The history of coronary artery surgery has taken place

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1 Coronary Artery Surgery Floyd D. Loop, MD Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Foundation, Cleveland, Ohio The history of coronary artery surgery has taken place across a continuum of discovery spanning more than 40 years, involving hundreds of physicians and scientists, and thousands of scientific studies. During this time, surgical techniques evolved through a labyrinth of success and failure (Fig 1). A generation of pioneering cardiothoracic surgeons established the efficacy of venous and arterial bypass grafts and refined patient selection. By the 1980s, coronary artery surgery was one of the most commonly performed major surgeries on earth, and excellent results had become routine. The pathway that eventually led to the development of coronary artery surgery began in 1902, with the work of Alexis Carrell, whose experiments in blood vessel anastomoses earned him the Nobel Prize in As early as the 1930s, surgeons were attempting myocardial revascularization by means of talc poudrage and omentopexy. Internal mammary ligation and implants were also tried. But modern cardiac surgery could not become a practical reality until the mid-20th century, with the development of the pump oxygenator and selective cine-coronary arteriography. The coronary arteriogram was the serendipitous discovery of Frank Mason Sones, a pediatric cardiologist at The Cleveland Clinic. In 1957, he was the first to combine cardiac catheterization with high-speed x-ray motion picture photography. During the next 4 years, he and Earl Shirey performed arteriograms in 1,000 patients, reporting their results in 1962 [1], and effectively launching the modern era of coronary artery surgery. In the early 1960s, Sones catheterized internal mammary (internal thoracic artery) implant patients operated on by Vineberg and Bigelow and showed that collaterals had formed between the implant and the coronary circulation. Several surgeons tried a more direct approach, by means of either bypass grafting or endarterectomy and patch grafts. One of these aortocoronary vein grafts, performed by Garrett and DeBakey in 1964, was found to be open 7.5 years postoperatively [2]. However, the series by Favaloro [3] from Cleveland and Johnson and associates [4] from Milwaukee demonstrated early patency of vein grafts even in patients with relatively poor left ventricular function. One of the most significant but unheralded events during that time was the determination and documentation of the natural history of coronary atherosclerosis by Presented at the 4th Annual Lillehei Heart Institute Symposium Celebrating the 50th Anniversary of Open-Heart Surgery by Cross Circulation, Minneapolis, MN, Oct 19 20, Address reprint requests to Dr Loop, Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44106; fdl@ccf.org. means of arteriography. The studies of Proudfit and colleagues [5] showed that the greatest determinant of survival was baseline left ventricular performance and secondarily by the extent of coronary atherosclerosis. Our knowledge of coronary artery disease has exploded in recent years. Treatment had traditionally been aimed at what was believed to be an inert collection of cholesterol, fibrosis, and calcium that grew unpredictably until it compromised or stopped blood flow. Today, we know that atherosclerosis is multifactorial, dynamic, episodic, and vulnerable to new therapies. What are the implications of this new view of atherosclerosis? We know that atherosclerosis is not a plumbing problem. The atherosclerotic plaque differs in cell composition. Cell types in the plaque, not the size of the plaques, determine the risk of fatal events. Inflammatory cells and various mediators influence the pathogenesis. Drugs and lifestyle modifications are able to reduce the number of clinical events. The traditional risk factors for atherosclerosis have been studied in a massive 52-country investigation, which concluded that smoking, adverse lipid profile, hypertension, and diabetes had greater relative effect on risk of myocardial infarction in younger compared with older individuals, indicating that most premature myocardial infarction is preventable [6]. Worldwide, the two most important risk factors are smoking and abnormal lipids. In particular, smoking even a few cigarettes a day increases risk. Evolution of Surgical Treatment The past 40 years alone have seen at least 50 major advances in cardiac specialties. Randomized prospective studies