The efficacy of mechanical thrombectomy (MT) from 6 to 24 hours after the onset of ischemic stroke was recently established with landmark DAWN trial. 

We retrospectively reviewed our hospital stroke registry from January 2014 to July 2018. Patients with occlusion of the intracranial internal carotid artery or proximal middle cerebral artery who were last seen normal 6 to 24 hours earlier, and who had a clinical to radiographic mismatch defined according to age (<80 or ≥80 years) were included. All pre-specified DAWN trial criteria for inclusion and exclusion were followed. These patients were divided in two groups: PreDAWN era (Group A - Jan 2014 to May 2017) and Post DAWN era (Group B- June 2017-July 2018). GraphPad Quick Calcs Web site was used to obtain descriptive statistics and intergroup differences.

Total of 2423 patients with ischemic strokes were studied; 262 patients underwent MT. Out of these, 77 (29.3%) patients (males 36, Mean age 72 years) met the DAWN study criteria. Fifty patients were in Group A and 27 patients in Group B. Early NIHSS improvement of ≥ 10 points as specified in the DAWN trial was seen in 24% (Group A; 12/50) versus 45 % (Group B; 12/27). While good outcomes at 90-days were not statistically different; poor outcomes were statistically significant: 20% (Group A; 10/50) versus 10% (Group B; 3/27)(p<0.05). Rates of complications or Symptomatic intracranial hemorrhage were similar to DAWN trial (6.4% (n=5), p=ns).

DAWN results and subsequent improvements in protocols resulted in improved outcomes of MT in ischemic stroke patients presenting between 6-24 hours of last known well.  Multicenter registries are required to corroborate our findings.