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Acute kidney injury (AKI) after cardiac bypass surgery (CABG) is common and carries a significant association with morbidity and mortality. Since minocycline therapy attenuates kidney injury in animal models of AKI, we tested its effects in patients undergoing CABG. This is a randomized, double-blinded, placebo-controlled, multi-center study. We screened high risk patients who were scheduled to undergo CABG in two medical centers between Jan 2008 and June 2011. 40 patients were randomized and 19 patients in each group completed the study. Minocycline prophylaxis was given twice daily, at least for four doses prior to CABG. Primary outcome was defined as AKI [0.3 mg/dl increase in creatinine (Cr)] within 5 days after surgery. Daily serum Cr for 5 days, various clinical and hemodynamic measures and length of stay were recorded. The two groups had similar baseline and intra-operative characteristics. The primary outcome occurred in 52.6 % of patients in the minocycline group as compared to 36.8 % of patients in the placebo group (p = 0.51). Peak Cr was 1.6 ± 0.7 vs. 1.5 ± 0.7 mg/dl (p = 0.45) in minocycline and placebo groups, respectively. Death at 30 days occurred in 0 vs. 10.5 % in the minocycline and placebo groups, respectively (p = 0.48). There were no differences in post-operative length of stay, and cardiovascular events between the two groups. There was a trend towards lower diastolic pulmonary artery pressure [16.8 ± 4.7 vs. 20.7 ± 6.6 mmHg (p = 0.059)] and central venous pressure [11.8 ± 4.3 vs. 14.6 ± 5.6 mmHg (p = 0.13)] in the minocycline group compared to placebo on the first day after surgery. Minocycline did not protect against AKI post-CABG.

This is the third in a series on coronary artery bypass which reviews three alternative arterial conduits. The radial artery has become the most widely used of the three and accumulating experience demonstrates better patency at 10 years versus saphenous vein. Drawbacks are a long incision on the forearm, the propensity for spasm and persistent sensory disturbance in about 10%. The first is answered by endoscopic harvest which may yield a shorter conduit but reduces sensory nerve injury. Spasm is managed pharmacologically and by less harvest trauma. The gastroepiploic artery is used in situ and free and although the abdominal cavity is entered complications are minimal and patency compares favorably with the radial artery. Use of the inferior epigastric artery remains minimal and its similar length often requires composite use but limited patency data are supportive. Other arteries have had rare use and this is unlikely to change because the three presented here have significant advantages and acceptance.

ObjectiveRadial artery harvesting has been questioned because of purported long-term circulatory consequences. Previous midterm Doppler ultrasonographic results are inconsistent regarding ulnar arterial effects. Flow-mediated vasodilatation more sensitively measures response to shear stress as index of arterial reactivity and function.MethodsWe contacted 231 patients who had undergone radial artery harvesting at least 10 years previously (mean follow-up, 12.9 ± 0.8 years). Subcohort of 25 volunteers (mean age, 69.2 ± 8.4 years) underwent ultrasonographic evaluation of ipsilateral (harvest) and contralateral (control) ulnar arteries. Flow-mediated vasodilatation compared changes in ulnar arterial diameters before and after occlusion.ResultsIn subcohort, peak systolic velocity of harvest ulnar artery was 0.82 ± 0.15 m/s, versus 0.63 ± 0.23 m/s on control side (P

The evolution of percutaneous intervention has reduced the prevalence of coronary bypass surgery in a patient population that is older, with more comorbidity and advanced coronary disease. Despite this less favorable group, perioperative mortality has continued to decline as the operation improves. The latter includes off-pump coronary grafting, smaller incisions, better intraoperative myocardial preservation, improving management of cardiopulmonary bypass, perioperative glucose control, and increasing use of arterial conduits as the radial artery comes of age and the gastroepiploic artery is reborn as a free graft. This brief review of the basics of coronary artery bypass is part experience with an effort to be fair-minded and balanced and to include that which is new and promising. It is imperative that we continue to innovate and distill the best from the old so that we can provide the optimal intervention for coronary artery disease.

Coronary artery bypass in 150 patients with angina has been accomplished with 225 IMA grafts and 85 saphenous vein grafts. There were 7 (4.7%) hospital deaths. Posterative catheterization in 85% of patients revealed that 9 (4.7%) IMA grafts and 11 (15%) vein graft had thrombosed. One-year catheterization in 32 patients (38 IMA grafts and 13 vein grafts) revealed no additional graft failures. The better patency of the IMA grafts appears to be related to their smaller size and therfore greater velocity of blood flow and freedom from intimal proliferation.

Enthusiasm for new therapeutic modalities frequently results in a ground swell of overuse, which recedes to leave a trough of negativism before a definitive level is established. In the case of CABG, the ground swell has become a 10-year flood tide, without an ebb, although ripples have marred the surface. It is generally agreed that suitable control populations are needed to determine the role of a therapy and that the best controls would arise from randomized prospective trials. At present, the best randomized trial is the VA study which has shown that operation does not enhance longevity for single vessel disease, but clearly does for left main coronary disease. In those individuals with two- and three-vessel disease, the VA study has not shown that surgical therapy is better than medical treatment. However, three other studies containing patients selected by the VA criteria indicate that operation provides significantly greater longevity for patients in these two categories. Acceptance of this position requires acknowlegement of the validity of the VA study and the comparison of extramural concurrent surgical series.

