Mechanical Thrombectomy in Prestroke Disability: Data from the Italian Endovascular Stroke Registry

BACKGROUND: The benefits and safety of mechanical thrombectomy (MT) in patients with prestroke disability, classified as modified Rankin Scale (mRS) score of 3 to 4, and anterior circulation stroke remain uncertain. This study aims to evaluate these factors using data from the Italian Registry of Endovascular Treatment in Acute Stroke. METHODS: We analyzed data collected between 2015 and 2021, comparing functional outcomes (mRS), symptomatic intracerebral hemorrhage, and recanalization rates (Thrombolysis in Cerebral Infarction) at 90 days post-MT in patients with prestroke mRS score of 3 to 4 versus 0 to 2. A good outcome was defined as no change in the mRS score from baseline. Subgroup analysis was stratified by age. RESULTS: A total of 11.411 (96%) patients with prestroke mRS score of 0 to 2 and 477 (4%) patients with prestroke mRS score of 3 to 4 were included. Compared with patients with a baseline mRS score 0 to 2, those with mRS score 3 to 4 were older (82 versus 75 years; P<0.001) and predominantly female (71.7% versus 53%; P<0.001). The maintenance of the same mRS score after MT was observed in 100 (23.3%) patients with prestroke mRS score 3 to 4, compared with 2332 (22.1%) patients with mRS score 0 to 2 (P=0.556). Mortality was significantly higher in the mRS score 3 to 4 group (n=159 [37.1%] versus n=1939 [18.4%]; P<0.001). Successful recanalization (Thrombolysis in Cerebral Infarction score ≥2b) was lower in the mRS score 3 to 4 group (n=333 [71.6%] versus n=8706 [77.7%]; P=0.002), while no significant differences in symptomatic intracerebral hemorrhage were found. The benefit of MT was maintained in patients aged 80 to 85 and over 85 years with prestroke mRS score 3 to 4, although mortality remained higher. CONCLUSIONS: Our data suggest that prestroke disability does not imply less chance of returning to prestroke conditions after MT, even in octogenarians, despite higher mortality and lower recanalization rate. More data are warranted to better understand the benefit of MT in this subgroup of patients.