The Effect of Low-Dose Ticagrelor on Platelet Function Profiles in Patients With Stable Coronary Artery Disease in Trinidad: The TWIST Pilot Study

INTRODUCTION: This prospective, pharmacodynamic study aimed to explore the potential applicability of a low-dose ticagrelor regimen in a heterogeneous Trinidadian subpopulation. METHODS: Patients with stable coronary artery disease (n = 25) who were actively treated with dual antiplatelet therapy of aspirin 81 mg daily and clopidogrel 75 mg daily were recruited. Platelet function was measured with the VerifyNow P2Y(12) assay (Accriva Diagnostics, San Diego, CA, USA) and assessed before initiation of and after 14 days of treatment with a low-dose ticagrelor 45 mg twice daily maintenance dose regimen. Results were compared with a paired t test. RESULTS: The mean P2Y(12) reaction units (PRU) score on ticagrelor was significantly less compared to that of clopidogrel (50.4, 95% confidence interval (CI) 29–73.9; vs. 149.6, 95% CI 129.4–169.9; p value < 0.001). Of the patients, 4% experienced Medical Research Council class 1 dyspnea, and Bleeding Academic Research Consortium class 1 bleeding on the ticagrelor regimen (one patient each). CONCLUSIONS: Significantly attenuated platelet reactivity was seen on the low ticagrelor maintenance dose as compared to clopidogrel. This dedicated pharmacodynamic study could be applicable and informative for Trinidadian stable coronary artery disease patients. Further studies are required to confirm these exploratory findings.(Funded by the University of the West Indies, St. Augustine). TRIAL REGISTRATION: ClinicalTrials.gov number NCT04206176.