Measurement of Platelet Dense Granule Release in Healthy Volunteers

NCT00942617 | Withdrawn

• 2 other identifiers: IRB# 080895NIH/NHLBI #81009
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief Summary

Aspirin has been shown to reduce cardiovascular events in at risk individuals. Elucidation of mechanisms of aspirin resistance and a possible loss of effect of aspirin over time with chronic aspirin treatment necessitate a more precise method of measuring the "release phase" of platelet activation, including the release of dense granules from platelets.

Conditions

Platelet Aggregation

Keywords

platelet aggregation; granule secretion; thromboxane production; cyclooxygenase-1; ATP release; aspirin resistance; platelet activation; flow cytometry; Platelet aggregation in healthy volunteers

Outcome Measures

Primary Outcomes (1)

• The primary measurement will be platelet 5-HT release induced by ADP after 1 and 2 weeks administration of daily ASA.

  3 weeks

Secondary Outcomes (1)

• Measurements will include platelet COX-1 activity, flow cytometric measurement of markers of platelet activation, platelet aggregation and ATP release, and serum thromboxane B2 (TxB2) levels, at each timepoint.

  3 weeks

Study Arms (1)

40 mg non-enteric coated aspirin

EXPERIMENTAL

40 mg non-enteric coated ASA once daily for 21 + or - 2 days

Drug: Aspirin

Interventions

Aspirin DRUG

40 mg non-enteric coated ASA once daily for 21 + or - 2 days

40 mg non-enteric coated aspirin

Eligibility Criteria

• Age: 18 Years+
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Males over age 18
• Non-smokers
• No chronic medical illness
• No chronic medications

You may not qualify if:

• ASA/NSAID use previous 14 days.
• History of chronic NSAID use.
• Currently taking NSAIDs, opioid analgesics, corticosteroids, or anticoagulants.
• History of coronary artery disease, myocardial infarction, coronary artery bypass grafting, percutaneous angioplasty, diabetes mellitus or stroke.
• History of hypertension
• BMI \>35
• Smokers
• History of gastric, duodenal, or esophageal ulcers or serious gastrointestinal bleed.
• History of frequent headaches, pain syndrome, or other condition requiring frequent use of analgesics.
• History of adverse reaction to ASA.
• Initial platelet count \<100K/µl or \>500K/µl.
• Initial hematocrit \<35% or \>50%.
• Weight less than 110 pounds.
• Female subjects will be excluded to avoid possible confounding uterine smooth muscle production of prostaglandins which various throughout the menstrual cycle.

Sponsors & Collaborators

• Vanderbilt University: lead

Study Sites (1)

Vanderbilt University

Nashville, Tennessee, 37232, United States

Location

MeSH Terms

Interventions

Aspirin

Intervention Hierarchy (Ancestors)

Salicylates; Hydroxybenzoates; Phenols; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Organic Chemicals

Study Officials

• John A Oates, M.D.

  Vanderbilt University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Medicine and Pharmacology

Study Record Dates

• First Submitted: July 17, 2009
• First Posted: July 21, 2009
• Study Start: July 1, 2009
• Primary Completion: June 1, 2012
• Study Completion: June 1, 2012
• Last Updated: December 7, 2015

Record last verified: 2015-12

Locations

US (1)