Background and purpose The DAWN and DEFUSE-3 trials demonstrated the benefit of endovascular thrombectomy (ET) in late-presenting acute ischemic strokes due to anterior circulation large vessel occlusion (ACLVO). Strict criteria were employed for patient selection. We sought to evaluate the characteristics and outcomes of patients treated outside these trials.

Methods A retrospective review of acute ischemic stroke admissions to a single comprehensive stroke center was performed during the DAWN trial enrollment period (November 2014 to February 2017) to identify all patients presenting in the 6–24 hour time window. These patients were further investigated for trial eligibility, baseline characteristics, treatment, and outcomes.

Results Approximately 70% (n=142) of the 204 patients presenting 6–24 hours after last known well with NIH Stroke Scale score ≥6 and harboring an ACLVO are DAWN and/or DEFUSE-3 ineligible, most commonly due to large infarct burden (38%). 26% (n=37) of trial ineligible patients with large vessel occlusion strokes received off-label ET and 30% of them achieved functional independence (modified Rankin Scale 0–2) at 90 days. Rates of symptomatic intracranial hemorrhage and mortality were 8% and 24%, respectively

Conclusion Trial ineligible patients with large vessel occlusion strokes receiving off-label ET achieved outcomes comparable to DAWN and DEFUSE-3 eligible patients. Patients aged <80 years are most likely to benefit from ET in this subgroup. These data indicate a larger population of patients who can potentially benefit from ET in the expanded time window if more permissive criteria are applied.