Randomized comparison of platelet function monitoring to adjust antiplatelet therapy versus standard of care: rationale and design of the assessment with a double randomization of (1) a fixed dose versus a monitoring-guided dose of aspirin and clopidogrel after DES implantation, and (2) treatment interruption versus continuation, 1 year after stenting (ARCTIC) study.

Background: individual response to oral antiplatelet therapy is subject to variability, and bedside monitoring offers the opportunity of individualizing therapy for stent implantation. Time and consequence of discontinuation of thienopyridine after stenting is also an unsolved issue after drug eluting stent (DES) implantation.
Study Design: the ARCTIC trial is designed to demonstrate the superiority of a strategy of platelet function monitoring with dose adjustment in suboptimal responders as compared to a more conventional strategy without monitoring and without dose adjustment to reduce the primary end point evaluated 1 year after DES implantation. At the end of the 1-year follow-up, all patients will be randomized again to test the superiority of a strategy of pursuit of dual antiplatelet therapy beyond 1 year as compared to a strategy of interruption. ARCTIC is a multicenter, prospective, open-label study with parallel arms and a double randomization. Two thousand four hundred sixty-six patients with stable angina/ischemia or non-ST-elevation Acute Coronary Syndrome undergoing percutaneous coronary intervention (PCI) with DES implantation are being enrolled. The primary end point for the 2 tested hypotheses is the time to first occurrence of all-cause mortality, nonfatal myocardial infarction, definite/probable stent thrombosis, urgent revascularization, or nonfatal stroke. Platelet function analyses will be performed at the time of PCI and repeated 2 to 4 weeks after PCI.
Conclusion: ARCTIC tests the hypothesis of personalized oral antiplatelet therapy at the time of and after DES implantation. It also examines the clinical impact of thienopyridine interruption 1 year after DES implantation.