These data would suggest that hypothermia combined with potassium cardioplegia enhances protection of the ischemic myocardium over other available techniques. The ideal conduct of this myocardial protection is not yet apparent but certain aspects are worthy of emphasis. (1) With the onset of ischemia cardioplegia should be immediately induced to abolish contractile activity and conserve energy. An advantage of blood cardioplegia is that there is no ischemia or it is trivial priorto cardioplegia. (2) The greater the degree of myocardial cooling the better. Although a myocardial temperature of 20 degrees C can commonly be achieved with perfusion hypothermia and topical hypothermia, it is possible to reduce myocardial temperature to 10 degrees C or lower with these same modalities. Because perfusion hypothermia provides fairly uniform rapid myocardial cooling, this should be maximally utilized by cooling of the systemic perfusate to 20 degrees C and cooling the cardioplegic infusate to 4-10 degrees C. Cardiac hypothermia should be maintained with crushed ice made from electrolyte solution or irrigation of the pericardial sac with cold electrolyte solution. The greater the degree of systemic hypothermia the less tendency for the myocardium to warm. (3) The ideal concentration of potassium is unknown at this time with a range of 15-40 mEq/l having been utilized without apparent potassium injury. (4) The ideal composition of the vehicle may never be defined and may not be of great importance. Whole blood would appear to offer physiological and pragmatic advantages over asanguinous vehicles. (5) The safe duration of ischemia has been moderately well defined. 1 h is well tolerated in the dog using profound cardiac hypothermia, whereas 30-45 min with lesser degrees of hypothermia is acceptable. When the interval of ischemia is to be 2 or 3 h reinfusion of potassium every 20-30 min has proven safe both experimentally and clinically.

Objective The radial artery has more smooth muscle in its wall than the other arterial conduits and is known to be vasospastic. Because it is frequently necessary to use vasoconstrictors early after coronary bypass surgery we investigated the effects of phenylephrine on conduit flow in this setting. Methods Thirty patients undergoing coronary artery bypass with all arterial conduits in which the radial artery was used as a T-graft were randomly assigned to receive intravenous infusions of normal saline (n = 10); nitroglycerin, 0.5 μg · kg · min (n = 11); or nicardipine, 0.5 μg · kg · min (n = 9), beginning early in the operation. After discontinuation of cardiopulmonary bypass and achievement of stable hemodynamics, control measurements were obtained, and this was followed by phenylephrine infusion to achieve a 20% increase in mean arterial pressure, after which the measurements were repeated. Results Mean radial artery flow increased similarly in all groups: normal saline, 40% ± 25%; nicardipine, 37% ± 27%; nitroglycerin, 48% ± 36% ( P = .533). Comparable changes occurred in arterial pressure and systemic vascular resistance, whereas the cardiac index remained unchanged. Conclusion Radial artery blood flow increases when the mean arterial pressure is increased with phenylephrine. There was no evidence of a conduit vasoconstrictive effect, which could limit or reduce conduit flow. Vasocontriction with phenylephrine is appropriate to provide adequate perfusion pressure for radial artery grafts.

Despite a known survival benefit with the use of the left internal mammary artery, it is used less frequently in women when compared with men. This study evaluated the hypotheses that the radial artery graft is used less frequently in women compared with men, that the radial artery is smaller in women compared with men, and that the use of the radial artery influences operative mortality and long-term survival in women.The use of a radial artery graft was evaluated in 2,633 patients who underwent isolated coronary artery bypass. Radial artery size and flow were compared in 207 patients who had intraoperative radial artery diameter and flow measurements. Propensity scoring was utilized to compare short- and long-term outcomes in a matched cohort of 588 women.Of 862 women (33%) who had isolated coronary artery bypass grafting, only 301 (35%) received a radial artery graft versus 44% of men (786 of 1,771, p0.001). Radial artery size and flow were significantly less in women. Operative mortality was not different between women with a radial artery graft and women without; however, 5-year survival was significantly better in women with a radial artery graft than in those without.Women received fewer radial artery grafts than men. Radial artery size and flow were significantly less in women than in men. Use of a radial artery graft did not influence operative mortality among women. However, 5-year survival among women who received a radial artery graft was significantly better than among women who did not.

Complete revascularization is important in young patients undergoing coronary artery bypass grafting, but this principle remains less absolute in elderly patients. The purpose of this study was to determine how complete revascularization influenced long-term survival after coronary artery bypass grafting in octogenarians.From 1986 to 2003, 500 consecutive patients 80 to 94 years of age underwent coronary artery bypass grafting. Complete revascularization was defined as placement of at least one graft to each of the three major vascular regions that included a 50% diameter lesion. Revascularization was complete in 400 (80%) patients and incomplete in 100 (20%) patients. Mean (+/- standard deviation) follow-up was 51 +/- 41 months and was 99% complete (2,102 total patient-years).Operative mortality was 8% +/- 2% (+/-95% confidence interval) and was statistically lower with complete (7% +/- 3%) versus incomplete (13% +/- 7%) revascularization (p0.05). Of 459 operative survivors, there were 261 late deaths. Multivariate regression analysis identified six independent predictors of late death: earlier operative year, male sex, peripheral or cerebrovascular disease, congestive heart failure, and incomplete revascularization (p0.03 for all). Excluding operative deaths, mean survival (Kaplan-Meier) was 82 months with complete revascularization compared with 65 months with incomplete revascularization (p0.008). Survival was 62% +/- 3% with complete versus 45% +/- 6% with incomplete revascularization at 5 years and 39% +/- 3% with complete versus 25% +/- 6% with incomplete revascularization at 8 years (p0.008).In octogenarians undergoing coronary artery bypass grafting, complete revascularization correlated with improved long-term survival, increasing mean survival by almost 25% compared with incomplete revascularization.

