PACT (Platelet Activity After Clopidogrel Termination)

NCT00619073 | Completed Results

• 1 other identifier: CPFS 2008-1
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

Clopidogrel is a medication that is used to decrease the ability of platelets to form blood clots. The theory has been proposed that, in patients with coronary artery disease or stroke, increased platelet function after discontinuation of clopidogrel therapy is associated with an increased clotting risk. However, this theory has never been rigorously tested. The goal of this research is to determine whether discontinuation of clopidogrel results in increased platelet function.

Conditions

Blood Platelets; Clopidogrel

Keywords

blood platelets; platelet aggregation inhibitors; antiplatelet drugs; clopidogrel

Outcome Measures

Primary Outcomes (1)

• Change From Baseline in Platelet Surface Activated GPIIb-IIIa Complex at 45 Days After Intervention.

  Value at 45 days after intervention minus value at baseline in platelet surface activated GPIIb-IIIa complex using flow cytometry.The types and concentrations of agonists used in the flow cytometry assays reported here were: ADP 0.5, 1, and 20 µmol/L; thrombin receptor activating peptide (TRAP) 1 and 20 µmol/L; and a combination of collagen 5 µg/mL and epinephrine 5 µmol/L. Mean Florescence Intensity (MFI) is used as unit of measure. MFI indicates relative degree of shift in fluorescence intensity of a population of platelets in arbitrary units.

  Baseline and 45 days after intervention

Study Arms (2)

Clopidogrel + aspirin

ACTIVE COMPARATOR

The subjects will be randomized to clopidogrel 75 mg plus aspirin 81 mg orally daily for 14 days. The study drug (i.e., clopidogrel) will then be discontinued and aspirin continued for another 43 days.

Drug: clopidogrel + aspirin; Drug: Aspirin

Placebo + aspirin

PLACEBO COMPARATOR

The subjects will be randomized to placebo plus aspirin 81 mg orally daily for 14 days. The study drug (i.e., placebo) will then be discontinued and aspirin continued for another 43 days.

Drug: placebo; Drug: Aspirin

Interventions

clopidogrel + aspirin DRUG

Clopidogrel 75mg plus aspirin 81mg, tablet by mouth daily for 14 days.

Also known as: Plavix, aspirin

Clopidogrel + aspirin

placebo DRUG

Placebo plus aspirin 81 mg, tablet by mouth daily for 14 days.

Also known as: aspirin

Placebo + aspirin

Aspirin DRUG

Aspirin 81mg tablet by mouth continued daily alone for 43 days after day 14.

Clopidogrel + aspirin; Placebo + aspirin

Eligibility Criteria

• Age: 21 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Must be a normal healthy subject
• Must be between 21-70 years old
• Must be able to take aspirin and clopidogrel.
• Must be able to have blood drawn 16 times over approximately 3 months.

You may not qualify if:

• Subject who is currently taking aspirin or another anti-platelet drug such as clopidogrel. Subject must be free of these medications for 10 days before enrolling in this study.
• Subject who is currently taking a non-steroidal anti-inflammatory drug such as ibuprofen or naproxen. Subject must be free of these medications for 3 days before enrolling in this study.
• Subject who is currently taking medications for depression or medications that lower blood pressure or lower blood sugar.
• Subject who are pregnant or may become pregnant during the study or who is breast feeding.
• Subject with a known allergy to aspirin or clopidogrel.
• Cigarette smoking or use of other nicotine product.
• Subject with a history of any of the following: coronary artery disease; stroke; bleeding disorder; ongoing bleeding; previous life-threatening hemorrhage; stomach ulcers; gastrointestinal bleeding within the past 1 month; major surgery within the past 1 month; minor surgery within the past 2 weeks; or platelet transfusion within the past 7 days.
• Subject with a blood count, measured on the pre-study drug blood sample, that is not in the normal range.
• Subject who is enrolled in another clinical trial of an investigational drug.

Sponsors & Collaborators

• University of Massachusetts, Worcester: lead
• Sanofi: collaborator
• Bristol-Myers Squibb: collaborator

Study Sites (1)

University of Massachusetts Medical School

Worcester, Massachusetts, 01655-0002, United States

Location

Related Publications (1)

• Frelinger AL 3rd, Barnard MR, Fox ML, Michelson AD. The Platelet Activity After Clopidogrel Termination (PACT) study. Circ Cardiovasc Interv. 2010 Oct;3(5):442-9. doi: 10.1161/CIRCINTERVENTIONS.110.937961. Epub 2010 Aug 24.

  PMID: 20736449 RESULT

Related Links

• Home page of the study principal investigator

MeSH Terms

Interventions

Clopidogrel; Aspirin

Intervention Hierarchy (Ancestors)

Ticlopidine; Thienopyridines; Thiophenes; Sulfur Compounds; Organic Chemicals; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Salicylates; Hydroxybenzoates; Phenols; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons

Results Point of Contact

• Title: Alan D. Michelson, M.D.
• Organization: Children's Hospital Boston

alan.michelson@childrens.harvard.edu

617-919-2116

Study Officials

• Alan D. Michelson, M.D.

  University of Massachusetts, Worcester

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 6, 2008
• First Posted: February 20, 2008
• Study Start: April 1, 2008
• Primary Completion: May 1, 2009
• Study Completion: May 1, 2009
• Last Updated: May 31, 2018
• Results First Posted: November 6, 2012

Record last verified: 2018-04

Locations

US (1)