Predictors and a Nomogram for Parenchymal Hematoma After Endovascular Thrombectomy in Large Core Ischemic Stroke.

OBJECTIVE: We sought to establish a nomogram with internal validation to predict parenchymal hematoma (PH) following endovascular thrombectomy (EVT) in patients with large core infarcts. METHODS: We retrospectively enrolled 133 consecutive patients with large core anterior circulation infarctions receiving EVT from March 2018 to December 2024. Following univariable analysis (p < 0.1), LASSO and multivariable logistic regression were utilized to investigate predictive factors and establish a PH prediction nomogram. Model performance was assessed via ROC, calibration, decision, and clinical impact curves, with 1000-bootstrap internal validation. Subgroup analyses were stratified by age, baseline ASPECTS, and prior intravenous thrombolysis (IVT). RESULTS: PH occurred in 26 patients (19.5%). Baseline NIHSS score (OR 1.109, 95% CI 1.017-1.221; p = 0.023), monocytes (OR 0.002, 95% CI 9.74 × 10-6-0.174; p = 0.012), platelets (OR 0.989, 95% CI 0.978-0.998; p = 0.028), post-thrombectomy fasting blood glucose (FBG) (OR 1.326, 95% CI 1.121-1.616; p = 0.002), and number of passes (OR 2.312, 95% CI 1.443-3.990; p = 0.001) were significantly associated with PH and incorporated to construct the nomogram. The model showed good discrimination (AUC = 0.876; adjusted AUC = 0.844) and acceptable calibration (Hosmer-Lemeshow p = 0.928; adjusted Brier score = 0.128). Subgroup analyses indicated a significant interaction between number of passes and IVT (P for interaction = 0.020): increased passes elevated PH risk only in patients without bridging IVT (OR 2.055, 95% CI 1.318-3.204; p = 0.001). CONCLUSIONS: This nomogram provides a robust tool for predicting post-thrombectomy PH in large core infarctions. The interaction between IVT and the number of passes potentially indicates minimizing unnecessary passes in direct thrombectomy. Multicenter prospective validation is warranted.