How does diabetes mellitus influence CABG outcomes and graft patency?

• A. Diabetes increases risk of graft occlusion, infection, wound healing problems, and mortality; arterial grafts and optimized metabolic control can improve outcomes.
• B. Diabetes has no impact on CABG outcomes.
• C. Diabetes reduces the need for arterial grafts.
• D. Diabetes improves wound healing.

Answer: (A)

Diabetes mellitus raises risk in CABG by promoting higher rates of graft occlusion, infection, wound-healing problems, and death. This happens because hyperglycemia and its metabolic consequences drive immune dysfunction, increased inflammation, endothelial damage, and diffuse vascular disease, all of which blunt healing and favor clotting and graft failure. When arterial conduits are used—such as internal mammary arteries—they tend to stay open longer than vein grafts, and this advantage is especially important in diabetics who have accelerated atherosclerosis and graft occlusion risk. Pairing this with optimized metabolic control around the time of surgery further reduces infection, improves wound healing, and supports better graft patency and overall outcomes. So the statement that diabetes adds risk and that arterial grafting with good metabolic control can improve results best describes the impact on CABG outcomes and graft patency. The other ideas—no impact, reduced need for arterial grafts, or improved wound healing in diabetes—don’t fit the evidence.