Metabolic syndrome increases operative mortality in patients undergoing coronary artery bypass grafting surgery.

OBJECTIVES: The aim of this study was to determine the impact of the metabolic syndrome (MS) on operative mortality after a coronary artery bypass grafting surgery (CABG). BACKGROUND: Diabetes and obesity are highly prevalent among patients undergoing CABG. However, it remains unclear whether these factors have a significant impact on operative mortality after this procedure. We hypothesized that the metabolic abnormalities associated with MS could negatively influence the operative outcome of CABG surgery. METHODS: We retrospectively analyzed the data of 5,304 consecutive patients who underwent an isolated CABG procedure between 2000 and 2004. Of these 5,304 patients, 2,411 (46%) patients met the National Cholesterol Education Program-Adult Treatment Panel III criteria for MS. The primary end point was operative mortality. RESULTS: The operative mortality after CABG surgery was 2.4% in patients with MS and 0.9% in patients without MS (p < 0.0001). The MS was a strong independent predictor of operative mortality (relative risk 3.04 [95% confidence interval (CI) 1.73 to 5.32], p = 0.0001). After adjusting for other risk factors, the risk of mortality was increased 2.69-fold (95% CI 1.43 to 5.06; p = 0.002) in patients with MS and diabetes and 2.36-fold (95% CI 1.26 to 4.41; p = 0.007) in patients with MS and no diabetes, whereas it was not significantly increased in the patients with diabetes and no MS. CONCLUSIONS: This is the first study to report that MS is a highly prevalent and powerful risk factor for operative mortality in patients undergoing a CABG surgery. Thus, interventions that could contribute to reduce the prevalence of MS in patients with coronary artery disease or that could acutely modify the metabolic perturbations of MS at the time of CABG might substantially improve survival in these patients.     

Risk factors for operative mortality and morbidity in patients undergoing coronary artery bypass surgery for stable angina pectoris

Risk factors for a poor early outcome of surgery for stable angina pectoris were evaluated in 2659 consecutive patients from a defined population. The total operative mortality (death within 30 days after surgery) was 2.6% and the frequency of myocardial injury (increase in S-ASAT to greater than 2.0 mu kat l-1 and in S-CKMB to greater than 1.5 mu kat l-1 within 48 h postoperatively or death in the operating room) 14%. Mortality was related to New York Heart Association (NYHA) classification (P less than 0.001), age (less than or greater than 70 years, P = 0.001), duration of symptoms (less than or greater than 8 years, P = 0.001), aortic cross-clamp (ACC) time (P less than 0.001), and cardiopulmonary bypass (CBP) time (P less than 0.001). A multivariate analysis showed that the combination of NYHA class, ACC time and age best predicted operative mortality. Myocardial injury was related to NYHA functional class (P less than 0.001), duration of symptoms (P less than 0.001), regrafting procedure (P less than 0.001), cardiac related dyspnoea (P = 0.015), ACC time (P = 0.001), CPB time (P = 0.001), relative volume of cardioplegic solution (P less than 0.001), and thromboendarterectomy procedure (P = 0.004). The set of variables that best predicted myocardial injury consisted of ACC time, relative volume cardioplegic solution, NYHA class, regrafting procedure and duration of symptoms. However, these risk factors indicated only moderately high risks, and high-risk patients could not be selected with sufficient accuracy.     

Coronary artery surgery: conventional coronary artery bypass grafting versus off-pump coronary artery bypass grafting

PURPOSE OF REVIEW: Coronary revascularization has become the principal treatment modality in patients with severe coronary artery disease. The broader application of percutaneous coronary interventions in patients with multivessel disease and the recent introduction of drug-eluting stents have both lead to a decline in the number of patients referred for surgical revascularization. Conventional coronary artery bypass grafting using cardiopulmonary bypass is an excellent treatment, however less invasive surgical approaches such as off-pump coronary artery bypass grafting have appeared in the past few years. The exact role of off-pump coronary artery bypass grafting is still vaguely defined and being critically evaluated. Our aim is to provide an objective review of the recent literature in regard to surgical outcomes. RECENT FINDINGS: A critical review of all relevant clinical series from May 2003 to May 2005 was conducted. Current prospective data suggests that both techniques have similar rates of mortality, in regard to morbidity, multiple prospective studies suggest a decrease in stroke rates for off-pump coronary artery bypass grafting. The incidence of postoperative myocardial infarction does not appear to differ between techniques. When analyzed carefully, the results presented herein seem to indicate that both techniques provide similar rates for long-term patency and freedom from surgical reintervention. SUMMARY: Coronary artery bypass grafting and off-pump coronary artery bypass grafting are both safe and beneficial in patients with multivessel coronary artery disease. It appears that elderly patients with additional co-morbid risk factors may benefit most from off-pump coronary artery bypass grafting. It has become increasingly apparent that off-pump coronary artery bypass grafting can be performed safely in reference centers.     

