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To clarify the value of serum enzymes in the detection of intraoperative and postoperative myocardial injury associated with coronary artery bypass grafting, we evaluated 70 consecutive patients (151 grafts). We used electrocardiograms and serial determinations of serum levels: serum glutamic oxaloacetic transaminase (SGOT), creatinine phosphokinase (CPK), lactic dehydrogenase (LDH), and LDH isoenzymes on Days zero, 1, 3, 5, 7, and 10. Patency of all grafts 1 week postoperatively was 92 per cent. Fourteen patients (20 per cent) had ECG evidence of acute myocardial infarction (AMI) or ischemia lasting longer than 48 hours. This incidence of AMI was attendant with no deaths or discernible changes in postoperative ventriculography. LDH-1 (cardiac fraction) was elevated in all patients with myocardial injury. Late elevation of LDH-1 occurred in 2 patients at the time of postoperative catheterization, 1 of whom had negative findings on ECG. Diagnostic correlation was not observed with total LDH, CPK, or SGOT. Predisposing factors to AMI included preinfarction angina (4 of 14 patients), occluded grafts (4 of 14), and a bypass time greater than 120 minutes.

Impedance reduction with a continuous infusion of hydralazine was evaluated in 20 patients following cardiopulmonary bypass. Patients were selected for therapy when the cardiac index (CI) was less than 2.2 L/m2/min, when the systemic vascular resistance index (SVRI) was greater than 2,500 dyne sec cm-5, or when both conditions were present. No other vasoactive or cardiotonic drugs were used intraoperatively or postoperatively. Responses were measured at 15, 30, 60, 120, 180, and 240 minutes and compared with control measurements. Significant responses appeared by 15 minutes in the mean arterial pressure, CI, and SVRI, which were maximal by 2 hours. At 4 hours, the SVRI was 1,520 +/- 276 dyne sec cm-5 (control, 3,235 +/- 222) and pulmonary vascular resistance index, 365 +/- 102 dyne sec cm-5 (control, 592 +/- 71). The CI was 3.20 +/- 0.29 L/m2/min (control, 1.96 +/- 0.16) and mean arterial pressure, 75 +/- 2.3 mm Hg (control, 92 +/- 2.4). Left atrial, pulmonary artery diastolic, and right atrial pressures increased from control but not significantly: 11.4 +/- 0.8 to 13.3 +/- 1.2 mm Hg, 13.6 +/- 1.6 to 17.2 +/- 1.5 mm Hg, and 6 +/- 1.6 to 9.4 +/- 1.7 mm Hg, respectively. In 16 patients, hydralazine was continued for 24 hours and in 11, the transition to oral therapy was made. Hydralazine by infusion effectively reduces after load, avoids the fluctuations of bolus therapy, and allows the transition to oral therapy if needed.

Of 2,782 patients undergoing isolated coronary artery bypass grafting (CABG) from 1970 through 1979, 196 exhibited severe global impairment of left ventricular (LV) wall motion preoperatively (LV score, greater than or equal to 15; ejection fraction, less than 0.40 in all patients and less than 0.30 in 67%). The initial 89 patients (Group 1) underwent CABG without potassium chloride cardioplegia. The subsequent 107 patients (Group 2) were given potassium chloride cardioplegia intraoperatively. Group B patients received more grafts per patient (3.1 versus 2.5; p less than 0.001) and were completely revascularized more often (72.9% versus 58.4%; p less than 0.05). Operative mortality was lower in Group B (3.7% versus 12.4%; p less than 0.025), and 5-year cumulative survival was better in Group B (88.8% versus 63.9%; p less than 0.0001). Preoperative congestive heart failure resulted in higher operative mortality (14.3% versus 4.5%; p less than 0.05) and lower 5-year survival (65.0% versus 81.8%; p less than 0.02). Complete revascularization led to higher 5-year survival (82.2% versus 66.0%; p less than 0.02) but did not alter operative mortality significantly (6.9% versus 9.1%). Potassium chloride cardioplegia may influence operative survival favorably by reducing perioperative myocardial infarction in patients with severe LV dysfunction. Long-term survival relates to completeness of revascularization and severity of congestive heart failure as variables independent of methods of myocardial protection.

We identified 420 medically treated and 231 surgically treated patients (coronary graft plus myocardial surgery in 30%) who had severe left ventricular dysfunction manifest by an ejection fraction below 0.36 and markedly abnormal wall motion. Compared with medically treated patients, those treated surgically had more severe angina (56.7% vs 29.0% class III or IV; p less than .001), less heart failure as predominant symptom (11.1% vs 18.8%; p less than .003), more severe coronary disease (66.7% vs 50.2% three-vessel disease; p less than .001), a greater concentration of left main coronary artery lesions greater than 70% (12.6% vs 3.8%: p less than .001), and a greater estimated extent of jeopardized myocardium (p less than .001). Multivariate regression analysis of survival, which adjusts for the above covariates, showed that surgical treatment prolonged survival (p less than .05), although it ranked below severity of heart failure symptoms, age, ejection fraction, and left main stenosis greater than 70% in determining prognosis. Surgical benefit was most apparent for patients with ejection fractions below 0.26 who had a 43% 5 year survival with medical treatment vs 63% with surgery. Surgically treated patients experienced substantial symptomatic benefit compared with medically treated patients if their presenting symptoms were predominantly angina; however, there was no relief of symptoms caused primarily by heart failure. We conclude that patients with predominantly ischemic pain symptoms, despite poor left ventricular function, benefit from surgery; however, operative mortality in this high-risk subset must equal or better the 6.9% obtained in this study.

