再次冠状动脉旁路移植术312例临床分析

目的研究再次冠脉搭桥术（CABG）的影响因素及手术效果。方法1992～1996年Hartford医院所作的CABG312例资料进行分析。结果病人平均年龄65±9岁。距上次手术的时间为11．8±4．5年。共搭桥1069根，其中动脉桥386根，包括胸廓内动脉、桡动脉和胃网膜右动脉，静脉桥682根，Gore－Tex桥1根。死亡14例（4．5％），围术期心肌梗塞15例（4．8％），术后低心排46例。有131例病人术前、术中或术后应用主动脉内气囊反搏装置（IABP），其中119例心功能恢复而脱离IABP。结论再次CABG难度、风险均增大，但仍可获得相当满意的手术效果。

冠状动脉旁路术前存活心肌的评价(附13例报告)

目的对１３例准备行冠状动脉旁路术（ＣＡＢＧ）的冠心病患者术前行硝酸异山梨酯（ＩＳＤＮ）介入２０１ＴＩ心肌断层显像，评价其检测存活心肌及预测心功能恢复的价值。方法ＣＡＢＧ术前患者于多巴酚丁胺负荷高峰时注射２０１ＴＩ行负荷、３小时再分布心肌显像后，静脉点滴ＩＳＤＮ并再次注射２０１ＴＩ（ＩＳＤＮ／ＲＩ）进行心肌显像，ＣＡＢＧ术后３个月复查静态心肌显像，并比较术前后左室射血分数。结果１３例患者负荷像共有４８个节段灌注异常，ＩＳＤＮ／ＲＩ显像后有２９个节段灌注改善，其中２６个节段在术后心肌灌注亦有改善；不可逆灌注或异常加重的１９节段中，术后仍有１７个节段灌注无改善，ＩＳＤＮ／ＲＩ显像检测存活心肌的准确性为８９．５％。且左室射血分数的提高与ＩＳＤＮ／ＲＩ显像可逆灌注节段数密切相关（ｒ＝０．７３，Ｐ＜０．００５）。结论ＩＳＤＮ／ＲＩ２０１ＴＩ心肌显像在估测存活心肌和预测心功能恢复方面有较高的临床实用价值。

Sevoflurane Versus Propofol for Myocardial Protection in Patients Undergoing Coronary Artery Bypass Grafting Surgery: a Meta-analysis of Randomized Controlled Trials

Objective To systematically review randomized controlled trials to compare myocardial protection profiles of sevoflurane with propofol in patients undergoing coronary artery bypass grafting （CABG） surgery. Methods Electronic databases were searched to identify all randomized controlled trials comparing sevoflurane with propofol for protecting myocardium in adult patients undergoing CABG surgery. Two authors independently extracted patients＇ perioperative data, including patients＇ baseline characteristics, surgical variables, and outcome data. For continuous variables, treatment effects were calculated as weighted mean difference （WMD） and 95% confidential interval （C/）. For dichotomous data, treatment effects were calculated as odds ratio （OR） and 95% CI. Each outcome was tested for heterogeneity, and randomized-effects or fixed-effects model was used in the presence or absence of significant heterogeneity （Q test P〈0.05）. Sensitivity analyses were done by examining the influence of statistical model on estimated treatment effects. Publication bias was explored through visual inspection of funnel plots of the outcomes. Statistical significance was defined as P〈0.05. Results Our search yielded 13 studies including 696 patients, and 402 patients were allocated into sevoflurane group and 294 into propofol group. There was no significant difference in postoperative mechanical ventilation time, inotropic support, mortality, myocardial infarction, and atrial fibrillation between the two groups （all P〉0.05）. Patients randomized into sevoflurane group had higher post-bypass cardiac index （WMD=0.39, 95% CI： 0.18 to 0.60, P=0.0003）, lower troponin I level （WMD=-0.82, 95% CI：-0.87 to -0.85, P=0.0002）, lower incidence of myocardial ischemia （OR=0.37, 95% CI： 0.16 to 0.83, P=0.02）, shorter ICU and hospital stay length （WMD=-10.99, 95% CI： -12.97 to -9.01, P〈0.00001; WMD=-0.78, 95% CI： -1.00 to -0.56, P〈0.00001, respectively）. Conclusion This meta-analysis has found some evidence showing that sevoflurane has better myocardial protection than propofol in CABG surgery.

