The Journal of Thoracic and Cardiovascular Surgery, Vol 71, 348-354, Copyright © 1976 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Surgical treatment of unstable angina by saphenous vein and internal mammary artery bypass grafting
AS Geha, AE Baue, RJ Krone, RE Kleiger, GC Oliver, JR McCormick and A Salimi
During a 3 year period, direct myocardial revascularization was performed
on an urgent basis in 48 patients with intermittent resting chest pain
which persisted more than 24 hours despite in-hospital medical therapy and
was accompanied by electrocardiographic changes representative of ischemia.
Sixteen patients had saphenous vein (SV) grafts exclusively, and 32
patients each had one or two internal mammary artery (IMA) grafts with or
without additional vein grafts. Follow-up ranges from 5 to 41 months (mean,
22 months). Twelve patients had single grafts to the left anterior
descending coronary artery (LAD), 18 had double grafts, 16 had triple
grafts, and 2 had quadruple grafts. The LAD required grafting in every
patient. There was one operative death (2 per cent) and one late death from
noncardiac causes. There were two (4 per cent) early postoperative
myocardial infarcts and no late infarcts. Actuarial analysis projects a
survival rate of 96 per cent 3 years postoperatively. Eighty-one per cent
of the survivors are in Functional Class I, 17 per cent are in Class II,
and 2 per cent are in Class III. All patients had postoperative angiography
2 weeks after operation. Eighty-six per cent of the SV grafts and all IMA
grafts were open. No significant differences were observed between mean
preoperative and postoperative left ventricular end-diastolic pressures or
ejection fractions, but these parameters were noted to improve after
operation in several patients. The remarkably high early and late survival
rates, the low incidence of myocardial infarction, and the excellent
functional results after rather long follow-up indicate that emergency
coronary revascularization provides an effective therapy for unstable
angina. The use of IMA grafts, when feasible, is a safe and possibly
preferable approach in these patients.