Of currently available methods for mechanical circulatory support, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most versatile and effective. Since 1981, 48 patients, aged 15 to 71 years (mean 43.0), with profound cardiogenic shock refractory to conventional therapy with drugs and intra-aortic balloon support, were supported with the Pierce-Donachy ventricular assist device. There were four patient groups. The largest group consisted of 30 patients with cardiogenic shock after cardiac operations. Nine required left ventricular support, six needed right ventricular support plus an intraaortic balloon pump, and 15 had biventricular support. Duration of support ranged from 3 hours to 22 days (mean 3.6 days). Eight of the first 11 patients died in the operating room of bleeding and/or biventricular failure. However, 16 patients, (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (36%) were discharged. Of the last 19 patients, 47% survived. Frequent factors in nonsurvivors were myocardial infarction (75%) and renal failure (90%). Common complications in all patients were bleeding (52%) and infection (27%). The second group consisted of 11 patients with end-stage cardiomyopathy or acute myocardial infarction in whom the Pierce-Donachy ventricular assist device was used as a bridge to transplantation (left ventricular support, four patients; biventricular support, seven patients). Renal failure, infection, or coagulopathy that precluded transplantation developed in five patients. Five patients were supported for 8 hours to 75 days (mean 20.7 days) before undergoing successful transplantation, with one late death (six months) from rejection owing to noncompliance. One has subsequently undergone successful transplantation after 84 days of support. The third group consisted of four patients, aged 40 to 56 years (means 47.2), who had refractory cardiogenic shock after cardiac transplantation caused by pulmonary hypertension (two patients), hyperacute rejection (one patient), or graft failure (one patient). Despite biventricular support in all four (biventricular assist devices, two patients; right ventricular assist device plus intraaortic balloon pump, two patients), all died of infection and/or renal failure after 12 hours to 6 days (mean 3.4 days) of support. The final group consisted of three patients, aged 36 to 51 years (mean 45), with cardiogenic shock caused by acute myocardial infarction. One patient was supported with biventricular assist devices (3.5 days) and two patients were supported with a left ventricular assist device (8.5 and 15 days).(ABSTRACT TRUNCATED AT 400 WORDS)

Between 1962 and 1986, 51 patients 50 years of age or older (mean, 59.7 years; range, 50 to 77 years) underwent operative closure of atrial septal defect. The mean pulmonary vascular resistance was 1.7 +/- 0.79 wood units and the mean pulmonary blood flow-systemic blood flow ratio was 2.8 +/- 1.4. Patch closure with pericardium or Dacron was performed in 36 patients (70%), while 15 patients (30%) underwent primary closure. There were no operative deaths, and one patient was not available for follow-up. The remaining 50 patients (98%) have been followed up for 0.5 to 25 years (mean, 9.6 years). Mean preoperative New York Heart Association classification was 2.40 +/- 0.70. This improved significantly to 1.21 +/- 0.42 at follow-up, with all patients improving by at least one category. No patient received long-term anticoagulation treatment, and no pulmonary or systemic emboli were identified. Two (13%) of 15 patients who underwent primary closure developed septal dehiscence. Actuarial survival was 93%, 86%, and 79% at 5, 10, and 15 years, respectively. Atrial septal defect closure can be safely performed in older patients with excellent results, provided the ratio of systemic to pulmonary blood flow is greater than or equal to 1.5 to 1.0, the pulmonary vascular resistance is low, and the shunt remains left to right. Primary closure should be discouraged, and postoperative anticoagulation therapy appears unwarranted.

Cardiac arrest was achieved in 84 patients using asanguineous cardioplegia and in 97 patients using cold blood potassium cardioplegia. The patient groups were similar in age, sex ratio, and preoperative risk factors. Other than the cardioplegic solution used, the conduct of each operation was identical. There were no differences in mean total pump time (118 minutes for the asanguineous cardioplegia group versus 117 minutes for the cold blood cardioplegia group) or cross-clamp time (73.5 versus 70 minutes, respectively). However, the blood cardioplegia group had a greater number of distal anastomoses per patient (3.9 versus 3.7; p less than 0.05). Myocardial protection was assessed clinically and by serial electrocardiograms. Cellular integrity was determined by release of the myocardial isoenzyme of serum creatine kinase (CK-MB). Cellular morphology was studied in 6 randomly selected patients in each group by electron microscopic examination of left ventricular myocardial samples obtained before and after bypass. Three patients given blood cardioplegia and 5 given asanguineous cardioplegia required intraaortic balloon counterpulsation at termination of bypass. There were no ultrastructural changes in either group. Electrocardiographic changes (Minnesota code) occurred in 12 of 84 patients receiving asanguineous cardioplegia versus 12 of 97 patients receiving cold blood potassium cardioplegia. To maintain a satisfactory cardiac index (greater than 2.0 L/min/m2), 38 of 84 patients given asanguineous cardioplegia versus 25 of 97 patients given blood cardioplegia required inotropic support up to 24 hours postoperatively (p less than 0.05). Infarct size determined from CK-MB release was significantly greater (p less than 0.05) in patients given asanguineous cardioplegia (36.27 gm-equivalents) than in those given blood cardioplegia (26.7 gm-equivalents).(ABSTRACT TRUNCATED AT 250 WORDS)

Results of coronary artery bypass grafting were evaluated in 856 nonrandomized patients in the Coronary Artery Surgery Study (CASS) registry with mild angina (Canadian Cardiovascular Society Classes I and II) and three-vessel disease, defined as 70% or more stenosis in the proximal or middle segment of the three major coronary arteries. There were 413 patients with medical therapy and 443 with early operation. Patients with delayed operation were kept in the medical group for analysis. Six-year survival adjusted for left ventricular (LV) function and number of proximal stenoses was 67% for medical and 84% for surgical patients (p less than 0.0001). Patients with normal LV function had equal survival with medicine or surgical intervention. Those with mild or moderate LV dysfunction (CASS LV wall motion score 6 to 9 and 10 to 15, respectively) and at least one proximal stenosis (the dominant right coronary artery) had increased probability of being alive at six years with surgical treatment. In patients with severe LV impairment (LV score higher than 15) and in those whose only proximal stenosis of 70% or more (in three-vessel disease) was located in the left anterior descending coronary artery, increased survival with surgical treatment could not be demonstrated. This is a nonrandomized observational study with the limitations of such studies: the need to adjust for differences in baseline traits between medical and surgical groups and the possibility of an unrecognized imbalance in baseline characteristics. In a Cox analysis of variables influencing outcome, early surgical treatment was an independent predictor of survival with 43% the risk of medical treatment (95% confidence range: 29 to 62%). Adjustment by propensity analysis to reduce selection bias from known differences in baseline variables did not alter results.

