Abstract Body: Introduction: Current guidelines do not support the use of stenting for severe symptomatic intracranial atherosclerotic disease (ICAD) over maximal medical therapy (MMT) as first line treatment. This is largely due to the Stenting and Aggressive Medical Management Therapy for Preventing Recurrent Stroke in Intracranial Arterial Stenosis (SAMMPRIS) trial results which featured a high periprocedural stroke rate. In this study, we examined the rates of ischemic stroke in the territory of the qualifying artery (SIT) periprocedurally as well as over time between MMT alone and stent+MMT.

Methods: The primary outcome of interest was SIT. Periprocedural stroke was defined as <7d from stent placement. Log-rank analysis and Kaplan-Meier survival curves were performed to compare time to SIT between MMT and stent+MMT (with day of stent set as day 0 to account for periprocedural stroke and arterial changes post-stent).

Results: Of 451 patients in SAMMPRIS, 435 were included (MMT: n=227; stent+MMT: n=208). The SIT event rate was 15.6% (68 total SIT events- MMT: n=31; stent+MMT: n=37). The median time from qualifying ischemic event (QIE) to stent+MMT in all patients with SIT was 8d (range: 1-34d) with median time of stent to SIT of 4d (IQR:1,215). Thirteen patients with SIT were stented early (<7d from QIE) with median time to stent+MMT of 4d (IQR:3,5) and median time of stent to SIT of 6d (IQR:0,233). Twenty four patients had SIT after delayed stent (>7d) with median time to stent+MMT of 10.5d (IQR:8.75,19) and median time of stent to SIT of 3d (IQR:1,161.75).

Twenty of the 37 stented patients had periprocedural SIT (7 early; 13 delayed). However, over the course of the entire follow up period (1626d), the difference in SIT between MMT and stent+MMT was not significant (p=0.2, Figure 1), with 31 strokes in MMT and 17 non-periprocedural strokes in stent+MMT.

Conclusions: Contrary to guidelines, periprocedural SIT rates did not vary by time of stenting relative to QIE of the parent artery. The majority of SIT were isolated to the periprocedural period, and the difference over time was not significant between MMT and stent+MMT. The rate of SIT over the full study period was higher in MMT when excluding periprocedural strokes from stent+MMT, suggesting that MMT alone may not be the most effective treatment for ICAD. This also suggests that with improvements in safety of stenting in the periprocedural period, intracranial stenting may remain a viable treatment option for ICAD.