单中心体外和非体外循环下冠状动脉旁路移植术后远期临床效果研究

目的:对比研究体外和非体外循环下冠状动脉旁路移植(CABG)术后的长期临床效果以及影响长期预后的危险因素。方法:回顾性分析2005年1月至2005年12月,在北京安贞医院单纯行CABG术顺利出院751例患者的临床资料,对其进行随访,所有病例随访截止时间为2018年7月,随访结果为生存时间(月)、死亡事件、再次心肌血运重建(经皮冠状动脉介入治疗和CABG术)、前降支通畅率,用倾向得分匹配(1∶1)和生存分析的方法评估患者的临床效果差异。结果:随访时间为150～162个月,随访期内死亡176例(23.4%),其中与心脏相关死亡125例(16.6%)。体外循环(OPCABG)组和非体外循环(ONCABG)组术后10年、13年生存率分别为71.4%vs. 78.1%、69.6%vs. 75.0%,两组生存率差异无统计学意义(P0.05)。COX回归分析表明,年龄(RR=0.544,P=0.00)、吸烟(RR=6.678,P=0.00)、糖尿病(RR=2.937,P=0.00)、EuroSCORE3(RR=2.245,P=0.035)。OPCABG和ONCABG的前降支通畅率为87.6%和90.4%(P0.05)。结论:OPCABG和ONCABG对冠心病患者治疗的远期效果无明显差异,高龄(60岁)、吸烟、糖尿病、EuroSCORE评分3分(中高危)是影响患者长期预后的独立危险因素,而体外循环的运用并不影响患者的长期临床效果。     

Analysis of mortality in low-risk patients undergoing coronary artery bypass grafting

Aim

The aims of this study were to determine the early mortality rate in low-risk coronary artery bypass graft (CABG) patients and examine the causes of death, to identify problems that could be avoided in future surgeries.

Methods

All low-risk patients (EuroSCORE ≤ 2) who died after CABG were included. Their peri-operative information was meticulously studied by internal and independent external reviewers to identify causes of death, which were classified as: cardiac or non-cardiac; and a further division as: (1) non-preventable, (2) preventable (technical error), and (3) preventable (system error).

Results

Early mortality was 0.93% (24/2 570). Eleven patients (45.8%) were classified as preventable deaths. In six of them the main problem was identified as graft thrombosis, which was secondary to a technical error of either the harvesting or anastomosis of the left internal mammarian artery. There were also five system errors identified as delays in the treatment of an identified and potentially reversible problem.

Conclusions

Correction of technical and system errors, such as harvesting of the left internal mammarian artery, haemostasis during surgery, and establishing standard protocols for the transfer of patients from ward to intensive care units will eventually lead to improvement in both the quality of care and patient outcomes, even in low-risk groups.     

Diabetes mellitus increases short-term mortality and morbidity in patients undergoing coronary artery bypass graft surgery

