Clinical trial NCT01039480: Aspirin and Clopidogrel Resistance Study
Official title: Aspirin- and Clopidogrel-Resistance: Non-compliance and Other Contributing Factors
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Drug Resistance
Keywords: pharmacological biomarker
compliance monitoring
platelet aggregometry
resistance
Platelet Aggregation Inhibitors
Medication Non-Compliance
Lead sponsor: University Hospital, Basel, Switzerland
Sponsor class: OTHER
First posted: 2009-12-25
Enrollment: 82
Sex: ALL
Minimum age (years): 45
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: Patients with a prescription for aspirin and/or clopidogrel seeing their general practitioner (GP) for any purpose

Brief summary: Resistance to antiplatelet drugs (aspirin, clopidogrel) is a recognized phenomenon with a prevalence from 17% to 35%. Resistance as detected by in vitro tests such as Multiple Electrode Aggregometry (MEA) has been shown to predict clinical therapy failure. Resistance can be caused by clinical, cellular and pharmacogenetic factors. Non compliance is suspected to be an important contributing factor. In this study, compliance will be assured with an electronical compliance monitoring system. Factors to non response will be identified to find plausible explanations when in vitro platelet aggregation inhibition is insufficient despite assured compliance. This study will help to disclose the relationship between compliance, biomarker and clinical outcome as well as to quantify the impact of non compliance to the resistance phenomenon as measured by MEA.


Eligibility criteria: Inclusion Criteria:

* Patients prescribed aspirin and/or clopidogrel for both including both cardiovascular and cerebrovascular indications seeing their general practitioner in or nearby Olten/SO for any medical purpose
* Patients with oral and written German language ability

Exclusion Criteria:

* Patients living in care homes
* Patients not preparing their drugs on their own (e.g. outpatient medical assistance through "spitex").
* Patients with acute cardiac symptoms

Primary outcomes:
measure: Platelet aggregation, initial and after one week under compliance monitoring.
timeFrame: 1 week
Secondary outcomes:
measure: Data on compliance (measured by electronic compliance monitoring, Morisky MMAS-8 and BMQ Score)
timeFrame: 1 week
measure: Frequency of contributing factors to non-response in responders compared to non-responders (pharmacogenetics, clinical factors and drug-drug interactions)
timeFrame: 4 weeks
Other outcomes:
Locations:
city: Olten
country: Switzerland
facility: Study Centre at Aarelab AG, Olten
state: Solothurn
Study officials:
affiliation: Pharmaceutical Care Research Group, Departement of Pharmacy, University Basel
name: Kurt E Hersberger, PhD
role: STUDY_CHAIR
affiliation: Kardiologische Praxis, Olten/SO
name: Michel Romanens, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Hemostaseology Lab, University Hospital Basel
name: Dimitrios Tsakiris, MD
role: STUDY_DIRECTOR
affiliation: Pharmaceutical Care Research Group, Department of Pharmacy, University of Basel
name: Philipp N Walter, MSc
role: PRINCIPAL_INVESTIGATOR
References:
citation: Walter PN, Tsakiris DA, Romanens M, Arnet I, Hersberger KE. Antiplatelet resistance in outpatients with monitored adherence. Platelets. 2014;25(7):532-8. doi: 10.3109/09537104.2013.845743. Epub 2013 Oct 31.