The purpose of this study was to compare operative mortality and midterm outcome of patients with ischemic mitral regurgitation (MR) undergoing either coronary artery bypass grafting (CABG) alone or CABG with mitral valve (MV) repair.From 1996 to 2001, 51 consecutive patients underwent CABG with MV repair for ischemic MR. All patients in this group were matched to similar patients with ischemic MR undergoing CABG alone during the same 6-year period using propensity analysis (considering 24 covariates, including severity of MR and New York Heart Association [NYHA] class).Propensity score matching yielded 51 closely matched control patients. Preoperative MR severity was 3+ or 4+ in 94% of CABG with MV repair and 96% of CABG-alone patients, and 86% of patients in each group were NYHA class III or IV. Operative mortality was 3.9% +/- 2.8% in both groups. Survival was also similar between CABG with MV repair and CABG alone at 1 year (84% +/- 5% versus 82% +/- 5%) and 3 years (70% +/- 7% versus 71% +/- 7% (p = 0.43). Among survivors, NYHA class improved at follow-up (50 +/- 20 months) from 3.4 +/- 0.7 to 1.7 +/- 1.0 for CABG with MV repair (p0.001) and from 3.4 +/- 0.7 to 1.8 +/- 1.0 for CABG alone (p0.001).Operative mortality, midterm survival, and late functional class were similar between two well-matched groups of patients undergoing CABG for ischemic MR, differing only in the addition of MV repair. Whereas MV repair can be added safely to CABG in this group of high-risk patients without increasing mortality, its impact on late survival and functional class may be limited.

The first three decades of coronary artery surgery have provided the foundation for the next century of this evolution. It is apparent that a multitude of events including the development of cardioplegia, improving surgical instrumentation, technological advances including endoscopic approaches and computer assisted robotics and biologic discoveries such as the role of the endothelium have provided the underpinnings for improved surgical outcomes. However, the single most important determinant of late results is the type of bypass conduit used for grafting. Thus, use of the left internal thoracic artery (ITA) grafted to the left anterior descending coronary is a more important determinant of survival than is any other factor (progression of coronary artery disease, increased age, poor left ventricular function, diabetes, female gender and offpump operations).1,2 Use of two ITAs provides further benefit3–8 and it is likely that three or more arterial conduits will be shown to be advantageous in this regard in due time. Japanese cardiothoracic surgeons have made significant contributions to the continuing evolution of coronary bypass surgery and particularly to the advance of arterial conduits. This report will address those contributions to this evolution.

Objective: The purpose of this study was to evaluate the effect of target vessel characteristics on radial artery patency when used as a composite T graft. Methods: Between October 1993 and March 2001, 1022 patients underwent coronary bypass with the internal thoracic artery–radial artery composite T graft. Of these, angiography has been performed on 109 patients at a mean 27.1 months (range, 2-70 months) postoperatively for symptoms of ischemia. By means of Cox proportional hazard models, the relationships between anastomotic patency and target vessel location, proximal stenosis, target diameter, and quality were assessed. Results: A total of 231 radial artery anastomoses were evaluated. The mean stenosis for patent anastomoses was 82% compared with 71% for occluded anastomoses (P

Objective: To assess the incidence of myocardial ischemia in patients receiving radial arterial and left internal thoracic arterial conduits (RA+LITA) during the postrevascularization period. Design: Nonrandomized observational sequential cohort. Setting: University hospital. Participants: Thirty adult patients, scheduled for elective coronary artery bypass graft surgery with RA+LITA, compared with 30 patients who received saphenous vein graft and left internal thoracic arterial conduits. Interventions: None. Measurements and Main Results: Myocardial ischemic episodes were defined as reversible ST-segment depressions or elevations ≥1 mm and ≥2 mm at J +60 msec and lasting ≥1 minute using 2-channel Holter monitoring. During the post-cardiopulmonary bypass period, a significantly higher number of patients with ≥2 mm ischemic episodes (21.7%; p = 0.015) and higher number of ≥2 mm ischemic episodes per hour (0.19 ± 0.4 episodes/hr; p = 0.03) were observed in the radial artery group versus the comparison group (0% of patients and 0 episodes/hr). During the postoperative period (24 hours), a significantly longer duration of ≥2 mm ischemic episodes was observed in the radial artery group (24 ± 33 minutes v 8.4 ± 21 minutes; p = 0.046). Radial artery graft, preoperative calcium antagonists, and pulmonary arterial mean pressure were independent predictors of the duration and area under the ST-segment curve of ≥2 mm ischemic episodes during the postoperative period. Conclusion: There is an association between the use of the radial artery graft and the incidence and severity of ≥2 mm postrevascularization ischemic episodes. Copyright © 2001 by W.B. Saunders Company

Background . Proximal anastomosis of the radial artery to the side of the internal thoracic artery (ITA) permits complete arterial revascularization in most patients, with the aim of improving long-term results of coronary artery bypass through greater long-term graft patency. The short-term results, however, have yet to be defined. We therefore reviewed our early experience with this grafting strategy. Methods . Between October 1, 1993, and September 1, 1998, 649 patients aged 30 to 85 years (mean, 60 ± 10 years) had primary coronary artery bypass using an ITA and radial artery in a T-graft configuration. Left ventricular function was severely depressed (ejection fraction Results . A total of 937 distal anastomoses were performed with the left ITA (1.4 per patient) and 1,452 with the radial artery (2.2 per patient). There was one perioperative death (0.2%). There were 32 (5%) q-wave myocardial infarctions, and 14 patients (2%) had transient low output syndrome. There was one episode of hypoperfusion corrected by lengthening the left ITA. Angiography for clinical indications in 27 patients 1 to 35 months postoperatively (mean, 9.5 ± 8.3 months) demonstrated a distal anastomotic patency of 100% for ITA and 82% for radial artery grafts. Conclusions . Complete arterial revascularization can be achieved with an ITA and radial artery T-graft with low operative risk and acceptable early patency. These results support the continued investigation of this grafting strategy.