were one of the first technological developments. The early trials were instrumental in refining selection and setting surgical standards. During the next decade as myocardial protection and extracorporeal circulation improved, coronary artery surgery techniques became standardized and the mortality dropped from greater than 10% to less than 5%. The cardiothoracic anesthesiologists advanced the specialty by standardizing pulmonary artery pressure monitoring and cardiac output techniques. Antegrade and retrograde blood cardioplegia improved myocardial protection [7]. Conduits changed, left ventricular support was added, the cardiologists developed balloon angioplasty and stents, and patients with aneurysms or akinetic areas underwent left ventricular remodeling. Minimally invasive and offpump techniques are being continually improved, and now account for about 20% of all cases. The objective of coronary artery surgery is (1) to preserve 2005 by The Society of Thoracic Surgeons Ann Thorac Surg /05/$30.00 Published by Elsevier Inc doi: /j.athoracsur

2 S2222 LILLEHEI HEART INSTITUTE SYMPOSIUM LOOP Ann Thorac Surg Fig 1. Evolution of coronary artery surgery. This maze indicates significant events in the evolution of coronary artery surgery. The major discoveries of extracorporeal circulation and coronary arteriography enabled coronary artery bypass to be performed with improving rates of success. (CABG coronary artery bypass grafting; IMA internal mammary artery; OPCAB off-pump coronary artery bypass grafting.) or even improve left ventricular function, (2) to relieve symptoms, (3) to reduce the incidence of late cardiac events, and (4) extend longevity. Indications for surgery depend on symptoms, evidence of ischemia, extent of disease, and left ventricular status. Angina is no longer treated until it is intractable. The four A s are worth considering in selection: age, activity, attitude, and associated disease. Age is no contraindication per se, but advanced age often brings additional risks of comorbidity. Trends in mortality from The Cleveland Clinic are representative of nationwide trends the curve represents calculable risk, ie, a severity score (Fig 2). Clinical, angiographic, and operative variables are used to calculate this severity score, which predicts mortality and morbidity after coronary artery bypass graft surgery [8]. Risk increases with time as a result of older age patients who have more comorbidity; yet, the hospital mortality (including reoperations) is decreasing to about 1%. Although risk is dynamic, objective variables are commonly used to estimate risk preoperatively and to adjust for risk in outcome studies. The factors most predictive of hospital mortality include (1) emergency operations, (2) elevated serum creatinine, (3) severe left ventricular dysfunction, (4) anemia, (5) advanced age, (6) pulmonary disease, (7) prior vascular surgery, (8) reoperation, and (9) severe mitral regurgitation. The improvement in mortality and morbidity is attributed largely to better myocardial protection and extended use of arterial grafts. Sex also affects outcome. Women may have lower risk of developing coronary atherosclerosis early in life, but after menopause, women have higher serum lipids than men and the same incidence of atherosclerosis. Approximately a quarter of surgical candidates are women (Fig 3), and their hospital mortality may be twice that for men (p 0.001). Increased surgical risk for women is ac- Fig 2. Trends in hospital mortality for isolated coronary bypass grafting are displayed by the bars (left ordinate). The severity score denotes a risk-adjustment calculation. The rising calculated risk is depicted by the curve, and the severity score is displayed on the right ordinate. Risk increased with time as a result of older age patients who have more comorbidity, yet the hospital mortality is decreasing to about 1% and reoperations are included. Fig 3. The rise in number of women surgical candidates during a 20-year period is shown, reaching approximately a quarter of surgical candidates today. Women tend to have more false-positive exercise tests than men and tend to be older at the time of surgery. Their risk is slightly higher because they are older and have more comorbidity. Complete revascularization is attained equally although women have a higher hospital mortality. Their long-term survival after surgery is approximately the same as men. (BSA body surface area; CABG coronary artery bypass grafting; Cor Athero coronary atherosclerosis; PCI percutaneous coronary intervention.)

