Risk factors and predictive model for futile recanalization after mechanical thrombectomy in patients with acute ischemic stroke: A multicenter retrospective study

ObjectiveTo identify risk factors for futile recanalization after mechanical thrombectomy in patients with acute ischemic stroke and develop an interpretable nomogram for risk stratification.MethodsThis multicenter retrospective study included 350 patients with acute ischemic stroke who underwent mechanical thrombectomy. A development cohort consisting of 260 patients was derived from two centers, and an external validation cohort comprising 90 patients was obtained from an independent center. Futile recanalization was defined as a 90-day modified Rankin Scale score >2 despite successful recanalization. Clinical, imaging, and perioperative variables were collected. The development cohort was randomly divided into training and test cohorts in a 7:3 ratio. Least absolute shrinkage and selection operator regression and multivariable logistic regression were used to identify independent predictors, and a nomogram was developed. Model performance was evaluated using receiver operating characteristic analysis, calibration assessment including calibration curve, calibration slope, calibration intercept, and Brier score, and decision curve analysis. External validation was performed to evaluate model generalizability.ResultsOf 350 included patients, 152 (43.43%) experienced futile recanalization. Higher baseline National Institutes of Health Stroke Scale score, lower Alberta Stroke Program Early CT Score, elevated admission blood glucose levels, poor collateral circulation, and longer onset-to-recanalization time were identified as independent predictors of futile recanalization. The nomogram demonstrated acceptable discriminative ability, with area under the receiver operating characteristic curve values of 0.84 (95% confidence interval: 0.78-0.84), 0.86 (95% confidence interval: 0.78-0.86), and 0.8 (95% confidence interval: 0.7-0.8) in the training, test, and external validation cohorts, respectively. Calibration was satisfactory, and decision curve analysis indicated potential clinical utility.ConclusionsThis multicenter retrospective study developed a nomogram with acceptable discriminative ability, satisfactory calibration, and potential clinical utility for predicting futile recanalization after mechanical thrombectomy in acute ischemic stroke. The model may support perioperative risk stratification and individualized management; however, further validation in larger prospective cohorts is warranted.