Ticagrelor vs clopidogrel followed by ticagrelor re-loading in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: A randomized, pharmacodynamic comparison

Abstract

Among patients allocated to ticagrelor in the primary percutaneous coronary intervention (PCI) cohort of Platelet Inhibition and Patient Outcomes (PLATO) trial, 40.7% had received pre-randomization 600 mg of clopidogrel. This scenario is frequently employed in real-world practice. In a prospective, three-center, single-blind, parallel design study, 74 P2Y₁₂ inhibitor-naive patients undergoing primary PCI were randomized (Hour 0) to ticagrelor 180 mg loading dose (LD) vs clopidogrel 600 mg LD followed after 2 h by ticagrelor 180 mg re-LD. Platelet reactivity (VerifyNow, in PRU) was assessed at Hour 0, 2, 4, 6, and 24. The primary comparison was non-inferiority of ticagrelor to clopidogrel followed by ticagrelor re-LD regarding platelet reactivity at 24 h using a prespecified margin of <35 PRU for the upper bound of the one-sided 97.5% confidence interval (CI). Ticagrelor was proven non-inferior to clopidogrel followed by ticagrelor re-LD with a difference between arms of 13.5 PRU (28.8 upper 97.5% CI), p = 0.001. At Hour 2, platelet reactivity was lower in ticagrelor only vs clopidogrel followed by ticagrelor re-LD groups with least square estimate mean difference (95% CI) −105.7 (−140.6 to −70.8), p < 0.001, without significant difference thereafter. In conclusion, in patients undergoing primary PCI, a strategy of ticagrelor LD only was proven non-inferior to clopidogrel LD followed by ticagrelor re-LD, in terms of antiplatelet efficacy at 24 h post-randomization and provided an earlier onset of platelet inhibition.

Keywords:

• Angioplasty
• myocardial infarction
• pharmacology
• platelets

Funding

The study was supported by the Research Committee of Patras University, Program Grant B758.

Declaration of interest

Dr Alexopoulos has received speaker honoraria by AstraZeneca and Advisory Board fees by AstraZeneca, Boeringer Ingelheim, Bayer, and the Medicines Company. All other authors have no declarations of interest.

Additional information

Funding

The study was supported by the Research Committee of Patras University, Program Grant B758.