Background: High on-treatment platelet reactivity (HTPR) despite use of P2Y12 antagonists has been associated with adverse cardiac events. The long-term variability in response to prasugrel and ticagrelor in patients with acute coronary syndrome (ACS) is unclear. Therefore, we aimed to assess the variability in response and rates of HTPR during treatment with prasugrel vs. ticagrelor in patients with ACS.
Methods: Patients with ACS treated with percutaneous coronary intervention (PCI) and either prasugrel or ticagrelor were tested for platelet reactivity using the VerifyNow P2Y12 assay and multiple electrode aggregometry (MEA). Tests were performed at 2-4 days and at 30-days post-PCI.
Results: The study sample included 114 patients. Sixty-two were treated with prasugrel (mean age 58±8, 21% women, 29% diabetes), and fifty-two with ticagrelor (mean age 63±9, 19% women, 37% diabetes). Variability in response was lower with ticagrelor than with prasugrel at both time-points. At 2-4 days post-PCI, HTPR rates were higher in the prasugrel group (8.1% according to VerifyNow P2Y12 reaction units and 11.3% according to MEA as compared to none in the ticagrelor group). At 30-days, rates of HTPR were also higher in the prasugrel group (8.7% and 10.9%, respectively, as opposed to none in the ticagrelor group).
Conclusion: In patients with ACS undergoing PCI, treatment with ticagrelor resulted in lower HTPR rates and less variability in response to treatment compared with prasugrel, up to 30 days after the event.
