Abstract T MP11: Does Onset To Recanalization Time Influence The Effect Of Penumbra Pattern On Clinical Outcomes In Acute Ischemic Stroke Patients Receiving Endovascular Treatment?

Background: Whether penumbra pattern (PP) can identify patients who are most likely to benefit from endovascular treatment (EVT) for acute ischemic stroke remains unclear. We aimed to establish whether onset to recanalization time modifies the effect of PP on outcomes of EVT. Methods: Based on a prospective stroke registry database, we identified patients with acute ischemic stroke who underwent perfusion and diffusion MRI before EVT, had anterior circulation stroke and received EVT within 12 hours of symptom onset, and whose recanalization was confirmed during EVT (mTICI ≥ 2b). Favorable PP was defined as predicted infarct core ≤ 70 ml, and a ratio between the volume of critically hypoperfused tissue (Tmax > 6s) and the ischemic core of 1.8 or more with their absolute difference of 15 mL or more. Onset to recanalization time was dichotomized by median value. Primary outcome was functional independence defined as a modified Rankin Scale score of 0 - 2 at 3 months. Safety outcome was symptomatic hemorrhagic transformation. Results: Among 72 eligible patients, the mean age was 44.0 years and median initial NIHSS score was 14 (IQR, 9 - 19). Favorable PP was detected in 58 patients (80.6%), and median onset to recanalization time was 233 min (range 180 - 371). Among all study subjects, the proportion of functional independence was higher in those with favorable PP compared to those without it (62.1% vs. 7.1%; OR, 21.27; 95% CI, 2.60 - 174.06; P < 0.001), but was not different between early and late recanalization groups (61.1% vs. 41.7%; OR, 2.20; 95% CI, 0.86 - 5.65; P = 0.099). Favorable PP was associated with functional independence in either early recanalization (75.0% vs. 12.5%; P = 0.003) or late recanalization groups (50.0% vs. 0%; P = 0.030). For functional independence, there was no interaction between the PP and onset to recanalization time (P = 0.751). No patients developed symptomatic hemorrhagic transformation. Conclusions: Contrary to previous knowledge, this retrospective analysis shows that favorable PP may predict functional independence independent of onset to recanalization time.