Safety and Efficacy of Thrombectomy in Vietnamese Stroke Patients Selected through Perfusion Imaging with an Onset Time between 6 and 24 Hours

Abstract

Introduction: Recent trials have demonstrated the remarkable benefit of endovascular treatment (EVT) up to 24 h 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 6-24-h window.

Methods: This is a prospective study of consecutive patients with anterior circulation LVO stroke who underwent EVT within 6-24 h 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 h (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. HIR is a robust indicator of collateral status and could made it a valuable addition to stroke imaging workup in clinical setting.

Keywords: 6–24 h; Acute ischemic stroke; Collaterals; Endovascular treatment of acute stroke; Hypoperfusion intensity ratio; Late window; Perfusion imaging.