Impact Of Performing Vascular Imaging At Local Stroke Centers On Functional Outcome In The Drip And Ship Model. A Racecat Sub-study

Background: Although recommended, impact of vascular imaging performed to determine a large vessel occlusion (LVO) at local stroke centers on functional outcome in the drip and ship model is uncertain. Our aim was to compare functional outcomes in patients with (VI+) and without (VI-) vascular imaging at local stroke center using data from the RACECAT trial. Methods: RACECAT study was a multicenter, cluster-randomized trial that compared drip-n-ship vs. mother-ship models in acute stroke patients with LVO suspicion based on the prehospital RACE scale, performed in the period of March 2017 to Juny 2020. Patients allocated to Local-center arm, were included in this substudy to evaluate the impact of performing VI (CT-Angiography) at Local-center on functional outcome at 3 months assessed by modified Rankin scale (mRS) Results: From 690 patients, ischemic stroke or transient ischemic attack was diagnosed in 467. Among these, a vascular imaging was performed at the Local-center in 55.6% (n:260), of which an LVO was confirmed in 76.1% (n:198). No differences in baseline characteristics were observed between VI+ and VI- groups. The rate iv-tPA treatment at Local-centers was higher in VI+ (67.8% vs. 54.2%; p=0.004) with shorter door-to-needle times time (VI+: 31 (24-44) Vs VI-: 39 (27-56) minutes, p=0.003). The rate of patients receiving endovascular treatment at the comprehensive center was similar (VI+: 41.9% Vs VI-:39.4%; p=0.602), however VI+ patients presented shorter time from EVT-center arrival to groin-puncture (VI+: 37 (26-48) Vs VI-:52 (42-70) minutes; p<0.001). Overall, the time from symptom onset to groin puncture was not significantly different between both groups (VI+:279 (228-355) Vs VI-: 233 (214-327) minutes; p=0.068). The common odds ratio for a better distribution of scores on the mRS at 3 months was 1.48 (95% confidence interval [CI], 1.059 to 2.068; P=0.022), favoring the VI+ group. Conclusion: Initial evaluation in a local stroke center capable to efficiently perform vascular imaging might be associated with better long term functional outcome in stroke patients with high suspicion of LVO. Whether this association is related to vascular imaging acquisition or a better performance of centers in which it is acquired should be further evaluated.