3 Ann Thorac Surg LILLEHEI HEART INSTITUTE SYMPOSIUM LOOP S2223 Fig 4. Serial angiographic studies of approximately 5,000 bypass grafts were examined at 1 year, 5 years, and up to 15 years after surgery [10]. Note the percentage of grafts that occluded with time continues to rise so that approximately 50% of grafts are closed at 15 years. Only a small percentage of patent grafts are free of perceptible atherosclerotic narrowing at 15 years. counted for by their small stature, which probably reflects a small diameter of coronary arteries. Smaller patients, regardless of sex, face increased risk of surgical mortality even after allowing for angiographic differences and other risk factors. Body surface area analysis shows that men and women of the same size, having the same status of other clinical angiographic and operative variables, do not have significantly different risks of surgical death. Although long-term survival is about the same, women report more recurrent symptoms than men [9]. Characteristics of Conduits Saphenous Vein Grafts Saphenous vein bypass grafts are the best human model for accelerated atherosclerosis. After surgery, intimal hyperplasia develops in all vein grafts, and thrombotic occlusion occurs in up to 20% in the first year, primarily as a consequence of poor distal runoff. After 36 months, atherosclerosis in vein grafts frequently appears and is generally progressive. The fate of vein grafting is best depicted by the serial angiographic investigations conducted by Fitzgibbon and colleagues [10] of 5,000 vein grafts in military personnel: early patency was 88%, at 1 year 81%, 5 years 75%, and 10 to 15 years 50%. About half of the vein grafts showed luminal defects at 5 years, and 80% had luminal defects at greater than 15 years (Fig 4). Early determinants of graft closure relate to endothelial injury during procurement, technical errors in construction of anastomoses, poor runoff, and lack of antiaggregant therapy. Vein grafts constructed to the anterior descending coronary artery tend to have a higher early patency than those constructed to the circumflex or right coronary artery. Vein grafts with multiple sequential anastomoses tend to have a higher patency than a graft with one distal anastomosis. Late vein graft patency may be compromised by elevated serum lipids, cigarette smoking, diabetes (which accelerates atherosclerosis), and the absence of prescribed lipid-lowering therapy [11]. Coronary endarterectomy was one of the first procedures to be introduced as a technique for direct revascularization. Today endarterectomy is used infrequently but may be of benefit in totally obstructed right or even anterior descending coronary arteries [12]. In both instances an onlay graft is sewn over the arteriotomy. Endarterectomy patency is lower compared with patency for conventional vein bypass grafting. In the past 30 years, tobacco has been implicated in the formation of atherosclerosis. Cigarette smoke is one of the best drug delivery systems because of its acute effects on coronary vasomotor tone. Carbon monoxide in cigarette smoke produces endothelial hypoxia, allowing intimal lipid infiltration and enhanced platelet adhesion to the subendothelial layers, and may stimulate intimal smooth muscle proliferation. Continued cigarette smoking after surgery is one of the greatest determinants of early vein graft thrombosis [13]. Smokers are at higher risk of myocardial infarction and reoperation compared with patients who stopped smoking. Patients who continued to smoke 1 year after surgery had more than twice the risk for myocardial infarction and reoperation compared with patients who stopped smoking before surgery. There is now incontrovertible evidence that lipidlowering therapy has the potential to stabilize atherosclerotic plaques. The question is whether statin therapy affects vein graft atherosclerosis? The only answer so far is the Post Coronary Artery Bypass Graft Trial, which studied lovastatin alone or combined with cholestyramine and low-dose anticoagulation in patients with vein graft atherosclerosis (Fig 5) [14]. When low-density lipoprotein was lowered to 85 mg/dl or less (aggressive treatment), additional revascularization by angioplasty or bypass surgery occurred significantly less frequently Fig 5. The Post Coronary Artery Bypass Graft Trial [14, 15] reviewed the results of aggressive (black bars) and moderate (gray bars) lipid-lowering therapy on the progression of vein graft atherosclerosis. The percentage of grafts patent with no progression is shown for each of the treatment categories. Aggressive lipid-lowering therapy correlated with less native vessel and vein graft occlusion and a lower incidence of new lesions in native vessels.

