Internal mammary artery bypass grafting: influence on recurrent angina and survival in 2,100 patients

Internal mammary artery (IMA) bypass grafting to the anterior descending coronary artery was performed in 2,100 patients between January 1978 and July 1986. The average number of additional saphenous vein grafts (SVGs) per patient was 1.8. During the same period, 1,753 patients underwent coronary artery bypass grafting using an SVG (average number of grafts per patient, 3.2). The average patient age was similar: 62.3 years for IMA grafts and 64.7 years for SVGs. Men constituted two thirds of each group. Left ventricular function was impaired (ejection fraction less than 45%) in 1,071 (51%) of IMA grafts and 847 (48.3%) of SVGs. Other aggregate risk factors, ie, elevated blood pressure, diabetes mellitus, previous myocardial infarction, and congestive heart failure, were similar in each group. Operative results and postoperative mortality of the IMA and SVG patients were comparable. However, the long-term probability of cumulative survival and occlusion-free survival were significantly greater and the probability of recurrent angina and reoperative coronary artery bypass grafting were significantly less in IMA graft patients (p less than 0.015). The relative risk of occlusion in an SVG was 4 to 5 times greater than that of the IMA graft. These data indicate that a patent IMA graft to the anterior descending coronary artery protects against recurrent angina and death from cardiac-related causes, and that the IMA should be the conduit of choice.     

Internal mammary artery bypass: effect on longevity and recurrent angina pectoris in 2900 patients

Internal mammary artery bypass (IMA) to the anterior descending coronary artery was performed in 2900 patients from January 1978 to December 1987. The average age of the patients was 64 years. Males accounted for 68% (1972 patients) and 82% (2378 patients) were in New York Heart Association (NYHA) class III. Left ventricular function was impaired in 51%. The average number of additional saphenous vein grafts per patient was 1.8. The operative mortality was 1.6%. Mediastinitis occurred in 29 patients (1%). Reoperation for bleeding was necessary in 32 patients (1.1%). Perioperative myocardial infarction (MI) was seen in 58 patients (2%) and neurological complications occurred in 32 patients (1.1%). Repeat coronary angiography was performed in 703 patients (25%) and demonstrated a patency rate of 96% in IMA grafts and 81% in saphenous vein grafts (SVG). Survival at 9 years was 90% from all causes and 95% when noncardiac deaths were excluded. Recurrence of angina occurred in 522 patients (18%) and reoperation was performed in 15 patients (0.5%). During the same time period, 1783 patients underwent coronary artery bypass utilizing a SVG. Survival at 9 years was 78% from all causes and 83% when noncardiac deaths were excluded. Recurrent angina was present in 546 patients (39%). These data suggest that a patent-IMA to the anterior descending protects against recurrent angina and death from cardiac causes and should be the conduit of choice.     

Internal mammary artery: methods of use and their effect on survival after coronary bypass surgery

Hazard analysis of total and cardiac mortality after isolated primary coronary artery surgery was performed using univariate and multivariate methods with special emphasis on the importance of the use and method of use of the internal mammary artery (IMA) as a bypass graft. The clinical data of 5880 consecutive patients were studied. The sum of the real follow-up periods studied was 27,948 years. The hazard of total and cardiac mortality could be defined in three-phase parametric models with an early, a constant and a late phase. The total survival was 82% +/- 1% at 10 years and 59% +/- 3.6% at 15 years. The construction of a single IMA distal graft (using left or right IMA) had a positive influence on the hazard (P = 0.0004) in the late phase after surgery with a high estimate (-1.6). The cardiac survival was 89% +/- 0.8% at 10 years and 74% +/- 3.5% at 15 years. The use of the left IMA had a positive influence (P = 0.001) in the late phase after surgery with a very high estimate (-2.3). The generated simulation of the total survival of a median patient with an IMA graft is 97% at 5 years and 94% at 10 years; for a median patient without an IMA graft, it is 97% at 5 years and 88% at 10 years. If a patient has other risk factors reducing his life expectancy, the influence can be dissipated because of lower survival rates at 5 years after surgery, when the effect of the IMA becomes most apparent.(ABSTRACT TRUNCATED AT 250 WORDS)     

Aorta-coronary bypass grafting with the internal mammary artery: clinical experience in 70 patients.

Clincal and angiographic results in 70 patients who received free internal mammary artery (IMA) grafts are reviewed. One postoperative death occurred, but it was not related to the free IMA technique. Forty-seven patients underwent postoperative arteriography. The average interval between operation and catheterization was 10.7 months, and the patency rate for 49 free IMA grafts was 89.8 per cent. Of the 29 patients who recieved free IMA grafts as the only revascularization procedure, 21 patients (80 per cent) progressed to Functional Class I and only 5 patients did not have improvement in their functional status.     

