Internal mammary artery bypass: thirteen years of experience. Influence of angina and survival in 5125 patients.

Internal mammary artery (IMA) bypass to the anterior descending coronary artery (ADA) was performed in 5125 patients from January 1978 to December 1990. The average age of patients was 68 years; males accounted for 68% (3485 patients) and 82% (4203) were NYHA Class III. Left ventricular function was impaired (ejection fraction < 40%) in 68% (3485 patients). The average number of additional saphenous vein graft (SVG) per patient was 2.2. Operative mortality was 1.8%. Mediastinitis occurred in 51 patients (1.0%). Reoperation for bleeding was necessary in 56 patients (1.1%). Perioperative myocardial infarction was seen in 102 patients (2.0%) and neurological complications occurred in 51 patients (1%). Repeat coronary angiography was performed in 1414 patients (28%) and demonstrated a patency rate of 96% in IMA grafts and 75% in SVG grafts (p < 0.001). Survival at 13 years was 80% from all causes and 90% when non-cardiac deaths were excluded. Recurrence of angina occurred in 768 patients (15%) and reoperation or PTCA was performed in 61 (1.2%). During the same time period, 2345 patients underwent coronary artery bypass utilizing solely SVG. Survival at 13 years was 68% from all causes and 78% when non-cardiac deaths were excluded (p < 0.001). Recurrent angina was present in 727 patients (31%) (< 0.001). This data suggests that long-term probability of cumulative survival and occlusion free survival were significantly greater and the probability of recurrent angina and reoperative CABG and death from cardiac causes were significantly less in the IMA patients and should be the conduit of choice in coronary bypass surgery.