The predictive role of systemic immune-inflammation index on futile recanalization in acute ischemic stroke with mechanical thrombectomy

Futile recanalization (FR) occurs in patients who achieve successful vessel recanalization but still have a poor prognosis. The aim of this study was to explore the association between systemic immune-inflammation index (SII) and futile recanalization following mechanical thrombectomy (MT) in acute ischemic stroke (AIS). We retrospectively analyzed patients with AIS due to large vessel occlusion in the anterior circulation who achieved successful recanalization after MT. The SII was calculated as platelet count × neutrophil count / lymphocyte count from preoperative peripheral venous blood. FR was defined as a modified Rankin Scale (mRS) score of ≥ 3 at 3 months despite successful recanalization. Binary logistic regression was performed to identify independent predictors of FR. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive value of identified factors for FR. We retrospectively analyzed 262 patients, with the median age of 70 (58.75 - 78.00) years old. The SII in the FR group was significantly higher than in the non-FR group. After eliminating confounding factors, binary logistic regression analysis indicated that SII was an independent influencing factor for FR (OR=1.999, 95% CI: 1.324 - 3.018, P < 0.001). The ROC curve suggests that SII can effectively predict adverse outcomes 3 months after MT [area under the curve (AUC) value: 0.687, p<0.001], and can help the comprehensive model better predict FR (AUC value: 0.807 versus 0.772). A high preoperative SII may be associated with FR in anterior circulation AIS patients with mechanical thrombectomy.