Here we report a retrospective multicenter analysis on consecutive patients with minor AIS due to isolated occlusion of the M2 segment that received best medical management (BMM) only or that initially received BMM but were then subjected to rescue mechanical thrombectomy (rMT) following an early worsening of symptoms. Our primary purpose was to define predictors of clinical outcome. The secondary aim was to identify predictors of early neurological deterioration (END).

END is frequent in patients with AIS due to involvement of the M2 segment and represents the most important predictor of long-term poor outcome in such patients. In case of END, rMT represents a feasible treatment option that can improve the clinical outcome. Hence, the search of baseline features for the identification of patients that are at risk for END is relevant.

208 patients, admitted between 2016 and 2021, were collected. END was reported in 87 patients that were therefore all subjected to rMT. In a logistic regression model, END (OR 3.386, 95% CI 1.428-8.032), baseline NIHSS score (OR 1.362, 95% CI 1.004-1.848) and a pre-event mRS score=1 (OR 3.226, 95% CI 1.229- 8.465) were associated with unfavorable outcome. In patients with END, successful rMT was associated with favorable outcome (OR 4.549, 95% CI 1.098-18.851). Among baseline features, presence of atrial fibrillation was a predictor of END (OR 3.547, 95% CI 1.014-12.406).