To better define the merits of the bileaflet and tilting-disc valves, we prospectively randomized 102 patients whose age, 57 years; range, 11 to 85 years) to receive either the St. Jude (n = 55) or the Medtronic-Hall (n = 47) mitral valve prosthesis between September 1986 and May 1991. The two groups were not different with respect to preoperative New York Heart Association class, incidence of mitral stenosis and insufficiency, angina score, extent of coronary artery disease, ventricular function, completeness of revascularization, or cross-clamp or bypass time. The hospital mortality (14.5% versus 10.6%, St. Jude versus Medtronic-Hall) and late mortality (7.3% versus 2.1%) were not significantly different. Follow-up was complete in 84 of 89 hospital survivors (94%) with a mean of 26 months (range, 1 to 60 months). The linearized rates of valve-related events and the 3-year actuarial survival demonstrated no significant differences between both cohorts. Comparison of the clinical outcome and echocardiographic parameters obtained at the time of follow-up demonstrated no significant differences between the two prostheses. These data indicate that the Medtronic-Hall and St. Jude mitral prostheses are similar with respect to their rates of valve-related complications and hemodynamic profiles. This study suggests that there is no difference between the St. Jude and Medtronic-Hall prostheses with regard to early clinical performance or hemodynamic results and therefore does not support the preferential selection of either prosthesis.

The ideal temperature for blood cardioplegia administration remains controversial.Fifty-two patients who required elective myocardial revascularization were prospectively randomized to receive intermittent antegrade tepid (29 degrees C; group T, 25 patients) or cold (4 degrees C; group C, 27 patients) blood cardioplegia.The two cohorts were similar with respect to all preoperative and intraoperative variables. The mean septal temperature was higher in group T (T, 29.6 degrees +/- 1.1 degrees C versus 17.5 degrees +/- 3.0 degrees C; p0.0001). After reperfusion, group T exhibited significantly greater lactate and acid release despite similar levels of oxygen extraction (p0.05). The creatine kinase-MB isoenzyme release was significantly lower in group T (764 +/- 89 versus 1,120 +/- 141 U x h/L; p0.04). Hearts protected with tepid cardioplegia demonstrated significantly increased ejection fraction with volume loading, improvement in left ventricular function at 12 hours, and decreased need for postoperative inotropic support (p0.05). The frequency of ventricular defibrillation after cross-clamp removal was lower in this cohort (p0.05). There were no hospital deaths, and both groups had similar postoperative courses.Intermittent antegrade tepid blood cardioplegia is a safe and efficacious method of myocardial protection and demonstrates advantages when compared with cold blood cardioplegia in elective myocardial revascularization.

Anomalous origin of the left coronary artery from the pulmonary artery is rare and more so in the adult. Reimplantation of the left main coronary into the aorta is successful in early life, but it may be more difficult in the adult who had a previous repair. We report a successful reoperation of anomalous origin of the left coronary artery from the pulmonary artery in an adult patient using a left internal thoracic and radial artery "Y"-graft. Composite arterial grafting has become an established and straight forward technique in coronary surgery, and it is appropriate and recommended for congenital lesions in adults and at any age if necessary.

Background— The radial artery is often used as the second arterial graft for coronary artery bypass grafting. Little is known about the differences in long-term patency between radial free and T grafts. This study was performed to determine long-term radial artery patency over a 15-year period. Methods and Results— Radial arteries were used as free grafts or T grafts for coronary artery bypass grafting over a 15-year period. Patients were contacted to determine if postoperative cardiac catheterization was performed and examination of any reports and films was performed. Grafts were graded as patent, luminal irregularity, or occluded. Each sequential graft was counted separately. Between September 1993 and December 2008, 13 926 patients underwent isolated coronary artery bypass grafting and 3248 patients had at least one radial artery graft used as a conduit. Catheterizations were performed at a mean of 7.4±3.8 years (range, 3 days to 14.4 years) on 372 radial artery grafts (103 free and 269 T) in 215 patients. Kaplan-Meier freedom from occlusion for radial free and T grafts at 1 and 10 years was 97.1% and 75.4% and 99.6% and 62.9%, respectively ( P =0.146 free versus T). Kaplan-Meier survival to 15 years was not statistically different between free and T graft patients ( P =0.5). Conclusions— In 215 patients with postoperative catheterization after coronary artery bypass grafting with a radial artery graft, radial free and T grafts had similar and acceptable long-term patency to support their use as a coronary artery bypass graft conduit.

From March 1990 through January 1992, 108 patients undergoing myocardial revascularization had one (91) or both (17) inferior epigastric arteries (IEA) used for myocardial revascularization. The internal thoracic artery (ITA) was used bilaterally in 87 patients. Of the 373 distal anastomoses, 210 (56%) were with the ITA, 130 (35%) with the IEA, and 12 (3%) with the gastroepiploic artery. Nineteen patients (18%) received 21 saphenous veins. When compared with the ITA, the IEA demonstrated a longer harvest time (36.5 vs 29.6 min, P0.0001), a shorter usable length (11.9 cm vs 16.5 cm, P0.001), and similar flow (49.7 cc/min vs 48.7 cc/min, P = NS). The operative mortality was 2.8%. Two deaths resulted from low cardiac output and the one remaining death from complications of a cerebral vascular accident. The most common major complication was respiratory insufficiency, which occurred in 11 patients (12%). There were two sternal infections (2%), and two abdominal wound infections (2%), none of which were fatal. The IEA is an acceptable additional arterial conduit. It can be safely employed with one or both ITAs. Short-term and long-term patency must be established before preferential use of this conduit is advised.

