COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH: Menu

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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01586975
Recruitment Status : Completed
First Posted : April 27, 2012
Results First Posted : December 3, 2015
Last Update Posted : December 31, 2015
Information provided by (Responsible Party):
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.

Condition or disease Intervention/treatment Phase
Stroke Myocardial Infarctions Drug: Clopidogrel Drug: Aspirin 81 mg Drug: Aspirin >300 mg Phase 2 Phase 3

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.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 93 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Multiphase Study to Determine if Platelet Function Analysis Results Correlate With Ischemic Events and Bleeding Complications
Study Start Date : July 2007
Actual Primary Completion Date : April 2010
Actual Study Completion Date : December 2011

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Clopidogrel 75 mg
Clopidogrel 75 mg daily
Drug: Clopidogrel
Clopidogrel 75 mg QD
Other Name: Plavix

Active Comparator: Aspirin 81 mg
open-label Aspirin 81 mg daily
Drug: Aspirin 81 mg
Aspirin 81mg QD
Other Names:
  • Acetylsalicylic Acid
  • ASA

Active Comparator: Aspirin > 300mg
open-label Aspirin over 300 mg daily
Drug: Aspirin >300 mg
Aspirin >300 mg QD
Other Names:
  • Acetylsalicylic Acid
  • ASA

Primary Outcome Measures :
  1. PFA1 [ Time Frame: 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."

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

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

Exclusion Criteria:


Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01586975

Layout table for location information
United States, Illinois
Northwestern University
Chicago, Illinois, United States, 60611
Sponsors and Collaborators
Northwestern University
Layout table for investigator information
Principal Investigator: Mark J Alberts, MD Northwestern University
Layout table for additonal information
Responsible Party: Northwestern University Identifier: NCT01586975    
Other Study ID Numbers: Aspirin Resistance and Stroke
IRB#0996-007 FUND#7810 ( Other Identifier: Northwestern Memorial Hospital )
First Posted: April 27, 2012    Key Record Dates
Results First Posted: December 3, 2015
Last Update Posted: December 31, 2015
Last Verified: December 2015
Additional relevant MeSH terms:
Layout table for MeSH terms
Myocardial Infarction
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases
Pathologic Processes
Myocardial Ischemia
Heart Diseases
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Inflammatory Agents
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors