BACKGROUND: Repeat imaging after interhospital transfer for endovascular treatment (EVT) remains controversial because EVT eligibility may change during transfer, whereas routine repeat imaging may delay reperfusion. We investigated factors associated with complete recanalization and extensive infarct progression, and their implications for post-transfer reassessment.

METHODS: We retrospectively analyzed 200 consecutive patients with anterior circulation large vessel occlusion transferred for EVT between 2016 and 2020 who underwent repeat non-contrast CT, CT angiography, and serial neurological assessment. Primary outcomes were complete recanalization on repeat CT angiography and extensive infarct progression (ASPECTS 0-3) precluding EVT. Factors associated with both outcomes were evaluated using multivariable Firth penalized logistic regression.

RESULTS: Changes affecting EVT eligibility occurred in 19 patients (9.5%), including complete recanalization in 10 (5.0%) and extensive infarct progression in 9 (4.5%). Intravenous thrombolysis was associated with complete recanalization (OR 4.87, 95% CI 1.08-46.25; P = 0.039), while greater neurological improvement showed a consistent direction of association (OR 1.09, 95% CI 1.00-1.18; P = 0.059). Greater neurological deterioration (OR 0.83, 95% CI 0.70-0.97; P = 0.018) and lower baseline CTA source-image ASPECTS (OR 0.55, 95% CI 0.34-0.79; P = 0.001) were associated with extensive infarct progression.

CONCLUSIONS: Approximately one in ten transferred patients experienced clinically meaningful changes affecting EVT eligibility. Neurological reassessment combined with baseline CTA source-image ASPECTS may help identify patients most likely to benefit from repeat imaging and supports a selective rather than routine repeat imaging strategy after interhospital transfer.