The role of retrograde coronary sinus cardioplegia in patients undergoing aortic valve replacement for aortic stenosis alone or in combination with myocardial revascularization has not been fully defined. Sixty-three patients undergoing elective aortic valve replacement received cold potassium blood cardioplegic solution via either the aortic root (36 patients) or the coronary sinus (27 patients). The patients were similar with respect to age, degree of aortic stenosis, ventricular function, severity of coronary artery disease, crossclamp time, completeness of revascularization, and mean volume and temperature of the infusion solution. The mean septal temperature and the release of myocardium-specific isoenzyme in the first 2 hours after crossclamp removal was higher in the retrograde group (p horac C ardiovasc S urg 1992;104:130–8)

Ultrasonic decalcification of the aortic valve was performed in 22 elderly patients with critical aortic stenosis (aortic valve areas less than 0.8 cm2) as an alternative to prosthetic valve replacement. All of the patients had symptoms. The mean New York Heart Association class was 3.3 +/- 0.9. Adequate decalcification with restoration of leaflet mobility was achieved in all patients, including seven with bicuspid aortic valves. Leaflet perforation occurred and was successfully repaired in five patients. Ten patients underwent concomitant myocardial revascularization. There were two operative deaths (9%) and three late deaths. Echocardiograms were obtained preoperatively, postoperatively, and at 6 months. The mean aortic valve area increased significantly from 0.72 +/- 0.17 to 1.42 +/- 0.31 cm2 (p less than 0.001) and the peak gradient decreased from 74 +/- 34 to 25 +/- 13 mm Hg (p less than 0.001). At 6 months the aortic valve area (1.29 +/- 0.48 cm2) and peak gradient (31 +/- 12 mm Hg) continued to be significantly better than the preoperative measurements (p less than 0.001), but the 6-month aortic valve area was slightly decreased and the gradient increased when compared with the immediate postoperative values (p less than 0.02). The prevalence of mild to moderate aortic insufficiency increased from 50% of the patients preoperatively to 87% at 6 months (p less than 0.05). Two patients subsequently required aortic valve replacement for restenosis and aortic insufficiency. Ultrasonic decalcification is effective in relieving aortic stenosis, but subsequent restenosis and insufficiency may limit its application.

One hundred consecutive patients who had coronary artery bypass grafting using both internal thoracic arteries (ITAs) and saphenous veins, operated on during a 3-year period between 1972 and 1975, have been compared retrospectively with a series of 100 patients operated on during the same period who had one ITA graft along with saphenous vein grafts. The two groups were similar with respect to age, sex, risk factors for coronary artery disease, angina class, extent of coronary artery disease, left ventricular function, number of coronary bypass grafts performed, and completeness of revascularization. Single ITA operative mortality was 2% and double ITA, 9% (p = NS). The mean follow-up of hospital survivors was 14.4 +/- 2.7 years; all but 7 patients had follow-up for at least 10 years. At 13 years, the actuarial patency of the right ITA was 85% and the left ITA, 82%. These data strongly suggest a survival benefit for patients with double ITA grafts among hospital survivors (74% versus 59%; p = 0.05). Patients receiving two ITA grafts had a significant freedom from subsequent myocardial infarction (75% versus 59%, p less than 0.025), recurrent angina pectoris (36% versus 27%, p less than 0.025), and subsequent total ischemic events (32% versus 18%, p less than 0.01). These data also suggest improved freedom from coronary artery interventional therapy (percutaneous transluminal coronary angioplasty and reoperation) when two ITA grafts were used. These results support the use of bilateral internal thoracic artery grafting in selected patients.

At present a rapid and profound change in myocardial revascularization has evolved from the work of Gruentzig. The recent technological advances have been so fast paced that there has not been ample time to fully assess each new facet of technology and pharmaceutics before another arrives. The interface between percutaneous intervention (PCI) and coronary artery bypass (CAB) is not well defined as previously so that continental, national and regional differences exist. The progress in PCI from balloon angioplasty to drug eluting stents has seen a progressive decline in restenosis and reintervention but relief of symptoms has not equaled that attained with CAB. Survival benefit for CAB over PCI has not been demonstrated in the many randomized clinical trials which are limited by selection of only 5-12% of potential patients so that higher risk patients and those with more extensive and complex coronary disease are excluded. These excluded patients are included in the registries where survival benefit for CAB over PCI is clearly evident. Situations less amenable to PCI include: left main disease; three vessel disease; vessels that are smaller, diffusely diseased or with distal lesions which are frequently associated with diabetes; ostial and bifurcation lesions; and coronary arteries that are tortuous, calcified or with very long lesions. It is in these situations that PCI does not provide revascularization equivalent to CAB. Surgeons must appreciate the success of PCI, acknowledge their reduced role in revascularization and strive to provide the best operation possible when the clinical situation demands it.

Background Complex use of arterial conduits has resurrected concerns about the adequacy of conduit flow. The T-graft is the extreme example of this trend. Our purpose was to identify the limitation of single source inflow and to compare flow capacity with completion coronary flow. Methods Between February 1999 and November 2001, 372 patients underwent total arterial revascularization with the T-graft alone. Intraoperative flows were recorded for each limb of the T-graft before and after distal anastomoses in 204 patients. Independent predictors of T-graft flow were identified by multivariate analysis. Results Free flow for the radial arterial (RA) limb was 161 ± 81 mL/min, the internal thoracic artery (ITA) limb 137 ± 57 mL/min (combined 298 ± 101 mL/min) versus simultaneous limb flow of 226 ± 84 mL/min giving a flow restriction of 24% ± 14%. Completion coronary flow was 88 ± 49 mL/min for the RA, 60 ± 45 mL/min for the ITA, and 140 ± 70 mL/min for both limbs simultaneously to give a flow reserve (vs simultaneous free flow) of 160% or 1.6. Independent predictors of completion RA limb flow are RA proximal diameter ( p = 0.005), number of anastomoses ( p = 0.018), and target stenosis ( p = 0.005). Conclusions A flow reserve of 1.6 compares favorably with an ITA flow reserve of 1.8 at 1-month postoperatively and 1.8 for both the ITA T-graft and the ITA/RA T-graft at 1-week postoperatively as reported by others. Proximal RA diameter and competitive coronary flow influence completion T-graft flow. These data quantitate the limitation of single source inflow of the T-graft configuration and support its continued use.

