Trial of Endovascular Therapy for Mild Stroke with Large-Vessel Occlusion

Summary

MILD-MT randomized 304 patients in China with anterior-circulation large-vessel occlusion, NIHSS less than 6, a small infarct core, and substantial perfusion mismatch within 24 hours to thrombectomy plus medical management or medical management alone; 300 were included in the modified intention-to-treat analysis. Excellent 90-day outcome (mRS 0-1) occurred in 69.4% versus 50.0% (OR 2.32, 95% CI 1.41-3.81; P<0.001). Symptomatic intracranial hemorrhage occurred in 3 patients in each group, while serious procedure-related complications occurred in 19 of 144 thrombectomy patients (13.2%).

Why it matters

The trial challenges a default medical-management approach for mild-deficit LVO when perfusion imaging shows substantial tissue at risk. For a highly selected patient with mild symptoms and LVO, early thrombectomy-center consultation is more defensible, but these data do not support indiscriminate EVT for every low-NIHSS LVO.

Main findings

• mRS 0-1 at 90 days occurred in 69.4% with thrombectomy versus 50.0% with medical management alone (OR 2.32, 95% CI 1.41-3.81; P<0.001).
• Symptomatic intracranial hemorrhage within 48 hours occurred in 3 patients in each group.
• Serious procedure-related complications occurred in 19 of 144 thrombectomy patients (13.2%).
• One death occurred among all participants, in the thrombectomy group.

Limitations

The study was open-label, conducted in China, and selected patients using small-core and large-perfusion-mismatch imaging criteria. Serious procedure-related complications occurred in 13.2%, and applicability outside the studied population remains uncertain.