Impact of Stenosis Degree on Outcomes of Stent Placement versus Medical Treatment Alone for Symptomatic Intracranial Stenosis: A Pooled Individual Patient Data Analysis.

Abstract

Background and purpose: Whether differences in stenosis degree affect treatment selection in patients with intracranial artery atherosclerotic stenosis (ICAS) still remains unclear. This study explores the impact of stenosis degree on outcomes of stent placement compared with medical therapy alone in patients with symptomatic intracranial artery stenosis.

Materials and methods: Patients with a TIA or nondisabling ischemic stroke, attributed to 70%-99% stenosis of a major intracranial artery, were included. The patient cohort was drawn from the China Angioplasty and Stenting for Symptomatic Intracranial Severe Stenosis and the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis trials. The primary outcome was a composite of stroke or death within 30 days or stroke in the qualifying artery territory beyond 30 days through 1 year.

Results: Of 806 patients, 92 patients (11%) met the primary outcome. As the degree of stenosis increased, the risk of the primary end point was significantly lower in the stent placement group (R = -0.886, P = .03). For stenosis below or equal to 85%, stent placement is worse than medical therapy given the high perioperative risk (13% versus 8.0%, hazard ratio [HR], 1.67, 95% CI, 1.04-2.67; P = .04); at stenosis degree above 85%, stent placement was preferred over medical therapy given the potential for better long-term prevention (14% versus 21%, HR, 0.67, 95% CI, 0.29-1.56; P = .36).

Conclusions: Patients with higher degrees of stenosis are more likely to benefit from stent placement. Patients with intracranial artery stenosis exceeding 85% may be the focus of future studies. If innovations in interventional techniques significantly reduce perioperative risk, the critical threshold of 85% as the degree of stenosis might be reconsidered.