Introduction: Mechanical thrombectomy (MT) is the first line treatment in acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Approximately half of patients treated with MT does not have a favorable outcome 3 months after stroke. The aim of this study was to identify predictors of futile recanalization (FR) in patients with LVO treated with MT. Methods: A retrospective analysis of consecutive patients with acute ischemic stroke due to anterior circulation LVO who underwent MT. Patients with a TICI score of 2b or 3 were included. We distinguished two groups, FR and meaningful recanalization (MR), according to patients' disability three months after stroke (FR: mRS score > 2; MR: mRS score < 2). Results: We enrolled 238 patients (FR, n = 129, 54.2%; MR, n = 109, 45.8%). Age (OR 1.05, 95% CI 1.01–1.09, p = 0.012), female sex (OR 2.43, 95% CI 1.12–5.30, p = 0.025), stress hyperglycemia, as measured by the GAR index, (OR 1.17, 95% CI 1.06–1.29, p = 0.002), NIHSS at admission (OR 1.15, 95% CI 1.07–1.25, p = 0.001) and time from symptoms onset to MT (OR 1.01, 95% CI 1.00–1.01, p = 0.020) were independent predictors of FR. The AUC for the model combining age, female sex, GAR index, NIHSS at admission and time from symptoms onset to MT was 0.81 (95% CI 0.76–0.87; p < 0.001). The optimal GAR index cut-off score to predict FR was 17.9. Discussion: FR is common after MT. We recognized older age, female sex and baseline NIHSS as non-modifiable predictors of FR. On the other hand, time from symptoms onset to MT and stress hyperglycemia were modifiable pre- and post-MT factors, respectively. Any effort should be encouraged to reduce the impact of these modifiable predictors.