4 S2224 LILLEHEI HEART INSTITUTE SYMPOSIUM LOOP Ann Thorac Surg Table 1. Comparison of Arterial Bypass Conduits Variable ITA GEA IEA Radial Patency excellent good moderate good, short term Versatility yes no limited potentially yes Complications fear of mediastinitis infrequent minor but rare hand ischemia Effect on survival and event-free survival excellent contributory with ITA unknown unknown GEA gastroepiploic artery; IEA inferior epigastric artery; ITA internal thoracic artery. compared with patients who experienced moderate lipid lowering. Progress in native vessel atherosclerosis occurred less frequently (27% versus 39%); late graft occlusion, new lesions in native vessels, and repeat revascularization all occurred less frequently in the aggressive treatment group [15]. Unfortunately, only about a third of the patients reached the goal of aggressive treatment. Warfarin had no early effect. Arterial Grafts in Coronary Artery Surgery A comparison of arterial bypass conduits is shown in Table 1. In 1968 Green [16] reported the first series of internal mammary artery-to-coronary artery anastomosis. Now called the internal thoracic artery (ITA), it has become the most widely used arterial conduit. Concerns about mediastinitis persist in relation to the use of this conduit [17]. But in my experience careful surgical technique nasal antibiotics, fine procurement, minimal chest wall cautery, short operating time, and intensive insulin therapy in diabetics results in very low infection rates even with bilateral ITA grafting. The gastroepiploic artery is far less versatile and is used mainly for the branches of the right coronary artery. The gastroepiploic artery is highly vasoactive and vulnerable to twisting, kinking, and other technical error. Variable in size, generally limited to branches of the right coronary artery, and difficult technically in obese patients, it nonetheless may compliment ITA grafting and favorably influence outcome. The inferior epigastric artery is rarely used unless no other conduits are available. The radial artery has been advocated as the next best choice after ITA use. Early efforts at radial artery grafting were fraught with low patency because of graft spasm and probable endothelial damage during extraction [18]. Later studies demonstrated 80% to 90% patency with improved techniques [19]. The length of the radial artery ( 20 cm) makes it suitable for extensive grafting. Disadvantages of radial artery usage include the need to assess ulnar collateral circulation to avoid ischemia, and the potential for sensory abnormalities. The ITA is the most frequently used arterial conduit for coronary artery surgery. The options include end-to-side, free, sequential, and T or Y grafts. The ITA is indicated in young and old, patients with bad and good left ventricular function, for single vessel and multivessel disease, in reoperation, for diabetics, and even in selected emergency cases. The only relative contraindications are radiation damage, replacing patent atherosclerotic grafts that perfuse large areas (danger of hypoperfusion), and documented subclavian stenosis. Why is the ITA a biologically better conduit [20]? The reasons for ITA immunity to atherosclerosis have been studied extensively and appear to be related to the structure and metabolic function in the wall of this artery: (1) there is no vaso vasorum; (2) the endothelium releases nitric oxide and prostacyclin; (3) the internal elastic lamina in the ITA is more dense; and (4) lipid and glycosaminoglycan composition of the ITA compared with the saphenous vein indicates that the ITA is less atherogenic. The other important feature of the ITA is that it exhibits flow adaptation as a function of time. Late Surgical Results Three of the many nonrandomized studies that show significant advantage of arterial grafting over vein grafts are reviewed here. The first of these, published in 1986 from The Cleveland Clinic [21], showed significant improvement in 10-year longevity for patients with one-, two-, and three-vessel disease, all of whom had significant left anterior descending (LAD) coronary artery narrowing (Fig 6). In addition to greater survival, patients who received an ITA graft to the LAD had significantly greater freedom from late cardiac events. This was the Fig 6. An internal thoracic artery (ITA) graft to the left anterior descending coronary artery (LAD), with or without vein grafts, has been compared with vein grafts only during a period of 10 years [21]. The three frames depict one-vessel (left anterior descending disease), two-vessel with the left anterior descending involved, and three-vessel disease. In each instance, the patient who received an ITA graft to the left anterior descending, with or without vein grafts, had a better 10-year survival than those who received vein grafts only.

