Differentiated risk factors for stroke recurrence in anterior versus posterior circulation intracranial atherosclerosis: A high-resolution vessel wall imaging study

Background and purpose: The risk factors for recurrent stroke in intracranial atherosclerosis (ICAS) may differ between the anterior and posterior circulations. This exploratory study aimed to investigate and compare these risk factors, leveraging plaque characteristics identified by high-resolution vessel wall imaging (HR-VWI). Methods: We retrospectively analyzed 166 patients with ICAS-related ischemic stroke, categorized into ACIS (n = 123) and PCIS (n = 43) groups. Each group was subdivided into recurrent (ACIS: 25; PCIS: 11) and non-recurrent (ACIS: 98; PCIS: 32) cohorts based on follow-up (mean: 16.69 ± 10.18 months). Clinical and imaging risk factors were compared, with multivariable Cox regression analysis employed to identify independent predictors of recurrence. Predictive performance was assessed using the area under the receiver operating characteristic (ROC) curve (AUC). Results: For ACIS, older age, multiple infarcts, and significant plaque enhancement were associated with recurrence (all q < 0.05). For PCIS, diabetes mellitus and intraplaque hemorrhage (IPH) were associated with recurrence (all q < 0.05). Multivariable analysis confirmed older age (>55.5 years), multiple infarcts, and significant plaque enhancement as independent risk factors for ACIS recurrence, whereas diabetes mellitus and IPH were independent predictors for PCIS recurrence. A combined predictive model for ACIS achieved a fair-to-good predictive performance (AUC: 0.821, 95% CI: 0.72-0.92), while the model for PCIS yielded a more uncertain performance (AUC: 0.770, 95% CI: 0.61-0.93) with a wide confidence interval, reflecting the small sample size. Conclusion: The drivers of recurrent stroke in ICAS appear to differ between the anterior and posterior circulations. These exploratory findings suggest that integrating clinical data with HR-VWI plaque features may enhance risk stratification. However, due to significant limitations, these results should be interpreted with caution and require validation in larger, prospective cohorts before being applied to clinical practice. This study underscores the potential need for circulation-specific secondary prevention strategies.