Aspirin Resistance and Stroke Risk: Platelet Function Analysis in Patients With Ischemic Events

Phase 2

Completed

• Conditions: Stroke; Myocardial Infarctions
• Interventions: Drug: Aspirin 81 mg; Drug: Aspirin >300 mg; Drug: Clopidogrel

• Registration Number: NCT01586975
• Lead Sponsor: Northwestern University

Brief Summary

The purpose of this study is to determine if PFA results correlate with ischemic event outcomes as well as bleeding complications. Hypothesis is antiplatelet agents will be more efficacious if they are administered in a dose-adjusted manner using PFA results as a guide.

Detailed Description

Atherothrombotic disease is a leading killer of adults throughout the world. The current mainstay for the prevention of ischemic vascular events is the use of aspirin Antiplatelet agents are used routinely for the primary and secondary prevention of vascular events in patients with a prior history of stroke, TIA, or at high risk for the development of cerebrovascular disease. Numberous individual studies and meta-analyses have shown that essentially all of the oral antiplatelet agents have limited efficacy, with relative risk reductions in the range of 20-35%. The purpose of this study is to perform serial platelet function assays (PFAs) on patients with cerebrovascular disease who are taking antiplatelet agents and perform a pilot study to determine the feasibility of administering ASA as a dose adjusted medication using PFA. The long term goal of this study is to determine whether antiplatelet therapy will be more efficacious and/or safer if it is administered in a dose-adjusted manner.

Study Timeline

• Study Start: 2007-07
• Primary Completion: 2010-04
• Study First Submitted: 2011-08-03
• Study Completion: 2011-12
• Study First Submitted QC: 2012-04-26
• Study First Posted: 2012-04-27
• Results First Submitted: 2015-06-29
• Results First Submitted QC: 2015-10-27
• Status Verified: 2015-12
• Last Update Submitted: 2015-12-02
• Results First Posted: 2015-12-03
• Last Update Posted: 2015-12-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 93

Inclusion Criteria

• Patient must be taking Aspirin or Plavix
• Patient must have had a stroke, TIA or cerebrovascular disease

Exclusion Criteria

-None

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Aspirin 81 mg	Aspirin 81 mg	open-label Aspirin 81 mg daily
Aspirin > 300mg	Aspirin >300 mg	open-label Aspirin over 300 mg daily
Clopidogrel 75 mg	Clopidogrel	Clopidogrel 75 mg daily

Primary Outcome Measures

Name	Time	Method
PFA1	3-6 months (Collected once between regulalary scheduled follow-up visit between 3-6 months)	Platelet Function Analysis (PFA) lab results: PFA was performed using the PFA 100 device (Dade-Behring), which uses a higher sheer stress flow cytometry paradigm to measure the time in seconds to closing of an aperture. Normal is defined as \<172 seconds."

Trial Locations

Locations (1)

Northwestern University; 🇺🇸 Chicago, Illinois, United States