Off-pump coronary artery bypass grafting versus on-pump coronary artery bypass grafting： which is better in patients with chronic obstructive pulmonary disease？

To evaluate the clinic outcome of off-pump coronary bypass grafting (OPCABG) of patients with coronary heart disease and chronic obstructive pulmonary disease, we collected and analyzed 1998-2002 data on 28 patients with these two diseases who had received off-pump coronary bypass operation in our hospital, and compared with data on those who also had the same two diseases but received on-pump coronary artery bypass at same time. There were no operation-related death;one died of respiratory failure 14 days after operation while staying in hospital; there were more respiratory complications in the conventional coronary artery bypass grafting group (CCABG) than in the OPCABG group; and the PaO2/FiO2 in the CCABG group was higher than that in the OPCABG group during operation because of CPB, but lower than that in the OPCABG group 6-12 hours after operation. OPCABG seemed more suitable than CCABG for coronary artery disease patients with chronic obstructive pulmonary disease due to less damage to their oxygen-exchange capability and the fewer respiratory complications.

Coronary artery bypass grafting in the octogenarians： should we intervene, or leave them be？

Objective Coronary artery bypass grafting （CABG） is gradually increasing in the elderly population. We aimed to investigate the risk factors and the results of CABG along with the long term survival in patients at an age of 80 and older. Methods Between Januaa-y 2002 and December 201 I, a total of i01 consecutive patients at an age of S0 and older who underwent CABG in our hospital were included in the study. The patients were followed and the long-term survival was estimated. Results The mean age of the patients was 82.98 ~ 2.27 years. Sixty-four （63.4%） were males and 37 （36.6%） were females. Emergency surgery, duration of cardiopulmonary bypass, the intensive care unit （ICU） stay, inotropic support, intra aortic balloon pulsation application, amount oferythrocyte transfusion and flesh frozen plasma transfusion and ventilation period were significantly higher in the patients who died in the hospital. The duration of cardiopulmonary bypass （CPB） was found to be an inde- pendent predictor of mortality （OR： 1.18, 95% CI 1.01-1.38, P = 0.034）. The in-hospital mortality was 16.8%. Kaplan-Meier analyses revealed a survival ratio of 91.3% at one year, 82.9% at three years and 69.0% at five years. Conclusions Patients at the age of 80 and older can be candidates for the CABG procedure bearing in mind that they may have a longer ventilation period and intensive care unit stay. The morbidity and mortality of this age group is considered within an acceptable range. Approaches to minimize CPB, or the choice of off-pump surgery, may be a preventive method to lower the incidence of mortality. Hence, CABG may be performed in this age group with a satisfactory survival ratio.

Retrospective analysis of exercise capacity in patients with coronary artery disease after percutaneous coronary intervention or coronary artery bypass graft

Objectives:To describe the current state of exercise capacity as well as to identify its predictors in patients with coronary artery disease (CAD) following percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) in the mainland of China.Methods:A retrospective study design was employed.We evaluated 230 CAD patients following PCI or CABG in a cardiac rehabilitation center from January 2019 to October 2019.The patients were referred to undergo incremental cardiopulmonary exercise testing with a cycle ergometer.The Zung Self-Rating Anxiety Scale and the Zung Self-Rating Depression Scale were used to evaluate patients' mental health.Statistical analysis was performed using the chi-square test,Fisher's exact test,t-test,Mann-Whitney U test,and binary logistic regression.Results:Among the 230 patients,223 patients demonstrated reduced exercise capacity.Resutlts of the logistic regression analysis showed that anxiety (OR =1.13,95% CI 1.01-1.32,P =0.029) was an independent risk factor for reduced exercise capacity in patients following the PCI or CABG.Conclusions:Exercise capacity of Chinese CAD patients after PCI or CABG was relatively poor.Alleviating symptoms of anxiety and making exercise prescriptions according to the results of the cardiopulmonary exercise test should be considered during the intervention to improve CAD patients' exercise capacity.

