The Effect Of Ticagrelor On Saphenous Vein Graft Patency In Patients Undergoing Coronary Artery Bypass Grafting Surgery

Rationale: Acetylsalicylic acid (ASA) is used to prevent the occlusion of grafts placed during coronary artery bypass grafting surgery (CABG) and to reduce the incidence of atherothrombotic events during follow-up. Graft occlusion occurs predominantly in saphenous vein grafts (SVGs) and can result in symptoms of chest pain, myocardial infarction (MI) and even death. The anti-thrombotic effect of ASA is a result of the inhibition of the generation of thromboxane A2 (TXA2) in blood platelets. Despite ASA therapy, 6.8% to 26% of SVGs occlude in the first year after CABG, mainly due to thrombus formation. This might be due to the fact that ASA is not equally effective in all patients, indicated by a substantial amount of patients that still generate TXA2 and show activated platelets, despite adequate ASA use. We hypothesize that more potent platelet inhibition by the addition of ticagrelor to standard ASA therapy could decrease the rate of SVG occlusion. Main objective: To investigate whether a combination of ticagrelor 90mg twice daily and ASA 80mg once daily is superior to ASA 80mg once daily alone in the prevention of SVG occlusion in patients who underwent CABG with use of one or more SVGs, as assessed with coronary computed tomography angiography (CCTA) at 1 year after randomization. Study design: Randomized, double-blind, placebo-controlled, multicenter trial. Number of patients: Approximately 500 patients will be randomized. Study population: Patients undergoing CABG with one or more SVGs, CABG being an isolated procedure or part of combined surgery. Informed consent procedure, screening and sample size: We will screen patients and obtain informed consent before CABG. After CABG patients who gave informed consent are screened again to check if the patient fulfills the inclusion criteria and does not have any exclusion criteria. A total of 500 patients will receive randomized study medication after CABG. Intervention: Patients will be randomly assigned to treatment with 90mg of ticagrelor or a matching placebo twice daily in addition to standard treatment with ASA for the duration of 1 year. Patients will be prescribed 80mg of ASA once daily according to routine clinical practice. Graft patency will be assessed with CCTA 1 year after randomization. If the patient consents to participate in the substudies, platelet function tests will be performed before surgery and 3 days and 1 year after randomization. Thirty day and one-year follow-up of clinical events will be obtained for all patients by screening the (electronic) patient file, telephonic interviews, study site visits and possibly with questionnaires.