Abstract TP14: Final Infarct Volume as an Early Indicator the Clinical Outcome: Insight from ESCAPE Trial

Background and Purpose: The goal of reperfusion therapy in acute ischemic stroke is to limit the extension of the ischemic core. The objectives of the present study were to assess the relationship between endovascular treatment and final infarct volume. Methods and Results: ESCAPE is a multicenter prospective randomized open-label trial with blinded outcome evaluation that enrolled 315 patients (endovascular treatment n=165; control n=150). Of these, 314 patient infarct volumes at 24 hours on CT or MRI were measured blinded to clinical data. Because infarct volumes were non-normally distributed, final infarct volumes were analysed by quartiles. Final infarct volumes were compared by treatment assignment and recanalization/reperfusion status measured by 2-8h CT angiogram in the control group and by formal angiography in the intervention arm. Results: Median final infarct volume among all study participants was 21 mL (IQR: 7 to 72). Median final infarct volume in endovascular treatment arm at 15.5 mL (IQR: 5 to 46.5) was significantly lower than median final infarct volume in control arm 33.5 mL (IQR: 11 to 95; P=0.0004). Small infarcts, defined as 1st quartile of infarct volumes were more common in the endovascular group compared to control (relative risk [RR] 1.5, CI95 1.02-2.3). Successful recanalization and reperfusion was highly associated with small infarcts (RR 2.2, CI95 1.4-3.4). The proportion of large hemispheric stroke (defined as an infarct volume in the 4th quartile) was much less frequent in the endovascular treatment arm (RR 0.6, CI95 0.3-0.8). Conclusions: This analysis supports the primary results of ESCAPE trial as endovascular treatment was associated with significantly smaller final infarct volumes. Recanalization/reperfusion was associated with smaller final infarct volume.