Off-pump coronary artery bypass grafting using a bilateral internal mammary artery Y graft

Objective To evaluate the outcome of off-pump coronary artery bypass grafting （OPCABG） using a bilateral internal mammary artery （BIMA） Y configuration graft to achieve total arterial myocardial revascularization. Methods From October 2002 to December 2008, 208 patients （196 males and 12 females） underwent OPCABG using a BIMA Y configuration graft. The average age of the patients was 56.5 ± 11.3 years, with an age range of 33-78 years. A total of 167 （80.2%） cases had triple-vessel disease. Left main stem disease was found in 33 （15.9%） cases, and double-vessel disease was found in 8 （3.9%） cases. The semi-skeletonization technique was used to harvest the two internal mammary arteries （IMAs）, and then the free right internal mammary artery was connected end-to-side to the left internal mammary artery （LIMA） in situ to complete the Y configuration graft. Off-pump and sequential anastomosis methods were used to perform coronary artery bypass surgery in all patients. Graft patency was assessed intm-operatively with the HT311 transit time flowmeter. Results A total of 728 distal anastomoses were performed in 208 patients, with the average being 3.5± 1.3 per person. No one died or experienced recurrent angina within 30 days after the operation. Conclusions OPCABG using the BIMA Y graft was safe and effective to achieve total arterial revascularization. This method avoids surgical operation on the ascending aorta and other incisions.

Tei index evaluates left ventricular function changes after on-pump and off-pump coronary artery bypass surgery

Objective： To compare function recovery of left ventricle after off-pump and on-pump coronary artery bypass （OPCAB and ONCAB） using Tel index. Methods： Twenty-four patients with coronary artery disease were enrolled, twelve of which received OPCAB and the others underwent ONCAB. Left ventricular ejection fraction （LVEF）, E/A ratio at mitral orifice and Tel index were measured using transthoracic echocardiography before surgery and 3-7 days, 1 month, 3 months and 6 months after surgery. Results：Tel index of both groups decreased 3-7 days after surgery, with OPCAB group＇s lower than ONCAB group＇s. The difference between pre-and post-OPCAB was significant （P〈0.01）, but not for ONCAB group （P〈0.05）. Tel index of ONCAB decreased more significant than that of OPCAB 1 month after surgery, there was statistical difference between 3-7 days and 1 month after surgery in ONCAB （P〈0.01）. Afterwards, Tel index of the 2 groups decreased steadily with no significant difference between them at other time points. LVEF and E/A ratio decreased at first, then increased gradually, with no statistical differences between the 2 groups at all time points. Conclusion： The recovery of left ventricular function after OPCAB is earlier than ONCAB. Tel index is more sensitive than LVEF and E/A ratio in detecting cardiac function recoveries and can be considered as an accurate and simple method to evaluate left ventricular systolic and diastolic function.

