不同循环方式对老年患者冠状动脉旁路移植术预后的影响

目的 比较老年冠状动脉粥样硬化性心脏病(冠心病)患者接受不同循环方式下冠状动脉旁路移植术(CABG)后围手术期的心肌损伤程度,分析其对预后的影响.方法 2008年7月至2009年6月,我院收治的125例老年冠心病患者分别在非体外循环(A组,70例)、心肺转流(CPB)不停跳(B组,33例)、CPB停跳(C组,22例)下行CABG.分别于术前,术后0、24、72和168 h取静脉血标本,分别测定心肌肌钙蛋白Ⅰ(cTnI)和肌酸激酶同工酶-MB(CK-MB)的水平,另外记录并发症及病死率.结果 三组术前、术后168 h的cTnI和CK-MB差异无统计学意义(P>0.05).术后0、24、72 h的cTnI和CK-MB值A组低于B、C组(P<0.05).术后0、24、72 h的cTnI和CK-MB值B组低于C组(P<0.05).A组并发症发生率低于B、C组(P<0.05),A组病死率低于B组(P<0.05),但与C组的差异无统计学意义.B组与C组的并发症发生率和病死率差异无统计学意义.结论 对于老年冠心病患者,非体外循环CABG造成的心肌损伤小于CPB不停跳和CPB停跳.非体外循环CABG能够减少老年冠心病患者围手术期并发症的发生.     

Preoperative statin use and in-hospital outcomes following heart surgery in patients with unstable angina

Objective: Unstable angina (UA) is characterized by a state of coronary artery vascular inflammation and endothelial dysfunction. Statins mitigate inflammation and endothelial dysfunction and decrease mortality associated with percutaneous interventions for UA. We determined whether preoperative statin use is associated with decreased mortality and morbidity following coronary artery bypass±valve surgery for UA. Methods: Patients with CCS Class IV angina having CABG±valve surgery were identified (n=1706). A logistic regression model determined the association of preoperative statin use with in-hospital mortality (IHM). Propensity score analysis was used to match two sub-groups of patients (GrpI, on statins, n=534; GrpII, not on statins, n=534) on factors known to affect outcomes. Outcomes were IHM, intra-aortic balloon pump (IABP) use, perioperative myocardial infarction (PMI), prolonged (>24 h) ventilation (p-vent), stroke, and a composite outcome (comp) defined as any one or more of the above. Results: Of the 1706 patients, 1075 were on statins and 631 were not. Patients on statins were more likely to have isolated CABG, EF>40%, and be on a β-blocker (P=0.0001); and less likely to have renal failure, MI<7 days, CHF, and undergoing urgent/emergent surgery (P=0.0001). Unadjusted rates of IHM (9 vs. 5%, P=0.001), stroke (4.4 vs. 2.3%, P=0.015), p-vent (28.4 vs. 19%, P=0.0001), and comp (32.5 vs. 22.8%, P=0.0001) were lower in patients receiving statins. After adjustment, statin use was not associated with a reduction in IHM (OR=1.0, 95% CI=0.6–1.5, P=0.85) or comp (OR=1.1, 95% CI=0.8–1.4, P=0.69). No significant differences were found in any of the propensity-adjusted outcomes for GrpI vs. GrpII: IHM (7.1 vs. 6.4%), PMI (2.8 vs. 1.7%), IABP use (3 vs. 3.8%), stroke (3.8 vs. 3.9%), p-vent (26.4 vs. 23.8%), comp (31.5 vs. 27.5%). Conclusions: Preoperative statin use is not associated with a reduction in IHM or major morbidity following CABG±valve surgery in patients with UA.     

A coronary active perfusion system for off-pump coronary artery bypass grafting in an experimental porcine model: the relationship between flow rate and myocardial function

Abstract:  We developed a coronary active perfusion system (synchronized arterial flow ensuring system [SAFE-System]) to prevent myocardial ischemia during distal anastomosis in off-pump coronary artery bypass grafting (CABG). The purpose of this study was to identify the relationship between the flow rate of the SAFE-System and myocardial function. Studies were performed on pigs, which were divided into five groups: external shunt perfusion group (group A, n  = 6); 0.1 mL/beat flow rate for the SAFE-System group (group B, n  = 6); 0.2 mL/beat flow rate group (group C, n  = 6); 0.3 mL/beat flow rate group (group D, n  = 6); and 0.4 mL/beat flow rate group (group E, n  = 6). Regional myocardial blood flow and left ventricular function were monitored for 30 min. The regional myocardial blood flow in group A was severely decreased ( P  < 0.001), and was significantly lower than in the other groups ( P  <  0.001). The slope of the end-systolic pressure–volume relationship, and the slope of the preload recruitable stroke work relationship in groups A, D, and E were lower than in groups B and C. As compared with the use of a passive external shunt, a coronary active perfusion system provides adequate myocardial blood flow and hemodynamics. It was possible to maintain left ventricular function when using 0.1 or 0.2 mL/beat flow rate. The use of a coronary active perfusion system appears to make the off-pump CABG procedure safer and may increase the application of off-pump bypass grafting.     