OBJECTIVES: The aim of this study was to determine the impact of diabetes mellitus (DM) on short-term mortality and morbidity in patients undergoing coronary artery bypass surgery (CABG). BACKGROUND: Diabetes mellitus is present in approximately 20% to 30% of patients undergoing CABG, and the impact of diabetes on short-term outcome is unclear. METHODS: We performed a retrospective cohort study in 434 hospitals from North America. The study population included 146,786 patients undergoing CABG during 1997: 41,663 patients with DM and 105,123 without DM. The primary outcome was 30-day mortality. Secondary outcomes were in-hospital morbidity, infections and composite outcomes of mortality or morbidity and mortality or infection. RESULTS: The 30-day mortality was 3.7% in patients with DM and 2.7% in those without DM; the unadjusted odds ratio was 1.40 (95% confidence interval [CI], 1.31 to 1.49). After adjusting for other baseline risk factors, the overall adjusted odds ratio for diabetics was 1.23 (95% CI, 1.15 to 1.32). Patients treated with oral hypoglycemic medications had adjusted odds ratio 1.13; 95% CI, 1.04 to 1.23, whereas those on insulin had an adjusted odds ratio 1.39; 95% CI, 1.27 to 1.52. Morbidity, infections and the composite outcomes occurred more commonly in diabetic patients and were associated with an adjusted risk about 35% higher in diabetics than nondiabetics, particularly among insulin-treated diabetics (adjusted risk between 1.5 to 1.61). CONCLUSIONS: Diabetes mellitus is an important risk factor for mortality and morbidity among those undergoing CABG. Research is needed to determine if good control of glucose levels during the perioperative time period improves outcome.     

Microembolic signals in patients undergoing coronary artery bypass grafting. Effect of aortic atherosclerosis

The aim of this prospective study was to determine whether aortic atherosclerotic plaques are associated with increased frequency of microembolic signals and stroke in patients who undergo coronary artery bypass grafting. A total of 69 such patients were monitored by transcranial Doppler ultrasonography for 30 minutes before and after surgery. To our knowledge, this study is the 1st in which in vivo pathologic analysis of aortic plaques was systematically performed-and microembolic signals monitored-before and after open-heart surgery. Plaques were assessed by transesophageal echocardiography and by biopsy of materials taken during surgery. The frequency of microembolic signals was evaluated with regard to the occurrence of postoperative stroke. In the preoperative phase, only 10 of 48 patients with aortic plaques had microembolic signals, and the mean count of microembolic signals was 3.2 +/- 1.2 per hour. At the conclusion of 24 postoperative hours, 29 patients (42%) displayed such signals (mean count, 9.8 +/- 3.1/h). Seven of the 48 patients (15%) with aortic atherosclerosis had cerebral ischemic events, but none of those with normal aorta (21 patients) experienced stroke during the postoperative phase. During postoperative monitoring, patients with stroke had higher microembolic-signal counts than did those with normal aorta (174 +/- 3.3/h vs 5.9 +/- 3.1/h; P <0.05). Our findings suggest that microembolic signals can be a marker of severe aortic atherosclerosis and that monitoring these signals should enable the application of appropriate surgical methods to coronary artery bypass patients who are at higher risk of stroke.     

非体外循环冠状动脉旁路移植术中血糖调控的应用

目的 探讨非糖尿病患者非体外循环冠状动脉旁路移植术围术期血糖调控的效果。方法 将70例行OPCAB的非糖尿病患者随机分为2组,每组35例。分别接受胰岛素输注(试验组)或生理盐水输注(对照组),观察麻醉诱导前、搭桥前、搭桥后、关胸后、术后ICU1h、ICU6h、ICU12h、血糖值。结果 1.试验组与对照组相比,术后呼吸机使用时间(13.78±6.42vs19.02±9.74)、术后住院时间(19.54±5.72vs22.48±6.45)均显著缩短,术后心律失常发生率显著降低。2.试验组与对照组相比较,血糖在麻醉诱导前无统计学差异,而搭桥前、搭桥后、关胸后、ICU1h、ICU6h、ICU12h的血糖显著降低。结论 非糖尿病患者行OPCAB围术期高血糖可能影响预后,输注胰岛素输注可以有效控制血糖、改善雨后。     

Prospective evaluation of glucose metabolism in patients undergoing coronary artery bypass grafting

