Dual antiplatelet therapy in stroke and ICAS: Subgroup analysis of CHANCE

Area of Science:

• Neurology
• Cardiology
• Clinical Trials

Background:

• Intracranial arterial stenosis (ICAS) is a significant risk factor for recurrent stroke.
• The optimal antiplatelet strategy for patients with acute minor stroke or high-risk transient ischemic attack (TIA) and ICAS remains under investigation.

Purpose of the Study:

• To evaluate the efficacy and safety of clopidogrel plus aspirin versus aspirin alone in patients with and without ICAS.
• To determine if treatment effects differ based on the presence or absence of ICAS.

Main Methods:

• A subanalysis of the CHANCE trial (NCT00979589) including 1,089 patients with available magnetic resonance angiography (MRA) data.
• Patients were categorized as having ICAS (n=608) or no ICAS (n=481).
• Interaction analysis assessed treatment effects of clopidogrel plus aspirin vs. aspirin alone concerning stroke recurrence and bleeding events.

Main Results:

• Patients with ICAS had significantly higher rates of recurrent stroke at 90 days (12.5% vs. 5.4%; p<0.0001).
• No statistically significant interaction was found for the primary outcome of any stroke (p=0.522) or the safety outcome of any bleeding event (p=0.277).
• Hazard ratios for clopidogrel plus aspirin versus aspirin alone were 0.79 [0.47-1.32] for patients with ICAS and 1.12 [0.56-2.25] for patients without ICAS regarding stroke.

Conclusions:

• Patients with minor stroke or high-risk TIA and ICAS exhibit a higher risk of recurrent stroke.
• The combination of clopidogrel plus aspirin demonstrated no significant difference in efficacy or safety compared to aspirin alone between patients with and without ICAS.
• This Class II evidence suggests that for acute minor stroke or TIA patients, the addition of clopidogrel to aspirin does not offer a significant benefit over aspirin alone in preventing recurrent stroke, irrespective of ICAS presence.