Abstract WP165: Clinical And Radiological Characteristics Of Exponential And Non-exponential Infarct Growth Patterns In Anterior Circulation Large Vessel Occlusion Stroke

Abstract

Introduction: Infarct evolution is a highly dynamic process that varies among individuals. This study aimed to identify clinical and radiological features associated with an exponential infarct growth rate (IGR) pattern in stroke patients with large vessel occlusion (LVO). Methods: This is a retrospective cohort study of anterior LVO stroke patients who underwent mechanical thrombectomy (MT) and achieved complete recanalization (mTICI 2c-3). Infarct volumes were calculated at two time points, pre-MT: CT perfusion (CTP) using Rapid software to estimate the CBF<30% volume; and post-MT: using DWI-MRI. Early IGR was defined as CBF<30% (ml) / Time from stroke onset to CTP (hours); and late IGR as [DWI-MRI - CBF<30%] (ml) / Time from CTP to reperfusion (hours). Exponential IGR pattern was established when late IGR was at least three times its respective early IGR. Patients who did not meet this criterion were considered to have a non-exponential IGR. Hypoperfusion intensity ratio 0.4 identified patients with poor collateral status. Good functional outcome was defined as 90-day modified Rankin scale (mRS) 0-2. Results: Of the 159 patients (median age 71 [6-82], 45% male, median NIHSS 14 [9-18]) included in the analysis, 91 (57%) patients had an exponential IGR pattern. These patients had higher CT ASPECTS (9[7-10] vs 8[7-9], p=0.038), higher glucose levels (126[114-150] vs 117[106-135], p=0.022), lower Tmax<6.0s (88[55-129] vs 113[81-173, p=0.014]), and higher rate of poor collaterals (31% vs 68%, p<0.001) when compared to patients with a non-exponential IGR pattern. Patients with exponential IGR pattern had lower rates of mTICI 3 (82% vs 96%, p=0.008) but no significant differences in mRS 0-2 at 90 days. Conclusions: Parameters associated with exponential infarct growth might help to stratify the most time sensitive vulnerable LVO population in which newer therapeutic and triage strategies should be prioritized. Fig. Infarct Growth Rate Plots and Collateral Status . A shows IGR with an exponential pattern . B shows IGR with a non-exponential pattern.