Internal mammary artery bypass graft--long-term patency rate and follow-up

Between December, 1968, and January, 1974, 814 internal mammary artery and 351 saphenous vein bypass graft procedures were performed in 628 patients. Operative mortality during the past 3 years has been 1.7%. Internal mammary artery bypasses were performed to the anterior descending, circumflex, obtuse marginal, distal right, and posterior descending right coronary arteries. Ninety-one patients having 137 internal mammary artery and 32 saphenous vein grafts were studied angiographically 12 to 36 months postoperatively. All but 2 internal mammary artery bypasses were patent, a patency rate of 98.5%; 27 of the 32 saphenous vein bypasses in this group were patent (84.3%). The majority of the internal mammary artery bypasses were to distal coronary arteries, while the saphenous veins were used primarily for proximal anastomosis. Cineangiographic volume/flow studies were also performed. The average flow in the more distal internal mammary artery bypasses was 61 ml. per minute as compared with 91 ml. per minute in the proximal saphenous vein grafts.     

Internal mammary artery to coronary artery bypass in paediatric cardiac surgery

The internal mammary artery is regarded as the optimal conduit for coronary artery bypass grafting in adults. Use of this conduit in paediatric surgery is rare and has been reported mainly in patients with Kawasaki's disease. We report five patients who required internal mammary-coronary artery grafting due to adverse anatomical disposition of the coronary artery. In two cases an internal mammary graft was required during correction of transposition of the great arteries. The other cases involved correction of a left coronary artery arising anomalously from the pulmonary artery. Late angiography shows satisfactory growth and patency of the conduits.     

Internal mammary artery grafting. Clinical results, patency rates, and long-term survival in 833 patients

This report reviews 833 patients who underwent internal mammary artery grafting alone or with vein grafts between 1968 and 1981. Use of the internal mammary artery was indicated in young or middle-aged patients with the following characteristics: a significant lesion of the proximal left anterior descending artery or its diagonal branch alone (70.1%) or combined with diffuse atherosclerosis (19.9%) or a small caliber (3.4%); absent or unsuitable veins for grafting (5.5%); atherosclerosis or an aneurysm of the ascending aorta (0.6%); and failure of previous vein grafts (0.5%). The left anterior descending artery system was grafted by the left internal mammary artery in 53.2%, and the arterial graft was complimented by vein grafts in 2.6%. In 45.2% of the patients, grafts of the left anterior descending artery by the left internal mammary artery were supplemented by vein grafts to the right coronary artery (23.8%), to the circumflex artery (15.2%), or to both (6.2%). The overall operative mortality was 2.2%. It rose to 16.7% with associated cardiac procedures and to 18.5% in patients who were in New York Heart Association Class IV. If these two high-risk categories of patients are excluded, the perioperative death rate in the remaining 750 was only 0.4%. Of the 815 patients who survived the perioperative period (mean 53.1 months follow-up), 63.1% were relieved of angina and 83.4% were in Class I or II of the New York Heart Association, as compared to 27.4% before the operation. At cardiac recatheterization (mean 18.9 months), 87.9% of the internal mammary artery grafts and 63.3% of the vein grafts were patent (p less than 0.05). The cumulative actuarial 10 year survival rate was 88.6% +/- 1.3%.     

Surgical treatment of unstable angina by saphenous vein and internal mammary artery bypass grafting.

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.     

Internal mammary artery graft: retrospective report with 17 years' survival

This report describes one of the earliest cases of successful internal mammary artery grafting. A left internal mammary-right coronary artery titanium stent anastomosis was performed on Jan. 5, 1968, at Allegheny General Hospital. Repeated cardiac catheterization 2 weeks, 6 months, and 6 years after the operation showed a patent anastomosis. The patient survived over 17 years after the operation.     

Coronary artery bypass surgery in patients with angina pectoris and hypothyroidism.

The treatment of hypothyroidism in patients undergoing coronary artery bypass surgery is a difficult clinical problem. To determine perioperative thyroid replacement therapy in patients with hypothyroidism, plasma total thyroxine (T4), total triiodothyroxine (T3), free T4, free T3 and thyroid-stimulating hormone levels were measured preoperatively and at 1, 2, 3, 7, and 14 days after operation in 9 patients with hypothyroidism and were compared with levels in 14 patients with normal thyroid function who underwent coronary bypass surgery. In the normal control group, total T4 decreased to its lowest level on the 1st postoperative day and then increased gradually to the preoperative level at 7 days. Total T4 remained within the normal range throughout the entire postoperative course. In 6 patients with hypothyroidism who were treated with thyroid hormone before surgery, total T4 decreased immediately after operation and only increased after starting thyroid replacement therapy. In 3 hypothyroid patients without prior thyroid replacement, total T4 showed a change similar to patients in the control group but remained below the normal range until starting thyroid replacement therapy. Coronary bypass surgery was performed safely in patients with hypothyroidism. Preoperative thyroid replacement with suboptimal doses was safe in patients with severe hypothyroidism. Adequate postoperative thyroid replacement was achieved in all patients without complications.     