The radial artery (RA) can be used as either an aortocoronary (RA-Ao) or composite graft (T graft). Optimum use for the RA has yet to be established. We compared RA patency with these two techniques.Between October 1993 and June 2001, 1505 patients underwent coronary artery bypass grafting using the RA as either a composite (n = 1022) or RA-Ao graft (n = 483). Angiograms performed on 203 (13.5%) patients with signs or symptoms of ischemia at an average of 26.1 +/- 18.5 months postoperatively were reviewed.Patients with RA-Ao grafts had a greater incidence of postoperative angiography versus patients with composite grafts (19% versus 11%; p0.01). Patients receiving T grafts had a greater number of anastomoses per patient (4.1 +/- 0.6 versus 3.0 +/- 1.0; p0.01) and a higher incidence of total arterial revascularization (100% versus 41%; p0.01). Regardless of grafting strategy, patency was significantly worse for targets of the right coronary artery (58% T graft; 67% RA-Ao; p0.01 for both) and for targets with less than or equal to 70% stenosis (59% T graft; 57% RA-Ao; p0.01 for both). The site of proximal anastomosis failed to effect RA patency (relative risk, 1.2; 95% confidence interval, 0.7 to 1.8; p = 0.50).The site of the proximal anastomosis does not appear to influence patency. Both RA-Ao and composite conduits are sensitive to target location and stenosis. Advantages of composite grafting include greater conduit length and minimizing aortic manipulation at the expense of increased complexity and the potential for hypoperfusion. These factors should be considered when choosing an RA grafting strategy.

Fifteen patients who had coronary artery bypass grafting with the left internal thoracic artery (2 also had in situ right internal thoracic artery grafts placed) underwent catheterization for recurrent angina 15 to 21 years later. Angiographic assessment revealed widely patent conduits without evidence of conduit atherosclerosis. Translocation of the internal thoracic artery to the coronary circulation does not appear to be associated with accelerated atherosclerosis of the conduit, and freedom from serious conduit atherosclerosis can be anticipated for at least 20 years.

In the initial decade of coronary surgery, serial angiography of internal thoracic artery grafts revealed increased caliber in some, decreased caliber in others, and "string sign" in a few, which was occasionally documented to be reversible. Although we speculated on possible causes of these changes, it was not until discovery of the endothelial role in modulating arterial diameter to maintain shear stress in a narrow range that we began to gain insight into the mechanisms responsible for remodeling of the arterial wall. This review provides a glimpse of the physiology and biology of arterial remodeling and summarizes observations on the various arterial conduits when subjected to flow alterations.

Objective To report the authors' 7-year experience with the internal thoracic artery/radial artery (ITA/RA) T graft as the only conduits for myocardial revascularization in two- and three-vessel disease. Background Data One and two arterial conduits provide increasing survival benefit for coronary grafting and reduce the need for reintervention. Exclusive use of arterial conduits may provide further benefit. Methods From October 1993 to November 2000, 1,020 patients underwent complete arterial revascularization with the ITA/RA T graft. The authors focus on the 909 having initial bypass, with a mean age of 60 and 20% age 70 or older. The incidence of triple-vessel disease was 73%, female gender 28%, diabetes mellitus 27%, peripheral vascular disease 11%, cerebrovascular disease 10%, and chronic obstructive pulmonary disease 6%; ejection fraction was less than 35% in 11%. Perioperative data were collected prospectively. Follow-up information was obtained at a mean of 35.4 months (range 1-88) and was 95% complete. Results There were seven (0.08%) deaths within 30 days of surgery. The incidence of perioperative infarction was 3.3%, low cardiac output 2.7%, stroke 2.2%, reoperation for bleeding 3.8%, and deep sternal infection 0.8%. The actuarial survival rate was 90% at 5 years, freedom from infarction was 94%, freedom from catheterization was 83%, and freedom from reintervention (angioplasty or reoperation) was 93%. Conclusion The ITA/RA T graft for complete arterial revascularization is associated with a low rate of perioperative death and complications and 5-year survival and freedom from reintervention values consistent with other revascularization strategies.

Vineberg used the internal thoracic artery (ITA) to achieve indirect myocardial revascularization in 1950, and Green reported direct coronary anastomosis with an operating microscope in 1968. It was not until the early 1980s that superior 10-year patency compared with saphenous vein was established for the ITA. In 1986, Loop proved better patient survival at 10 years when the left ITA was grafted to the left anterior descending artery rather than vein in patients with triple-vessel disease having complete revascularization. Only in 1998 has Lytle shown enhanced survival with use of two ITAs over one in triple-vessel disease. This report came 4 months after a report showing no additional benefit from the second ITA. Increasingly, complex use of arterial conduits allows complete revascularization with two arterial conduits (both ITAs or one ITA and one radial artery) in most patients (with 10-year data soon to be available in the former). The T-graft configuration (ITA T-graft or radial T-graft) is highly complex and utilizes single-source inflow to the entire heart (in addition to native coronary flow), which may not provide adequate inflow and remains controversial. Although patency for the ITA is well established, this cannot be said for the radial artery (one report of 55 conduits to 5.5 years), the gastroepiploic artery (one report of 44 conduits to 7 years), or the inferior epigastric artery (one report of 154 conduits to 43 months). Long-term follow-up of each conduit and each configuration is required to prove its durability and, therefore, value in the operative management of coronary disease.

Neurological injury is a devastating complication of cardiac surgery that results in a longer duration of hospitalization, increased costs, and increased likelihood of death. Such injury can affect any level of the central nervous system, and its manifestations are broad, ranging from neurocognitive dysfunction to frank stroke. Many variables have been found to be indicative or risk for perioperative neurological injury, but the predictive models are more useful for stroke risk than for neurocognitive dysfunction. Strategies aimed at reducing neurological injury during cardiac surgery have focused, for the most part, on the technical aspects of cardiopulmonary bypass. The concomitant performance of carotid endarterectomy and cardiac surgery continues to be controversial, although the management of patients with symptomatic carotid stenosis is better defined. Cerebral embolism, including atheroembolism from the ascending aorta, has an important role in the pathogenesis of neurological injury of all types. Epiaortic ultrasound imaging of the aorta is a sensitive technique for the identification of atherosclerosis of the ascending aorta at the time of surgery, which can allow it to be avoided and therefore reduce the risk for atheroembolism. Results of laboratory investigations have provided insight into the mechanisms of ischemic neuronal injury and a basis for the development of neuroprotective drugs. Neuroprotection may best be accomplished during cardiac surgery because, in contrast to nonsurgical situations, potential agents can be administered before the neurological insult occurs. Reducing the incidence of perioperative stroke will require a multidisciplinary approach that includes novel diagnostic and therapeutic strategies.