MR IMAGING OF CORONARY ARTERY BYPASS GRAFT:A PRELIMINARY STUDY

Objective. To make a preliminary investigation of the patency and function of coronary artery bypass grafts(CABG) by magnetic resonance(MR) images and to establish a suitable method for followup study after CABG operation among Chinese. Methods. MR imaging was performed with a Toshiba 15T unit in 27 patients with 74 grafts. All patients were examined with a breathhold ECGgated twodimensional fast field echo (FFE) sequence to evaluate the patency of bypass grafts, among them 16 patients with 42 grafts were further examined with a phase shift magnetic resonance angiography flow (PSMRAflow) sequence to evaluate the grafts patency as well as the flow velocity and flow volume vs. time. Results. The results showed that 66 of the 74 grafts in the patients of the present series studied with FFE were patent with a patency rate of 892% The results evaluated both with FFE and PSMRAflow remained the same except that two grafts were patent with FFE and the results with PSMRAflow were uncertain. Diastolic perfusion pattern curves were found in 25 of the 32 grafts in patients of the present series. Comparing the flow curves of the grafted left internal mammary artery with those of the native right internal mammary artery in 7 patients, the systolic peak velocity value(SPV) of the grafted arteries was significantly lower than that of the ungrafted ones, whereas the diastolic peak velocity value(DPV) and the ratio of DPV to SPV were significantly greater than that of the ungrafed ones. Conclusion. The FFE and PSMRAflow sequences were efficient in evaluating patency and obtaining the curves of flow velocity and volume of the bypass grafts. Therefore, they may offer a noninvasive screening method for followup study in patients after CABG surgery, although its accuracy should be further evaluated in more patients and comparatively studied with other methods.

Predictors of atrial fibrillation after coronary artery bypass graft： a meta-analysis

Objectives Postoperative atrial fibrillation （AF） has been associated with less favorable outcomes in patients undergoing coronary artery bypass graft surgery （CABG） and may result in increased post-operative morbidity and mortality. A systematic review and meta-analysis of published studies was conducted to examine the risk factors of occurrence AF after CABG. Methods Using the Medline database, the Cochrane clinical trials database and online clinical trial databases, we reviewed all randomized controlled trials （RCTs） and observational studies examining the risk factors of occurrence of AF after CABG. We searched for literature published April 2009 or earlier. Results Our review identified 8 studies （observational studies）, involving 14548 patients, that examined the risk factors of occurrence of AF after CABG. Although studies provide conflicting results, the overall outcomes suggests that advanced age, previous hypertension, numbers of bridge vessels may increase the occurrence of AF after CABG, while no significant difference of diabetes, preoperative myocardial infarction, and preoperative medication of 13 -Blocker have been observed between the AF patients and no-AF patiens. Conclusions Patients with advanced age, previous hypertension and more numbers of bridge vessels had higher risk for the occurrence of AF after CABG, and perioperative medication and care must be intensified to decrease the postoperative occurrence ofAF（J Geriatr Cardio12009; 6：162-167）.

COMPARISON BETWEEN CORONARY ARTERY BYPASS SURGERY AND DRUG-ELUTING STENTS IMPLANTATION TO DIABETIC PATIENTS WITH MULTIVESSEL CORONARY ARTERY DISEASE

Objective To evaluate the safety and efficacy of drug-elating stents （DES） implantation in diabetic patients with multivessel coronary artery disease （MVD） compared with coronary artery bypass graft （CABG） on the clinical outcomes. Methods From May 2003 to April 2005, 150 consecutive type 2 diabetic patients with MVD underwent revascularization, 84 by percutaneous coronary intervention （PC1） with DES and 66 by CABG. The study end point was the incidence of major adverse cardiovascular events （MACEs） during hospital interval after procedure and follow-up. Results Most preoperative characteristics were similar in two groups, but left main disease （30% vs 4%, P = 0. 001 ） and three-vessel disease （ 70% vs 54%, P = 0. 045 ） were more prevalent in CABG group. Complete revascularization was achieved in more patients in CABG group than that in PC1 group （82% vs 67%, P =0. 037）. Cumulative incidence of MACEs in hospital was similar between two groups （2.4% PC1 vs 9. 1% CABG , P =0. 069） despite the higher early morbidity （6. 1% vs 0%, P =0. 022） associated with CABG. Patients were followed up clinically for a mean of 18 - 8 months （ range 13- 36 months）. The incidence of MACEs remained higher after PC1 with multiple DES （21.4% vs 9. 1%, P =0. 041 ） mainly driven by a more require for repeat revascularization （ 13. 1% vs 3. 0%, P = 0. 030 ）. Conclusion PC1 with DES implantation, combined with tight glycemic control, aggressive cardiovascular risk factor modification and antiplatelet treatment, may be a safe and feasible alternative to CABG for selected diabetic patients with multivessel disease.

