Abstract TMP70: Relevance Of Persistent Perfusion Deficits On Clinical Outcome After Sucessful Endovascular Treatment

Abstract

Introduction: After achieving successful reperfusion some acute stroke patients still exhibit persistent perfusion deficits. These deficits have been defined in a heterogeneous manner by using CBF, CBV or Tmax maps as a perfusion deficit in the previous ischemic penumbra (impaired microcirculation perfusion-IMP) or inside the infarcted tissue (no reflow-NR). The significance, frequency and pathophysiology of this phenomenon are so far unknown. Methods: Prospective cohort of patients with isolated anterior intracranial occlusion undergoing endovascular treatment (EVT) and achieving complete recanalization (final mTICI≥2B). Brain MRI was performed on arrival (pre-EVT) and &lt2h after EVT (post-EVT). Infarcted tissue was segmented on DWI pre-EVT. Pre and post-EVT perfusion maps were obtained with Olea software. NR was defined in the post-EVT perfusion maps as the region inside the infarcted tissue which showed a CBV&lt15% compared to the contralateral side, while IMP was the equivalent area inside the previous tissue in penumbra. We evaluated the association between both NR and IMP and NIHSS at 24h, NIHSS at discharge and modified Rankin score (mRS) at three months adjusting by baseline NIHSS and final mTICI. Results: Thirty-five patients were included. All of them had IMP areas and 25 (71%) had NR areas. The median volume of NR and IMP was 3.43ml [IQR 1.43-8.81], corresponding to 17.9% of the infarcted tissue [IQR 4.2-50.3] and 33.9ml [IQR 14.0-69.3] (27.7% [IQR 8.2-51.2] of the penumbra) respectively. Patients with NR areas had higher NIHSS at 24 h and at discharge and higher mRS at 3 months. Volume of NR was independently associated with higher NIHSS at 24 h and at discharge. No independent association was found with IMP volume. Neither NR nor IMP were associated with hemorrhagic transformation. Patients receiving rTPA previous to EVT showed higher perfusion values inside the infarct than patients with primary EVT (2.31 mL/100g [1.48-2.43] vs 0.92 [0.7-1.47] p=0.02), although NR areas appeared in the same proportion in both groups. Conclusions: No reflow phenomenon can be a marker of poor outcome in the early evaluation of successfully recanalized stroke patients especially when the persistent perfusion deficit is located inside the infarcted tissue.