To evaluate the importance of severe biventricular failure in patients with postcardiotomy ventricular failure, we analyzed the data from 30 patients treated with ventricular assist devices (VADs) over a five-year period. All patients had profound postoperative ventricular failure refractory to drugs and an intraaortic balloon (IAB). Evaluation of preoperative ventricular function did not allow prediction of which patients would require VADs. However, the development of perioperative myocardial infarction was an important determinant of the need for postoperative support with a VAD. Twenty patients received only a left VAD (LVAD). Four of them had isolated left ventricular failure; 3 were weaned, and 2 survived. None of the 16 patients with biventricular failure who received only an LVAD were weaned. Ten other patients with biventricular failure received biventricular support, either with a right VAD and IAB, or with two VADs. Of these 10 patients, 5 were weaned and 3 survived. Considering all 26 patients with biventricular failure, those receiving biventricular mechanical support (10) had a better chance (p less than 0.025) of being weaned (5/10) and surviving (3/10) than those who received only an LVAD (0/16). We conclude that biventricular failure is common in patients with postcardiotomy ventricular failure and is often the result of perioperative infarction. While patients with isolated left ventricular failure did well with an LVAD only, those with biventricular failure required biventricular mechanical support for survival.

The overall surgical survival data in the Coronary Artery Surgery Study (CASS) registry have not been published to date, pending the report of the randomized medical-surgical comparison (CASS randomized trial). Non-randomized surgical survival data from the CASS registry are given in this article. The overall medical survival data from the registry were reported previously as a natural history study. There were 8,991 patients in the registry portion of CASS who had primary isolated coronary artery bypass grafting and 8,971 with follow-up of more than 30 days. The 5-year survival for all 8,971 patients was 90%, and the operative mortality was 2.37%. Patients with left main coronary artery disease had an operative mortality of 3.84% and a 5-year survival of 85%, while patients with lesions in other vessels had an operative mortality of 2.12% and a 5-year survival of 91%. Among patients without left main coronary disease, the 5-year survival was 93% in those with single-vessel and 92% in those with double-vessel disease (operative mortality was 1.50% and 1.92%, respectively) and 88% in patients with triple-vessel disease (operative mortality was 2.62%; p = 0.009). When results for patients with left main coronary artery obstruction were compared with those for triple-vessel disease, the 5-year survival figures were 85% and 88%, respectively (p = 0.02) and the operative mortality, 3.84% and 2.62%, respectively (p = 0.03). Patients with normal or nearly normal left ventricular (LV) function (i.e., LV segmental wall motion scores ranging from 5 through 11) had a 5-year survival of 92% and an operative mortality of 1.97%. Patients with moderate impairment (LV score range, 12 through 16) had a 5-year survival of 80% and an operative mortality of 4.21%. In those with poor ventricular function (LV score of 17 or greater), the 5-year survival was 65% and the operative mortality was 6.21%. The difference in survival among the three groups was significant (p less than 0.0001). Of 29 variables used in a stepwise Cox regression analysis, LV wall motion score, congestive heart failure score, age, number of operable vessels, smoking history, LV end-diastolic pressure, and percent of left main coronary artery stenosis were found to have a significant effect on long-term survival (excluding 30-day mortality), and these variables plus surgical priority and height influenced surgical mortality. When height was used in the Cox proportional hazards model, female sex was no longer a significant variable.

The technique of multiple coronary artery bypass grafting has included separate conduits, snake grafts, and Y-grafts. Against the Y-graft have been reports of lesser patency and several theoretical objections. The theory is discussed and a laboratory model presented which demonstrates a flow difference of 2 ml/5 sec or less between Y-grafts and single grafts. In conjunction with this, 171 patients having aortocoronary bypass were analyzed and showed a combined one-year graft patency of 77% with no significant difference between single grafts and Y-grafts. It is concluded that the technical simplicity of Y-grafts is advantageous and that, if the operation is performed within the guidelines set forth, revascularization with Y-grafts is an acceptable method.

The influence of three methods of myocardial preservation used during coronary artery bypass grafting on operative mortality and perioperative myocardial infarction was evaluated in seven institutions participating in the Coronary Artery Surgery Study (CASS). Both operative mortality and perioperative infarctions were comparable with either normothermic and topical hypothermic myocardial preservation. The addition of potassium cardioplegia to hypothermia lowered both operative mortality and perioperative myocardial infarction (p less than 0.01 and p less than 0.001, respectively). Stepwise multivariate discriminant analysis revealed that the high-risk clinical and angiographic variables were the most important determinants of operative mortality, followed by surgical priority and the use of potassium cardioplegia. However, none of the clinical, angiographic and surgical variables other than the use of potassium cardioplegia influenced the incidence of perioperative myocardial infarction.

The late suquelae of myocardial injury occurring at the time of direct myocardial revascularization are unknown. Fifty of 500 consecutive patients undergoing aortocoronary bypass grafting developed both electrocardiographic and enzymatic evidence of myocardial injury. They were matched with 50 patients of similar age, sex, history of previous infarction, severity of angina, degree of coronary arteriosclerosis, and level of ventricular function as determined by preoperative angiographic studies. The conduct of the operation was identical in each group except for prolongation of total cross-clamp time in those patients with myocardial injury. The total number of vessels grafted, the conduit used, and the operative mean graft flow were similar. Results of treadmill stress testing at 24 to 36 months were not significantly different between groups. Angina status, long-term survival, graft patency, and ventricular function were not adversely affected by intraoperative myocardial injury. However, postoperative ventricular function and stress test performance were related to graft patency.

To clarify the value of isoenzymes in the detection of acute myocardial injury (AMI) associated with coronary artery bypass grafting, 350 consecutive patients (804 grafts) were evaluated with serial electrocardiograms (ECG) and serum levels of serum glutamic oxaloacetic transaminase (SGOT), total creatinine phosphokinase (CPK), and lactic dehydrogenase (LDH) on Days 0, 1,2,3,4,5, and 7. Graft patency 1 to 6 months postoperatively was 92%. Sixty patients (18%) had ECG evidence of AMI. Four patients died (1.1%) Of the 185 patients with serial LDH isoenzyme analysis, 46 had elevated cardiac fraction (LDH-1). Only 35 of these had AMI by ECG. The others had nonspecific ECG changes, but associated enzymatic andhemodynamic evidence of AMI. The CPK-MB band was elevated in all patients in the immediate postoperative period, but did not correlate with ECG, hemodynamic, or enzymatic evidence of AMI. The diagnosis of AMI following coronary artery bypass could not be substantiated by evaluation of total LDH, CPK, or CPK-MB. LDH-1 is specific in detecting AMI after a coronary artery bypass graft.

