Aortocoronary bypass for critical stenosis of the left main coronary artery.

Over a 2-year period 33 patients with symptomatic stenosis (greater than 75%) of the left main coronary artery underwent aortocoronary bypass. Intra-aortic balloon counterpulsation was used preoperatively in only two patients as a therapeutic measure for medically unstable angina. There were no operative deaths. Follow-up study 3 to 27 months (mean 13.3 months) after operation revealed one death. Twenty-two patients were free of pain. The authors conclude that aortocoronary bypass surgery for severe stenosis of the left main coronary artery can be safely accomplished, without prophylactic use of intra-aortic balloon counterpulsation in the majority of cases, with an acceptable operative mortality and morbidity.     

Prospective evaluation of coronary arteries: influence on operative risk in coronary artery surgery.

OBJECTIVE: Coronary angiography data included in the analysis of operative mortality after coronary artery surgery are generally limited to left main coronary artery stenosis and classification into one-, two- or three-vessel disease, but the role of stenoses and quality of distal runoff on each main coronary artery have never been analysed. The aim of this study was to assess the influence of coronary artery status (stenoses and distal runoff) on operative mortality in patients undergoing coronary artery surgery. METHODS: Stenoses of the five main coronary arteries and their distal runoff were prospectively evaluated in a series of 2461 patients undergoing isolated coronary artery surgery. These angiographic variables were included in analysis of operative mortality in combination with conventional preoperative data. RESULTS: Univariate analysis founded 21 preoperative variables being significant: age >70, body surface area <1.8 m2, arterial disease of lower limbs, history of peptic ulcer, CCS class IV angina, unstable angina, post-infarction unstable angina, congestive heart failure, left ventricular ejection fraction <50%, urgency, preoperative intra-aortic balloon pump, previous myocardial infarction, previous cardiac surgery, previous coronary bypass graft, presence of significant stenosis on the left main coronary artery or the circumflex marginal branch or the distal circumflex artery or the right coronary artery, absence of significant stenosis on the left anterior descending artery, impaired distal runoff on the left anterior descending artery or the circumflex marginal branch (for all, P < 0.05). Multivariate analysis identified poor quality distal runoff in the left anterior descending artery and circumflex marginal branch as independent risk factor (P = 0.0005 and P = 0.04, respectively), while left main coronary artery stenosis was not. This lesion appears to be a significant risk factor only in a small subgroup of patients with CCS class IV angina. Other independent risk factors were CCS class IV angina, previous cardiac surgery, body surface area <1.8 m2, diabetes mellitus, age <70, history of peptic ulcer, left ventricular ejection fraction <50%. Impaired distal runoff or the presence of stenoses on the diagonal branch, right coronary artery, or distal circumflex artery does not significantly influence the operative mortality rate. CONCLUSIONS: The quality of distal runoff of the most frequently grafted vessels is a significant risk factor for operative mortality in coronary artery surgery. Left main coronary artery stenosis was not identified as a risk factor when these angiographic variables were included in the analysis. Functional status remains the most powerful predictive factor.     

Unstable angina pectoris. Factors influencing operative risk.

Experience was reviewed with 471 consecutive patients who had coronary artery bypass (CAB) operation alone. The hospital mortality rate was 2% in 341 patients operated on for treatment of stable angina pectoris. There were ten deaths (7.7%) in the 130 patients who underwent CAB for treatment of unstable angina. In this series, age greater than 70 years, poor left ventricular function, distal coronary arteries unfavorable for grafting and the presence of main left coronary artery disease were factors associated with increased operative mortality. In 78 patients with unstable angina who had none of these increased risk factors, the mortality rate was 1.3%. Hospital mortality was 33% in patients older than 70 years and 29% in patients with poor left ventricular function and/or distal vessels unfavorable for grafting. In 23 of the 130 patients, the only increased risk factor present was severe stenosis of the main left coronary artery and one of them (4.3%) died. Thus, when elderly patients and patients with poor left ventricular function or poor distal vessels were excluded, the hospital mortality rate associated with CAB in patients with unstable angina was low (2.0%, 2/101 patients) and equal to that for operation in patients with stable angina pectoris.     