Patients with hypertrophic cardiomyopathy (HCM) may have hyperdynamic systolic function, left ventricular outflow tract obstruction, systolic anterior motion of the mitral valve, and mitral regurgitation. 15 Stress, volume depletion and peripheral vasodilation can all result in an increased degree of outflow obstruction,~ increased systolic anterior motion of the mitral valve, worsening mitral regurgitation, and hemodynamic collapse. 6 Patients with mild or moderate HCM, small intraventricular gradients, no systolic anterior motion of the mitral valve, and no mitral regurgitation normally have a benign prognosis. 1 We report a patient with mild HCM without a significant intraventricular gradient, and with no systolic anterior motion of the mitral valve or mitral regurgitation who developed acute, severe left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve, severe mitral regurgitation, and hemodynamic collapse following cardiac catheterization and successful coronary angioplasty for single-vessel coronary disease. Conventional therapy directed at hypotension and pulmonary edema (i.e., positive inotropic agents and diuretics) may exacerbate the underlying decompensated HCM, but alternative therapies for HCM (i.e., negative inotropic agents and fluid resuscitation) are potentially lethal in the same circumstances. This case illustrates the critical management dilemma existing in such patients. A 71-year-old man with coronary artery disease underwent coronary artery bypass surgery of the left anterior descending, right coronary artery, and first obtuse marginal branch in 1983. He did well until 1 month prior to admission, when he developed recurrent chest pain for which he underwent successful coronary angioplasty of an intermediate artery. The saphenous vein grafts were patent. He

The superior long-term patency and survival of the internal thoracic artery in coronary artery bypass grafting, compared with saphenous vein, established the internal thoracic artery as the conduit of choice for myocardial revascularization. Use of the internal thoracic artery has expanded, and the possibility of similar performance by other arteries has motivated surgeons to investigate alternative arterial conduits (eg, the gastroepiploic artery, inferior epigastric artery, and radial artery). Although these grafts have become more technically feasible and have shown benefits, more follow-up data are needed to determine the long-term patency, freedom from arteriosclerosis, and efficacy of alternative conduits.

Patent internal thoracic and radial artery T-graft will adequately perfuse the heart during reoperation. Five of 1,023 patients with prior T-grafting had aortic (3) or mitral valve redo operations in which the heart was allowed to beat (after an initial dose of cardioplegia) during the operation without clamping the patent T-graft. Rapid resumption of cardiac function after one dose of cardioplegia and no intraoperative or postoperative evidence of myocardial infarction indicated adequacy of perfusion without apparent myocardial injury. This approach avoids injury to the T-graft from dissection and clamping, saves time, and simplifies the operation.

To define better the performance of the bileaflet St. Jude and the tilting-disc Medtronic-Hall valves, we retrospectively analyzed 122 patients (St. Jude, 80 patients; Medtronic-Hall, 42 patients) who received simultaneous aortic and mitral replacement from May 1984 until June 1994. The two groups were not different with respect to preoperative clinical and hemodynamic parameters and New York Heart Association functional class. The hospital mortality and late mortality were not significantly different. Risk analysis identified advanced age and previous myocardial revascularization as predictors of operative death. Follow-up was complete in 96 of 103 hospital survivors (93%) and was similar in both groups. The actuarial survival, linearized rates of valve-related complications, and actuarial freedom from valve-related complications were similar in both cohorts. The presence of coronary artery disease negatively influenced the actuarial survival after simultaneous aortic and mitral valve replacement. Postoperative New York Heart Association functional class was not significantly different in either group. These data indicate that the Medtronic-Hall and St. Jude prostheses are not significantly different with respect to their clinical performance and valve-related complications for simultaneous double-valve replacement.

A DENOSINE (ADO, MW = 267.24) is an endogenous nucleoside (Fig I), which is the end-product of highenergy adenosine triphosphatc (ATP) catabolism during reduced oxygen (02) supply/demand states resulting from hypoxia and ischemia.’ In regard to the cardiovascular system, ADO may be considered a self-protective hormone or autocoid, because it is secreted by myocardial cells during ischemiaihypoxia while having many beneficial effects against arrhythmias, myocardial ischemia. and reperfusion ischemia.‘-a Leung et al” have published the first preliminary evidence that 5aminoimidazole-4-carboxamide riboside (AICAR) infusion reduces the frequency of perioperative myocardial infarctions (PMI) during coronary artery bypass graft (CABG) by increasing endogenous ADO in ischemic myocardium. The following is a critical review of published Englishlanguage articles regarding residual myocardial injury and potential metabolic therapy with either ADO or AICAR during CABG surgery.

Surgical treatment for ischemic heart disease continues to evolve. The long-term benefit of coronary artery bypass grafting can be shown to extend for 15 to 20 years. The long-term patency achieved with internal thoracic artery grafts has extended the already good results of coronary artery bypass grafting. It is the surgeon's hope that the pursuit of multiple arterial grafting will further extend these results. Operations continue to increase in complexity and include a growing number of reoperations. Techniques to deal with these situations have continued to evolve so that the operative mortality remains low. The role of angioplasty in patients with multiple-vessel coronary artery disease has not been firmly established. However, increasing data indicate that in patients with triple-vessel disease and depressed ventricular function, complete surgical revascularization is the treatment of choice.