The role of retrograde coronary sinus cardioplegia in patients undergoing elective coronary artery bypass grafting has not been fully defined. Forty patients undergoing coronary artery bypass grafting received either aortic root (20 patients) or coronary sinus (20 patients) cold potassium blood cardioplegia. The patients were similar with respect to age, ventricular function, severity of coronary artery disease, cross-clamp time, completeness of revascularization, frequency of internal mammary artery grafting, and mean infusate volume and temperature. The time required to deliver the initial dose of cardioplegic solution and the time to achieve arrest were prolonged in the coronary sinus group (p less than 0.001 and p less than 0.02, respectively). There were no differences between the two groups postoperatively with regard to enzymatic indices, hemodynamic measurement, or clinical outcome. Right ventricular function was preserved equally in both groups. We conclude that coronary sinus cardioplegia is a safe alternative to aortic root perfusion, but offers no advantage in elective myocardial revascularization.

Two categories--patients alive and free from new myocardial infarction (MI) and time to first new MI (nonfatal and fatal)--were compared in medical and early surgical groups in the Coronary Artery Surgery Study (CASS) registry with Class I or II angina and three-vessel disease in a six-year follow-up. There were 413 in the medical group and 443 in the early surgical group. A broad definition of MI using ECG and clinical criteria on hospital discharge and follow-up was used to include as many new MIs as possible, including perioperative MIs. Stratification was by left ventricular wall motion score and number of proximal segment stenoses and by quintile of propensity score to reduce selection bias in therapy groups. Adjusted by propensity analysis, 79% of medical and 88% of surgical patients (p = .005) were free from new MI; death without diagnosis of new MI was censored. Similarly adjusted, 57% of medical and 76% of surgical patients (p less than .0001) were alive and free from new MI at six years. For patients with previous MI, surgery offered the probability of protection from new MI: with multiple prior MIs, 66% of medical and 88% of surgical patients were free from new MI at six years (p = .0019). This is a nonrandomized, observational study with the limitations of such studies: the need to adjust for differences in baseline traits in medical and surgical groups and the unknown effects of unobserved variables. Fifty-one variables, including therapy, were tested by Cox model with time to new MI as the end point. Early surgery was the strongest independent predictor of freedom from new MI (p = .002) with a relative risk of 51% compared with medical therapy (95% confidence limits of 33 to 78%). In patients with multiple prior MIs, the new MI risk with early surgery was 24% of that for medicine, with an upper 95% confidence point of 64%.

From July, 1977, to July, 1980, intermittent cold blood potassium cardioplegia was used in 208 patients undergoing aortic valve replacement. Aortic root injection of the cardioplegic solution at 10 degrees C was followed every 20 to 30 minutes by infusions of the solution through Silastic cannulas sutured in the coronary orifices or reinserted with each injection. Symptoms of myocardial ischemia developed in 6 patients 3 to 30 months postoperatively. Coronary angiography confirmed new stenoses of the left orifice (3 patients), left main trunk (1 patient), left anterior descending coronary artery (2 patients), circumflex coronary artery (1 patients), and right orifice (3 patients). Four patients underwent saphenous vein grafting procedures, with 2 deaths; 2 patients refused reoperation. A seventh patient with 80% stenosis of the circumflex coronary artery and a posterolateral myocardial infarction died 2 months after double-valve replacement. Intermittent cold blood potassium cardioplegia instead of continuous perfusion did not prevent coronary arterial injury. Injuries occurred in the distal coronary arteries as well as the orifices and were not prevented by withdrawal of the cannulas between injections. Tight-fitting cannulas and high-pressure injection should be avoided. A careful search for coronary arterial injury should be made in all symptomatic patients following aortic valve replacement.

Fifteen institutions participating in the Collaborative Study in Coronary Artery Surgery (CASS) have performed isolated coronary artery bypass surgery upon 6630 patients (1061 women and 5569 men) for coronary artery disease. The overall operative mortality (OM) was 2.3% (range 0.3-6.4%). Mortality increased with age, from 0 in the group 20-29 years old to 7.9% in the group 70 years and older. OM was higher for women in each group, ranging from 2.8% for ages 30-39 years to 12.3% for age 70 years and older (0.8% and 5.8% for men). Clinical manifestations of congestive heart failure were associated with increased OM. Mortality was 1.4% in one-vessel, 2.1% in two-vessel and 2.8% in three-vessel disease (diameter narrowing greater than or equal to 70%). Among 1019 patients with left main coronary artery (LMCA) stenosis, OM ranged from 1.6% in patients with mild stenosis and a right-dominant system to 25% in patients with severe (greater than or equal to 90%) stenosis and left dominance. OM varied with ejection fraction (EF) (1.9% for EF greater than or equal to 50% to 6.7% for EF less than 19%) and left ventricular wall motion score (1.7% for least abnormal to 9.1% for most abnormal). For elective surgery, OM was 1.7%, for urgent surgery 3.5%, and for emergency surgery 10.8%. Mortality was 40.0% among 30 patients with severe LMCA stenosis who underwent emergency revascularization. Advanced age, female sex, symptoms of heart failure, LMCA stenosis, impaired left ventricular function and nonelective surgery are associated with a higher OM. These factors should be considered in the selection of patients for coronary artery surgery.

There are institutional variations in the operative mortality of coronary artery bypass graft surgery (CABG). Patient selection, based on clinical and angiographic criteria, is a significant factor. Even after adjustment for patient selection, institutional differences remain. Operative experience and volume of cases are also related to institutional variations. Recent attention to the technique of myocardial preservation has highlighted its significance in reducing the incidence of perioperative myocardial infarction and operative mortality. Institutional heterogeneity also exists in the nonoperative management of ischemic heart disease. However, undetected factors probably significantly affect the outcome. These institutional variations emphasize a major advantage of randomized clinical trials--that they should equalize these unknown factors.

