recurrence. Early identification of high-risk imaging features may facilitate individualized monitoring and secondary prevention strategies during the acute period.