DAWN: another brand new day

The publication of the DAWN (DWI or CTP Assessment with Clinical Mismatch in the Triage of Wake-up and Late Presenting Strokes Undergoing Neurointervention with Trevo) trial is yet another milestone in the endovascular management of acute stroke.1 DAWN extends the application of mechanical thrombolysis (MT) beyond previously established time frames and builds upon the positive results of earlier, randomized controlled trials that demonstrated the clear superiority of MT in the treatment of emergency large vessel occlusion (ELVO).2–6 Specifically, the study evaluated outcomes at 90 days in ELVO patients with neurological deficits that were disproportionately severe in comparison to their infarct volumes as assessed by diffusion-weighted MRI or perfusion CT. Patients were last known well 6 to 24 hours before presentation. The efficacy of MT plus standard medical care was compared with standard medical care alone. The trial was halted at 31 months when a pre-specified interim analysis determined that patients in the thrombectomy group had a higher likelihood of functional independence (49% vs 13% at 90 days) and higher scores on the utility-weighted modified Rankin scale (5.5 vs 3.4 at 90 days). These results demonstrated a clear benefit for MT in ELVO patients presenting beyond previously established time windows, including the large group of patients with ‘wake up’ strokes. Enrollment in the trial was …