Background and purpose Endovascular therapy is associated with improved clinical outcomes in patients presenting with large vessel occlusions (LVO) however outcomes are typically worse in patients presenting as inter-facility transfers. A further understanding of the sources and impact of transfer delays is essential to improving outcomes in this population.

Methods Data were analyzed from consecutive acute ischemic stroke patients with proximal large vessel occlusions (LVO) transferred to our comprehensive stroke center for consideration of endovascular therapy. The following variables were studied: door-in-door-out time (DIDO), baseline NIHSS/mRS, initial CT ASPECT, site of LVO, treatment and clinical outcome.

Results 309 patients transferred from 14 referral hospitals to our CSC during the study period (January-December 2016). 61 (20%) had a proximal anterior LVO (53) or basilar artery occlusion (8). 40 (66%) underwent endovascular thrombectomy. 21 (34%) did not undergo endovascular thrombectomy – due to clinical improvement (33%), large core or poor ASPECTS (48%), high baseline disability (5%) and hemorrhagic transformation (5%). Median DIDO time in the endovascular thrombectomy group (98.5 minutes) was significantly better (p value=0.001) than the Median DIDO time in patients who did not get endovascular thrombectomy (185 minutes). The likelihood decreased by 0.5% for receiving endovascular therapy and 0.25% for good outcomes for every minute of DIDO.

Conclusions Shorter DIDO time is associated with higher likelihood of receiving endovascular therapy and good outcomes. DIDO may be used as a clinical performance metric for stroke referring hospitals.

Disclosures S. Desai: None. K. Shah: None. T. Jovin: None. A. Jadhav: None.