Course of angina 1 to 12 years after aortocoronary bypass surgery related to changes in grafts and native coronary arteries.

Among 500 patients who received aortocoronary saphenous vein grafts at the Montreal heart Institute between September 1969 and August 1972, the condition in 88% of survivors with respect to angina pectoris was improved 1 year after surgery and 47% were still better after 12 years. One year after grafting, 202 patients underwent follow-up angiography; symptoms of angina had lessened in 89% who had at least one graft patent but in only 57.5% of those with all grafts occluded. This difference was still obvious 12 years after surgery. Loss of improvement decreased at a mean annual rate of 3.7%. Of the 59 angina-free patients at 1 year who had angiographic follow-up at 10 to 12 years, angina developed subsequently in 30 (51%); 25 (83%) of these were found to have obstructive changes that reduced the lumen by at least 50% in grafts or in ungrafted coronary arteries, compared with only 13 (45%) of the 29 angina-free patients who did not have angina subsequently. Improvement in the degree of angina and its recurrence after bypass surgery are closely related to graft patency and subsequent development of atherosclerosis in the grafts or in the native coronary arteries.