Non-depolarizing cardioplegia activates Ca-ATPase in sarcoplasmic reticulum after reperfusion

Objectives: Depolarizing cardioplegia is the most common method for myocardial preservation in cardiac operations. However, depolarizing cardioplegia causes depolarization of the membrane potential by extracellular hyperkalemia, resulting in depletion of energy stores and calcium overload. This study examined the hypothesis that non-depolarizing cardioplegia would provide superior protection compared with depolarizing cardioplegia. Methods: In an isolated rat heart Langendorff model, hearts were perfused for 10 min with St. Thomas' Hospital cardioplegic solution (Group I: n=20), St. Thomas' Hospital cardioplegic solution+Lidocaine 1 mM (Group II: n=20) or non-depolarizing cardioplegia (Group III: n=20). The hearts then were subjected to 60 min of normothermic global ischemia, after which they were perfused with Krebs–Henseleit buffer at 37 °C for 30 min. The percent recovery of functional data, myocardial cyclic AMP contents, and myocardial cyclic GMP contents were recorded at each time point (base, after the administration of cardioplegia, after global ischemia, and after 30 min of reperfusion). Ca²⁺-ATPase in sarcoplasmic reticulum was measured at pre-ischemia and 30 min of reperfusion. Results: The percent recovery of developed pressure and ±dp/dt were significantly higher in Group III than in other groups. Myocardial cyclic AMP and GMP contents were elevated after reperfusion in all groups. However, in Group III, myocardial cyclic AMP contents after 30 min of reperfusion were significantly higher than in other groups (Group III: 14.7±1.6 vs. Group I: 8.7±1.0, Group II: 8.3±0.2 pmol/mg dry weight, P=0.05) but not cGMP. The sarcoplasmic reticulum Ca²⁺-ATPase activities at 30 min of reperfusion significantly increased in Group III compared with Groups II and I (Group III: 70.3±3.6 vs. Group I: 46.8±3.4, Group II: 53.9±6.1 μmol Pi/mg per h, P=0.025 and P=0.030). Conclusions: Non-depolarizing cardioplegia induced the activity of Ca²⁺-ATPase in sarcoplasmic reticulum after reperfusion. The activity would be increased by the cyclic AMP pathway. These findings suggested that non-depolarizing cardioplegia prevented calcium overload after reperfusion, especially decreased cytosolic calcium during the diastolic phase.     

On-pump versus off-pump coronary artery bypass grafting: more heat-shock protein 70 is released after on-pump surgery

Objectives: The use of cardiopulmonary bypass in coronary artery bypass grafting (CABG) may contribute to the postoperative inflammatory response. The molecular chaperone heat-shock protein (HSP) 70 may be induced by ischemia, and has been detected both in the myocardium and in the circulation after CABG. In vitro, extracellular HSP70 may activate both innate and adaptive immunity. Hypothesizing that use of cardiopulmonary bypass (CPB) leads to more circulating HSP70, we explored the release of it in 10 patients undergoing CABG with the use of CPB, and in 10 patients undergoing off-pump surgery CABG (OPCAB). Methods: Blood samples were taken preoperatively, twice peroperatively, 2 and 6 h postoperatively and the next day. Serum analyses were performed by means of immunoassays. Results: We detected a significant difference in postoperative circulating HSP70 between on-pump and off-pump patients (median peaks of 2849 and 756 pg/ml, respectively, P<0.01, 2 h postoperatively). Interleukin-6 and -8 increased in all patients, without significant differences between the groups. Serum interleukin-10 increased at the end of the operation in 7 of 10 patients operated with cardiopulmonary bypass (median 51.7 pg/ml), but in none of the off-pump patients. Furthermore, in the first group, interleukin-10 correlated with the HSP70 concentration at the end of the operation, r=0.75, P<0.05. Serum markers of myocardial damage were higher in conventional than off-pump patients on day 1 postoperatively: median cardiac Troponin T was 0.358 and 0.126 μg/l, respectively, P<0.01. Correspondingly, median creatine kinase-MB was 23.6 and 7.8 μg/l in on-pump and off-pump patients, respectively, P<0.01. Peak HSP70 correlated with both Troponin T and creatine kinase-MB measured on day 1. Conclusions: Significantly more HSP70 was released into the circulation following conventional than following off-pump CABG. Circulating HSP70 may indicate cellular stress or damage. Furthermore, HSPs are suggested as immunoregulatory agents, and may be important in the host defence postoperatively.     