5 Ann Thorac Surg LILLEHEI HEART INSTITUTE SYMPOSIUM LOOP S2225 more effective the bilateral ITA strategy appears. These curves comparing one with two ITA grafts show the effect is greater in the second postoperative decade compared with the first and is important even in older patients. In other words, the longer the follow-up, the more effective the bilateral ITA strategy appears to be. However, the relatively low use of single and bilateral ITA grafts is discouraging. The Society of Thoracic Surgeons database shows overall usage of 88% for a single ITA and 3.5% for bilateral ITA procedures [24]. Fig 7. This 15-year follow-up from the Coronary Artery Surgery Study (CASS) Registry [22] showed significantly higher survival for patients who received an internal thoracic artery (ITA) graft compared with those who received vein grafts only. first comparative observational study that showed improved 10-year survival with arterial grafting compared with vein grafting only. The significant advantage of the left ITA to the LAD was not achieved at an increased perioperative risk. Results could be explained by consistently high patency of the ITA (approximately 95% at each year interval compared with deterioration of the vein grafts with time). The ITA to the LAD is the single most important determinant of survival and event-free survival, and numerous studies have now shown that it should not be withheld from any group of patients. In another important investigation, Cameron and others [22] reported a 15-year follow-up of more than 5,000 patients from the multicenter Coronary Artery Surgery Study (CASS) registry (Fig 7). The authors found little difference in the frequency of angina recurrence between ITA and vein graft patients at 10 years; however, patients who received only vein grafts had poorer survival than did patients who had angina and had received an ITA graft. In addition to significantly greater survival with the use of this conduit, there was further confirmation of improved freedom from reoperation and overall improved event-free survival compared with patients who had vein grafts only. It appears that both men and women realize a survival benefit. In other reports of up to 20 years of follow-up, it has been shown that performance of the left ITA graft to the LAD is a more important predictor of survival than progression of native artery atherosclerosis. A third study answered the question: If one ITA to the LAD is beneficial, does bilateral ITA grafting improve survival? Lytle and others [23] from The Cleveland Clinic (Fig 8) have found that the incremental benefit of bilateral ITA grafting may not be as large as the benefit of the left ITA to the LAD when compared with a vein graft only strategy, but the extended longevity after bilateral grafting is even greater in the second postoperative decade and the benefit increases up to 20 years postoperatively. It has taken some time to demonstrate this incremental benefit, but the longer the follow-up, the Clinical Trials The past 30 years constitutes an era of comparative clinical trials: first comparing surgery with medical treatment, then surgery with angioplasty, and now surgery with stents. Bear in mind that a clinical trial is designed to study the procedure, not the surgeon. Yet, the surgeon is still the most powerful determinant of success. Some results were statistically significant but clinically irrelevant. In his book, Clinical Judgment, Alvin Feinstein [25] wrote, when I am sick, I want a doctor that will treat me and not an average. I want a doctor who will recognize the various ways in which I differ... in my particular demographic, clinical, and other pertinent attributes. I want a doctor to recognize that the average obtained is a mixture of different results and different kinds of people. The doctor should then sort out those treatments and apply... the treatment... most suitable to me. Composite data from the angioplasty and surgery trials during 3 to 5 years (extended to 7 years) show equivalent survival except for diabetics. The high restenosis rate in diabetics who underwent angioplasty greatly favors surgical treatment [26]. Diabetes adversely affects angioplasty and stenting and to a lesser extent coronary artery surgery. Diabetes constitutes a strong and independent risk factor for atherosclerosis, especially in women. Diabetic patients have more diffuse and aggressive coronary Fig 8. Although the incremental benefit of bilateral internal thoracic artery (BITA) grafting compared with single internal thoracic artery (SITA) grafting is not as large as the benefit of a left internal thoracic artery graft to the left anterior descending coronary artery compared with vein grafts only, the extended longevity in the second decade is readily apparent [23].

