The Antiaggregation Monitoring (TAM) Registry (TAM)

Acetylsalicylic Acid in Outpatient Practice - Results From The Antiaggregation Monitoring (TAM) Registry

The purpose of this study is to investigate the incidence of acetylsalicylic acid resistance (ASA-R) among patients under chronic acetylsalicylic acid(ASA) treatment seen at our outpatient clinic.

Study Overview

• Status: Completed
• Conditions: Aspirin Causing Adverse Effects in Therapeutic Use
• Intervention / Treatment: Other: Measurement of platelet anti-aggregation

Detailed Description

Acetylsalicylic acid (ASA) resistance (R) is best defined as an ineffective inhibition of the platelet cyclooxygenase (COX)-1 pathway, and has been reported in 1 to 61 % of patients treated with ASA. Impaired response to ASA has been associated with an increased risk of ischemic events in patients with known coronary artery disease. We sought to investigate the incidence of ASA-R in clinical practice.

All consecutive patients under chronic ASA treatment (100mg/d) seen at our outpatient clinic were systematically included in the registry. All patients were on acetylsalicylic acid for CAD for at least 1 month. Patients were informed of ASA testing at start of consultation in the outpatient clinic. Eligible patients provided written informed consent. Peripheral venous blood samples were analyzed using the whole blood impedance platelet aggregometry Multiplate analyzer. The Multiplate analyzer device allows to measure platelet aggregation by the attachment of platelets to two silver coated copper electrodes leading to a rise of electrical resistance in the sample. The measurements are expressed as arbitrary aggregation units (AU) and the manufacturers defined cutoffs were used: normal values were 76-136 AU, partial antiaggregation was defined as ASA values between 31 and 75 AU and complete antiaggregation was defined as ASA values < 31 AU.

• Study Type: Observational
• Enrollment (Actual): 200

Contacts and Locations

Study Locations

• Switzerland
  • FR
    • Fribourg, FR, Switzerland, 1708
      • Service de Cardiologie, Hôpital Cantonal Fribourg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

All consecutive patients under chronic ASA treatment seen at our outpatient clinic

Description

Inclusion Criteria:

• patients under chronic ASA treatment for more then one month

Exclusion Criteria:

• concomitant use of nonsteroidal anti-inflammatory drugs (NSAIDs)
• thrombocytopenia
• thrombocytosis
• age <18 years

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
TAM patients; All consecutive patients under chronic ASA treatment (100mg/d) seen at our outpatient clinic.	Other: Measurement of platelet anti-aggregation; Whole blood impedance platelet aggregometry was performed with the Multiplate analyzer (Dynabyte, Munich, Germany) to test the response to ASA with arachidonic acid as the trigger.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Whole blood impedance platelet aggregometry to assess acetylsalicylic acid resistance rates	6 months

Collaborators and Investigators

• Sponsor: Stephane Cook
• Investigators: Principal Investigator: Stéphane Cook, Prof, Fribourg University

Study record dates

Study Major Dates

• Study Start: November 1, 2010
• Primary Completion (Actual): April 1, 2011
• Study Completion (Actual): April 1, 2011

Study Registration Dates

• First Submitted: March 30, 2011
• First Submitted That Met QC Criteria: April 1, 2011
• First Posted (Estimate): April 5, 2011

Study Record Updates

• Last Update Posted (Actual): October 22, 2021
• Last Update Submitted That Met QC Criteria: October 14, 2021
• Last Verified: November 1, 2010

More Information

Terms related to this study

• Keywords: acetylsalicylic acid resistance
• Other Study ID Numbers: 242/10A