This randomized controlled trial aims to evaluate the impact of different durations of Ticagrelor-based dual antiplatelet therapy (DAPT) on saphenous vein graft (SVG) patency in patients undergoing coronary artery bypass grafting (CABG). A total of 300 patients will be randomly assigned to receive Ticagrelor (90 mg BID) + Aspirin (100 mg QD) for 3 months, 6 months, or 12 months, followed by aspirin monotherapy.The primary outcome is 1-year graft patency, assessed via coronary CT angiography. Secondary outcomes include bleeding events (BARC classification), major adverse cardiovascular and cerebrovascular events (MACCE), and all-cause mortality. The study aims to determine the optimal DAPT duration to balance graft patency benefits and bleeding risks, ultimately guiding postoperative antiplatelet strategies for CABG patients.