African American antiplatelet stroke prevention study: Clinical trial design

Abstract

Background and purpose: African Americans are about two times more likely than European Americans to die of cerebrovascular disease or to experience stroke. Although this disparity exists, African Americans have been underrepresented in clinical trials. The African American Antiplatelet Stroke Prevention Study (AAASPS) is a multi-center, randomized, double-blind, clinical trial to compare the effect of ticlopidine and aspirin in the prevention of recurrent stroke, myocardial infarction, and vascular death in African Americans with recent, noncardioembolic ischemic stroke.

Trial design: There will be 1,800 African American noncardioembolic ischemic stroke patients at 40 sites nationally randomized to receive ticlopidine (500 mg/d) or aspirin (650 mg/d) at least 7 days but no more than 90 days after the qualifying event. Complete blood count and platelet count are monitored every 2 weeks during the first 3 months of active treatment to monitor for neutropenia and thrombocytopenia. Patients with transient cerebral ischemia, recent active peptic ulcer disease or lower gastrointestinal bleeding, bleeding diathesis, and women of childbearing potential are excluded. Study patients will be followed-up for a total of 2 years for occurrence of the primary outcome endpoint cluster of recurrent stroke, myocardial infarction, and vascular death. Safety analyses will focus on the incidence of severe adverse events such as neutropenia, thrombocytopenia, gastrointestinal bleeding, and liver dysfunction. Analyses for key endpoints will use the intention-to-treat principle and time-to-event data will be analyzed using Mantel-Haenszel and various regression methods.

Conclusion: African Americans have a survival disadvantage that substantially relates to the occurrence of stroke. AAASPS is the first secondary stroke prevention study exclusively for African Americans and promises to provide important information to guide recurrent stroke prevention treatment for this high-risk group.