顺逆灌结合开放前温血灌注在冠状动脉旁路移植术中的心肌保护作用

目的回顾研究顺逆灌结合开放前温血灌注在冠状动脉旁路移植术(CABG)中的心肌保护作用。方法择期CABG患者312例,男220例,女92例,年龄29~80岁(平均62岁);其中顺逆灌结合温血灌注188例(研究组),间断顺灌124例(对照组)。研究组采用顺行灌注2 min冷血停搏液600 ml,再逆行灌注2 min停搏液400 ml,之后每隔10 min进行顺逆灌各1 min停搏液200 ml,在开始吻合前降支时持续温血逆灌300 ml/min直至开放。记录搭桥数、心脏自动复跳率、CPB时间、主动脉阻断时间、机械通气时间、ICU停留时间、住院天数。结果研究组CPB时间、机械通气时间、住院天数明显短于对照组(P<0.05)。结论 CABG中采用顺逆灌结合开放前温血灌注的心肌保护效果优于常规间断顺灌方法,值得临床推广。     

Automatic connector devices for proximal anastomoses do not decrease embolic debris compared with conventional anastomoses in CABG

Objective: Emboli generated during cardiac surgery have been associated with aortic clamping and manipulation. Proximal anastomotic devices are thought to be less traumatic by eliminating partial clamping, potentially resulting in fewer adverse outcomes. Intra-aortic filtration has been shown to effectively capture particulate debris. We compared the amount of debris released using intra-aortic filtration and the clinical outcomes between conventionally handsewn and automated proximal anastomoses. Methods: Seventy-seven patients undergoing primary coronary artery bypass grafting with cardiopulmonary bypass were enrolled in a prospective randomized study. Patients were assigned to the anastomotic device Group I (Symmetry™ Aortic Connector, n=39) or the conventional handsewn anastomosis control Group II (n=38). Proximal anastomoses were performed before cardiopulmonary bypass in both groups. Intra-aortic Filter 1 (EMBOL-X^TM) was deployed prior to partial clamping or puncturing the aorta for device application and removed after the proximal anastomosis was completed. Prior to cross-clamp removal, a second filter was inserted (Filter 2). A core laboratory performed quantitative and histologic analyses of the debris captured. Clinical outcomes included adverse events, neurocognitive test scores, graft patency, and mortality. Results: Preoperative variables and risk factors were not significantly different between Groups I and II (EuroSCORE 3.9±2.6 vs. 4.2±2.5). Filter analyses showed no significant difference between Groups I and II in Filter 1 or 2 for either surface area of particles or total number of particles (P>0.05). There was a significant decrease between Filters 1 and 2 in both Groups for surface area of particles (Group I: 18.5±23.8 mm² vs. 10.7±16.3 mm², P=0.017; Group II: 15.0±15.4 mm² vs. 6.9±.6.5 mm², P=0.004), and for total number of particles in Group II (8.6±3.7 vs. 7.1±2.4, P=0.023). No significant differences were observed between Group I (device) and Group II (control) outcomes for myocardial infarction, neurocognitive deficit, stroke, length of stay, graft occlusion, or mortality. Conclusions: The application of proximal aortic connectors without partial clamping does not reduce particulate emboli or affect clinical outcomes compared with conventional anastomoses. Cross-clamping during cardiopulmonary bypass produces less particulate debris than conventional or automated proximal anastomoses performed off-pump, suggesting a major source of emboli is the anastomotic process.     

Does multi-vessel off-pump coronary artery bypass grafting reduce post operative morbidity compared to on-pump CABG?

