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Aspirin Resistance in Coronary Artery Disease

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ClinicalTrials.gov Identifier: NCT00753935
Recruitment Status : Completed
First Posted : September 17, 2008
Results First Posted : April 19, 2018
Last Update Posted : April 19, 2018
Sponsor:
Collaborator:
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
John Oates, Vanderbilt University

Brief Summary:
The purpose of this study is to evaluate possible mechanisms of aspirin resistance at a molecular level in aspirin-treated patients with coronary artery disease. We hypothesize that certain patient characteristics associate with aspirin resistance. In addition, we will compare the effects of enteric-coated aspirin and chewable aspirin.

Condition or disease Intervention/treatment Phase
Coronary Artery Disease Drug: enteric-coated aspirin Drug: Chewable aspirin Early Phase 1

Detailed Description:

Aspirin is commonly used for its antithrombotic effects in patients at risk for cardiovascular events. Its primary mechanism of action is the irreversible acetylation of platelet cyclooxygenase-1, thereby inhibiting platelet production of thromboxane A2, a potent vasoconstrictor and activator of platelets. Thromboxane A2, the major product of cyclooxygenase cytochrome oxidase (COX-1) in platelets, induces platelet aggregation. Thromboxane B2 is an inactive metabolite/product of thromboxane A2. This primary outcome measures the extent of inhibition of platelet COX-1 by measuring the amount of the metabolite thromboxane B2 in serum.

Previous studies have demonstrated that many patients have recurrent events despite treatment with aspirin, which has been termed "aspirin resistance" or "aspirin nonresponse." This study addresses some of the possible mechanisms for aspirin nonresponse; specifically, we will test the hypothesis that aspirin nonresponse results from states that produce high peroxide concentrations ("oxidative stress") in platelets. In addition, we will evaluate the effect of enteric coating on the pharmacologic efficacy of aspirin in patients with coronary artery disease.


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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 92 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Investigator)
Primary Purpose: Basic Science
Official Title: Evaluation of Aspirin Resistance at a Molecular Level in Aspirin-Treated Patients With Coronary Artery Disease
Study Start Date : June 2006
Actual Primary Completion Date : August 2011
Actual Study Completion Date : March 2014

Resource links provided by the National Library of Medicine

Drug Information available for: Aspirin

Arm Intervention/treatment
Experimental: Enteric-coated aspirin
patients received enteric-coated aspirin 81 mg qd for 2 weeks
Drug: enteric-coated aspirin
enteric-coated aspirin 81mg daily for 2 weeks
Other Name: acetylsalicylic acid

Active Comparator: Chewable aspirin
Patients received chewable aspirin 81 mg qd for 2 weeks
Drug: Chewable aspirin
chewable aspirin 81mg daily for 2 weeks
Other Name: acetylsalicylic acid




Primary Outcome Measures :
  1. Change in Serum Thromboxane B2 [ Time Frame: after 2 weeks on aspirin ]
    Thromboxane A2, the major product of cyclooxygenase cytochrome oxidase (COX-1) in platelets, induces platelet aggregation. Thromboxane B2 is an inactive metabolite/product of thromboxane A2. This primary outcome measures the extent of inhibition of platelet COX-1 by measuring the amount of the metabolite thromboxane B2 in serum.



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Ages Eligible for Study:   40 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • On aspirin 81-325mg daily at time of enrollment
  • Documented stable coronary artery disease or > 6 months after coronary artery bypass grafting or interventional cardiac procedure
  • Written informed consent

Exclusion Criteria:

  • Pre-menopausal female
  • Renal disease (creatinine >= 2 mg/dl)
  • Anemia (Hematocrit < 30%)
  • Thrombocytopenia (platelet count < 135,000/ul)
  • Use of NSAIDs or coxibs within the previous 2 weeks
  • Concurrent use of other anti-platelet agents
  • Uncontrolled hypertension (systolic BP > 180 mmHg)
  • Decompensated congestive heart failure
  • Recent coronary syndrome (< 6 months)
  • History of significant GI bleeding

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 ClinicalTrials.gov identifier (NCT number): NCT00753935


Locations
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United States, Tennessee
Vanderbilt University
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
National Heart, Lung, and Blood Institute (NHLBI)
Investigators
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Principal Investigator: Mary B Taylor, MD, MSCI Vanderbilt University

Publications of Results:
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Responsible Party: John Oates, Professor of Medicine and Pharmacology, Vanderbilt University
ClinicalTrials.gov Identifier: NCT00753935     History of Changes
Other Study ID Numbers: 040065
5P50HL081009-03 ( U.S. NIH Grant/Contract )
First Posted: September 17, 2008    Key Record Dates
Results First Posted: April 19, 2018
Last Update Posted: April 19, 2018
Last Verified: March 2018

Keywords provided by John Oates, Vanderbilt University:
aspirin
aspirin resistance
aspirin nonresponse
cyclooxygenase
thromboxane
oxidative stress

Additional relevant MeSH terms:
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Aspirin
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arteriosclerosis
Arterial Occlusive Diseases
Vascular Diseases
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Analgesics
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
Antipyretics