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Objectives: This study defined long-term patency of saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts., Background: This VA Cooperative Studies Trial defined 10-year SVG patency in 1,074 patients and left IMA patency in 457 patients undergoing coronary artery bypass grafting (CABG)., Methods: Patients underwent cardiac catheterizations at 1 week and 1, 3, 6, and 10 years after CABG., Results: Patency at 10 years was 61% for SVGs compared with 85% for IMA grafts (p < 0.001). If a SVG or IMA graft was patent at 1 week, that graft had a 68% and 88% chance, respectively, of being patent at 10 years. The SVG patency to the left anterior descending artery (LAD) (69%) was better (p < 0.001) than to the right coronary artery (56%), or circumflex (58%). Recipient vessel size was a significant predictor of graft patency, in vessels >2.0 mm in diameter SVG patency was 88% versus 55% in vessels 2.0 mm in diameter.

Background: High-dose aprotinin reduces transfusion requirements in patients undergoing coronary artery bypass grafting, but the safety and effectiveness of smaller doses is unclear. Furthermore, patient selection criteria for optimal use of the drug are not well defined., Methods: Seven hundred and four first-time coronary artery bypass grafting patients were randomized to receive one of three doses of aprotinin (high, low, and pump-prime-only) or placebo. The patients were stratified as to risk of excessive bleeding., Results: All three aprotinin doses were highly effective in reducing bleeding and transfusion requirements. Consistent efficacy was not, however, demonstrated in the subgroup of patients at low risk for bleeding. There were no differences in mortality or the incidences of renal failure, strokes, or definite myocardial infarctions between the groups, although the pump-prime-only dose was associated with a small increase in definite, probable, or possible myocardial infarctions (p = 0.045)., Conclusions: Low-dose and pump-prime-only aprotinin regimens provide reductions in bleeding and transfusion requirements that are similar to those of high-dose regimens. Although safe, aprotinin is not routinely indicated for the first-time coronary artery bypass grafting patient who is at low risk for postoperative bleeding. The pump-prime-only dose is not currently recommended because of a possible association with more frequent myocardial infarctions.

Background: The Perma-Flow prosthetic coronary graft is a 5-mm polytetrafluoroethylene tube into which is incorporated a Venturi flow restrictor. An aorto-superior vena caval fistula is created and coronary anastomoses are constructed proximal to the resistor in side-to-side fashion, where arterial pressure is maintained. From November 1992 through December 1995, eight investigational centers in North America have implanted this graft in 40 patients with inadequate autologous alternatives., Methods: Patients were selected for inclusion in this study if coronary artery bypass grafting was required and adequate autologous conduit to complete revascularization was not available. Operative data were completed by the implantating surgeon and referred to a central center, the Minneapolis Heart Institute, for correlation. Follow-up was conducted by data coordinators at each institution, and follow-up data were obtained directly from these coordinators for inclusion in the study., Results: Patient age ranged from 53 to 82 years, and 15 patients were undergoing reoperations (38%). On each Perma-Flow graft one to four coronary side-to-side anastomoses were constructed. In addition, left internal mammary artery (n = 26), greater saphenous vein (8), right internal mammary artery (4), and gastroepiploic artery (4) were used to complete revascularization. Aortic (2) or mitral valve replacement (1) was also carried out. There were seven operative deaths (18%) and two late deaths (4 and 6 months). After 1 to 37 months (mean, 13 +/- 9 months) of follow-up, 29 of 31 surviving patients are asymptomatic. Echocardiographic heart size has not increased from the postoperative value, indicating limited volume load has not affected heart size. Protocol catheterization (n = 32) in 28 patients 1 week to 1 year postoperatively revealed 7 of 73 studied coronary anastomoses (9.5%) and two distal extensions and resistors were occluded (7%). In 1 patient during sternal debridement at 1 year, no flow was found in the graft., Conclusions: The Perma-Flow graft is a useful adjunct to complete revascularization in patients with deficient autologous conduit.

