A 55-year-old man suffers from an acute myocardial infarction after occlusion of the left anterior descending coronary artery. The patient undergoes coronary bypass surgery 3 days later. Which of the following is the most frequent cause of saphenous vein graft failure several years following coronary bypass surgery?

Saphenous veins are used as autografts in coronary artery bypass surgery. These grafts usually undergo a series of adaptive and reparative changes. Venous grafts in place for 5 to 10 years typically show atherosclerotic plaques that are indistinguishable from those found in native coronary arteries, a process referred to as atherosclerotic "restenosis."Diagnosis: Atherosclerosis