Quantitative assessment of myocardial performance and graft patency following coronary bypass with the internal mammary artery
Vogel, J.H.; McFadden, R.B.; Spence, R.; Jahnke, E.J.; Love, J.W.
Journal of Thoracic and Cardiovascular Surgery 75(4): 487-498
1978
ISSN/ISBN: 0022-5223 PMID: 642544 Document Number: 133851
The internal mammary artery (IMA) has failed to gain wide acceptance as a bypass conduit because of doubt as to its effectiveness for myocardial perfusion. To assess the functional capacity of the IMA, 95 patients, receiving only an IMA graft, were followed up to 58 mo. Forty-five patients had preinfarction angina, 23 had unstable angina, 6 had acute myocardial infarction, 10 had paroxysmal ventricular tachycardia-fibrillation, 7 had congestive heart failure, 11 had stable angina and 4 were asymptomatic. Of 140 IMA grafts, 79 were to the left anterior descending coronary artery, 30 to the right coronary artery, 2 to the diagonal, 28 to the circumflex and 1 to a perforator. Thirty-six patients had 3 vessel disease, 35 had 2 vessel disease and 24 had 1 vessel disease. Systolic ejection fractions were less than 49% in 26 patients. Early postoperative studies were performed in 90 patients. Of 133 grafts studied, 132 were patent. Late studies in 6 patients showed enlargement of the IMA. The systolic ejection fraction improved in 32 patients, including 16 of 28 with values of less than 50% preoperatively. Of 119 treadmill stress tests performed, 71 produced normal responses at maximal load and 41 produced normal responses at submaximal load. No late graft closure was documented. Of the patients, 95% are free of angina, and all are free of arrhythmias. There were 7 late deaths, 3-22 mo. postoperatively, all occurring in patients with preoperative ejection fractions less than 48%. The IMA is apparently an excellent conduit for myocardial revascularization in all positions except the distal right coronary artery.