Resistance to Aspirin and/or Clopidogrel Among Patients With PAD.

Intermittent Claudication Clinical Trial

Official title:

Prevalence of Resistance to Aspirin and/or Clopidogrel Among Patients With PAD. Prognostic Significance of Resistance to Aspirin

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00262561
• Other study ID #: 2005-003844-68
• Status: Completed
• Phase: Phase 4
• First received: December 6, 2005
• Last updated: January 25, 2014
• Start date: January 2006
• Est. completion date: January 2008

Study information

• Verified date: January 2014
• Source: Aalborg Universitetshospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Denmark: Danish Medicines AgencyDenmark: The Danish National Committee on Biomedical Research Ethics
• Study type: Interventional

Clinical Trial Summary

263 patients with peripheral atherosclerosis were examined to evaluate the activity of the platelets during the standard treatment, including aspirin. A subgroup of 43 received 600 mg of clopidogrel 2 h before platelet reactivity analysis.

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 5 years.

Description:

Patients with peripheral atherosclerosis 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 ischemic events. 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, as measured by various laboratory methods. We do not know which way resistance is best described, but it has been described that 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.

Methods:

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

Endpoints:

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

Recruitment information / eligibility

• Status: Completed
• Enrollment: 263
• Est. completion date: January 2008
• Est. primary completion date: January 2008
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Atherosclerosis of the lower limbs, defined by one of the following criteria:

Ankle-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

Study Design

Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic

Related Conditions & MeSH terms

• Intermittent Claudication

Intervention

Drug:
• Aspirin
The effect of Aspirin on platelet function was assessed.

Locations

Country	Name	City	State
Denmark	Department of Vascular Surgery, Aalborg Hospital	Aalborg

Sponsors (2)

Lead Sponsor	Collaborator
Aalborg Universitetshospital	Danish Heart Foundation

Country where clinical trial is conducted

Denmark, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Myocardial infarction, Unstable angina, Cerebral infarction, Transitory cerebral ischaemia, Percutaneous or surgical vascular intervention, Sudden deterioration of symptoms, Amputation, Death.		5 years	No