Evaluation of Early Graft Patency Using 640-Slice CT Scan among Patients Undergoing CABG at Rawalpindi Institute of Cardiology

Background: Early graft patency is a key determinant of outcomes following coronary artery bypass grafting (CABG). Invasive coronary angiography, though considered the gold standard, is associated with procedural risks. Advanced multislice CT, particularly 640-slice CT angiography, offers a non-invasive alternative for early graft assessment. Limited local data exist regarding its utility in Pakistan. Objective: To evaluate early graft patency using 640-slice CT angiography among patients undergoing CABG at Rawalpindi Institute of Cardiology and to assess graft type differences and associated clinical predictors. Methods: This prospective observational study included patients undergoing CABG at Rawalpindi Institute of Cardiology, Rawalpindi, Pakistan. Study was conducted over 6 months (July to December 2024). All patients underwent 640-slice CT angiography within 7–10 days postoperatively. Graft patency was assessed for arterial (LIMA) and venous (SVG) grafts. Data were analyzed using SPSS version 25. Associations between graft patency and clinical variables were evaluated using appropriate statistical tests, with p < 0.05 considered significant. Results: A total of 435 grafts were analyzed in the study population with a mean age of 56.3 ± 8.4 years; 91.3% were male. Hypertension was present in 37.3%, diabetes mellitus in 23.3%, and 50% were ex-smokers. Overall early graft patency was 97.3%, while 2.7% grafts were abnormal. Among abnormal grafts, most involved venous conduits, including occlusions and distal runoff disease, with only one LIMA occlusion observed. Arterial and venous graft complication rates were comparable (1.5% vs 1.7%). No significant association was found between graft patency and hypertension, diabetes, or smoking (p > 0.05). Early mortality was 1.3%. Conclusion: 640-slice CT angiography is a reliable and highly accurate non-invasive modality for early evaluation of graft patency following CABG, demonstrating excellent patency rates and low complication detection in the early postoperative period.