Increase in severity of proximal coronary disease after successful distal aortocoronary grafts. Its nature and effects.

Aortocoronary vein grafts were placed in seven patients to bypass severe proximal stenosis in nine coronary arteries. Routine postoperative angiography showed patent grafts in all patients and substantial increase of proximal occlusive disease, diffusely or at the points of narrowing, in six of nine arteries (four patients), with complete obstruction of four of the six vessels. Two of the four patients experienced improvement in angina which was sustained despite the advanced proximal disease. The third patient suffered a late postoperative myocardial infarction and the fourth had recurrence of angina, both probably as a result of the increased proximal disease. The possibility is considered that a successful vein graft, by diverting flow from the poststenotic segment, may accelerate its occlusion and that consequences of advancing occlusive disease may not be prevented by vein-grafting surgery.