Demonstrate efficacy of mechanical thrombectomy (MT) in large vessel occlusion acute ischemic strokes (LVO AIS), in >90 years old (yo).

Between February 2015 and June 2017, 180 patients (N=162 in ≤90yo; N=18 in >90yo), who underwent MT for LVO AIS were retrospectively analyzed for baseline characteristics, cerebrovascular risk factors, atrial fibrillation (AF) rates, anticoagulant use, intravenous thrombolysis rate, door-to-groin puncture (DTG) times, recanalization rate, hemorrhagic conversion rate, NIH stroke scale (NIHSS) score, and discharge modified Rankin score (mRS).

Between the two groups (≤90yo vs. >90yo), there were no major differences in baseline characteristics, cerebrovascular risk factors, or AF rates (49.7% vs. 61.1%; p=0.36). There was significant difference in baseline anticoagulation use (19.8% vs. 0%; p=0.038), despite 55% (6/11) patients in >90yo had prior AF diagnosis. There were no major differences in proportion of patients receiving intravenous thrombolysis, in DTG times, or in patients achieving ≥TICI 2b recanalization. There was no difference in hemorrhagic conversion rate (30.9% vs. 22.2%; p=0.45), although a higher proportion of patients in >90yo trended to higher symptomatic hemorrhage (sICH) rate (32% vs. 75%; p =0.086). There were no major differences in baseline NIHSS or NIHSS at 24-36 hours post-MT. There was also a trend in >90yo requiring more passes during MT (1.7±1.1 vs. 2.2±1.3; p=0.09). Finally, there was no significant difference between good functional outcome (i.e. discharge mRS ≤3) rates. Notably, zero patients in the >90yo had discharge mRS ≤2.

These findings suggest that including discharge mRS=3 as part of the good functional outcome definition in very elderly patients >90yo could allow for a justified increase in MT. Evidence exists for similar recanalization and hemorrhagic conversion rates vs. ≤90yo, with possibly higher sICH rate, in this population.