Intraaortic balloon pump therapy facilitates posterior vessel off-pump coronary artery bypass grafting in high-risk patients

Background. Displacement of the heart to expose posterior vessels during coronary artery bypass grafting (CABG) without cardiopulmonary bypass (off-pump CABG, or OPCAB) may impair cardiac function. We used the intraaortic balloon pump (IABP) preoperatively to reduce operative risk and to facilitate posterior vessel OPCAB in high-risk patients with left main coronary artery disease (> 75% stenosis), intractable resting angina, postinfarction angina, left ventricular dysfunction (ejection fraction < 35%), or unstable angina.

Methods. One hundred and forty-two consecutive patients who underwent multivessel OPCAB including posterior vessel revascularization were studied prospectively. The patients were divided into group I (n = 57), which received preoperative or intraoperative IABP, and group II (n = 85), which did not receive IABP. In group I, there were 34 patients with left main coronary artery disease, 24 patients with intractable resting angina, 8 patients with left ventricular dysfunction, 5 patients with postinfarction angina, and 40 patients with unstable angina. Seven patients received intraoperative IABP support owing to hemodynamic instability during OPCAB.

Results. There was no operative mortality in group I and 1 death in group II. The average number of distal anastomoses was not different between group I and group II (3.4 ± 0.9 versus 3.5 ± 0.9, p = not significant). There were no significant differences in the number of posterior vessel anastomoses per patient. There were no differences in ventilator support time, length of stay in the intensive care unit, hospital stay, and morbidity between the two groups. There was one IABP-related complication in group I.

Conclusions. IABP therapy facilitates posterior vessel OPCAB in high-risk patients, and surgical results are comparable with those in lower-risk patients.     

Early mortality predictors in coronary artery bypass grafting patients required intra-aortic balloon pump in perioperative and postoperative periods

AIM: The intra-aortic balloon pump (IABP) is commonly used for decreasing myocardial oxygen demand by systolic unloading in perioperative heart failure. The aim of this study was to determine perioperative prognostic factors for in-hospital mortality in coronary artery bypass grafting patients who received the intraaortic balloon pump. METHODS: A total of 271 patients who underwent coronary artery bypass grafting and received intra-aortic balloon pump perioperatively between January 2002 and September 2006 were studied. The preoperative, operative and postoperative risk factors for early death were evaluated. RESULTS: Early mortality rate in the study population was 17.3%. From variables entered into multivariate logistic regression the following parameters were identified as prognostic factors for early death: left main disease, diabetes, postoperative renal failure and cardiac arrest (P<0.05). The minor and major intra-aortic balloon pump related complications were not significant in univariate and multivariate analysis and its rate was 3.6%. CONCLUSION: According to our study the mortality of IABP group is low compared to other studies, as well as IABP-associated complications. Also it revealed that there is no correlation between IABP-associated complications and early mortality.     

Postinfarction angina: an expanding subset of patients undergoing coronary artery bypass