6 S2226 LILLEHEI HEART INSTITUTE SYMPOSIUM LOOP Ann Thorac Surg atherosclerosis, higher restenosis rates, and, consequently, greater risk of death, myocardial infarction, and stroke. In surgical studies diabetic patients with sequelae of renal failure or peripheral vascular disease have significantly decreased survival. Diabetic patients without comorbidities have similar but slightly lower survival after surgery. The event-free survival rates even with crossovers indicates that the coronary artery surgery patients fare significantly better. These clinical trials comparing angioplasty with surgery enrolled about 5% of multivessel coronary atherosclerosis candidates, and generally these were good-risk patients. Surgery offers more complete revascularization because of the ability to bypass totally obstructed coronary arteries. In studies of costeffectiveness, bypass surgery patients with multivessel disease had better outcomes, which resulted in lower cost. Coronary arterial stenting constitutes a major improvement. Vascular remodeling, which is an important feature in restenosis after angioplasty, is greatly reduced by stent implantation. One-year results from a randomized trial [27] showed significantly lower target vessel failure with Paclitaxel-eluting stents compared with bare-metal stents. Comparing standard stenting with coronary artery surgery in the first post-procedure year showed equivalent mortality and cardiac morbidity but stenting was associated with a greater need for repeat revascularization [28]. According to a comprehensive review of interventional cardiology, many proposed drug-eluting stents have been supported by sound scientific data, but only a few have proven clinical viability [29]. Nevertheless, this technology is likely to completely replace bare metal stents for percutaneous coronary intervention. The lessons learned from clinical trials indicate that surgery is best for ischemia, left main disease, threevessel disease, and left ventricular dysfunction. Angioplasty alone is efficacious in one-vessel and two-vessel Fig 9. The prevalence of cardiac procedures is shown for the past decade from the northern New England Registry (E Nowicki, personal communication, 2004). Coronary artery bypass grafting (CABG) surgery peaked in 2000 and has fallen significantly in the past 2 years. The prevalence of coronary artery stenting is thought to account for this decrease in surgical procedures. In contrast, the number of aortic valve and mitral valve procedures has increased with time. disease (low risk) but now has virtually been replaced by stenting, which, with less reported restenosis, still shows event-free survival that is significantly less than modern surgery. As percutaneous interventions have increased, the incidence of isolated bypass grafting in cases per 100,000 has decreased beginning in early 2000 (Fig 9). This information from the northern New England Registry (E Nowicki, personal communication, 2004) depicts trends in major adult cardiac surgery. Isolated coronary artery bypass grafts peaked in 2000 at 207 procedures/100,000 population and then declined to 166/100,000 in In contrast, aortic valve procedures have increased from 20 to 35/100,000 during a 13-year period. Mitral valve procedures have tripled in frequency from 9 to 31 procedures/100,000 population, with repair accounting for more than one half of mitral cases. Summary Atherosclerosis is a distinct entity... it is not inevitable, nor is it irreversible. Rather, it is preventable and, at least up to a point, curable. In the course of three decades, we have seen the era of procrastinated medical treatment give way to a reluctant acceptance of coronary artery surgery. This has been followed by broader surgical indications and better results, and now, almost unbridled enthusiasm for cardiologic interventions. Treatment tends to outrun methodology because measurable subsets of patients are difficult to categorize, collect, and analyze without bias. Selection for revascularization should focus on relieving symptoms, protecting the left ventricle, improving survival, and reducing subsequent cardiac events. In surgical revascularization today, conduit performance carries more prognostic weight than any other factor. The development of coronary artery surgery has been one of the most positive developments in human history. A 1983 Lancet editorial [30] sums it up best, Let us not forget the impact of coronary artery surgery on the well-being of individuals. Anyone participating in a center blessed with technically abled cardiac surgeons will testify to the health and well being of most patients returning for follow-up. This is not a small percentage change. It is a quantum jump in the quality of life. References 1. Sones FM Jr, Shirey EK. Cine coronary arteriography. Mod Concepts Cardiovasc Dis 1962;31: Garrett HE, Dennis EW, DeBakey ME. Aortocoronary bypass with saphenous vein graft: seven-year follow-up. JAMA 1973;223: Favaloro RG. Saphenous vein autograft replacement of severe segmental coronary artery occlusion: operative technique. Ann Thorac Surg 1968;5: Johnson WD, Flemma RJ, Lepley D Jr, Ellison EH. Extended treatment of severe coronary artery disease: a total surgical approach. Ann Surg 1969;170: Proudfit WL, Brushchke AV, Sones FM Jr. Natural history of obstructive coronary artery disease: 10 year study of 601 non-surgical cases. Prog Cardiovasc Dis 1978;21:53 78.

