Abstract WP125: The Presence of a Ghost Infarct Core is Associated With Fast Core Growth in Acute Ischemic Stroke

Abstract

Introduction: The overestimation of ischemic core volume by computed tomography perfusion (CTP) is a critical concern in the selection of candidates for reperfusion therapy. This phenomenon is termed a ghost infarct core (GIC). Core growth rate has emerged as an indicator of ischemic severity. The aim of the present study was to elucidate the association between the presence of a GIC and the core growth rate. Methods: Consecutive patients with acute ischemic stroke due to large vessel occlusion who underwent mechanical thrombectomy in our institute from March 2017 to July 2022 were enrolled. The initial ischemic core was measured by pretreatment CTP, and the final infarct volume (FIV) was measured by diffusion-weighted imaging. A GIC was defined by initial ischemic core volume minus FIV >10 mL. The core growth rate was calculated by dividing the initial ischemic core volume by time from stroke onset to CTP acquisition. Univariable analysis and a multivariable logistic regression model were used to evaluate the association between GIC-positive and the core growth rate; complete recanalization, onset to imaging time, and imaging to recanalization time were included as covariates. Results: Ninety-one patients were included in the study. Of these, 21 patients (23.1%) were GIC-positive. The GIC-positive group had higher core growth rate (14.2 [2.6-46.7] vs 4.8 [1.6-17.1] mL/h, p=0.021) and complete recanalization (n=15 (71.4%) vs 29 (41.4%), p=0.016) compared to the GIC-negative group. On receiver operating characteristic curve analysis, the optimal cutoff point of the core growth rate to predict GIC-positive was 22 mL/h (sensitivity, 0.48; specificity, 0.85; area under the curve, 0.67). Multivariable logistic regression analysis showed that core growth rate ≥22 mL/h (OR 6.44, 95% CI [1.59-26.10], p=0.006) and complete recanalization (OR 3.72, 95% CI [1.14-12.08], p=0.022) were independent predictors of GIC-positive. Conclusions: A GIC was associated with fast core growth in acute ischemic stroke. Overestimation of the initial ischemic core may be determined by core growth speed, not a clock time.