Successful thrombectomy is beneficial in patients with pre-stroke disability: Results from an international multicenter cohort study

Background: Patients with pre-stroke disability, defined as a modified Rankin Scale (mRS) >= 3, were excluded from most trials of endovascular thrombectomy (EVT) for acute stroke. We sought to evaluate the prognostic factors associated with favorable outcome in stroke patients with known disability undergoing EVT, and the impact of successful reperfusion. Methods: Consecutive acute stroke patients with pre-stroke disability, undergoing EVT, were retrospectively collected between 2016 to 2019 from a Canadian cohort and a multicenter French cohort (Endovascular Treatment in Ischemic Stroke registry-ETIS). Favorable outcome was defined as an mRS equal to pre-stroke mRS. Patients achieving successful reperfusion (defined as a modified Thrombolysis in Cerebral Infarction score of 2b/3) were compared with patients without successful reperfusion to determine if successful EVT was associated with better functional outcomes. Results: Among 6220 patients treated with EVT, 280 (4.5%) patients with a pre-stroke mRS >= 3 were included. Sixty-one patients (21.8%) had a favorable outcome and 146 (52.1%) died at 3 months. Patients with successful reperfusion had a higher proportion of favorable 90-day mRS (27.6% versus 19.6%, p = 0.025) and a lower mortality (48.3% versus 69.6%, p = 0.008) than patients without successful reperfusion. After adjusting for baseline prognostic factors, successful reperfusion defined by TICI >= 2b was associated with favorable functional outcome (OR 3.16 CI95% [1.11-11.5]; p 0.048). Conclusion: In patients with pre-stroke disability, successful reperfusion is associated with a greater proportion of favorable outcome and lower mortality.