Evaluation of Coronary Artery Bypass Graft Patency using CT Angiography: A Prospective Observational Study

Introduction: Coronary Artery Bypass Graft (CABG) surgery is a cornerstone in managing advanced coronary artery disease, and graft patency significantly influences long-term outcomes. Coronary Computed Tomography (CT) Angiography (CCTA) offers a reliable, non invasive method to evaluate graft patency. Aim: To assess graft patency in post CABG patients using CCTA, focusing on graft type (arterial vs. venous), time since surgery, and the impact of diabetes mellitus on graft occlusion and stenosis. Materials and Methods: A prospective observational study was conducted on 42 post CABG patients undergoing CCTA between June 2023 and September 2024 at the Department of Radiodiagnosis, GVP Institute of Healthcare and Medical Technology, Visakhapatnam, Andhra Pradesh, India. Data on graft type, patency, occlusion, stenosis, and associated clinical factors were analysed using Statistical Package for Social Sciences (SPSS) software (version 22). Categorical data were represented as frequencies and proportions, while the Chisquare test was applied as the test of significance. Continuous data were expressed as mean and standard deviation. A p-value of <0.05 was considered statistically significant. Results: The mean age of participants was 61.75±18.33 years. Males constituted 88.1% of the participants, while females comprised 11.9%. Of the 118 grafts evaluated, 92 (77.9%) were patent, with arterial grafts demonstrating higher patency (42 out of 45, 93.3%) compared to venous grafts (50 out of 73, 68.5%). Diabetes was associated with slightly higher occlusion rates in venous grafts (8 out of 34, 23.5% in diabetics vs. 6 out of 39, 15.38% in non diabetics), though the differences were not statistically significant. The most common graft was LIMA to LAD, accounting for 37 grafts (31.3%). Most patent grafts were observed within 1-5 years post surgery, with 31 arterial grafts (68.8%) and 42 venous grafts (57.5%) remaining patent. Mild stenosis was more common than severe stenosis. Severe stenosis and occlusion were more frequent in venous grafts, with 14 occlusions (19.18%) compared to one occlusion (2.22%) in arterial grafts. Conclusion: CCTA is an effective tool for evaluating CABG graft patency, with arterial grafts, particularly LIMA, showing superior long-term outcomes. These findings reinforce the importance of early post-surgical imaging and targeted management strategies to improve outcomes in high-risk groups.