Optimal Dose of Acetylsalicylic Acid After Coronary Artery Bypass Grafting

This is a single-center, open-label, randomized controlled trial. Patients with stable angina pectoris without use of dual antiplatelet therapy or anticoagulation therapy scheduled for coronary artery bypass grafting (CABG) at Karolinska University Hospital in Stockholm, Sweden will be eligible. This study investigates in patients having undergone CABG whether increasing the dose or the frequency of acetylsalicylic acid (ASA) treatment improves the efficacy of ASA regarding platelet inhibition compared to the standard dosing for cardiovascular prevention (75 mg once daily) in the first three months after surgery. Patients will be randomly assigned to postoperative ASA dose 75mg once daily, 75mg twice daily or 160 mg once daily. The study dose ASA will be started at hospital discharge and continued of three months. Blood samples for serum thromboxane B2 (TxB2) and other analyses will be taken before surgery, before discharge, and after one and three months. All available data will be collected prospectively. Informed consent will be obtained from patients meeting the inclusion criteria before the initiation of any study-specific procedures.