Background Cardiopulmonary bypass (CPB) may contribute to the complications and it is assumed that eliminating cardiopulmonary bypass has the potential of reducing post operative morbidity after coronary artery bypass grafting (CABG). The study was carried out to compare mortality and morbidity in the off-pump and on-pump CABG groups. Methods We prospectively analysed 200 patients undergoing CABG. Group A consists of 100 patients underwent multi-vessel off-pump CABG and group B consists of 100 patients underwent CABG with CPB. The incidence of complications (mortality, re-exploration for bleeding, myocardial infarction, atrial fibrillation, neurological events, new onset renal failure (s. creatinine>1.6 mg/dL) pulmonary complications, length of ICU stay and hospital stay were recorded, analysed and compared. Results OPCAB patients received 2.73±0.61 grafts/patient and on-pump CABG patients received 3.39±0.75 grafts/patient (p value<0.00001). There was no significant statistical difference in mortality, incidence of stroke between OPCAB and CABG with CPB patients. Length of ICU stay was 32.84±4.22 vs 44.85±7.18 hrs (p value<0.00001) and hospital stay was 6.52±0.69 vs 7.94±0.92 days (p value<0.00001) between group A and group B respectively. Incidence of atrial fibrillation was less in OPCAB group 7% vs 12% although it was statistically not significant (p value 0.33). It was observed in our study that there was no significant deference in worsening of existing renal failure between on-pump CABG and OPCAB 6% vs 2% (P value 0.28). Blood utilization was significantly less in OPCAB group (p value<0.001). Conclusion There was no statistically significant difference in terms of mortality, incidence of stroke and new onset renal failure in both groups. But there was lesser incidence of post operative atrial fibrillation, worsening of existing renal failure in off-pump group though statistically not significant. There was significant reduction in blood utilization, length of ICU and hospital stay in OPCAB group.     

700例冠状动脉旁路移植术的临床回顾

作者对阜外医院７００例冠状动脉旁路移植术（ＣＡＢＧ）患者的临床资料和手术结果，按时间分Ａ、Ｂ两组进行对比分析，结果显示合并糖尿病、高血脂症、心功能Ⅲ～Ⅳ级、左主干病变、广泛三支病变等在患者中所占比例近三年有显著的增高（Ｐ＜０．０５）；合并高血压病（４１．３％）、陈旧性心肌梗塞（６５．０％）、有左室室壁瘤（２４．３％）、术后需使用ＩＡＢＰ（９．４％）发生率高，但两组间无显著性差异。心肌保护方法的改进、冠状动脉充分再血管化技术的提高和内乳动脉的广泛采用，使术后早期死亡率（Ｂ组９．６％，Ａ组２．７％）及围术期心梗发生率（Ｂ组９．０％、Ａ组３．２％，Ｐ＜０．００５）明显下降。     

Combined approach for internal carotid artery stenosis and cardiovascular disease in septuagenarians – a comparative study

Objective: The best surgical approach for concomitant carotid artery and cardiac disease remains controversial. Many studies proved the safety and efficiency of simultaneous surgery. We aimed to demonstrate the same benefits for patients ≥70 years. Methods: We retrospectively evaluated 205 patients simultaneously operated upon between 1988 and 1998. Group A comprised patients <70 years (n=110), group B ≥70 years. (n=95). Risk factors, neurologic and cardiac history, angiographic findings, operative data, morbidity and mortality (30-day-postoperatively) were analysed. The mean age was 62 years in group A and 75 years in group B. All patients with symptomatic carotid artery disease, stenosis >70% or ulcerative carotid disease had simultaneous surgery. Always, the carotid artery was addressed first. Results: Patients in group B had a higher prevalence of peripheral vascular disease (P=0.0005), renal insufficiency (P=0.0011) and COPD (P=0.03). Urgent operation was indicated in 19% of group A patients vs. 37% in group B. In group A 70% were asymptomatic regarding the carotid vs. 48% in group B. Left ventricular dysfunction was present in 45% (group A) and 58% (group B). In the present study 4% in group A and 7% in group B suffered a perioperative myocardial infarction. Pathologic changes of the contralateral carotid were found in 42 vs. 57% (A vs. B). Mortality due to cardiac causes was 1 and 5%, respectively. The combination of persistent neurologic deficit and neurologic death occurred in 3% in group A (n=3) and 5% in group B (n=5). Postoperative neuro-cognitive dysfunction was more common in group B (35 vs. 16%; P=0.01). Conclusions: The incidence of persistent neurologic deficits and neurologic mortality in patients ≥70 years is acceptable, and low in patients <70 years. Preoperative risk factors are increasing with age and are related to the higher mortality in elderly patients. Due to our results we will conclude that the combined approach for carotid stenosis and cardiovascular disease is the method of choice in this high-risk population.     

