Abstract 166: Clinical Outcome Strongly Associated with the Degree of Endovascular Reperfusion Achieved in Target Mismatch

Abstract

Background and Purpose: The aim of this study was to investigate the relationship between the degree of early reperfusion achieved following endovascular therapy and clinical outcomes. We hypothesized that this relationship would differ in Target mismatch (TMM) vs. No Target mismatch (No TMM) patients. Methods: This is a DEFUSE 2 substudy. The volume of hypoperfusion on PWI (Tmax >6 sec) was assessed before and within 12 hours after endovascular therapy. The degree of reperfusion was defined as the relative difference between the baseline and the follow-up PWI lesion volumes. Patients were grouped into quartiles according to the degree of reperfusion that they achieved. We assessed the association between the degree of reperfusion and clinical outcomes in patients with and without Target Mismatch. Favorable clinical response (FCR) was defined as an improvement in the NIHSS of 8 or more points between baseline and day 30 or an NIHSS score <1 at day 30. Good functional outcome (GFO) was defined as a modified Rankin Scale <2 at day 90. Results: Out of 104 patients enrolled, 87 had interpretable perfusion images at baseline and follow-up PWI. Of these, 69 had TMM. The median degree of reperfusion did not differ in TMM patients (69%) vs. No TMM patients (57%) (p=0.22). The degree of reperfusion correlated with FCR (p<0.001) and GFO (p<0.05) in TMM patients (see figure) but not in the No TMM patients. The rate of FCR was significantly higher in TMM patients who achieved complete reperfusion vs. incomplete reperfusion (94% vs. 46%, OR 18.7; 95% CI 2.3-151.3). Similarly, TMM patients who achieved complete reperfusion had a high rate of GFO (76% vs. 42%, OR 4.4; 95% CI 1.3-15.4). Conclusion: The degree of reperfusion documented on PWI following endovascular therapy corresponds closely with the rate of favorable clinical outcomes in TMM patients; there was no association in No TMM.