Resistance to Aspirin and/or Clopidogrel Among Patients With PAD. - Full Text View

Sponsor:	Aalborg Hospital
Information provided by:	Aalborg Hospital
ClinicalTrials.gov Identifier:	NCT00262561

Purpose

1000 patients with atherosclerosis of lower limbs are examined to evaluate the activity of the platelets during the standard treatment, including aspirin. A minor group will receive clopidogrel instead of aspirin for 2 weeks.

The main hypothesis is that high platelet activity at the beginning of the study is associated with a higher risk of atherothrombosis. Follow up time is 6 years.

Condition	Intervention	Phase
Intermittent Claudication	Drug: Clopidogrel	Phase IV

Study Type:	Interventional
Study Design:	Allocation: Non-Randomized Endpoint Classification: Safety/Efficacy Study Intervention Model: Single Group Assignment Masking: Open Label Primary Purpose: Diagnostic
Official Title:	Prevalence of Resistance to Aspirin and/or Clopidogrel Among Patients With PAD. Prognostic Significance of Resistance to Aspirin

Resource links provided by NLM:

Drug Information available for: Acetylsalicylic acid Clopidogrel Clopidogrel Bisulfate

U.S. FDA Resources

Further study details as provided by Aalborg Hospital:

Primary Outcome Measures:

Myocardial infarction
Unstable angina
Cerebral infarction
Transitory cerebral ischaemia
Percutaneous or surgical vascular intervention
Sudden deterioration of symptoms
Amputation
Death

Estimated Enrollment:	1000
Study Start Date:	January 2006

Detailed Description:

Patients with atherosclerosis of the lower limbs are at high risk of atherothrombosis, mainly heart attack and stroke. The medical treatment of these patients include platelet inhibiting drugs, usually aspirin, to reduce the risk of blood clot formation. Clopidogrel is another platelet inhibiting drug, which is prescribed less often, primarily because of the high costs compared to aspirin.

Phenomena of 'resistance' to these drugs have been described by numerous investigators. Essentially resistance means that the effect of the drug described is less than expected or missing, when described by various laboratory methods. We still do not know which way resistance is best described, and we still do not know if patients who are 'resistant' to either drug are less protected against future heart attacks or strokes.

Main objectives:

To measure the activity of platelets in these patients during aspirin treatment.
To measure the activity of platelets in a minor population of these patients during clopidogrel treatment.
To evaluate the prognostic significance of resistance to aspirin in these patients.

Secondary objectives:

To describe the relation between drug resistance and the level of inflammatory markers in the blood.

Methods:

Platelet activity is measured by the PFA-100 (Dade Behring) and by traditional turbidimetric aggregation.

Patients:

Number needed is 1000.

Follow up:

6 years

Endpoints:

Myocardial infarction, unstable angina, cerebral infarction, transitory cerebral ischaemia, sudden deterioration of symptoms, percutaneous or surgical vascular intervention, amputation, death.

Eligibility

Ages Eligible for Study:	18 Years and older
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	No

Criteria

Inclusion Criteria:

Atherosclerosis of the lower limbs, defined by one of the following criteria: Ancle-Brachial Pressure Index (ABPI)< 0.9, intermittent claudication, ischaemic pain at rest, ischaemic ulcers or gangrene.
Age > 18 years
For fertile women: Use of safe contraception (intrauterine contraceptive device, the pill, hormonal skin patches, progestogen injections, progestogen implant, vaginal ring)

Exclusion Criteria:

Allergy to either Aspirin or Clopidogrel
Known bleeding disorder
Platelet count < 140 mia/L or > 400 mia/L
Intake of NSAID's, SSRI's or Dipyridamol within the preceding 14 days
Not radically treated gastrointestinal ulceration within the last 6 month
Greater surgical procedures performed within the last 3 month
Severe renal disease
Severe hepatic disease
Breast feeding
Pregnancy

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00262561

Contacts

Contact: Esben H Madsen, MD	+01-604 221 1536	ehmadsen@gmail.com
Contact: Norbert Gehr, MD	+45-99 32 29 79	aas.u30030@nja.dk

Locations

Denmark
Department of Vascular Surgery, Aalborg Hospital	Recruiting
Aalborg, Denmark, 9000
Contact: Nils Johannesen, MD
Contact: Norbert Gehr, MD
Principal Investigator: Nils Johannesen, MD

Sponsors and Collaborators

Aalborg Hospital

Investigators

Principal Investigator:

Nils Johannesen, MD

Department of Vascular Surgery, Aalborg Hospital

More Information

No publications provided

ClinicalTrials.gov Identifier:	NCT00262561 History of Changes
Other Study ID Numbers:	2005-003844-68
Study First Received:	December 6, 2005
Last Updated:	September 27, 2006
Health Authority:	Denmark: Danish Medicines Agency; Denmark: The Danish National Committee on Biomedical Research Ethics

Keywords provided by Aalborg Hospital:

Intermittent Claudication
Aspirin resistance
Clopidogrel resistance

Additional relevant MeSH terms:

Intermittent Claudication
Arteriosclerosis
Arterial Occlusive Diseases
Vascular Diseases
Cardiovascular Diseases
Signs and Symptoms
Aspirin
Clopidogrel
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Analgesics
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Pharmacologic Actions

Anti-Inflammatory Agents
Therapeutic Uses
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Cardiovascular Agents
Hematologic Agents
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors
Antipyretics
Central Nervous System Agents
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists

ClinicalTrials.gov processed this record on February 09, 2012