The efficacy of coronary sinus cardioplegia administered into the right atrium has not been fully defined. Thirty-two consecutive patients undergoing elective myocardial revascularization were prospectively assigned to receive cold blood cardioplegia exclusively into the aortic root (15 patients) or the right atrium (17 patients). The two groups were similar with respect to age, ventricular function, severity of coronary disease, cross-clamp time, and mean infusate volume and temperature. Completeness of revascularization was greater in the aortic root cardioplegia group (p less than 0.007). The mean septal temperature and time to achieve electromechanical arrest was greater in the right atrial cardioplegia group (p less than 0.05). The right ventricular temperature and the release of myocardial isoenzyme were similar in both groups. Left and right ventricular stroke work index was preserved equally in both cohorts. Volume loading studies performed immediately after termination of bypass suggested better left ventricular function in the aortic root cardioplegia group. Myocardial performance with a loading challenge assessed late postoperatively was superior in the right atrial cardioplegia group (p less than 0.05). There were no differences between the groups with respect to clinical outcome. The data suggest that right atrial cardioplegia (1) possesses clinical safety equal to aortic root cardioplegia, (2) possesses inferior ventricular septal cooling, and (3) yields adequate preservation of both the right and left ventricles. We conclude that right atrial cardioplegia possesses no apparent advantage over aortic root delivery in the setting of elective myocardial revascularization.

Prevention of ventricular fibrillation after aortic unclamping using lidocaine hydrochloride as an additive to cold potassium blood cardioplegia was studied prospectively in 46 patients undergoing elective myocardial revascularization. Patients were similar with respect to age, ventricular function, severity of coronary artery disease, cross-clamp time, completeness of revascularization, frequency of internal thoracic artery grafting, systemic temperature at the time of cross-clamp removal, and mean infusate volume and temperature. Patients receiving lidocaine blood cardioplegia (group 1, 23 patients) had a significant reduction in the incidence of ventricular fibrillation (22% versus 74%; p less than 0.0005) and in the mean number of cardioversion attempts required to defibrillate the heart (0.5 +/- 1.3 versus 1.9 +/- 0.97; p less than 0.0005) after cross-clamp removal compared with controls (group 2, 23 patients). There were no differences between the two groups postoperatively with regard to cardiac enzyme release, hemodynamic measurements, or clinical outcome. Patients receiving lidocaine blood cardioplegia tended to have a lower incidence of new postoperative atrial fibrillation (9% versus 26%). Ventricular function was preserved equally in both groups. We conclude that lidocaine is a safe additive to potassium blood cardioplegia and significantly reduces the incidence of ventricular fibrillation after aortic unclamping.

Noninvasive innovations have advanced the timing and precsion of diagnosis of acute dissection or enlarging aortic aneurysm. However, the need to perform coronary arteriography prior to surgical repair in these patients remains a question for many clinicians. This retrospective 10-year (1978 to 1988) review examined data of 54 patients undergoing urgent surgical repair of thoracic aortic tear, aneurysm, or dissection in our institution. Results of coronary arteriography and clinical variables (history of coronary artery disease, electrocardiographic abnormalities, surgical procedures, and in-hospital mortality) were tabulated. Twenty-seven patients had type A aortic dissection and 27 patients had type B. Twenty-four patients had aortic dissection or tear (type A or B) due to motor vehicle trauma. In patients with type A, a history and/or electrocardiogram suggestive of coronary artery disease was present in 16, in whom cardiac catheterization was performed in five. None required coronary bypass surgery or died. In the 11 patients with no clinical history of coronary artery disease or electrocardiographic abnormalities, six had cardiac catheterization, none had coronary artery disease, two had coronary reimplantation, and six died. Only 1 of the 27 patients with type A dissection had a perioperative myocardial infarction (a patient with a clinical history of coronary artery disease who did not undergo cardiac catheterization). In patients undergoing type B aortic repair, 10 had a clinical history or electrocardiogram consistent with coronary artery disease but only one underwent cardiac catheterization and subsequent coronary artery bypass graft surgery for coronary artery disease. Seventeen patients had no history of coronary artery disease, of whom only two had cardiac catheterization (no coronary artery disease, no deaths), with three deaths in the remaining 15—one with coronary artery disease found at autopsy. Death after aortic surgical repair in our series was most often due to postoperative bleeding complications without evidence of myocardial infarction. In patients with no prior history of coronary artery disease of electrocardiographic abnormalities, past and current surgical experience do not support routine use of coronary arteriography.

The prevalence and characteristics of silent myocardial ischemia as detected by 24-hour ambulatory electrocardiography ST-segment depression were prospectively assessed in 94 patients examined early (1 to 3 months) and 184 patients examined late (12 months) after coronary artery bypass grafting (CABG), and followed for a mean of 48 +/- 11 (range 4 to 62) months. The relation of ambulatory electrocardiographic silent ischemia to evidence of completeness of revascularization as defined by cardiac angiography performed 1 and 12 months after CABG, and to prognosis by follow-up of adverse clinical events was analyzed. Silent ischemia was detected early in 20% (19 of 94) and late in 27% (50 of 184) of patients, and showed a mean frequency of episodes ranging from 6 to 10 episodes/24 hours with a mean duration ranging from 15 to 23 minutes. The circadian distribution of episodes disclosed a significant peak of ischemic activity during the period of 6 A.M. to noon and a secondary peak between 6 P.M. and midnight (p less than 0.01 and p less than 0.001, respectively). Silent ischemia was not found by univariate analysis to be associated with graft or anastomotic site occlusions, low graft flow rates, grafted arteries with significant distal residual stenoses or ungrafted stenotic native coronary arteries. Kaplan-Meier analysis of time to cardiac event showed that silent ischemia was not predictive of an adverse clinical event in the early years after CABG. Cox regression analysis of 30 covariates only disclosed age (relative risk 1.06 [95% confidence interval, 1.01 to 2.94]) as having an effect on time to adverse clinical event.(ABSTRACT TRUNCATED AT 250 WORDS)