Trials Support Thrombectomy in Very Late Time Windows, Milder Strokes

Why It Matters

The findings support expanding thrombectomy indications beyond the traditional 24‑hour window and into milder stroke presentations, prompting potential guideline revisions and altering clinical decision‑making.

Key Takeaways

• LATE‑MT shows functional gain up to 72 hours after stroke onset
• Thrombectomy increased recanalization to 82% but raised hemorrhage risk
• MILD‑MT achieved 69% excellent outcomes versus 50% with medical care
• Mild‑stroke patients benefit from early thrombectomy, reducing deterioration

Pulse Analysis

The evolution of endovascular therapy for large‑vessel occlusion strokes has accelerated over the past decade, moving from a strict six‑hour window to the landmark DAWN and DEFUSE 3 trials that extended eligibility to 24 hours based on perfusion imaging. The newly reported LATE‑MT trial pushes this boundary even further, enrolling patients 24‑72 hours after onset who still exhibit a favorable mismatch profile. By randomizing 336 participants, the study confirmed a 53% odds reduction in poor functional outcomes, yet it also highlighted a trade‑off: mortality and any intracerebral hemorrhage rose modestly, emphasizing the need for meticulous patient selection.

In the late‑window cohort, recanalization rates surged to over 80% compared with 18% in the control arm, translating into measurable gains in quality‑of‑life scores and daily‑living independence. However, the safety signal—particularly the increase in symptomatic hemorrhage—reinforces that late‑window thrombectomy is not universally benign. Clinicians must weigh the potential for disability reduction against heightened procedural risk, especially in older or frailer patients. Advanced CT or MR perfusion metrics remain the cornerstone for identifying “slow progressors” whose penumbra persists despite elapsed time.

The MILD‑MT trial addresses a different gap: the management of patients with low NIHSS scores who traditionally receive conservative therapy. Among 300 randomized subjects, thrombectomy boosted the proportion achieving a modified Rankin Scale of 0‑1 at 90 days from 50% to nearly 70%, without a rise in symptomatic hemorrhage. This evidence validates a more aggressive stance toward mild‑stroke LVOs, suggesting that early reperfusion can preempt neurological decline. As these data permeate practice, stroke networks are likely to revise protocols, incorporate broader imaging criteria, and potentially update guideline recommendations, ultimately expanding access to life‑changing interventions for a larger patient population.