Patients with single distal MCA perfusion lesions have a high rate of good outcome with or without reperfusion

Background Reperfusion is associated with good functional outcome after stroke. However, minimal data are available regarding the effect of reperfusion on clinical outcome and infarct growth in patients with distal MCA branch occlusions. Aim The aim of this study was to evaluate this association and to determine the impact of the perfusion-diffusion mismatch. Methods Individual patient data from three stroke studies (EPITHET, DEFUSE and DEFUSE 2) with baseline MRI profiles and reperfusion status were pooled. Patients were included if they had a single cortical perfusion lesion on their baseline MRI that was consistent with a distal MCA branch occlusion. Good functional outcome was defined as a score of 0-2 on the modified Rankin Scale at day 90 and infarct growth was defined as change in lesion volume between the baseline DWI and the final T2/FLAIR. Results Thirty patients met inclusion criteria. Eighteen (60%) had a good functional outcome and twenty (67%) had reperfusion. Reperfusion was not associated with good functional outcome in the overall cohort (OR: 1.0, 95% CI 0.2-4.7) and also not in the subset of patients with a PWI-DWI mismatch (n=1.7; OR: 0.7, 95% CI 0.1-5.5). Median infarct growth was modest and not significantly different between patients with (0 ml) and without reperfusion (6 ml); P=0.2. Conclusions The overall high rate of good outcomes in patients with distal MCA perfusion lesions might obscure a potential benefit from reperfusion in this population. A larger pooled analysis evaluating the effect of reperfusion in patients with distal MCA branch occlusions is warranted as confirmation of our results could have implications for the design of future stroke trials.