INTRODUCTION: Disturbances of glucose metabolism are associated with increased risk of ischaemic heart disease (IHD). It is not uncommon that IHD and its complications precede diagnosis of glucose metabolism disturbances. Since publication of the American Diabetes Association's 2004 Guidelines for the assessment of glucose metabolism, no prospective evaluation of prevalence of carbohydrate metabolism disorders in patients referred for coronary artery bypass grafting (CABG) has been performed. AIM: Evaluation of prevalence of glucose balance disturbances in consecutive patients with stable IHD who underwent elective CABG procedures. METHODS: Prospective analysis of glucose metabolism was carried out on a group of 117 consecutive IHD patients (including 31 women) aged below 80 years, selected for elective CABG surgery. In all patients, history assessment and physical examination as well as basic biochemical studies and resting echocardiography were performed. Additionally, in all individuals without previous diagnosis of diabetes mellitus, oral glucose tolerance test (OGTT) was carried out. RESULTS: History analysis revealed glucose balance disturbances in 35 (29.9%) patients, including diabetes mellitus in 33 (28.2%) subjects and impaired glucose tolerance in 2 (1.7%) individuals. Based on OGTT results, among the remaining 82 (70.1%) subjects without previously known glucose metabolism disturbances 4 (3.4%) patients had abnormal fasting glycaemia, 32 (27.4%) subjects had impaired glucose tolerance, and diabetes mellitus was diagnosed in 12 (10.3%) individuals. No impaired glucose balance was found in only 34 (29.1%) examined subjects. CONCLUSIONS: Over 70% of all patients undergoing elective CABG procedure presented various forms of carbohydrate metabolism disturbances that were not diagnosed previously. Thus, it seems that the assessment of glucose regulation should be mandatory in all patients undergoing elective CABG surgery.     

The early outcome in patients undergoing off-pump coronary artery bypass grafting: our experience.

BACKGROUND: Many studies confirm that beating heart surgery is an alternative to on-pump myocardial revascularization. However, the clinical conditions of patients are currently considered as a major landmark in the indication for beating heart surgery. This retrospective non-randomized study was carried out to evaluate the efficacy and the advantages of this surgical technique when anatomical criteria are used to choose the surgical strategy. METHODS: From February to December 2003, 222 consecutive patients underwent isolated myocardial revascularization: 76 (34%) with an off-pump coronary artery bypass (OPCAB) and 146 (66%) with an on-pump coronary artery bypass (ONCAB) procedure. Selection for surgical treatment was based on coronary anatomy. All patients were stratified for mortality risk class according to the EuroSCORE system. Operative and postoperative data were analyzed. RESULTS: Morbidity and mortality did not differ significantly between the two groups but the release of creatine kinase-MB fraction was significantly higher in the ONCAB group (48.7 +/- 55.3 vs 20.8 +/- 16.6 U/ml, p < 0.001). Patients at high surgical risk were dealt with a more complicated clinical outcome; logistic regression analysis showed that this class was an independent risk factor for postoperative complications in both groups. CONCLUSIONS: We did not find any statistical difference in hospital mortality and morbidity either using ONCAB or OPCAB; however a lower release of creatine kinase-MB in beating heart revascularization group suggests that OPCAB reduces myocardial injury and preserves cardiac function when anatomical criteria are considered for patient selection.     

非体外循环冠状动脉搭桥手术后血糖控制水平分析

目的:探讨非体外循环下冠状动脉搭桥术后患者的血糖控制水平对手术后主要并发症的影响。方法:2年共观察患者83例,对住院准备手术的患者进行随机分组,术前将血糖控制在正常水平。实验组手术后48h内血糖控制在(4·4~7·1)mmol/L,对照组血糖控制在(7·1~11)mmol/L。观察术后呼吸机辅助呼吸时间、平均住院时间、术后7d内心房颤动的发生率、围手术期心脏事件发生率、伤口并发症情况。结果:实验组术后7d内心房颤动的发生率12%,较对照组低,差异有显著性。其余指标差异无显著性。结论:非体外循环下冠状动脉搭桥手术后血糖控制在较低水平对患者术后恢复有利。     

Mortality and morbidity in HIV-infected patients undergoing coronary artery bypass surgery: a case control study