7 Ann Thorac Surg LILLEHEI HEART INSTITUTE SYMPOSIUM LOOP S Yusuf S, Hawken S, Òunpuu S, et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet 2004;364: Buckberg GD, Beyersdorf F, Allen BS, Robertson JM. Integrated myocardial management. Background and initial application. J Card Surg 1995;10: Higgins TL, Estafanous FG, Loop FD, Beck GJ, Blum JM, Paranandi L. Stratification of morbidity and mortality outcome by preoperative risk factors in coronary artery bypass patients. A clinical severity score. JAMA 1992;267: Koch CG, Khandwala F, Nussmeier N, Blackstone EH. Gender profiling in coronary artery bypass grafting. J Thorac Cardiovasc Surg 2003;126: Fitzgibbon GM, Kafka HP, Leach AJ, Keon WJ, Hooper GD, Burton JR. Coronary bypass graft fate and patient outcome: angiographic follow-up of 5,065 grafts related to survival and reoperation in 1,388 patients during 25 years. J Am Coll Cardiol 1996;28: Bates ER, Holmes DR Jr, eds. Saphenous vein bypass graft disease. New York: Marcel Dekker, Brenowitz JB, Kayser KL, Johnson WD. Results of coronary artery endarterectomy and reconstruction. J Thorac Cardiovasc Surg 1988;95: Solymoss BC, Nadeau P, Millette D, Campeau L. Late thrombosis of saphenous vein coronary artery bypass grafts related to risk factors. Circulation 1988;78(Suppl 1):I The Post Coronary Artery Bypass Graft Trial Investigators. The effect of aggressive lowering of low-density lipoprotein cholesterol levels and low-dose anticoagulation on obstructive changes in saphenous vein coronary artery bypass grafts. N Engl J Med 1997;336: Campeau L, Knatterud GL, Domanski M, et al. Aggressive cholesterol lowering delays saphenous vein atherosclerosis in women, the elderly, and patients with associated risk factors. Circulation 1999;99: Green GE. Internal mammary artery-to-coronary artery anastomosis: three-year experience with 165 patients. Ann Thorac Surg 1972;14: Francel TJ. A rational approach to sternal wound complications. Semin Thorac Vasc Surg 2004;16: Acar C, Jebara VA, Portoghese M, et al. Revival of the radial artery for coronary artery bypass grafting. Ann Thorac Surg 1992;54: Desai ND, Cohen EA, Naylor DC, Fremes SE. A randomized comparison of radial artery and saphenous vein coronary bypass grafts. N Eng J Med. 2004;351: Loop FD. Internal-thoracic-artery grafts: biologically better coronary arteries. N Engl J Med 1996;334: Loop FD, Lytle BW, Cosgrove DM. Influence of the internalmammary-artery graft on 10-year survival and other cardiac events. N Engl J Med 1986;314: Cameron A, Davis KB, Green GE, Schaff HV. Coronary bypass surgery with internal-thoracic-artery grafts: effects on survival over a 15-year period. N Engl J Med 1996;334: Lytle BW, Blackstone EH, Sabik JF, Houghtaling P, Loop FD, Cosgrove DM. The effect of bilateral internal thoracic artery grafting on survival during 20 postoperative years. Ann Thorac Surg. 2004;78: The Society of Thoracic Surgeons. STS National Database Executive Summary Available at stsnationaldatabasefa112002executivesummary.pdf. 25. Feinstein AR. Clinical judgment. Baltimore: Williams & Wilkins, Detre KM, Holubkov R, Sopko G, et al. Coronary revascularization in diabetic patients. A comparison of the randomized and observational components of the Bypass Angioplasty Revascularization Investigation (BARI). Circulation 1999;99: Stone GW, Ellis SG, Cox DA, et al. A polymer-based paclitaxel-eluting in patients with coronary artery disease. N Engl J Med 2004;350: Serruys PW, Unger F, Sousa JE, et al. Comparison of cornary-artery bypass and stenting for the treatment of multivessel disease. N Engl J Med 2001;344: Sousa JE, Costa MA, Tuzcu M, et al. New frontiers in interventional cardiology. Circulation 2005;111: Coronary bypass surgery here to stay [Editorial]. Lancet 1983;2:197 8.