Internal mammary artery: a "live" conduit for coronary bypass

An angiographic study of the internal mammary artery graft 8 years postoperatively illustrates the physiological nature of this conduit. Changes in the caliber of the internal mammary artery graft are seen to occur in response to changes in the size of the coronary vascular bed, a phenomenon of autoregulation. This physiological adaptability differentiates the internal mammary artery graft from the saphenous vein graft and may be one of the reasons for excellent long-term performance of this conduit.     

70岁以上冠状动脉旁路移植术病人乳内动脉流量测量分析

目的 分析70岁以上冠状动脉旁路移植术病人乳内动脉旁路血管血流量的特点.方法 对2003年1月至2007年1月间78例70岁以上(含70岁)应用乳内动脉非体外循环冠状动脉旁路移植手术(OPCAB)的病人,使用瞬时超声血流测量技术对其乳内动脉平均血流量、搏动指数等指标进行测量并分析.结果 78例病人83根乳内动脉旁路血管平均流量(36.0±21.5)ml/min,平均搏动指数3.50±1.76,血流波形均以舒张期为主.男女性别比、平均流量和搏动指数差异无统计学意义[(39.0±23.1) ml/min对(28.0±14.7) ml/min;(3.30±1.50)对(4.10±2.22),P>0.05],但女病人平均流量较男病人偏低,搏动指数较男病人偏高.结论 70岁以上病人冠状动脉旁路移植术应用乳内动脉是安全、有效的;对老年病人乳内动脉流量的评价分析应当结合老年病人的病变特点.     

Internal mammary artery graft to pulmonary vasculature fistula: a cause of recurrent angina

Recurrent angina pectoris developed in a 59-year-old man 3 years after coronary artery bypass grafting using the left internal mammary artery. Cardiac catheterization showed a fistula between the left internal mammary artery and the pulmonary vasculature. This is an unusual documented case of postoperative internal mammary artery graft to pulmonary vasculature fistula after coronary artery bypass grafting. Division of this fistulous communication resulted in resolution of the patient's angina.     

Double and sequential mammary artery bypass grafts. Apropos of 184 patients

In this series of 184 patients (pts), 312 internal mammary arteries were used to graft 430 coronary arteries. Two mammary arteries were used in 104 pts and sequential anastomoses were performed in 118 pts. The operative mortality was 1.6% and the peri-operative myocardial infarction was 4.1%. 9% of patients had post-operative complications: 1% of bilateral phrenic paralysis, 2.1% of post-operative hemorrhage leading to reoperation, 1.6% of sternal infection, 0.5% of true mediastinal infection, 1.6% of sternal dehiscence and 2.7% of reversible psychiatric illness. A 3 month follow-up was available in 160 pts. 95% of patients became angina free, the thallium scan shown a normal uptake of thallium at maximal stress in the myocardial grafted area in 92% of the patients.     

Different responses of coronary artery and internal mammary artery bypass grafts to ergonovine and nitroglycerin in variant angina

The dynamic responses of a coronary artery and an internal mammary artery (IMA) graft to pharmacological intervention were examined by arteriography in 5 patients with variant angina who had undergone coronary artery bypass grafting with an in situ IMA to the left anterior descending coronary artery. Preoperative electrocardiographic findings included elevated ST segments in chest leads during attacks of angina, and all patients had severe fixed lesions in addition to marked spasm of the left anterior descending coronary artery after the administration of ergonovine maleate. Postoperatively with ergonovine stimulation, complete occlusion or marked subtotal narrowing was again observed at the primary fixed lesion in the proximal portion of the left anterior descending coronary artery, but the IMA graft and the coronary artery distal to the anastomotic site maintained satisfactory patency with no further occurrence of anginal pain or ST segment elevation. By computer-assisted graphic analysis, which allows highly reproducible measurements of vascular internal diameters, the diameter of the IMA showed only small changes under ergonovine (p = not significant) or nitroglycerin (p less than 0.05) stimulation in contrast to the marked vascular reactivity of the coronary artery (p less than 0.05 and less than 0.01, respectively). These findings indicate that the IMA graft is unresponsive to ergonovine at least in the amount required to produce coronary artery spasm in patients with variant angina and fixed lesions. The IMA graft appears to function well from a clinical and pharmacological viewpoint in patients with variant angina.