Pharmacodynamic Effects of Different Ticagrelor Maintenance Dosing Regimens With and Without Aspirin in Patients With Diabetes Mellitus: The OPTIMUS (Optimizing Antiplatelet Therapy in Diabetes Mellitus)-7 Study

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the standard of care for the prevention of thrombotic complications in patients with coronary artery disease (CAD) undergoing percutaneous coronary interventions (PCI). However, such ischemic benefit occurs at the expense of enhanced bleeding, the risk of which increases in a graded fashion with prolonged exposure to DAPT. Recent studies have shown that withdrawing aspirin and maintaining P2Y12 inhibitor monotherapy for up to 12 months post-PCI, after a brief period of DAPT, reduces bleeding without increasing ischemic harm. Such effects have shown to of particular benefit in patients with diabetes mellitus (DM). However, if an aspirin-free approach can be considered after this time frame is a matter of debate. In fact, current guidelines recommend maintaining P2Y12 inhibiting therapy for high risk patients but which all imply background use of aspirin. P2Y12 inhibitors for long-term (beyond 12 months) secondary prevention mainly include clopidogrel and ticagrelor. In particular, the dosing regimen for clopidogrel remains the standard 75 mg qd, whereas ticagrelor dosing is recommended to be reduced from 90 mg bid to 60 mg bid. However, of these regimens the pharmacodynamics (PD) effects of ticagrelor 60 mg in the absence of aspirin has not yet been tested. Because DM patients are likely to continue with long-term P2Y12 inhibitor therapy, defining the optimal antithrombotic approach for these patients is of critical importance. In light of the above made observations, patients with DM represent an ideal population to define the antiplatelet effects of a ticagrelor 60 mg monotherapy regimen. The aim of this study is to assess the PD effects of ticagrelor 60 mg with and without aspirin therapy in CAD patients and to compare this with a standard DAPT regimen of aspirin plus clopidogrel.