Abstract Body: Introduction:
Preliminary results demonstrated positive outcomes with the adjunct use of IV antiplatelets in patients presenting with large vessel occlusion secondary to underlying intracranial atherosclerosis (ICAS-LVO) undergoing mechanical thrombectomy (MT). We aimed to assess the outcomes of this approach in a prospective registry.

Methods:
This is a pre-specified secondary analysis of the RESCUE-ICAS registry, a prospective cohort study including patients with 50-99% residual intracranial stenosis or re-occlusion following MT. Patients were divided into three groups: MT alone, MT with adjunct IV antiplatelets, or MT with adjunct stenting. Periprocedural IV antiplatelets used in this study included tirofiban, eptifibatide, and cangrelor. Primary endpoint was modified Rankin scale (mRS) of 0-2 at 90 days. Statistical analysis included logistic regression model to assess the factors associated with good 90-day outcomes.

Results:
A total of 57 patients received periprocedural IV antiplatelets without stenting (group 1) compared to 182 patients who underwent MT alone (group 2) and 198 who underwent MT with adjunct stenting (group 3). Median age was 69 and 40.4% of patients were females. There was no significant difference in baseline demographic and clinical characteristics of patients in the IV antiplatelets group compared to groups 2 and 3. There was no significant difference in mRS 0-2 at 90 days between patients in the IV antiplatelets group compared to the MT alone group (19.3% vs 30.2% P=0.108). However, patients in the MT with adjunct stenting group had higher rate of 90-day mRS of 0-2 (42.4% vs 19.3%, P=0.001) compared to the IV antiplatelets group. On multivariable analysis, MT with adjunct stenting was independently associated with good 90-day outcome (AOR 3.946, 95% CI 1.845-8.439, P<0.001) (Table 1).

Discussion:
In patients presenting with ICAS-LVO, IV antiplatelets as an adjunct to MT was not associated with higher odds of favorable functional outcome compared to MT alone. Patients undergoing MT with adjunct intracranial stenting had better functional outcomes when compared to MT with IV antiplatelets group. Further studies are necessary to validate our findings in this unique stroke subgroup.