Considerable controversy exists regarding relative morbidity associated with the saphenous vein graft (SVG) and internal mammary artery (IMA) graft in patients undergoing myocardial revascularization. As a part of the cooperative study on use of antiplatelet drugs for graft patency, operative and postoperative data were prospectively collected on 1,150 patients who underwent either SVG (n = 656) or IMA anastomosis (n = 494) to the left anterior descending coronary artery. There were no differences in baseline characteristics of patients, distribution of randomization among treatment groups, and total number of distal anastomoses performed between the two groups. The aortic cross-clamp time, cardiopulmonary bypass duration, operative time, and chest tube drainage were greater (p = 0.0001) in the patients with IMA grafts compared with SVG. However, there was no difference in the operative mortality rate, the amount of blood and blood products received, the reoperation rate for control of postoperative bleeding, and incidence of wound complications between the two groups. The early and 1-year patency rates for the IMA were slightly but not significantly better than the SVG patency rates (92.8% versus 90.1% for 1-year patency; p = 0.309). In conclusion, use of IMA is associated with a longer operative time as well as increased postoperative bleeding compared with the SVG. It, however, does not increase operative mortality or postoperative morbidity.

The perioperative consequences of preoperative aspirin administration were assessed in a large prospective cooperative study of 772 patients undergoing coronary artery bypass grafting. The 772 patients were randomized to receive either aspirin (325 mg once a day), aspirin (325 mg three times a day), aspirin plus dipyridamole (325 and 75 mg together three times a day) (aspirin group), sulfinpyrazone (267 mg three times a day) or placebo (nonaspirin group). The therapy, except in the aspirin group, was started 48 h before the operation. In all aspirin subgroups, one 325 mg aspirin dose was given 12 h before surgery and maintained thereafter according to the assigned regimen. Patients in the aspirin group had significantly more postoperative bleeding and received more packed blood cells and blood products than did patients in the nonaspirin group. Although total operative duration and cardiopulmonary bypass duration were not different, the interval between completion of cardiopulmonary bypass and wound closure was significantly longer (p = 0.035) in the aspirin group. Thirty-one (6.6%) of 471 patients in the aspirin group and 5 (1.7%) of 301 patients in the nonaspirin group also required reoperation for control of postoperative bleeding (p = 0.002). The site of bleeding found at reoperation was not different between the two groups. There was no difference in operative mortality rates, incidence of other bleeding complications or occurrence of other post-operative complications between the two groups. Thus, antiplatelet regimens involving preoperative initiation of aspirin therapy, which has been shown to improve graft patency, increase the risk of abnormal postoperative bleeding and the need for reoperation.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe stenosis of the left main coronary artery developed in a 58-year-old woman 9 years after orthotopic heart transplantation. Because of serious reversible myocardial ischemia and the high-risk nature of the coronary disease, coronary artery bypass grafting was performed, with no complications. Possible risk factors for the development of coronary arterial disease and its management in the transplant population are discussed.

A prospective, randomized comparison of the hemodynamic effects of dopamine and dobutamine was performed in 20 patients following coronary artery bypass grafting. Approximately 6 hours postoperatively, when patients were hemodynamically stable, either dopamine or dobutamine was administered at 2.5, 5.0, and 7.5 micrograms per kilogram of body weight per minute. At 5.0 micrograms/kg, both drugs increased cardiac index without changing heart rate, mean arterial pressure, pulmonary capillary wedge pressure, or peripheral vascular resistance. At 7.5 microgram/kg, dobutamine caused a further increase in cardiac index without changing the other variables. In contrast, increasing dopamine from 5.0 to 7.5 micrograms/kg/min caused significant increases in mean arterial pressure, pulmonary capillary wedge pressure, and pulmonary vascular resistance but no further increase in cardiac index. We conclude that dobutamine is preferable to dopamine in patients following coronary artery bypass grafting, since it produces consistent, dose-related increases in cardiac index without increases in heart rate, mean arterial pressure, pulmonary capillary wedge pressure, or pulmonary vascular resistance.

We explored techniques that would allow the surgeon to localize coronary artery lesions demonstrated angiographically or to supplement angiographic information in patients who are undergoing coronary artery bypass procedures by intraoperative scanning of the coronary arteries using ultrasound. A 9-MHz electronically focused water-path ultrasound scanner was first used to image the coronary arteries in three anesthetized, open-chest sheep. In a subsequent study, 10 human subjects undergoing cardiac surgery for valve replacement who had normal coronary angiograms were scanned during heart surgery to provide images of normal coronary arteries. The ultrasound probe was sterilized with gas and placed directly on the beating heart by the surgeon. In the third phase of this study, 21 patients with coronary artery disease were scanned and the ultrasonic appearance of their imaged coronary lesions was compared to independently interpreted angiographic estimates of percent obstruction, with close correlation (r = 0.91). The ultrasound scan could be used to identify lesions in vessels beyond proximal occlusions, which are not visualized well angiographically, and could localize the site of lesions to determine placement of saphenous vein bypass grafts. This new technique may provide a method for evaluating coronary atherosclerotic lesions during coronary artery surgery and aid decisions regarding placement of saphenous vein grafts.