An analysis of patients undergoing coronary artery bypass for unstable postinfarction angina (less than or equal to 30 days of infarct) during two time periods was undertaken: Group I, January, 1982, through December, 1982; Group II, September, 1983, through August, 1984. Clinical, angiographic, and operative data were coded, and statistical analysis was used to compare the two patient groups, evaluate operative results, and identify risk factors. The incidence of unstable postinfarction angina as an indication for bypass grafting increased significantly (p less than 0.01) from the first to the second time frame, 8.7% (24/276) to 18% (51/283). A greater proportion of Group II patients were operated upon within 7 days of infarct (37% versus 21%, p less than 0.01). All other variables examined were similar in the two patient groups. Analysis of the combined Group I and II patients (N = 75) indicates the following: The ratio of transmural to nontransmural infarction was 39%/61%, and 39% of patients had a previous infarction. Three-vessel disease was present in 76%, two-vessel in 21%, one-vessel in 3%, and left main disease in 20%. Left ventricular ejection fraction was greater than or equal to 40% in 27% of patients, less than 40% in 32%, and not obtained in 41%. Mean left ventricular end-diastolic pressure was 19.5 mm Hg. Intra-aortic balloon pumping was necessary preoperatively in 39%. The mean interval from infarction to revascularization was 12 days, and the mean number of grafts was 3.1 (range one to six). The overall in-hospital mortality was 8% (6/75). Statistical analysis demonstrated that decreased ejection fraction was associated with an increased risk of mortality. No other variables were correlated with mortality. Mean follow-up for the combined Group I and II patients is 13 months (range 4 to 32). Ninety percent of survivors remain in Canadian Heart Association Functional Class I and 6% in Class II. No late deaths have occurred. Patients with unstable postinfarction angina constitute an ever-increasing subset of the coronary bypass population of the 1980s. Operation can be performed with a satisfactory mortality and excellent long-term outlook compared to less acceptable published results with medical management alone. Preoperative left ventricular function constitutes the major indicator of operative risk.     

Resection of left ventricular aneurysm during hypothermic fibrillatory arrest without aortic occlusion

From December, 1977, through September, 1984, 100 consecutive patients had ventricular aneurysmectomy during hypothermic fibrillatory arrest without aortic occlusion. In the series were 83 men and 17 women, mean age 57.2 years. Primary indications for operation were angina pectoris in 42 patients, congestive heart failure in 23, angina plus congestive failure in 22, and refractory ventricular irritability in 13. Emergency operation was required for 13 patients with an intra-aortic balloon pump. Mean New York Heart Association Class was 3.1. Mean left ventricular end-diastolic pressure was 19.5 mm Hg, and mean left ventricular ejection fraction was 0.37. Concomitant coronary artery grafting was performed in 97 patients (mean 3.2 grafts/patient). Pressor agents were used in 21 patients and an intra-aortic balloon pump in two patients. Perioperative myocardial infarction was documented in one patient (1%). There were two hospital deaths (2%), both in patients with refractory ventricular irritability. At late follow-up (mean 38.5 months), 13 additional patients (13.3%) had died. Actuarial survival rate at 73 months was 77.0%. Survival rate was better for 93 patients with anterior aneurysms if the left anterior descending and/or diagonal coronary arteries were grafted with aneurysmectomy (p less than 0.03). Although only ventricular arrhythmias predicted early death (p less than 0.03), ejection fraction (p less than 0.01) and ventricular arrhythmias (p = 0.03) predicted late death. Ventricular aneurysmectomy during hypothermic fibrillatory arrest without aortic occlusion can be performed with low hospital mortality and good long-term results. When possible, left anterior descending and/or diagonal coronary arteries should be grafted when anterior aneurysms are resected.     

Is the use of cardiopulmonary bypass for multivessel coronary artery bypass surgery an independent predictor of operative mortality in patients with ischemic left ventricular dysfunction?

