Stroke Severity and Early Ischemic Changes Predict Infarct Growth Rate and Clinical Outcomes in Patients With Large‐Vessel Occlusion

Background The infarct growth rate (IGR) measures ischemic stroke progression and varies among patients. Clinicoradiological phenotypes of IGR are poorly understood. We evaluated the association of presentation stroke severity and early ischemic changes with infarct progression in patients who underwent successful thrombectomy. Methods This is a retrospective cohort observational study of consecutive endovascular therapy patients with anterior circulation large‐vessel occlusion strokes and successful reperfusion (modified Thrombolysis in Cerebral Ischemia≥2b) from 2 comprehensive stroke centers. National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT [Computed Tomography] Score (ASPECTS) were scored at admission. IGR was defined as the final infarct volume after endovascular therapy divided by the time from stroke onset to successful reperfusion. We used the Youden J index to identify the optimal IGR cutoff to stratify fast and slow progressors. A multivariate logistic regression was used to identify variables associated with a fast IGR and clinical outcomes. Results A total of 212 patients were included in the study. The optimal IGR threshold was 3.2 mL/h, and 135 patients (63.6%) were classified as fast progressors. Presentation National Institutes of Health Stroke Scale score (odds ratio [OR], 1.12; 95% CI, 1.06–1.19) and ASPECTS (OR, 0.56; 95% CI, 0.41–0.73) were accurate predictors of a fast IGR after adjusting for significant confounders. For each 1‐point increase in National Institutes of Health Stroke Scale score at admission, the likelihood of being a fast progressor increased by 12%; for each 1‐point increase in ASPECTS, the likelihood of being a fast progressor decreased by 44%. In the early window (≤6 hours), all patients with ASPECTS