Combined repair of peripheral vascular disease and myocardial revascularization has become accepted treatment in selected patients. Two of our patients underwent such a procedure. One patient suffered an intraoperative dissection of the ascending aorta following myocardial revascularization. Ascending aortic replacement and vein graft reimplantation was accomplished as well as repair of the abdominal aortic aneurysm. Because of this experience we recommend that following myocardial revascularization, aortic cannulation be maintained during repair of the abdominal aortic aneurysm. This allows immediate access to cardiopulmonary bypass should untoward cardiovascular events occur during aneurysm repair.

Two areas of current controversy concerning coronary artery bypass operations involve the use of cardioplegia and the need for left ventricular venting. We wish to describe a very simple, safe, and effective method of accomplishing both cardioplegic arrest and venting using a single 14-gauge catheter inserted into the aortic root.

The hemodynamic effects of vasodilator treatment (afterload reduction) with nitroprusside at a constant heart rate were studied in 24 patients early after aorta-coronary bypass grafting. In 12 patients, dose-response relationships were determined. Graded incremental infusions of nitroprusside produced progressive decreases in mean arterial pressure (MAP), right and left atrial pressures, and stroke work index. Stroke volume index and cardiac index rose significantly until MAP was reduced below the range of 80 to 90 mm. Hg, and then they fell to base-line levels owing to insufficient preload. In an additional 12 patients, MAP was reduced with nitroprusside to the range of 80 to 90 mm. Hg, and left atrial pressure was then restored to base-line levels during continued vasodilator administration. This sequence resulted in further augmentation of stroke volume index to a level higher than that produced by nitroprusside alone. We conclude from this investigation that nitroprusside is a clinically useful agent for primary or adjunctive therapy of mild-to-moderate low cardiac output states immediate postoperatively and that simultaneous regulation of left ventricular preload and after load during its administration is necessary in order to achieve maximal hemodynamic benefit.

Purpose: To determine the efficacy of antiplatelet or anti-coagulant therapy in preventing graft occlusions after coronary artery bypass surgery., Data Identification: Studies published from 1966 to 1988 were identified through a computerized search using MEDLINE, by searching the bibliographies of all identified articles, and by consulting with the cardiologists and cardiothoracic surgeons in the Veterans Administration Cooperative Study Group on Antiplatelet Therapy After Coronary Artery Bypass Surgery., Study Selection: All studies selected were randomized, controlled clinical trials comparing at least one active drug with a placebo or nonplacebo control group., Data Extraction: Key data were extracted from each article, including the percentage of patients in each treatment group with one or more grafts occluded, the percentage of patients with completed postoperative catheterizations, timing of postoperative catheterization, and timing of start of treatment. These data were easily obtained from each article and did not require multiple observers., Results of Data Analysis: All studies had positive treatment-effect sizes in favor of active treatment, although some studies did not achieve statistical significance. A meta-analysis combining all treatment effects clearly shows that active treatment is beneficial (overall effect size = 0.30; CI, 0.21 to 0.38). Efficacy improves with early initiation of treatment., Conclusions: Early initiation of antiplatelet or anticoagulant drugs reduces the incidence of graft occlusions after coronary artery bypass surgery.

Two different operative techniques for aorta-coronary bypass grafting were utilized in two comparable groups of patients. In one group (155 patients) distal anastomoses were carried out with the aorta cross-clamped and myocardial protection provided by profound local hypothermia (clamped group). In a second group (149 patients) distal anastomoses were carried out with the aorta unclamped and the left ventricle fibrillating and vented (unclamped group). Mortality rates were similar in the two groups (0.6 per cent in clamped group versus 1.3 per cent in unclamped group). The incidence of perioperative infarction was 15 per cent in the unclamped group and 8 per cent in the clamped group (p less than 0.05). Postoperative serum glutamic oxaloacetic transaminase (SGOT) and lactic dehydrogenase (LDH) levels were significantly higher for the first 4 postoperative days in the unclamped group than in the clamped group. Hemodynamic studies in a subset of each group revealed no important differences in left ventricular function in the immediate postoperative period. The data demonstrate that in patients undergoing aorta coronary bypass grafting, performance of distal anastomoses with aortic cross-clamping and profound local hypothermia results in less intraoperative myocardial injury than performance of distal anastomoses in the perfused, fibrillating, and vented left ventricle.