BACKGROUND:l Coronary artery bypass grafting for patients with ischemic left ventricular dysfunction (ILVD) remains superior to medical therapy in terms of long-term survival. Recently, off-pump coronary artery bypass surgery has been shown to be very promising in achieving functional improvements with favorable operative mortality in this challenging group of patients. The aim of this study was to assess the risk factors responsible for operative mortality in this group of patients. METHODS: The records of 305 consecutive ILVD patients, who underwent primary isolated coronary artery bypass grafting for multivessel disease at The National Heart and Lung Institute, Imperial College, University of London, between January 1999 and January 2002, were reviewed retrospectively. Patients were considered to have ILVD if they had a left ventricular ejection fraction of 0.30 or less on preoperative coronary angiography. One hundred six patients were operated on using the off-pump coronary artery bypass surgery technique, and 199 patients were operated on using the conventional coronary artery bypass grafting technique with cardiopulmonary bypass. RESU;TS: Seven (6.6%) patients died in the off-pump coronary artery bypass surgery group, whereas 28 (14.1%) patients died in the cardiopulmonary bypass group (p = 0.05). Univariate analysis of all the preoperative characteristics was performed to identify the potential predictors of mortality in the whole group of ILVD patients. Potential predictors of mortality included symptom status (stable/unstable), chronic obstructive airway disease, dyspnea grade III and IV on the New York Heart Association classification, intravenous nitrates, preoperative use of intraaortic balloon pump, ventricular tachycardia or ventricular fibrillation, body surface area less than 2, and cardiopulmonary bypass. Only ventricular tachycardia or ventricular fibrillation was proved to act as an independent predictor of operative mortality in this group of ILVD patients, with an odds ratio of 29.6 (95% confidence interval, 8.9 to 98). CONCLUSIONS: This study showed that using cardiopulmonary bypass for multivessel coronary artery bypass grafting in patients with ILVD was not proved to act as an independent predictor of operative mortality.     

Left ventricular function and coronary obstruction as predictors of survival following aorta-coronary bypass.

A retrospective analysis was undertaken of clinical data and catheterization studies of 151 consecutive unselected patients who underwent aorta-coronary bypass at the University of Kansas Medical Center between 1971 and 1973. The purpose was to determine the effect of preoperative left ventricular function and extent and severity of coronary artery obstruction on operative mortality rate and long-term survival. The postoperative follow-up period ranged from 10 to 49 months and averaged 26 months. Left ventricular function was assessed by qualitative analysis of left ventricular angiograms. Severity of coronary obstruction was quantified by scoring coronary arteriograms according to the system of Friesinger and associates. Patients with normal or near normal ventriculograms were considered to have good left ventricular function. Patients showing moderate or severe impairment of contraction were considered to have poor left ventricular function. Obstruction scores ranging from 2 to 7 points were classified as low scores, and scores from 8 to 15 points were classified as high scores. Four groups of patients were identified based upon preoperative left ventricular function and obstruction severity: Group I, 29 patients with good left ventricular function and low scores; Group II, 22 patients with poor left ventricular function and low scores. Group III, 28 patients with good left ventricular function and high scores. Elective aorta-coronary bypass in these three groups was accompanied by no operative or late deaths. Group IV comprised 72 patients with poor left ventricular function and high scores. In this group there was a 10 per cent operative mortality rate (7 of 72 patients) and a 5 per cent year late mortality rate. Relief of angina occurred equally in all groups. Thus operative risk can be prospectively determined by analysis of left ventricular function and severity of coronary obstruction. Surgical treatment resulted in negligible operative and late mortality rates (0 per cent) in all patients except those in whom poor ventricular function was accompanied by severe and diffuse coronary artery obstruction. Operation should be offered to this latter group (Group IV) despite the higher operative and postoperative risk because of salutary postoperative results.     

非体外循环下冠状动脉旁路移植术治疗左冠状动脉主干合并3支血管病变

目的总结非体外循环冠状动脉旁路移植术(OPCAB)对左冠状动脉主干合并3支血管病变患者的治疗经验及体会。方法对33例左冠状动脉主干合并3支血管病变患者施行了OPCAB,用左乳内动脉作为移植血管与左前降支进行吻合,大隐静脉作为移植血管分别与回旋支、右冠状动脉/后降支、对角支和钝缘支进行吻合。结果每例患者行旁路血管移植2～5支,平均3.4支。无手术死亡,无围手术期心肌梗死、呼吸衰竭、肝肾功能衰竭等严重并发症,术后心绞痛均消失。结论OPCAB治疗左冠状动脉主干合并3支血管病变的高危冠心病患者是可行、有效的,手术损伤小;而积极的术前准备、主动脉内球囊反搏的应用、正确的手术方法和配合、建立一支熟练快速的应急队伍是确保手术成功的关键。     

