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

• ClinicalTrials.gov Identifier: NCT00262561
• Recruitment Status: Completed
• First Posted: December 7, 2005
• Last Update Posted: January 28, 2014
• Sponsor: Aalborg University Hospital
• Collaborator: Danish Heart Foundation
• Information provided by (Responsible Party): Esben Hjorth Madsen, Aalborg University Hospital

Tracking Information

• First Submitted Date: December 6, 2005
• First Posted Date: December 7, 2005
• Last Update Posted Date: January 28, 2014
• Study Start Date: January 2006
• Actual Primary Completion Date: January 2008 (Final data collection date for primary outcome measure)
• Current Primary Outcome Measures (submitted: January 25, 2014): Myocardial infarction, Unstable angina, Cerebral infarction, Transitory cerebral ischaemia, Percutaneous or surgical vascular intervention, Sudden deterioration of symptoms, Amputation, Death. [ Time Frame: 5 years ]

Original Primary Outcome Measures (submitted: December 6, 2005)

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

• Current Secondary Outcome Measures: Not Provided
• Original Secondary Outcome Measures: Not Provided
• Current Other Pre-specified Outcome Measures: Not Provided
• Original Other Pre-specified Outcome Measures: Not Provided

Descriptive Information

• Brief Title: Resistance to Aspirin and/or Clopidogrel Among Patients With PAD.
• Official Title: Prevalence of Resistance to Aspirin and/or Clopidogrel Among Patients With PAD. Prognostic Significance of Resistance to Aspirin

Brief 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.

Detailed 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.

• Study Type: Interventional
• Study Phase: Phase 4
• Study Design: Allocation: Non-Randomized; Intervention Model: Single Group Assignment; Masking: None (Open Label); Primary Purpose: Diagnostic
• Condition: Intermittent Claudication

Intervention

Drug: Aspirin

The effect of Aspirin on platelet function was assessed.

Study Arms

Active Comparator: Aspirin

All participants get Aspirin, and platelet reactivity measurements are performed.

Intervention: Drug: Aspirin

• Publications *: Not Provided

Recruitment Information

• Recruitment Status: Completed
• Actual Enrollment (submitted: January 25, 2014): 263
• Original Enrollment (submitted: December 6, 2005): 1000
• Actual Study Completion Date: January 2008
• Actual Primary Completion Date: January 2008 (Final data collection date for primary outcome measure)

Eligibility Criteria

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

Sex/Gender

• Sexes Eligible for Study: All

• Ages: 18 Years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Contacts: Contact information is only displayed when the study is recruiting subjects
• Listed Location Countries: Denmark

Administrative Information

• NCT Number: NCT00262561
• Other Study ID Numbers: 2005-003844-68
• Has Data Monitoring Committee: Yes
• U.S. FDA-regulated Product: Not Provided
• IPD Sharing Statement: Not Provided
• Responsible Party: Esben Hjorth Madsen, Aalborg University Hospital
• Study Sponsor: Aalborg University Hospital
• Collaborators: Danish Heart Foundation

Investigators

• Principal Investigator: Nils Johannesen, MD; Department of Vascular Surgery, Aalborg Hospital

• PRS Account: Aalborg University Hospital
• Verification Date: January 2014