Comparison between Internal Mammary Artery Implantation and Aorto-coronary Vein Bypass Grafting in Coronary Artery Disease with Significant Left Anterior Descending Stenosis

Summary

In 58 consecutive patients with coronary artery disease and significant left anterior descending (LAD) stenosis either internal mammary artery implantation (IMA group, n = 29) or aorto-coronary vein bypass grafting (SVG group, n = 29) were performed. The 2 groups showed no differences concerning age, left ventricular function, extent of coronary disease and, especially the extent of LAD disease. All patients were operated by the same surgeon. A coronary angiography was performed 3 months postoperatively. There was no early or late mortality. Duration of hospitalization was significantly shorter in IMA group compared to SVG group 11.5 vs 13.3 days, p < 0.05). In both groups 2.9 bypasses were implanted with a total patency rate of 88% and 76%, respectively (ins). A reexploration for bleeding had to be performed in 3 patients in IMA group and in one patient in SVG group; yet the amount of bleeding was not signficantly different in the 2 groups (1405 ml vs 1613 ml). After operation no statistical differences between the 2 groups could be found in the NYHA classes (1.15 vs 1.25) and the working capacity in the bicycle ergometery (87% vs 82% of the expected value). Postoperative left ventricular function was the same in both groups (EF = 59%). The patency rate of the IMA was 100% without any stenotic lesions. In SVG group 4 grafts were occluded, corresponding to a patency rate of 86%. Two venous grafts had a significant stenosis reducing the functional patency in SVG patients to 82%. Compared to IMA patency this difference is statistically significant (p < 0.02).

Conclusion: For the revascularization of the left ventricular anterior wall IMA implantation is preferred, provided the patient has no severe left heart hypertrophy, no left subclavian stenosis and the LAD lesion is significant (> 50% narrowing).

Key words

Left ventricular anterior wall revascularization - Internal mammary artery bypass graft - Saphenous vein graft - Coronary bypass patency