连续170例冠状动脉旁路移植术治疗冠心病

目的 回顾应用冠状动脉旁路移植术（ＣＡＢＧ）治疗冠心病的早期效果和经验。方法 １７０例（男１５２例,女１８例;年龄３５－８０岁,平均６６．７岁）冠心病病人中９７％为多支冠状动脉病变。８１例左室射血分数≤４５％,其中２１例〈３０％。８４％病人心绞痛ＣＣＳⅢ－Ⅳ级。除１例在左前外侧小切口非体外循环下手术,余均为正中开胸低温体外循环下ＣＡＢＧ。     

冠状动脉旁路移植术1018例临床分析

目的总结、探讨冠状动脉搭桥术的外科技术及临床治疗效果。方法回顾分析1997—2004年同一术者完成的冠状动脉搭桥术1018例患者的临床资料,其中非体外循环冠状动脉旁路移植术(OPCAB)510例,体外循环下冠状动脉旁路移植术(CCABG)508例。≥60岁的患者582例(57.2%)。不稳定性心绞痛患者852例;术前同时合并其他疾病患者784例(77.0%),包括瓣膜病、高血压病、糖尿病、陈旧性心肌梗死、室壁瘤、室间隔穿孔、脑梗死、阻塞性肺疾病(COPD)、慢性肾功能不全、恶性肿瘤术后等。左主干病变156例;三支病变671例,三支病变以下347例。结果死亡4例(0.39%),总体并发症(胸骨哆开、脑梗死、纵隔炎)发生率1.6%(16/1018)。OPCAB者平均搭桥(2.5±0.4)支,CCABG者平均搭桥(3.3±0.6)支。左乳内动脉使用率93.8%(955/1018),术后早期使用主动脉内气囊反搏29例。全组随访2个月～7年,随访1002例(98.4%)。结论科学的外科策略,精湛的手术技术及麻醉、体外循环技术的改进,可使CABG术的死亡率和并发症明显下降,冠状动脉旁路移植术安全、可靠,效果满意。     

Outcome of emergency conventional coronary surgery for acute coronary syndrome due to left main coronary disease.

BACKGROUND: Outcomes of emergency coronary artery bypass grafting (CABG) for acute coronary syndrome (ACS) due to left main coronary (LMT) disease remain unclear. This study aimed to assess prognoses for patients undergoing emergency CABG for ACS due to LMT disease. METHODS: One hundred and four patients undergoing emergency CABG for ACS due to LMT disease were retrospectively reviewed. All patients had intra-aortic balloon pumping (IABP) support and underwent surgery within 48 hours after onset. We determined predictors for operative mortality and calculated cardiac event free, actuarial survival, and cumulative graft patency rates. RESULTS: We found that 9 patients (8.7%) developed pre-operative cardiogenic shock and 7 of them required percutaneous cardiopulmonary support (PCPS). Operative mortality affected 9 patients (8.7%). Cardiac event free rate and actuarial survival rate at 10 years were 80.7 and 75.4%, respectively. Logistic regression analysis showed that pre-operative cardiogenic shock was the only predictor for operative mortality (p = 0.0146, odds 5.96). Cumulative graft patency rates for internal thoracic artery and saphenous vein (SVG) at 5 years were 92.6 and 72.4%, respectively. One year-graft patency rate for the radial artery (RA) was 100%. CONCLUSION: It is still very hard to treat patients with cardiogenic shock. We suggest that immediate percutaneous coronary intervention (PCI) with mechanical supports is required prior to CABG for survival of patients with left main shock syndrome.     

