Havenon, Adam de

Background: Embolic stroke of undetermined source (ESUS) comprises infarct mechanisms presumed to be embolic and non-lacunar. One explanation for the lack of superiority of anticoagulation over aspirin is the inclusion of subcortical infarcts with white matter disease (WMD), reflecting small vessel pathology. We hypothesized that WMD is associated with recurrent ischemic stroke (RIS) in ESUS and this risk is not lessened by anticoagulation. Methods: We conducted a secondary analysis of the multicenter Cardiac Abnormalities in Stroke Prevention and Recurrence (CASPR) registry, including ESUS patients from 27 U.S. centers (2015–2024). WMD severity was graded using the Fazekas scale from MRI and dichotomized as mild (0–1) vs. moderate-to-severe (2–3). The primary outcome was RIS. Secondary outcomes were major bleeding and all-cause mortality. Inverse probability of treatment weighting (IPTW) adjusted for baseline differences. Cox proportional hazards models assessed associations between WMD and outcomes. Subgroup analyses explored effect modification by age, risk factors, and treatment type. Results: Among 1,890 ESUS patients with MRI data, 684 (36.2%) had Fazekas 2–3. These patients were older with more vascular risk factors, but IPTW achieved covariate balance. In the weighted cohort, RIS occurred more frequently in Fazekas 2–3 vs. 0–1 (7.1% vs. 4.6%/year; HR 1.56, 95% CI 1.10–2.22, p = 0.01). Major bleeding and mortality were similar (bleeding: 1.7% vs. 1.8%/yr, HR 0.96, p = 0.92; death: 7.0% vs. 6.7%/yr, HR 1.04, p = 0.81). Subgroup analyses showed no interaction between WMD and age, vascular risk factors, or treatment type (antiplatelet vs. anticoagulation), suggesting consistent RIS risk in those with higher WMD. Discussion: Moderate-to-severe WMD identifies ESUS patients at higher risk of ischemic stroke recurrence, with no mitigation by anticoagulation. These findings suggest that WMD may indicate non-embolic mechanisms and support the use of imaging-based risk stratification in ESUS.

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: Although the embolic stroke of undetermined source (ESUS) construct was proposed as a unifying concept for embolic-appearing strokes without an identified cause, it includes patients with diverse and often unrecognized underlying mechanisms. This study investigates the differential rate of recurrent stroke according to the completeness of neurodiagnostic testing in a diverse multicenter cohort. Methods: This was a retrospective analysis of a multicenter observational cohort study (n=27 sites). Patients with ESUS were categorized into three groups: (1) established mechanism after further work up (ESUS-E), (2) patients who underwent a comprehensive diagnostic workup without an identified etiology (ESUS 2.0), and (3) no advanced workup (ESUS-NAW). The primary outcome of recurrent ischemic stroke was assessed by comparing ESUS 2.0 to both ESUS-E and ESUS-NAW groups using adjusted Cox proportional hazards models. Results: Of the 2,281 patients included, 694 (30%) were classified as ESUS-E, 344 (15%) as ESUS 2.0, and 1,443 (55%) as ESUS-NAW. The ESUS 2.0 group had a significantly lower annualized recurrence rate (1.98 per 100 person-years) compared to both the ESUS-NAW group (7.7 per 100 person-years; aHR 0.27, 95% CI: 0.11–0.62; p=0.002) and the ESUS-E group (6.10 per 100 person-years; aHR = 0.35; 95% CI 0.15–0.85, p=0.020). Within the ESUS-E group, cancer (aHR 5.33; 95% CI: 2.09–13.63; p < 0.001) and non-stenosing atherosclerotic disease or arch atheroma (aHR 3.40; 95% CI: 1.18–9.83; p = 0.023) were associated with significantly increased risk of recurrence when compared to ESUS 2.0. Conclusion: These findings demonstrate a lower risk of recurrent stroke in patients classified as ESUS 2.0, diverging from the 5–6% annual recurrence rates observed in prior ESUS trials. These findings suggest that patients who receive comprehensive diagnostic evaluation without identification of a specific etiology have a lower risk of recurrent stroke, an important consideration for the design of future ESUS studies.