| Autor: |
Ow KW; Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield , Sheffield, UK., Parker WAE; Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield , Sheffield, UK.; South Yorkshire Cardiothoracic Centre, Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust , Sheffield, UK., Porter MM; Manchester Royal Infirmary, Manchester University NHS Foundation Trust , Manchester, UK., Hanson J; Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield , Sheffield, UK., Judge HM; Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield , Sheffield, UK., Briffa NP; Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield , Sheffield, UK.; South Yorkshire Cardiothoracic Centre, Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust , Sheffield, UK., Thomas MR; Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham , Birmingham, UK., Storey RF; Department of Infection, Immunity and Cardiovascular Disease, The Medical School, University of Sheffield , Sheffield, UK.; South Yorkshire Cardiothoracic Centre, Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust , Sheffield, UK. |
| Abstrakt: |
Ticagrelor is an antagonist of both platelet adenosine diphosphate (ADP) receptor P2Y 12 and equilibrative nucleoside transporter-1. Optimal timing of ticagrelor cessation prior to coronary artery bypass grafting (CABG) remains unclear. We characterized the offset of ticagrelor's effects on platelets and cellular adenosine uptake in ticagrelor-treated patients (n = 13) awaiting CABG. Blood was drawn prior to CABG at multiple timepoints 2 to 120 (h) after the last dose of ticagrelor. Platelet function (n = 13) was assessed with multiple electrode aggregometry (MEA), expressed as arbitrary units (U) derived from area-under-the-curve (AUC) in response to ADP, and inhibition of adenosine uptake by high-performance liquid chromatography (n = 7). Mean±SD AUC was 20.3 ± 8.2 U (2 h post-ticagrelor), 33.0 ± 18.3U (24 h), 56.6 ± 30.6U (48 h), 61.4 ± 20.2U (72 h), 82.8 ± 24.2U (96 h) and 96.0 ± 15.3U (120 h). There was a significant difference between 72 h and 120 h ( p = .007), but not between 96 h and 120 h ( p > .99). By 96 h, all patients had AUC >31U, an accepted cutoff below which surgical bleeding risk is increased. Adenosine uptake showed no significant differences between the timepoints. These data suggest it takes 4 days for platelet reactivity to recover sufficiently after cessation of ticagrelor to avoid the excess risk of CABG-related bleeding. Discontinuing ticagrelor had no measurable effect on cellular adenosine uptake. |
