Mechanical Thrombectomy 24 to 72 Hours after Large-Vessel Ischemic Stroke

Summary

LATE-MT randomized 336 patients in China with anterior-circulation large-vessel occlusion, imaging-identified salvageable tissue, and presentation 24 to 72 hours after onset or last-known-well to thrombectomy plus medical care or medical care alone. At a median 38.5 hours to randomization, thrombectomy improved the 90-day modified Rankin scale distribution (common OR for better functional outcome 1.74, 95% CI 1.19-2.55). Symptomatic intracranial hemorrhage occurred in 4.8% versus 0%, and 90-day case fatality was 6.0% versus 1.8%.

Why it matters

This is randomized evidence that selected patients with salvageable tissue may benefit from thrombectomy beyond the current 24-hour evidence window. It supports urgent thrombectomy-center discussion for carefully selected very-late presenters, but does not establish universal treatment beyond 24 hours.

Main findings

• Common OR for a better 90-day functional outcome was 1.74 (95% CI 1.19-2.55) with thrombectomy.
• Median time from onset or last-known-well to randomization was 38.5 hours.
• Symptomatic intracranial hemorrhage occurred in 4.8% with thrombectomy versus 0% with medical care alone.
• Ninety-day case fatality was 6.0% versus 1.8%, respectively.

Limitations

The trial was open-label, conducted at comprehensive stroke centers in China, and required favorable imaging selection. The higher symptomatic hemorrhage and mortality signals, plus uncertain external validity, warrant caution pending replication and guideline integration.