The Influence of Intraoperative and Postoperative Parameters upon the Results of Coronary Artery Bypass Surgery

Summary

One thousand ninety-six consecutive patients treated with aorta-to-coronary-vein bypass grafts were followed up to 4 years postoperatively. Early mortality was 1.7 %, overall 4-year survival rate, computed by actuarial methods, was 93.1 %. The incidence of perioperative myocardial infarction was 1.9 %. After 4 years 94.4 % of the patients were free of peri/postoperative infarcts. Angina pectoris was eliminated in 64.3 % of the survivors during the first and in 48.5 % during the fourth postoperative year.

The influence of number of grafts, degree of revascularization, aortic cross-clamp time, graft patency and postoperative anticoagulation upon the operative results was studied. Graft occlusion proved to be the single most important factor influencing mortality as well as infarction rate and symptomatic improvement.

The patency rate of 476 bypass veins, determined by angiography at a mean of 7 months postoperatively, was 91.8 %. Grafts with an intraoperatively measured flow of 40 ml/min or less, grafts constructed to the postero-lateral branch of the circumflex coronary artery, and grafts attached to coronary arteries with a lumen caliber of less than 1.5 mm at the site of the anastomosis showed comparatively high occlusion rates. Postoperative anticoagulants had no effect upon graft patency.

Key-Words:

Aortocoronary bypass - Survival rate - Peri-postoperative myocardial infarction - Functional class - Graft patency rate