Intra-aortic balloon counterpulsation in high-risk cardiac patients undergoing noncardiac surgery

Patients undergoing noncardiac general surgical procedures after coronary artery bypass surgery have reduced mortality compared with those operated on without prior revascularization. The urgency of the noncardiac procedure and the potential reconstructability of the coronary artery anatomy may mitigate against timely revascularization. We report the successful outcome of prophylactic intra-aortic balloon counterpulsation in three patients with coronary artery disease and impaired left ventricular function undergoing noncardiac surgical procedures. Intra-aortic balloon counterpulsation may provide myocardial protection in high-risk cardiac patients requiring noncardiac surgery initially. A review of the literature is discussed.     

Conventional repair of abdominal aortic aneurysm in the high-risk patient: a plea for abandonment of nonresective treatment

Recent reports in the literature have promulgated nonresective treatment of abdominal aortic aneurysm as a safer procedure than conventional aneurysmectomy with graft replacement in high-risk patients. This review of 106 high-risk patients who underwent conventional aneurysm repair between 1980 and 1985 was undertaken to compare the relative risks, perioperative morbidity, and operative mortality of these patients to that reported for patients treated by nonresective therapy. Excluded were those patients who had rupture initially or underwent a concomitant renovascular procedure. Patients were considered to be at high risk if they met one or more of the following criteria: age equal to or greater than 85 years; receiving oxygen at home, PO2 less than 50 torr, or forced midexpiratory flow less than 25% of predicted; serum creatinine equal to or greater than 3 mg/dl; biopsy-proven cirrhosis with ascites; retroperitoneal fibrosis; or New York Heart Association functional class III-IV angina, left ventricular ejection fraction less than 30%, recent congestive heart failure, complex ventricular ectopy, large left ventricular aneurysm, severe valvular disease, recurrent congestive heart failure or angina after coronary artery bypass grafting, or severe unreconstructed coronary artery disease confirmed by angiography. The mortality rate for conventional aneurysm repair in high-risk patients was 5.7%, compared with a reported 7% mortality rate for nonresective therapy. In those patients with severe cardiac dysfunction, intraoperative pharmacologic manipulation and the selective use of intra-aortic balloon counterpulsation appeared helpful in achieving survival.(ABSTRACT TRUNCATED AT 250 WORDS)     

Myocardial revascularization for severe left ventricular dysfunction. Factors influencing early and late survival

The results of coronary bypass surgery have been assessed in 102 patients with severe left ventricular dysfunction who had a preoperative left ventricular ejection fraction of ⩽0.35 (mean(s.e.m.) 0.29 (0.01)). Independent risk factors influencing operative mortality were obesity (P = 0.0290) and the need for preoperative intra-aortic balloon counterpulsation (P = 0.0010). Cox regression analysis using as its end-point ‘cardiac-related death’ demonstrated three variables; the need for preoperative intra-aortic balloon counterpulsation (P = 0.001), advanced age (P = 0.011), and obesity (P = 0.036). In a subset of 43 patients who did not have these risk factors, the 4-year cardiac-related death rate was 95.1 (3.4)%. The operative mortality and long-term survival can be expected to be satisfactory in patients with severe left ventricular dysfunction, provided they have a viable myocardium rather than myocardial fibrosis.     

REOPERATION FOR RECURRENT CORONARY ARTERY DISEASE: RESULTS OF 200 CONSECUTIVE CASES

Background : It is well known that reoperation for recurrent coronary artery disease is more difficult than primary coronary artery bypass grafting. However, it is possible to reduce the morbidity and mortality of reoperation to the same level as the initial procedure with careful surgical technique. Methods : A retrospective study of the first 200 patients who underwent redo coronary bypass grafting was undertaken. Results : In the first 200 cases of redo coronary bypass grafting at St George Hospital, Sydney (August 1986–January 1995), there were five in-hospital deaths (2.5%). There was one case of sternal infection (0.5%), which required surgical debridement, three cases of stroke (1.5%), one case of postoperative bleeding (0.5%), which required a return to theatre and six cases (3%) required mechanical ventilation for more than 24h. The need for major postoperative support (such as intra-aortic balloon pumping/adrenaline infusion) was significantly affected by the degree of urgency and the degree of pre-operative ventricular impairment. Conclusions : The mortality rate of redo coronary artery bypass grafting in this series is similar to that of primary surgery described in other reports.     

