Alam, Shaista

Background: High-grade intracranial atherosclerosis (ICAS) is associated with an elevated risk of recurrent ischemic stroke, particularly in patients with severe stenosis (70–99%). Identifying predictors of early recurrence can inform risk stratification and guide treatment strategies. Methods: The Biomarkers and Recurrence Risk in Symptomatic Intracranial Arterial Stenosis (BIORISK-ICAS) study is a multicenter, international, retrospective cohort analysis pooling data from 35 comprehensive stroke centers. We included hospitalized adult patients with symptomatic ICAS, defined as 50–99% stenosis of an intracranial artery (intracranial vertebral, basilar, distal ICA, or M1 MCA), confirmed by vascular imaging and associated with a qualifying ischemic event. Patients with only high-grade stenosis (70-99%) were included in this analysis. The primary outcome was to determine predictors of recurrent ischemic stroke in the territory of the symptomatic artery within 90 days of the index event. Baseline demographic, clinical, and imaging characteristics were recorded. Multivariable Cox proportional hazards regression with stepwise selection (p < 0.1) was used to identify independent predictors of recurrence; model discrimination was assessed using Harrell’s C-statistics. Results: Among 2,050 patients, 1,476 had high-grade (70-99%) symptomatic ICAS. The mean age was 67 ± 12.5 years, and 767 (55%) were male. Most patients were non-Hispanic (90.1%), taking dual antiplatelet therapy (77.8%), and statins (94.5%). Recurrent stroke occurred in 160 patients (10.8%) within 90 days. In multivariable Cox model, independent predictors of recurrence included atrial fibrillation (HR 2.05; 95% CI, 1.26–3.33; p = 0.004), hyperlipidemia (HR 1.57; 95% CI, 1.10–2.24; p = 0.014), diabetes mellitus (HR 1.36; 95% CI, 0.98–1.88; p = 0.064), and home use of dual antiplatelet therapy (HR 1.60; 95% CI, 1.01–2.54; p = 0.043)(Harrell’s C-statistic=0.62). In patients who underwent perfusion(n=402), mistmatch >10seconds were associated with increased recurrence (HR 1.80; 95% CI 0.95-3.38, p=0.07) and atrial fibrillation (HR 2.06: 95% CI 0.03-4.60, p=0.78) though did not reach statistical significance. Conclusion: In this population, diabetes, hyperlipidemia, atrial fibrillation, and prior use of dual antiplatelet therapy were associated with increased risk of 90-day recurrent ischemic stroke. Perfusion imaging may help identify high-risk patients who could benefit from intensified secondary prevention.

Introduction: Intracranial atherosclerosis (ICAS) is a leading cause of ischemic stroke (IS) worldwide and carries a high risk of recurrence. Current guidelines favor 90 days of dual antiplatelet therapy (DAPT) for severe symptomatic ICAS, but recurrence remain high. Limited data suggest possible benefit of single antiplatelet plus anticoagulation (SAPT+AC). We compared the effectiveness and safety of DAPT versus SAPT+AC. We hypothesized that DAPT would lower 90-day recurrent IS risk without significantly increasing bleeding. Methods: This substudy of the Biomarkers and Recurrence Risk in Symptomatic Intracranial Arterial Stenosis (BIORISK-ICAS) included patients from 35 centers (Jan 2019–Jun 2024) with symptomatic 50–99% ICAS in the intracranial internal carotid, vertebral, basilar, or M1 segment of the MCA, presenting ≤72 hours from last known well. The primary efficacy outcome was recurrent IS in the same vascular territory at 90 days; the primary safety outcome was severe bleeding (symptomatic intracranial hemorrhage or major extracranial bleeding). Categorical variables were compared using χ 2 and continuous variables with the Student's t test; multivariable Cox regression adjusted for key covariates. Results: Of 2050 BIORISK-ICAS patients, 1658 met criteria (DAPT n=1499; SAPT+AC n=159). Mean age was 67 vs. 73 years, and 44% were women. At 90 days, recurrent IS occurred in 121 DAPT patients (8.07%) vs. 13 SAPT+AC patients (8.17%); unadjusted HR 0.83 (95% CI, 0.50–1.36; p=0.46). After adjustment for age, diabetes, coronary heart disease, atrial fibrillation, active smoking, and borderzone infarct, the adjusted HR was 0.99 (95% CI, 0.52–1.86; p=0.97). Severe bleeding occurred in 34 DAPT patients (2.26%) and 5 SAPT+AC patients (3.14%); unadjusted HR 0.79 (95% CI, 0.28–1.85; p=0.50), adjusted HR 0.66 (95% CI, 0.21–2.09; p=0.47). Conclusions: In patients with symptomatic ICAS, DAPT and SAPT+AC were associated with similar risks of 90-day recurrent ischemic stroke and severe bleeding. Well-powered randomized trials are needed to determine the optimal antithrombotic regimen in this high-risk population.

BACKGROUND: Intracranial atherosclerosis (ICAS) is associated with an increased risk of early recurrent ischemic stroke. We evaluated whether biomarkers of impaired distal perfusion—specifically, anterior circulation borderzone infarct, and hypoperfusion mismatch volume—were associated with recurrent ischemic stroke within 90 days. METHODS: The BIORISK ICAS (Biomarkers and Recurrence Risk in Symptomatic Intracranial Atherosclerosis) is a multicenter retrospective international study (35 sites) that included hospitalized patients with symptomatic ICAS (50%–99% luminal stenosis of the intracranial vertebral, basilar, distal internal carotid, or proximal middle cerebral artery) from January 2019 to June 2024. The primary outcome was recurrent ischemic stroke in the territory of the symptomatic artery within 90 days. In the primary analysis, the exposure was an acute anterior circulation borderzone infarct. In secondary analysis of the subset with presentation within 72 hours of last known normal and perfusion imaging completed, the exposure of interest was prespecified as hypoperfusion mismatch volume at T max (time to maximum) threshold of 6 seconds, dichotomized at the Youden index. We performed multivariable Cox regression to test associations between exposure variables and the outcome, adjusting for clinically relevant variables and those associated with the outcome ( P <0.1). RESULTS: Of 2050 patients with symptomatic ICAS, 1737 (84.7%) presented within 72 hours of symptom onset, among whom 509 (29.3%) underwent perfusion imaging. The primary analysis included 1891 patients; 174 (9.2%) patients had recurrent ischemic stroke in the symptomatic arterial territory. In adjusted Cox regression models, there was an association between anterior circulation borderzone infarct and recurrent ischemic stroke at 90 days (adjusted hazard ratio, 1.40 [95% CI, 1.02–1.93]). In the perfusion imaging analysis, hypoperfusion mismatch of ≥10 mL was associated with recurrent ischemic stroke (adjusted hazard ratio, 1.83 [95% CI, 1.03–3.28]). CONCLUSIONS: Biomarkers of impaired distal perfusion, anterior circulation borderzone infarct, and hypoperfusion mismatch were associated with increased risk of recurrent ischemic stroke. These findings support the use of perfusion imaging in ICAS as well as future trials investigating early reperfusion in high-risk patients with ICAS.