Intermittent cold ischemic arrest was compared with hypothermic potassium cardioplegia using cold blood as the vehicle in two consecutive series of patients having isolated coronary bypass grafting. Between January 1, 1977, and June 30, 1977, 196 patients were operated on using cold ischemic arrest. The incidence of perioperative infarction was 14.3%, and mean total myocardial ischemia time was 42 +/- 1.2 minutes. From July 1, 1977, to June 30, 1978, there were 428 operations done using cold blood with potassium. The incidence of perioperative infarction was 5.6% (p less than 0.005), and the mean total myocardial ischemic time was 80 +/- 2.1 minutes. In the five years prior to this study, the incidence of perioperative infarction was constant at 13% while operative mortality was declining from 5 to 1% and the need for postoperative myocardial support was declining also. Use of cold blood potassium cardioplegia compared with cold ischemic arrest for myocardial protection during coronary artery operations has significantly reduced the incidence of perioperative infarction while doubling cross-clamp time.

Stenosis of at least 50% of both the left anterior descending and circumflex coronary arteries proximal to their major branches has sometimes been called left main equivalent (LME) disease. During a 4-year interval, 189 LME patients were identified as surgical candidates by angiographic criteria. Coronary artery bypass grafting (CABG) was performed in 119 patients; 70 patients were managed nonoperatively. Treatment assignment was nonrandom. During the same interval, 203 patients with significant left main coronary artery (LMCA) stenosis and 742 patients with three-vessel disease without LMCA or LME stenosis underwent CABG. Follow-up is 99.2% complete at an average of 48 months (range 24--73 months). Operative mortality was significantly higher among LMCA patients (4.0%) than among LME surgical patients (0.8%) (p less than 0.05). Cumulative 5-year survival was better among LME surgical patients (98.2 +/- 1.3%) than among LME medical patients (75.9 +/- 5.7%) (p less than 0.0001) or LMCA surgical patients (92.8 +/- 2.1%) (p less than 0.03). All operative patient groups had a significantly lower incidence of myocardial infarction (10.3--13.4%) than the LME medical patients (25.7%) (p less than 0.05). Relief of angina was also significantly better in the operative groups (61--67.6%) than in LME medical patients (36%) (p less than 0.005). Major differences exist between LME and LMCA patients; LME is more properly considered a variant of multivessel coronary artery disease. Results of medical and surgical therapy suggest that patients with LME disease should be strongly considered for early operative therapy.

Combined proximal left anterior descending and proximal left circumflex, or "left main equivalent" (LMEQ), disease defines a prognostic angiographic high-risk patient population. We assessed the effect of coronary bypass surgery compared with medical therapy in 903 patients with LMEQ disease by stratified life table and Cox regression analysis. The 5 year survival rates of the 639 and 264 patients who received surgical vs medical therapy was 85% vs 55%, respectively (p less than .001). Analysis of patient subsets stratified by age, angina class, right coronary disease, and ejection fraction revealed a significant survival benefit for surgically treated patients in most strata. Cox regression analysis revealed improved survival for surgically treated patients after adjustment for important baseline variables known to influence prognosis. Surgically treated patients had significantly less angina and need for antianginal drugs compared with the medically treated group. When the Coronary Artery Surgery Study randomized and randomizable LMEQ patients were analyzed, coronary bypass surgery improved 5 year survival when preoperative ejection fraction was under 0.50 but not when ejection fraction was 0.50 or higher. Thus coronary bypass surgery prolongs and improves quality of life (as defined by angina status and need for antianginal drugs) in most patients with LMEQ disease but does not appear to improve 5 year survival in a small subset of LMEQ patients who are asymptomatic after myocardial infarction or who have mild chronic stable angina and are under age 65 with well-preserved left ventricular function.

Six instances of aortic aneurysm in children have been observed in the past 15 years. Four children with aortic stenosis and coarctation of the aorta had aneurysmal dilatation of the ascending aorta, and two children with coarctation of the aorta had ruptured post-stenotic dilatation of the descending aorta. Our observations suggest that aortic aneurysm can be the result of hemodynamic stress, although developmental anomaly of the aorta associated with aortic stenosis or coarctation could be responsible for the development of the aneurysm.

We examined survival rates during a 6-year follow-up of patients in the registry of the Coronary Artery Surgery Study who had three vessel coronary artery disease and Canadian Cardiovascular Society class III-IV angina pectoris. All patients had a stenosis of 70% or greater in either the mid or proximal segment of all three coronary arteries. There were 679 medically treated patients and 1921 surgically treated patients in this nonrandomized comparison. Patients were stratified by left ventricular wall motion score and number of proximal coronary artery stenoses; after adjustment for these variables, the estimated probability of being alive at 6 years was 82% for surgically treated patients and 59% for medically treated patients (p less than 0.0001). Among patients with the most severe left ventricular dysfunction (left ventricular wall motion score of 16 to 30), the 6-year survival rate was 63% for surgically treated patients and 30% for medically treated patients (p less than 0.0001). Those with three proximal lesions (all gradations of left ventricular score) had an 81% 6-year survival rate with surgical treatment and 40% with medical treatment (p less than 0.0001). Ninety percent of surgically treated patients with normal ventricular function were living at 6 years and 78% of medically treated patients (p less than 0.0001). Among these patients, the survival rate was significantly better after surgical treatment than after only medical treatment if two or three proximal stenoses were present. If no proximal lesions were present (all categories of left ventricular function), 84% of surgically treated patients and 67% of medically treated patients were alive at 6 years (p less than 0.0001). In a multivariate (Cox) analysis of preoperative clinical, hemodynamic, and angiographic factors, early operation was a strong predictor of survival (estimated relative risk 0.38).