Computational Investigation of Hemodynamics in Fully Stenosed CABG

Coronary Artery Bypass Graft (CABG) is an important surgical treatment for critically stenosed arteries. Unfortunately restenosis always occurs after CABG surgery, which bring about surgery failure. Intimal thickening in the CABG distal anastomosis has been implicated as the major cause of restenosis and long term graft failure. The nonuniform hemodynamics including disturbed flows, recirculation zones, oscillating wall shear stress, and long particle residence time were thought to be the possible etiologies. Numerical simulation was proved to be of great help and guidance meaning for the biofluid mechanics research and the CABG surgical plan. The present study was based on the hypothesis that the geometry configuration of CABG could greatly influence the hemodynamics in the vicinity of anastomosis. The hemodynamic features of two geometry models of end to side CABG were studied and compared. One simulated a conventional CABG with 1 way bypass graft, and the other simulated a modified CABG with symmetric 2 way bypass graft. The numerical investigations of hemodynamics in these two models with fully stenosed coronary arteries were accomplished using finite element method. The temporal and spatial distributions of hemodynamics were analyzed and compared. Results showed that the presence of symmetric 2 way bypass graft was of reasonable and favorable hemodynamics than 1 way bypass graft. The modified CABG model created a more hemodynamically efficient streamlined environment with higher mean and maximum axial velocities and lower radial velocities than the conventional 1 way model. Meanwhile, the symmetric 2 way bypass graft was featured with low pressure near the wall, high and uniform WSS in the host artery. All of these were favorable for inhibiting the development of intimal thickening, restenosis, and ultimate failure of the CABG, and it could considerably improve the flow conditions and decrease the probability of intimal hyperplasia and restenosis of CABG.

Hemodynamics Simulation of Stenosed Coronary Bypass Graft

By means of FEM, the physiologi cal blood flow in coronary bypass graft is simula ted. The stenosis in coronary artery is involved in the graft model, and the def ormation of graft end to allow the surgical suture with a smaller diameter coron ary is taken into consideration. The flow pattern, secondary flow and wall shear stress in the vicinity of anastomosis are analyzed. It is shown that a zone of low wall stress and high wall stress gradient exists downstream the toe. The flo or opposed to the anastomosis is an area of high wall stress and high wall stres s gradient. Both the toe downstream and the anastomosis bottom floor are prone t o intimal hyperplasia.

ANALYSIS OF 312 CASES OF REPEAT CORONARY ARTERY BYPASS GRAFTING

Objective To evaluate repeat coronary artery bypass grafting (CABG) in 312 patients. Methods The data of 312 patients (average age 65±9 years) who had CABG operation in Hartford hospital were collected and analyzed. The mean duration follow up after the first CABG was 11.8±4.5 years. A total of 1069 bypass grafts were performed. Among them, 386 were arterial grafts such as internal mammary artery, radial artery and gastroepiploic artery; 682 were venous grafts and 1 Gore-Tex graft. Results The operative mortality was 4.5%. Fifteen patients ( 4.8%) had peri-operative myocardial infarction and 46 patients (15%) had low cardiac output syndrome. Intra-aortic balloon pump (IABP) was used in 131 patients before, during and after operation. One hundred and nineteen patients weaned off IABP and recovered. Conclusion Although the difficulties and risk factors were increased, the results of redo CABG were still good.

ANGIOGRAPHIC STUDY ON THE PATENCY OF SINGLE VERSUS SEQUENTIAL VENOUS GRAFT BEFORE REDO CORONARY ARTERY BYPASS SURGERY

Objective:To compare the long-term patency and longevity of the single and sequential ve-nous graft.Methods:The coronary arterial angiographic data for 300 redo coronary bypass grafting(CABG) were collected.Among them 106 cases had both single(159) and sequential(118) grafts.Results:The oc-clusive and narrowness rate for the single grafts versus sequential grafts were:1 year,2% vs 2%;5 years,3% vs 4%;10years,18% vs 19%;15 years,60% vs 68%;and 23 years,76% vs 81% ,respectively.The differences were not significant in general.Conclusion:Sequential anastomosis itself does not has any adverse affects on short-term and long-term patency of the venous graft and its longevity in CABG operations in general.

