Background and Purpose: Recent completion of the DAWN trial supports the benefit of endovascular therapy in patients presenting in the 6-24 hour time window with anterior circulation large vessel occlusions. The scope and impact of these results on clinical practice remain unknown.
Methods: A retrospective review of ischemic stroke admissions to a single comprehensive stroke center was performed during the enrollment period (November 2015-February 2017) to identify patients meeting criteria for DAWN eligibility. Patients presenting beyond 6 hours were further investigated to clarify reasons for trial exclusion.
Results: Of the 2667 acute ischemic stroke patients admitted within the study period, 30% (n=792) presented within the 6-24 hour time window and 33% (890) had an NIHSS of 10 or higher. Of the 11% (n=298) patients meeting both criteria, trial exclusion occurred due to: absence of large vessel occlusion (LVO) (48%,n=143), presence of sub-occlusive, distal or posterior circulation LVO (18%, n=54), large core infarct or ASPECT < 7 (25%, n=73) or absence of clinical core mismatch (5%, n=16), mRS >1 (13%, n=38). There were 45 patients who met all DAWN criteria.
Conclusions: Of all acute ischemic stroke patients presenting to a single CSC, 1.7% of patients qualified for DAWN clinical trial enrollment. Of patients with proximal anterior circulation occlusion presenting in the 6- 24 hour time window with NIHSS of 10 or higher, 29% were eligible for treatment based on DAWN criteria. These data predict an increase in thrombectomy utilization with important implications for Comprehensive Stroke Center resource utilization and stroke systems of care.