During a 4 month interval, cultures taken at the time of porcine xenograft valve implantation grew a fastidious atypical mycobacterium, Mycobacterium chelonei (Runyon's groups IV), in eight of 20 patients. Initial growth occurred at 2 to 3 weeks in thioglycollate broth only; detailed biochemical and bacteriologic evaluation demonstrates altered catalase activity accounting for its initial slow growth. Only one patient has manifested clinical evidence of infection 5 months after mitral valve replacement. A large pericardial effusion required pericardiectomy. Pericardial tissue and fluid have grown M. chelonei with the same growth characteristics as the initial valve culture. It is recommended that manufacturers of xenograft valve bioprostheses maintain a quarantine of 6 weeks until cultures, smears of culture broth, and microscopic evaluation of aortic wall coupons are negative. Users of these prostheses should keep cultures for a minimum of 3 weeks. Should positive cultures result, antimicrobial therapy should be considered only with clinical evidence of infection.

Retrospective analysis of preoperative angiograms was conducted to determine potential candidacy for PTCA among the NHLBI Coronary Artery Surgery Study (CASS) Registry population undergoing initial and repeat CABG. Conservative criteria believed to be universally acceptable for PTCA were used. Patients were considered potential PTCA candidates if: (1) CABG had been performed to only 1 coronary artery system; (2) the critical disease was localized to the most proximal segment of that coronary artery system; (3) all distal segments of that coronary artery system were free of critical disease; and (4) the morphologic characteristics of the obstructing lesion were discrete and isolated. Left main CAD was excluded. Among persons who underwent initial CABG, 2.8% (261 of 9,369) were PTCA candidates, and 7.1% (20 of 283) of those who underwent repeat CABG were considered suitable for PTCA. The operative mortality risk of the PTCA candidates who underwent initial CABG was 0.4% (1 of 261). No PTCA candidates died during repeat CABG. Perioperative MI occurred in 2.3% (6 of 261) of the PTCA candidates who had initial CABG; none occurred among those who underwent repeat surgery. Total surgical complications occurred in 15.7% (41 of 261) of the PTCA candidates at initial CABG and in 5% (1 of 20) who had repeat CABG. These operative mortality and morbidity risks are lower than those reported for similar patients who undergo PTCA.

From January 1970 to December 1986, 2.7% (228/8509) of all patients having coronary artery bypass grafting had atherosclerotic coronary ostial stenosis of 50% or more. There were 126 males (55%) and 102 females (45%) with mean ages of 60.2 +/- 9.0 and 59.2 +/- 10.2 years (P = NS), respectively. The left ostium was involved in 176 (77.2%) patients, the right in 41 (18.0%) and both in 11 (4.8%). Isolated ostial stenosis (no associated coronary disease of 50% or more) was present in 38/228 (17%) with females predominating (29/38, 76%). Isolated ostial stenosis occurred more frequently on the right (10/41, 25%) than on the left (18/176, 16%). Associated coronary disease occurred in a single vessel in 42 patients, in two vessels in 72 and in three vessels in 76 resulting in a mean of 2.0 diseased vessels per patient. If patients with isolated ostial stenosis are excluded there were 2.3 diseased arteries per patient. There were 687 grafts performed in these patients, an average of 2.3 grafts per patient. One month surgical mortality was 4.8% (11/228), but has been 2% (2/104) in the last 4 years. Nine of 27 late deaths were noncardiac with a mean follow-up of 49 +/- 44 months. Ostial stenosis is hemodynamically equivalent to left main disease when the left ostium is involved. Symptomatic ostial lesions, whether right or left, require operative therapy.

From 1979 to 1985, 22 patients (18 male) underwent repair of acute traumatic rupture of the aorta. Ages ranged from 15 to 75 years (mean, 35 years). All patients sustained deceleration injuries in automobile accidents. The majority had injuries to multiple systems and evidence of mediastinal widening on routine chest roentgenograms. Aortography confirmed transection in the descending thoracic aorta near the ligamentum arteriosum in 20. Primary repair was achieved in 15 patients; it was performed in the last 10 consecutive patients. Seven patients had repair with a prosthetic graft. Survival was 82%. Postoperative morbidity usually was related to associated injuries. Primary repair of aortic transection can be accomplished in most patients without the use of prosthetic material.

This article examines institutional differences in therapeutic decision making in the Coronary Artery Surgery Study (CASS). The initial decision to use medical therapy or coronary artery bypass surgery for coronary artery disease is studied. Data from the CASS registry and a survey of CASS principal investigators were used to examine the effects of institutional characteristics, individual physician characteristics, and decision making responsibility on the recommended therapy, the actual therapy, and the ratio of the observed to expected number of surgeries. The results indicated that the experience and involvement of the surgeon in the decision making process were related to actual and recommended rates of surgery. The percentage of urgent transfers from other hospitals and the percentage of surgical referrals to outside hospitals were related to the ratio of the observed to expected numbers of surgery, an adjusted rate of surgery. A major conclusion of this study is that despite the effects of certain institutional constructs, scientific criteria in the form of clinical and angiographic data are the most important determinants of whether a patient receives coronary artery bypass surgery.

Between 1959 and 1975 at St. Louis University Medical Center, 71 patients underwent surgery with the Blalock-Hanlon technique. Thirty-nine had simple transposition of the great vessels. The mean age at the time of operation was 3.4 weeks. Sixty-four percent were less than 1 month of age. Eighty-five percent survived the operation. In 11 the Blalock-Hanlon procedure was performed after failure of ballon septostomy. Arterial saturation was increased from a mean of 47% to 73%. There were three late deaths prior to Mustard repair (intra-atrial baffle procedure). Sixteeen patients underwent Mustard repair at a mean age of 4 years and a mean follow-up of 2 1/2 years. There were three deaths after surgery and three late deaths after the Mustard procedure. The Blalock-Hanlon procedure achieves prolonged palliation, avoiding an emergency Mustard procedure in infancy with its risk of late vena caval obstruction.

