Abstract 17116: Influence of Adherence Monitoring Program on Long-Term Platelet Inhibition by Clopidogrel: Results of a Randomized Controlled Trial
Introduction: Oral P2Y12 antagonist clopidogrel is the mainstay of platelets inhibition treatment after percutaneous coronary intervention (PCI). However, there is strong evidence that the biological response to clopidogrel is variable and that a poor responsiveness is associated with the recurrence of cardiovascular events. Non-adherence to therapy is suspected to be a factor of poor response. We compared the long-term efficacy of different adherence monitoring programs on platelet inhibition by clopidogrel.
Methods: This is a randomized controlled trial including patients treated with clopidogrel 75 mg/day after elective coronary stenting. Patients were recruited between 3- 12 weeks after PCI and randomized in 3 groups, either to a “real-life” approach without monitoring, to an Usual Care strategy (UC) in which drug adherence data were registered by the electronic pillbox MEMSTM or to an Integrated Care (IC) approach which implied feedback on MEMS-registered adherence data to the patient. Clopidogrel potency was assessed with the VASP platelet reactivity index (PRI) at baseline and 6 months after inclusion. Clopidogrel non response was defined as VASP PRI > 50%.
Results: Data of 80 patients were available for the 6-month analysis. Results are reported in table 1. Drug adherence results were excellent in both monitored groups, but the IC approach was associated with an improved adherence. The incremental adherence rate in the IC group was not translated by a mean increase in clopidogrel potency. Clopidogrel non response was frequent in all groups.
Conclusions: An integrated care strategy significantly improve drug adherence to clopidogrel in cardiovascular patients compared to a usual care approach. There is a wide variability in clopidogrel responsiveness, even in patients with excellent drug compliance. Other biological mechanisms, such as the pharmacodynamic or pharmacogenomic proprieties of the drug, may be implicated.
- © 2012 by American Heart Association, Inc.