Coronary bypass revascularization with radial artery and internal mammary artery grafts

Objective To evaluate radial artery (RA) and internal mammary artery (IMA) grafts in coronary artery bypass and the use of color Doppler ultrasound in the peri-operative evaluation of IMA and radial-ulnar collateral circulation.Methods From June 1998 to June 2000, sixty cases of coronary bypass revascularization with RA and IMA were performed. Preoperatively, the radial-ulnar collateral circulation was evaluated with the modified Allen’s test, color Doppler ultrasound and noninvasive oxygen saturation measurement. The IMA lumen and blood flow were measured at the first intercostal space with color Doppler ultrasound preoperatively and postoperatively.Results One patient (1.7%) died of serious cardiac arrhythmia on the fourth postoperative day. There were no arterial graft harvest related complications. Before harvesting, the ulnar artery blood flow was 30.78±9.71?ml/min, and it increased to 43.36±13.98?ml/min (40.87% increase, P【0.01) after the operation. Compared with the baseline, there was no obvious change of IMA blood flow postoperatively (P】0.05), but the systolic/diastolic flow ratio markedly decreased from 8.57±3.98?ml/min to 3.41±4.87?ml/min (P【0.01).Conclusions Arterial grafts can be safely used for coronary bypass revascularization with good results. The ulnar artery blood flow can increase compensatively after RA harvesting. The diastolic blood flow of grafted IMA markedly increased postoperatively. Color Doppler ultrasound was very helpful both in evaluating the radial-ulnar collateral circulation before RA harvesting and in assessing the patency of the grafted IMA after coronary artery bypass grafting (CABG).

Predictors of atrial fibrillation after coronary artery bypass graft surgery

OBJECTIVE: To identify the clinical predictors of atrial fibrillation (AF) after coronary artery bypass grafting (CABG). METHODS: 322 consecutive patients who had undergone isolated CABG were reviewed. Preoperative, intraoperative and postoperative data were collected. Patients were grouped according to whether AF appeared postoperatively. RESULTS: AF occurred in 75 patients (23.3%). Most cases of AF (85.6%) appeared on or before the third postoperative day. The mean age for patients with AF was 62.5 years compared with 56.7 years for patients without AF (P or = 65 years (OR 2.7; 95% CI 1.5 to 5.1), lesions in the right coronary artery (OR 2.5; 95% CI 1.4 to 4.5), and early postoperative withdrawal of beta blocker (OR 3.9; 95% CI 2.1 to 7.7). CONCLUSIONS: AF remains the most common complication after CABG. Age and lesions in the right coronary artery can influence the incidence of AF, and beta blocker and magnesium may be the most economical and effective prevention for AF early after CABG.

Numerical Simulation of Coronary Artery Bypass Graft with an Assistant Graft

The conventional bypass design is to implant a graft on the stenosed host artery allowing blood to flow bypass the stenotic artery. However, restenosis is a challenging problem which finally results in reoperation. The purpose of this paper is to propose a new bypass graft design of coronary artery with an assistant graft for the treatment of coronary artery stenosis. An additional assistant graft was employed in the new design compared with the conventional ETS anastomosis. Numerical simulations were performed by means of finite volume method using computational fluid dynamics(CFD) solver. Results demonstrated that the new anastomoses model provided a more smooth flow at the distal ETS anastomosis without any stagnation point on anastomotic bed and vortex formation in the heel region. Oscillatory shear index(OSI) and time-averaged wall shear stress gradient(TAWSSG) at the artery bed of the distal ETS anastomosis were reduced. The coronary artery bypass graft with an assistant graft is feasible to improve the local hemodynamics and diminish the probability of restenosis in the treatment of coronary artery stenosis.