Inter-patient variability of platelet reactivity in patients treated with prasugrel and ticagrelor

Abstract

The aim of this study was to evaluate the distribution of platelet reactivity values in patients treated with prasugrel and ticagrelor. This prospective observational study enrolled 200 patients treated with prasugrel or ticagrelor. Platelet aggregation was determined by multiple electrode aggregometry after stimulation with adenosine diphosphate (ADP) in the maintenance phase of treatment with prasugrel or ticagrelor. Only 3% of patients in the prasugrel group and 2% of study participants in the ticagrelor group had high on treatment platelet reactivity (HTPR). The majority of patients displayed low on treatment platelet reactivity (LTPR; prasugrel: 69%; ticagrelor: 64%). The pharmacodynamic effect was similar in patients treated with prasugrel and ticagrelor: the median level of ADP-induced platelet aggregation was 15U (interquartile range IQR 9-21U) under prasugrel treatment and 17U (IQR 8–24U) under ticagrelor treatment (p=0.370). In conclusion, our study suggests that there is some degree of variability in ADP-induced platelet aggregation under treatment with prasugrel and ticagrelor.

Keywords:

• Platelet aggregation
• prasugrel
• ticagrelor
• therapeutic window
• variability

Declaration of interest

This study was partly supported by a study grant from Roche, partly by a grant from the Austrian Society of Cardiology and partly by the internal founding of the institution.

Jolanta M. Siller-Matula: lecture or consultant fees from AstraZeneca, Daiichi Sankyo and Eli Lilly

Betül Akca: none

Thomas Neunteufl: lecture or consultant fees from AstraZeneca, BMS/Sanofi Aventis and Eli Lilly-Daiichi Sankyo

Gerald Maurer: none

Irene M. Lang: has relationships with drug companies including AOPOrphan Pharmaceuticals, Actelion, Bayer, Astra-Zeneca, Servier, Cordis, Medtronic, GSK, Novartis, Pfizer and United Therapeutics. In addition, Irene Marthe Lang is an investigator in trials involving these companies, with relationships including consultancy service, research grants and membership in scientific advisory boards.

Rudolf Berger: Lecture or consultant fees form Menarini, Astra Zeneca, Daiichi Sankyo, Bayer, Abbott, Biotronik, Amacord

Gerhard Kreiner: none

Georg Delle-Karth: Lecture or consultant fees form Astra Zeneca, Daiichi Sankyo, Bayer, Abbott, Medtronic, Biotronik, Edwards