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Evevident
Original paper
2018NEJMNeurology

DAWN

Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct

RCTStroke thrombectomy

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Overview

In selected LVO stroke patients 6-24 hours from last known well, thrombectomy improved functional independence when clinical-core mismatch was present.

Clinical takeaway

DAWN extended thrombectomy beyond rigid clock windows for carefully selected patients with salvageable brain tissue.

Key result

Functional independence at 90 days was 49% with thrombectomy vs 13% with standard care.

Practice impact

Supports thrombectomy evaluation for selected wake-up/late-presenting LVO strokes.

Evidence

Study design

Randomized, open-label, blinded-endpoint (Bayesian adaptive) trial.

Enrollment

206

Follow-up

90 days.

Geography

Multinational

Clinical question

Does late-window thrombectomy improve outcomes in LVO stroke with clinical-imaging mismatch?

Population

  • Patients with anterior-circulation LVO 6-24 hours from last known well and mismatch between clinical deficit and infarct volume on CT/MR perfusion.

Intervention

Mechanical thrombectomy plus standard care.

Comparator

Standard care alone.

Primary outcome

Utility-weighted mRS at 90 days and functional independence (mRS 0-2) at 90 days.

Late-window thrombectomy in patients with clinical-core mismatch nearly quadrupled the rate of functional independence at 90 days (49% vs 13%).

Absolute difference / 33 / CI 95% CI 24-44 percentage points / p=>0.999 posterior probability of superiority

Key results

  • Functional independence (mRS 0-2) at 90 days: 49% with thrombectomy vs 13% with control (adjusted difference 33 percentage points; 95% CI 24-44).
  • Mean utility-weighted mRS: 5.5 with thrombectomy vs 3.4 with control (adjusted difference 2.0; 95% credible interval 1.1-3.0).
  • The trial was stopped early for efficacy at a prespecified interim analysis.
  • Selection required a small infarct core relative to the size of the clinical deficit.

Harms

  • Symptomatic intracranial hemorrhage did not differ significantly (6% thrombectomy vs 3% control).
  • 90-day mortality was similar between groups (19% vs 18%).

Clinical Use

When to cite

  • When evaluating late-presenting large-vessel ischemic stroke and using imaging mismatch to select patients for thrombectomy.

Practice impact

  • Supports thrombectomy evaluation for selected wake-up/late-presenting LVO strokes.

Applicability

  • Most applicable to patients with anterior-circulation large-vessel occlusion 6-24 hours from last known well who have a clinical-core mismatch on advanced imaging.

Limitations

  • Highly selected patients using strict clinical-imaging mismatch criteria; results do not apply to unselected late presenters.
  • Requires advanced perfusion imaging and rapid systems of care.
  • Modest sample size, stopped early for efficacy, which can overestimate effect.

Common misinterpretations

  • DAWN does not mean every late-presenting stroke should undergo thrombectomy; benefit depends on demonstrating a small core with a large deficit.
  • The companion trial DEFUSE 3 extended the window to 16 hours using a perfusion-based mismatch, complementing DAWN.

Related evidence

DEFUSE 3 - Similar QuestionMR CLEAN - Earlier Trial

Citation

Nogueira RG, Jadhav AP, Haussen DC, et al. Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct. N Engl J Med. 2018;378(1):11-21. doi:10.1056/NEJMoa1706442

Among patients with acute stroke who had last been known to be well 6 to 24 hours earlier and who had a mismatch between the severity of the clinical deficit and the infarct volume, outcomes for disability at 90 days were better with thrombectomy plus standard care than with standard care alone.