The use of highly active antiretroviral therapy (HAART) in patients with HIV infection has improved survival. This improvement combined with the metabolic effects of treatment has increased cardiovascular risk and the need for cardiac surgery in these patients. We compared morbidity and mortality in HIV-infected patients (cases, n=7) and non-HIV-infected patients (controls, n=21) who underwent isolated coronary artery surgery between 1997 and 2004. The durations of extracorporeal circulation and aortic cross-clamping were shorter in HIV-infected patients (P=.002 and P=.014, respectively). The percentage of patients who experienced complications was similar, at 57.1% in both groups, but there was a slightly higher number of complications per patient in non-HIV-infected individuals. The mean length of total hospitalization was greater in HIV-infected patients (27.1 [13.3] versus 8.8 [5.3] days; P=.003), as was that of postoperative hospitalization (18.2 [15.4] vs 7.9 [4.2] days; P=.08). No HIV-infected patient died or needed a repeat cardiac operation. No progression of the HIV infection was observed. Isolated coronary artery surgery in HIV-infected patients produces good results, and there is no increase in morbidity or mortality. Extracorporeal circulation did not influence disease progression.     

Monitoring blood transfusion in patients undergoing coronary artery bypass grafting: an audit methodology

BACKGROUND AND OBJECTIVES: The purpose of this work was to describe the methodology used to build a transfusion database that allows continuous audit of transfusion practices in coronary artery bypass surgery. MATERIALS AND METHODS: The transfusion database requires electronic data available from two sources: the hospital's patient administration system; and the local blood transfusion service. RESULTS: We demonstrated a reduction in the percentage of patients receiving red blood cell transfusion: from 47.4% in 1997/1998 to 31.6% in 2001/2002 (P<0.001). Reductions have also been shown in the percentage of patients receiving fresh-frozen plasma and platelet units. CONCLUSIONS: The data sourcing the transfusion database should be available to all hospitals through their patient administration systems and local blood transfusion service. Its use can help to reduce transfusion rates significantly.     

Coronary angioplasty in patients with previous coronary artery bypass grafting.

Between 1982 and 1990, in 134 patients with prior coronary artery bypass grafting and recurrent angina, repeat coronary angiography and balloon angioplasty of stenoses in grafts or native arteries were attempted. Mean age of grafts was 45.6 months, range three days to twelve years. At the time of angioplasty, 6 patients had one-vessel-disease, 33 had two-vessel-disease, and 95 had three-vessel-disease. A total of 182 lesions were dilated: 55 venous grafts, 3 internal mammary artery grafts, and 124 native vessels. Forty-nine of 55 (89%) venous grafts could be successfully dilated, and in 3 internal mammary artery grafts, a stenosis reduction greater than 50% was achieved. In 65 of 88 (74%) grafted native arteries, dilation success was achieved. Twenty-seven of 36 (75%) patients with prior bypass surgery to other arteries had successful angioplasty of nongrafted native arteries. Three patients underwent emergency bypass surgery after dissection and acute occlusion: one of them died in cardiogenic shock secondary to acute myocardial infarction. The angiographic success rate in grafts was slightly higher than in native arteries (90% vs 74%). These data indicate that percutaneous transluminal coronary angioplasty in patients after bypass surgery is possible at a low risk (3%) and constitutes an effective therapy in symptomatic patients.     

Analysis of morbidity and mortality in patients 70 years of age and over undergoing isolated coronary artery bypass surgery

With increasing frequency more elderly patients are referred for coronary artery bypass surgery. The operative results of 201 patients 70 years of age and over were compared with the results of 1242 patients under 70 years operated on since 1981. A larger percentage of the elderly patients had triple-vessel disease (66.2% vs 51.0%, p less than 0.001), left main coronary artery obstruction (34.8% vs 16.3%, p less than 0.01), and an ejection fraction of less than or equal to 45% (30.8% vs 21.1%, p less than 0.001). An increase percentage of the patients 70 years of age and over had perioperative myocardial infarction (7.9% vs 4.1%, p less than 0.05), required prolonged ventilatory support (7.9% vs 3.1%, NS), and had major neurologic complications (4.0% vs 1.1%, p less than 0.001). The mortality rate was significantly higher in the elderly patients (5.9% vs 1.9%, p less than 0.01) but did not correlate with degree of coronary artery disease, anginal pattern, or preoperative ventricular function. Only 2 of 12 deaths in the elderly patients were from cardiac causes. This data would suggest that elderly patients have an increased risk for significant cardiac and noncardiac morbidity and mortality following coronary artery bypass surgery and that the higher mortality rate in this age group may be a result of noncardiac organ failure.