Of 2144 patients age 65 years or older entered into the registry of the Coronary Artery Surgery Study (CASS) who had coronary arteriography, 1086 underwent isolated coronary artery bypass grafting. Complications of angiography included death in four patients and nonfatal myocardial infarction in 17. Eight patients suffered neurologic complications, which were transient in five. The perioperative mortality was 5.2% (57 of 1086), which is significantly greater than the perioperative mortality of 1.9% (151 of 7827) in patients younger than 65 years entered in CASS (p less than 0.001). There was a trend toward an increased mortality rate with age; it was 4.6% (37 of 803) in patients age 65-69 years, 6.6% (16 of 241) in those 70-74 years and 9.5% (four of 42) in those 75 years or older. The duration of hospital stay after operation was significantly longer for the patients 65 years or older than for the patients younger than 65 (13.3 vs 11.4 days; p less than 0.001). Stepwise linear discriminant analysis identified five variables predictive of perioperative mortality: presence of 70% or more stenosis of the left main coronary artery and a left-dominant circulation, left ventricular end-diastolic pressure, a history of current cigarette smoking, pulmonary rales on auscultation, and presence of one or more associated medical diseases. A second linear discriminant analysis, incorporating 7658 CASS patients who underwent isolated coronary artery bypass surgery irrespective of age, examined whether age 65 years or older was an independent predictor of perioperative mortality. The variables selected, in order of significance, were congestive cardiac failure score, left main coronary artery stenosis and a left-dominant circulation, age 65 years or older, left ventricular wall motion score, sex and history of unstable angina pectoris. In patients 65 years or older, the mortality from coronary arteriography is low, whereas mortality from coronary artery bypass surgery is greater than that in CASS patients younger than 65 years.

Of 531 patients who underwent coronary artery bypass grafting during 1970 to 1973, 181 were restudied by ventriculography and by graft and coronary angiography at least 5 years following operation. Five patterns of postoperative ventricular function were identified: improved ventricular function resulting in normal left ventricular (LV) function; normal ventricular function that was unchanged; abnormal ventricular function that improved but did not reach normal; abnormal ventricular function that remained unchanged; and deterioration of LV function. Patients who regained (40) and those who retained normal ventricular function (49) comprise 49% of the series and patients with deterioration of ventricular function, only 20%. Graft patency and angina relief were significantly better in those with normal LV function than in those with LV deterioration. Progression of disease in grafted coronary arteries was similar in all groups, but was significantly higher in ungrafted coronary arteries (61.3%) in the patients showing deterioration than in either the improved patients or those with an unchanged normal LV (33.3% each) (p less than 0.05). The high incidence of progression of disease in ungrafted coronary arteries in the group with deterioration suggests that low graft patency and deterioration of ventricular function in this group might both be related to intrinsic acceleration of coronary atherosclerosis unrelated to operative intervention.

Between August 1980 and January 1986, 23 patients aged 80 years or older underwent coronary artery bypass grafting (CABG) operations. These patients had a higher incidence of severe left main coronary artery narrowing (p less than 0.0001), 3-vessel coronary artery disease (p less than 0.05) and moderate to severe left ventricular dysfunction (p less than 0.05) than patients in the Coronary Artery Surgery Study registry older than 65 years. Of 14 patients undergoing elective simple CABG procedures, none died; of 19 elective cases overall, 2 patients died (11%). Three of 4 patients undergoing emergency procedures (75%) and 4 of 6 patients (67%) requiring intraaortic balloon counterpulsation died. Significant complications occurred in 9 of 18 survivors (50%). All operative survivors improved at least 1 New York Heart Association class, with a mean classification improvement of 3.7 to 1.6 (p less than 0.0001); 13 of 16 long-term survivors were in class I or II. Actuarial survival at 1 and 2 years is 94% and 82%, respectively. CABG can be performed electively in octogenarian patients with increased but acceptable mortality and morbidity risks. Functional improvement and long-term survival are excellent.

Three large cooperative randomized trials have evaluated the effects of medical and surgical management of ischemic heart disease on survival and other secondary end points. Both randomized and observational data from these trials show increased survival following coronary artery bypass grafting (CABG) in patients with left main coronary artery stenosis, triple-vessel disease, double-vessel disease, left ventricular (LV) functional impairment, or LV aneurysm. The incidence of fatal, but not nonfatal, myocardial infarction is reduced by CABG. Results in patients 65 years of age or older are similar to those in younger patients but are influenced by associated disease. Gainful employment and risk factors are uninfluenced by treatment. Symptoms of congestive heart failure were not improved by CABG alone but were improved by LV aneurysmectomy when this was performed.

This observational study evaluates the effects of the severity of angina pectoris and the treatment method upon the survival of 4,209 patients in the Coronary Artery Surgery Study registry. In this nonrandomized study, these patients met the criteria used in the Coronary Artery Surgery Study randomized trial, except for the degree of angina pectoris and the method of selection of treatment. The 5 year survival rate was greater than or equal to 93% in patients with Class I and II angina pectoris and normal left ventricular function, regardless of the number of involved vessels or treatment received. Late survival of surgically treated patients with Class III and IV angina pectoris and normal left ventricular function was similar, regardless of the number of vessels involved (greater than or equal to 92% at 5 years). Nonoperatively treated patients with Class III and IV angina pectoris and normal left ventricular function had poorer 5 year survival rates, lowest (74%) in patients with three vessel disease (p less than 0.0001). This difference was also observed in patients with abnormal left ventricular function, three vessel disease, and Class III and IV angina pectoris; the 5 year survival rates were 82% for the operative group and 52% for the nonoperative group (p less than 0.0001). These data confirm the importance of clinical as well as anatomic factors in determining the prognosis of patients with ischemic heart disease and indicate that coronary artery bypass grafting can improve late survival in patients with triple vessel disease and severe angina pectoris.

