Serial angiographic evaluation 1 year and 9 years after aorta-coronary bypass. A study of 55 patients chosen at random.

This study was designed to evaluate the late changes of aorta-coronary bypass grafts in patients who have been selected at random. Angiography was performed at mean intervals of 12 months (range 1 to 24 months) and 107 months (range 72 to 132 months) after operation in 55 randomly selected patients who were operated upon between 1971 and 1973. A total of 101 grafts were visualized. In particular, the evolution of early graft changes was investigated. At the first angiogram, 83% of the grafts were patent, including 7% with important narrowing. Later, the patency rate decreased to 65%, and there was a 9% incidence of significant narrowing in the graft or distal anastomosis. The patency rate was low in grafts to the circumflex artery and high in those to the left anterior descending artery. Early and late graft function was influenced by the viability of the corresponding region of the myocardium. It was not possible to predict late occlusions by the morphologic appearance of the graft at the early angiogram, nor did a distal stenosis in the recipient artery contribute to graft failure. These findings may be related to the long interval between angiograms as the yearly occlusion rate rose with increasing intervals between the studies. At 9 years, 25% of the patients had all grafts patent and no progression in nonbypassed vessels.