Vascular Occlusion Evolution in Endovascular Reperfusion Candidates Transferred from Primary to Comprehensive Stroke Centers.

BACKGROUND: The evolution of the symptomatic intracranial occlusion during transfers from primary stroke centers (PSCs) to comprehensive stroke centers (CSCs) for endovascular treatment (EVT) is not widely known. Our aim was to identify factors related to partial or complete recanalization (REC) at CSC arrival in patients with a documented large vessel occlusion (LVO) in PSC transferred for EVT evaluation to better define the workflow at CSC of this group of patients. METHODS: We conducted an observational, multicenter study from a prospective, government-mandated, population-based registry of stroke patients with documented LVO at PSC transferred to CSC for EVT from January 2017 to June 2019. The primary end point was defined as partial or complete REC that precluded EVT at CSC arrival (REC). We evaluated the association between baseline, treatment variables and time intervals with the presence of REC. RESULTS: From 589 patients, the rate of REC at CSC was 10.5% in all LVO patients transferred from PSC to CSC for EVT evaluation. On univariate analysis, lower PSC-NIHSS (median 12vs.16, p = 0.001), tPA treatment at PSC (13.7 vs. 5.0%; p = 0.001), presence of M2 occlusion on PSC (16.8 vs. 9%; p = 0.023), and clinical improvement at CSC arrival (21.7 vs. 9.6% p = 0.001) were associated with REC at CSC. On multivariate analysis, clinical improvement at CSC arrival (p < 0.001, OR: 5.96 95% CI: 2.5-13.9) and PSC tPA treatment predicted REC (p = 0.003, OR: 4.65, 95% CI: 1.73-12.4). CONCLUSION: REC at CSC arrival occurs exceptionally in patients with a documented LVO on PSC. Repeating a second vascular study before EVT would not be necessary in most patients. Despite its modest effect, tPA treatment at PSC was an independent predictor of REC.