Left ventricular aneurysm. Preoperative risk factors and long-term postoperative results.

The results of operative treatment of postinfarction left ventricular aneurysm in 169 patients undergoing operation since 1970 are analyzed in this report. Maximum follow-up extended to 7 year (average 2.9 years). Average patient age was 56 years (range 34 to 82 years). Nearly all patients (94%) had left anterior descending coronary artery disease with anterior aneurysm formation and 73% had multivessel disease. Sixty-eight percent of patients underwent aorta-coronary bypass grafting (ACBG) and/or mitral valve replacement (MVR) concomitantly with aneurysmectomy. The over-all operative mortality rate was 17.8%. Preoperative factors that correlated significantly (p less than 0.05) with increased operative risk reflected primarily the quality of left ventricular function, and included functional classification, cardiac index, contractile function of residual myocardium not involved by aneurysm, and mitral regurgitation. Patients whose primary preoperative disability consisted of angina pectoris (42 patients) exhibited significantly higher over-all survival rates (actuarial 5 year survival 75%) than those undergoing operation because of congestive heart failure (86 patients) or ventricular tachyarrhythmias (38 patients), whose 5 year survival rates were 52 and 57%, respectively. Concomitant ACBG (+/- MVR) was associated with a higher operative mortality rate than aneurysmectomy alone (21.1 versus 10.9%), but late postoperative attrition was similar. The over-all 5 year survival rate, including operative death, was 60%, and 90% of surviving patients were in Functional Class I or II at follow-up evaluation. We conclude from this analysis that the long-term prognosis of patients with symptomatic postinfection left ventricular aneurysms, although determined importantly by preoperative left ventricular function, is enhanced by surgical treatment.     

Determinants of operative mortality and long-term survival in patients with unstable angina. The CASS experience

To identify the factors that determine operative mortality and long-term survival, we analyzed the data from 3,311 patients who underwent surgical therapy for unstable angina according to clinical presentation. Overall operative mortality was 3.9% and no differences in operative mortality were found between patients with coronary insufficiency, new-onset angina, rest angina, or changing patterns of angina. Logistic regression analysis indicated that age, left ventricular score, and presence of a left main stenosis in a left dominant circulation were related to operative mortality. The 7 year cumulative survival rate was 79%. Features predictive of long-term outcome by Cox analysis included left ventricular score, congestive heart failure score, other illness, extent of coronary disease, and cardiomegaly. Operative mortality of those patients who underwent coronary bypass during their initial hospitalization with unstable angina was similar to that of patients who were discharged and readmitted for operation at a later date. Thus, patients with unstable angina demonstrate a relatively low operative mortality, which is unrelated to the clinical presentation. Long-term survival is primarily determined by clinical and angiographic markers of left ventricular dysfunction, associated illness, and the extent of coronary disease.     

Aortocoronary artery bypass: present indications and risk factors.

From 1969 through 1974, a total of 4,522 patients were operated on for coronary artery occlusive disease. This article is an in-depth analysis of a consecutive series of 275 of these patients, operated on during 1974. The mortality was 1.8% and perioperative myocardial infarction occurred in 3.6%. On analysis of risk factors, it was found that 24% of the patients were over the age of 60; 57% had some degree of left ventricular dysfunction; 9% had generalized hypokinesis; 24% were New York Heart Association functional class IV; 13% had left main coronary artery stenosis; and 11% had preinfarction angina. On analysis of the early mortality, the limiting factor was diffuse coronary arteriosclerosis combined with poor ventricular function. This resulted in inadequate or incomplete myocardial revascularization. Since these two risk factors are usually predictable, coronary artery bypass can be recommended not only for patients with intractable angina, but also for patients with impaired left ventricular function associated with angina, and in patients without angina who have a positive stress electrocardiogram.