Safety and Efficacy of Thrombectomy in Vietnamese Stroke Patients Selected Through Perfusion Imaging With an Onset Time Between 6-24 Hours.

Abstract

Introduction Recent trials have demonstrated the remarkable benefit of endovascular treatment (EVT) up to 24 hour in patients with large vessel occlusion (LVO) and target mismatch profiles; however, benefits of late-window EVT in Vietnamese population remain poorly understood. This study aims to evaluate the real-world outcomes of EVT in acute ischemic stroke (AIS) patients selected using perfusion imaging within the 6- to 24-hour window. Methods A prospective study of consecutive patients with anterior circulation LVO stroke who underwent EVT within 6 to 24 hours after last known well between August 2022 and March 2024. Patients were selected based on the DAWN/DEFUSE-3 criteria (Perfusion-RAPID, iSchemaView). The primary outcome was the proportion of patients with functional independence at 90 days (modified Rankin Scale score of 0-2). The secondary outcomes were successful reperfusion defined by thrombolysis in cerebral infarction (TICI) ≥2b on the final procedure, and subgroup analysis between good (Hypoperfusion intensity ratio (HIR) <0.4) and poor collaterals (HIR ≥ 0.4) groups. Safety outcomes were mortality rate and symptomatic intracranial hemorrhage (sICH). Results Of 122 enrolled patients, 68% met inclusion criteria of DEFUSE-3 trial, 61% met DAWN trial criteria. Mean age was 66 years, median baseline NIHSS was 13, median time from stroke onset to hospital arrival was 12.55 hours (9.50 - 16.48), and median infarct volume was 11.5 mL. The rate of functional independence at 90 days was 45.9%. Successful reperfusion (TICI score of ≥2b) was achieved by 83.6% of cases. The 90-day mortality rate was 10.7%, sICH was reported in 8 patients (6.6%). Patients with good collaterals had better functional outcome. Conclusions This real-world observational study suggests that late window EVT may be safe and effective in eligible Vietnamese patients selected based on perfusion imaging, thus supporting its practical use in this patient population. Hypoperfusion intensity ratio is a robust indicator of collateral status and could made it a valuable addition to stroke imaging work-up in clinical setting.