Ro, Jennifer

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.

Background: Multiple randomized clinical trials failed to show benefit of anticoagulation over antiplatelets in the secondary prevention for embolic stroke of undetermined source (ESUS). However, the benefit of combination antithrombotic regimens remains unexplored in the same patient population. Methods: This is a subgroup analysis of a multicenter retrospective observational cohort of consecutive adult patients with ESUS (n=27 sites, 2015-2024). Comparisons were made between patients treated with single (SAPT) or dual antiplatelet therapy (DAPT), exclusive anticoagulation (AC) (direct oral anticoagulant, vitamin K antagonist, low molecular weight heparin) and combination anticoagulation and antiplatelet therapy initiated within the first 7 days of index stroke. The primary composite outcome of recurrent ischemic stroke, major bleeding, or death was assessed using unadjusted and adjusted Cox proportional hazards regression. Secondary outcomes were individual outcomes of recurrent ischemic stroke, major bleeding, or death. Results: Of the 2201 included patients, 1456 (66.1%) were on SAPT, 527 (23.9%) were on DAPT, 195 (8.8%) were on exclusive AC and 23 (1.0%) were on AC+AP (all of which were on DAPT). Patients treated with AC+AP were older (median 66 years [IQR 51-78]), more likely to have history of hypertension, stroke, hyperlipidemia, PFO and left atrial enlargement. Compared to SAPT, all treatment strategies were associated with similar risk of the primary outcomes in the unadjusted and adjusted cox regression. Similarly, there was no difference in individual outcomes including recurrent stroke, major bleeding and death in the adjusted cox regression. However, there was an increased risk of major bleeding with AC+AP in the unadjusted cox regression (HR 4.0, [95% CI 1.2-12.8], p=0.02) but not in the adjusted model when compared to SAPT. Also, DAPT was associated with lower risk of death than SAPT in the unadjusted model (HR 0.61 [95% CI 0.4-0.8],p=0.005) but not the adjusted model. Additionally, when adjusted by the HASBLED score, there was no difference in major bleeding when AC+AP was compared to SAPT. Conclusion: Over 90% of ESUS patients in this cohort were prescribed SAPT or DAPT. Antithrombotic therapy with DAPT, exclusive AC, or AC+AP was not associated with any lower risk of recurrent ischemic stroke, major bleeding and death compared with SAPT in an unselected cohort of ESUS patients.

Background: It is known that there are discrepancies between insurance status and access to care for a variety of health conditions. In addition, differences have been shown in initial in-hospital management of stroke as well as outcomes in the acute setting. We sought to examine the relationship between insurance status and risk of recurrent stroke, major bleeding or death following an incident cryptogenic stroke. Methods: Patients with cryptogenic stroke included in a multicenter (n=27 sites) retrospective observational cohort and complete insurance status were evaluated for a primary composite outcome of recurrent stroke, major bleeding, or death. Insurance providers were categorized by Private/Veterans Administration, Medicare, Other, and Medicaid/pending/None, with the primary carrier ranked in that order when multiple insurance carriers applied. Descriptive statistics and an adjusted Cox proportional hazards regression were used to associate the primary insurance provider with the composite outcome, and with each unique secondary outcome, adjusting for age, stroke severity, pre-stroke disability, atherosclerotic risk factors, and potential embolic sources (e.g., patent foramen ovale). Results: Of the 2201 patients, 2006 (91.1%) had reported insurance information and were followed for a median of 1.50 years (interquartile range [IQR 0.41 - 2.99y]). The majority of patients were primary Medicare beneficiaries (42.3%), followed by private insurance (36.7%), Medicaid/none (18.1%) and Other (2.9%). Although there were important differences in demographic and neurodiagnostic results across insurance groups, compared to Private/VA beneficiaries, beneficiaries for Medicaid/pending/none had a higher rate of the composite outcome in adjusted regression (adjusted hazard ratio [HR] 1.35, 95% confidence interval [CI], 1.07-1.69) which was driven largely by the higher rate of recurrent stroke (adjusted HR 1.33, 95%CI, 1.02-1.73) with no significant difference in rate of major bleeding or death (p>0.05 for both). Conclusions: Independent of age, race, pre-existing disability, and atherosclerotic risk factors, insurance status was independently predictive of recurrent stroke in this diverse cohort of cryptogenic stroke.