Medical certification to return to work after coronary bypass surgery in occupations that carry a risk to public safety is controversial, particularly for airline pilots. To address this issue, 10,312 patients from the CASS registry who underwent coronary bypass surgery were studied and 2,326 men with clinical and postoperative characteristics similar to those of the average airline pilot who might apply to renew his license after surgery were selected. The 5 year probability of remaining free of an acute cardiac event, defined as acute coronary insufficiency, myocardial infarction or sudden death, was 0.92 +/- 0.01 (mean +/- SE) for the 1,207 men without previous myocardial infarction and 0.98 +/- 0.01 for the 122 men who never smoked and did not have a history of hypertension. Among the 1,119 men with a previous myocardial infarction, the probability of remaining free of acute cardiac events was 0.91 +/- 0.02 and 0.92 +/- 0.02 when left ventricular contraction score was 5 to 9 and 10 or greater, respectively. In this patient subgroup, mortality rate was similar to that of the age-matched U.S. male population when the left ventricular contraction score was 5 to 9 (4.0% versus 4.3%; p = NS) but significantly worse when the left ventricular contraction score was 10 or greater (7% versus 4.2%; p = 0.05). The data from this CASS registry study are pertinent to the question of operationally unlimited first-class medical certification of carefully selected airline pilots after coronary bypass surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

During the period January, 1970, through June, 1977, 1,541 patients underwent coronary artery bypass grafting; 241 of them were women (15.6%). Operative mortality rates for the entire study were 2.4% in men and 3.7% in women, but they showed a marked decline in women during 1975 to mid-1977, with only 2 deaths in 140 patients (1.4%). Women comprised a larger percentage of patients (16.7%) in these later years. Women were slightly older, received fewer grafts, had better preservation of ventricular function on preoperative studies, and had more severe anginal symptoms than men. Patency rates were significantly lower in women at 1 month, 1 year, and 3 years. Five-year survival was not significantly different between women (88.3%) and men (93.5%). Many of these findings may be explained on the basis of women having smaller coronary arteries than men. These favorable results differ from earlier reports of higher mortality rates in women and indicate that myocardial revascularization should not be withheld from female patients.

From October 1970 to June 1977, a total of 15 patients (12 women) were seen with atherosclerotic coronary ostial stenosis (14 left, one right). All patients had angina and two had aortic valve disease. Additional coronary arterial disease was present in nine. One patient declined surgery and died four months later after myocardial infarction. All patients had coronary bypass grafts and two had aortic valve replacement. One patient with valve replacement and one with preoperative cardiogenic shock died postoperatively. Angina recurred nine months postoperatively in one patient; the others (11) are free of angina. Postoperative catheterization from two weeks to 4.5 years in ten of 12 showed 11 of 13 vein grafts and eight of nine internal mammary artery grafts to be patent. In three patients, only a single left-sided coronary bypass was placed to the left anterior descending artery, because the circumflex branches were too small. Ideally, two left-sided bypass grafts should be placed for left ostial disease.

There are few data on the long-term effects of new Q waves on survival and morbidity after coronary bypass graft surgery (CABG). We followed 1340 patients who underwent CABG in 1978 at 10 hospitals participating in the Coronary Artery Surgery Study (CASS). The incidence of perioperative Q-wave infarction was 4.76% (range 0.0-10.3% by hospital). The rate of infarction was higher in patients who had an increased left ventricular end-diastolic pressure or cardiomegaly on the preoperative chest radiograph. Patients who received more grafts or who had longer cardiopulmonary bypass time were also at higher risk of infarction. In a stepwise discriminant analysis of 44 clinical, angiographic and surgical variables, cardiopulmonary bypass time, topical cardiac hypothermia and cardiomegaly entered the stepwise selection of variables. Long-term survival was adversely affected by the appearance of new postoperative Q waves. The hospital mortality was 9.7% in the 62 patients who had new postoperative Q waves and 1.0% in the 1278 patients who did not (p less than 0.001); the 3-year cumulative survival rates were 85% and 95%, respectively (p less than 0.001). In patients who survived to hospital discharge, the presence of new postoperative Q waves did not adversely affect 3-year survival (94% and 96%, respectively). The survival rates were worse in patients who had a history of infarction or who had impaired left ventricular function preoperatively. The number of readmissions to hospital after CABG among the patients who had a transmural perioperative infarction was similar to to that among patients who did not. We conclude that the appearance of new Q waves after CABG adversely affects survival. The major impact on mortality occurs before hospital discharge. Patients who are destined to have a perioperative infarct cannot be predicted from commonly measured preoperative and angiographic variables.

Intraaortic balloon (IAB) assistance in 64 patients over 2 1/2 years has resulted in a survival rate of 11% (1 patient) when used alone but 47% when utilized in patients treated surgically (long-term survival, 38% [21 patients]). Patients undergoing coronary artery bypass grafting or aortic valve replacement have a long-term survival of 50% (8 and 9 patients, respectively). The required duration of IAB support has a bearing on the clinical result. Complications have been minimal. Though it was originally developed to assist in the nonoperative management of complications of ischemic heart disease, IAB assistance offers significant promise as an adjuvant to operative therapy for both ischemic and valvular heart disease.

From January 1972 through December 1974, at Saint Louis University Medical Center (SLU), 345 patients similar to those of the VA Cooperative Coronary Artery Study received CABG. Operative mortality was SLU 2.3%, VA 5.6% (p < 0.05). Perioperative myocardial infarction rate was SLU 8.4%, VA 18% (p < 0.005). One year graft patency was SLU 87%, VA 71%; all grafts patent SLU 76%, VA 54%; at least one graft patent SLU 96%, VA 89%. SLU angina pectoris relief at five years was 90%. SLU patients free of myocardial infarction five years postoperatively was 83%. Comparative cumulative four year survivals were: [Table: see text] Cumulative four-year survival in 272 SLU patients (79%) completely revascularized was 94%, compared to SLU entire group of 95%, VA medical 86% (p < 0.002) and VA surgical 85% (p < 0.002). Comparing 1972-74 SLU results to VA medical and surgical groups, CABG prolonged life in patients with double and triple vessel disease and in those completely revascularized.

A servocontrol system was developed to regulate a single roller pump left atrial-aortic (La-A) assist device. Responsiveness of the servomechanism to blood volume changes, myocardial damage, and mitral regurgitation was evaluated in 5 sheep and 6 dogs. Myocardial damage was induced by occlusion of coronary arteries. and the hemodynamic effects of La-A assistance were evaluated. While La-A assistance reduced left atrial pressures to low levels, the left ventricular end-diastolic pressure remained elevated in the severely damaged heart. LaA-assistance was used in 3 patients. Two were weaned from cardiopulmonary bypass after failure of intraaortic balloon counterpulsation, and 1 is a long-term survivor. The third was supported for 48 hours after attempt repair of complex congenital heart disease. The servocontrol device added to the safety of prolonged La-A assistance. This mode of assistance should be considered when intraaortic balloon counterpulsation has failed.