This study evaluates the incidence and risk factors of early in-hospital graft occlusion in post-coronary artery bypass grafting (CABG) patients. The meta-analysis, including 22 studies with 35,798 patients, found a 5% occlusion rate. The rate varied based on symptom-driven or systematic graft patency assessments. Vein graft presence, female gender, and other factors like composite grafts may increase the risk of early occlusion.