- NEWS . 30 Mar 2020
Efficacy of ticagrelor monotherapy compared with ticagrelor plus aspirin in high-risk patients undergoing PCI
In high-risk patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents, ticagrelor monotherapy provides similar antithrombotic benefits as ticagrelor plus acetylsalicylic acid (ASA or aspirin). These findings come from a mechanistic substudy within the TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention) trial, which randomized patients undergoing PCI to ticagrelor plus placebo versus ticagrelor plus ASA after 3 months of dual antiplatelet therapy.
In view of the evolving shift to an ASA-free approach after PCI, researchers in this study aimed to compare the pharmacodynamic effects of ticagrelor alone versus ticagrelor plus ASA on blood thrombogenicity and platelet reactivity.
Participants were recruited into the substudy after randomization within the TWILIGHT trial, at which time ex vivo assays to quantify thrombus size under dynamic flow conditions and platelet reactivity were performed. Pharmacodynamic assessments were repeated 1–6 months thereafter. The primary endpoint was thrombus size at the post-randomization visit; secondary endpoints were platelet reactivity after stimuli to arachidonic acid, collagen, adenosine diphosphate (ADP) and thrombin.
Among the 51 patients enrolled, 42 underwent perfusion assays at baseline and follow-up with a median time between studies of 1.5 months. Results analysed using analysis of covariance revealed that the adjusted mean difference in post-randomization thrombus area was similar between the two treatment groups: -218.2 μm2 (95% confidence interval [CI], -575.9 to 139.9; p=0.22). Additionally, both groups showed similar levels of platelet reactivity with ADP and thrombin, but markers sensitive to cyclo-oxygenase-1 blockage, including platelet reactivity in response to arachidonic acid (mean difference, 10.9 U; 95% CI, 1.9 to 9.9) and collagen (mean difference, 9.8 U; 95% CI, 0.8 to 18.8), were higher in the placebo group.
Baber U, et al. Ticagrelor with or without aspirin after PCI: the TWILIGHT Platelet Substudy. J Am Coll Cardiol 2020;75:578-586.