Introduction Randomized trials provided evidence that thrombectomy is beneficial in stroke patients treated in the late time window (LTW), however, further insights of this subgroup remain limited.

Aim of Study To investigate effects of etiology on outcomes in stroke patients treated with thrombectomy in the extended time window.

Methods Available data of patients enrolled in the German Stroke Registry treated with thrombectomy for anterior circulation stroke in the LTW were included. Baseline characteristics, procedural, clinical outcome parameter, and complications were analyzed regarding stroke etiology and time window.

Results We observed a significant shift in etiology distributions in the early (n=8607) and LTW (n=616) with higher rates of cardioembolic (CE) strokes (CE, 51.8%, 4459; LAA, 22.7%, 1958) in the early time window towards an increase of large-artery atherosclerosis (LAA) strokes (CE, 40.7%, 251; LAA, 36%, 222) in the LTW. After adjustment, there was no significant effect of LAA on favorable functional outcomes (aOR, 1.18, 95% CI 0.64-2.1; p=0.596) but LAA was associated with lower odds for mortality (aOR, 0.48, 95% CI 0.26-0.89; p=0.672), and first-pass effect (aOR, 0.42, 95% CI 0.25-0.70; p=0.001). Rates of sICH were similar in both cohorts (LAA, 4.2% vs. CE, 4.7%; p=0.829)

Conclusion The distributions of etiology shifted from the early to LTW resulting in a significant increase of LAA rates. Adjusted analysis revealed that higher odds for favorable functional outcomes and lower mortality were observed in this subgroup, although successful thrombectomy and first-pass reperfusion was less likely in LAA strokes compared to CE strokes in LTW.

Disclosure of Interest no.