ASA failure: does the combination ASA/clopidogrel confer better long-term vascular protection?

Area of Science:

• Neurology
• Cardiology
• Clinical Trials

Background:

• Lacunar stroke is a significant cause of disability.
• Acetylsalicylic acid (ASA) is a standard treatment, but some patients experience ASA failure.
• The role of dual antiplatelet therapy in this population requires further investigation.

Purpose of the Study:

• To evaluate the long-term vascular protective effect of adding clopidogrel to aspirin in patients with lacunar stroke and ASA failure.
• To assess the impact on stroke recurrence and major hemorrhage events.

Main Methods:

• Post hoc analysis of 838 patients from the Secondary Prevention of Small Subcortical Strokes Trial (SPS3).
• Patients with ASA failure and recent lacunar stroke were randomized to aspirin plus clopidogrel or aspirin alone.
• Primary outcome: stroke recurrence; Safety outcome: major extracranial hemorrhage. Mean follow-up: 3.5 years.

Main Results:

• The risk of recurrent stroke was similar between the dual antiplatelet group (3.1% per year) and the aspirin-only group (3.3% per year).
• No significant difference in ischemic stroke recurrence was observed between the groups.
• Dual antiplatelet therapy led to a higher risk of gastrointestinal bleeding (HR 2.7) but not intracranial hemorrhage.

Conclusions:

• Adding clopidogrel to aspirin does not reduce vascular events in patients with recent lacunar stroke who are already taking aspirin.
• Dual antiplatelet therapy in this specific patient group did not provide additional vascular protection compared to aspirin monotherapy.
• The increased risk of gastrointestinal bleeding with dual therapy outweighs potential benefits in this population.