体外循环与非体外循环冠状动脉搭桥术后心电图胸前导联R波振幅变化的差异

目的 探讨体外循环与非体外循环冠状动脉搭桥术后心电图胸前导联R波振幅变化的临床意义。方法 监测38例非体外循环冠状动脉搭桥术后不同时点心电图胸前导联V4、V5的R波振幅的变化，同时测定不同时点的心肌细胞损伤的生物标记物肌酸磷酸激酶同功酶（CK-MB）和肌钙蛋白I（cTnI），并与同时期38例体外循环冠状动脉搭桥术病人进行比较。结果 非体外循环冠状动脉搭桥术后即刻、6、18和24h心电图胸前导联R波电位幅度无明显变化，CK-MB和cTnI也无明显变化，而体外循环冠状动脉搭桥术后相同时间点心电图胸前导联R波振幅明显减小（P〈0．01），CK-MB和cTnI明显增加（P〈0．01）。结论 非体外循环冠状动脉搭桥术比体外循环冠状动脉搭桥术对心肌损伤明显减小。     

Novel pharmacological preconditioning with diazoxide attenuates myocardial stunning in coronary artery bypass grafting

Objective: To investigate whether novel pharmacological preconditioning with diazoxide could protect the myocardial function and decrease myocardial injury in patients undergoing coronary artery bypass grafting (CABG). Methods: Forty patients with stable angina who were scheduled for isolated elective CABG operations were randomized into control group (n=20) and diazoxide (DZX) group (n=20). In the DZX group, 1.5 mg/kg diazoxide was infused intravenously within 5 min followed by a 5-min washout before commencing the cardiopulmonary bypass (CPB). In the control group, a time-matched period of placebo infusion was given. Hemodynamic data and biochemical markers of myocardial injury were measured perioperatively. Results: There were no adverse effects related to diazoxide. Cardiac index (CI) increased postoperatively as compared with baseline. In the DZX group, the improvement of CI was better than that in the control group (p=0.001). Left and right ventricular stroke work indexes decreased postoperatively, and recovered much faster in the DZX group (p=0.027 and p=0.049, respectively). There were no statistically significant differences in the other hemodynamic parameters. The creatine kinase cardiac isoenzyme (CK-MB) was highest in both groups on the first postoperative day (control 28.8±23.8 and DZX 27.3±19.4, N.S.). The cumulative release of CK-MB postoperatively was lower in the DZX patients as compared with the controls, but the difference remained not significant (p=0.09). Conclusions: Pharmacological preconditioning of the human heart with diazoxide is feasible; it confers additional myocardial protection beyond that provided by the cardioplegia alone by attenuating myocardial stunning after CABG operations.     

Bypass graft material and myocardial protective procedure in combined coronary artery bypass grafting and valve surgery.

OBJECTIVE: The aortic cross clamping time is prone to be longer when coronary artery bypass grafting (CABG) is combined with valve surgery. Therefore, the myocardium that is revascularized by in-situ internal thoracic artery graft is at risk to ischemia, and, myocardial protection is especially important in such operation. In this study, the effect of myocardial preservation of combined antegrade, retrograde and terminal warm blood cardioplegia during combined valve surgery and CABG using the internal thoracic artery as a bypass conduit was evaluated. METHODS: From November 1992 to August 1999, 15 patients received combined CABG and valve surgery. Among these 15 patients, 13 patients who did not need hemodialysis were divided into 2 groups, and a comparative study was done. In Group I (n = 5), only the saphenous vein graft was employed for combined CABG and valve surgery, and myocardial protection was done by combined antegrade and terminal warm blood cardioplegia. In Group II (n = 8), at least 1 in-situ internal thoracic artery graft was employed for CABG and valve surgery, and myocardial protection was done by combined antegrade, retrograde and terminal warm blood cardioplegia. RESULTS: Despite longer aortic cross clamping time in Group II, the peak creatine kinase-MB of Group II was significantly lower. In addition, the postoperative administration of dopamine tended to be less in Group II. CONCLUSION: Myocardial protection by combined antegrade, retrograde and terminal warm blood cardioplegia may be an effective adjunct to combined valve surgery and CABG employing the in-situ internal thoracic artery graft.     

Coronary endothelial damage during off-pump CABG related to coronary-clamping and gas insufflation

Objective: Although off-pump coronary artery bypass grafting (CABG) has been recognized less invasive than conventional CABG on cardiopulmonary bypass, off-pump CABG may be partly invasive especially to the coronary endothelium. The present study was designed to evaluate the adverse effects of coronary snaring with looped sutures and gas insufflation on the coronary endothelium. The protective efficacies on the coronary endothelium of coronary snaring with elastic sutures or humidified gas insufflation with/without heparin and dipyridamole-added were also tested. Methods: Thirty-six mongrel dogs were used. After systemic heparinization (150 U/kg), a 5 mm longitudinal coronary incision was made with looped non-elastic monofilament sutures or elastic sutures applied proximally and distally. The incised coronary artery was exposed to non-humidified carbon dioxide, humidified carbon dioxide with lactated Ringer solution, or humidified carbon dioxide with heparin and dipyridamole-added lactated Ringer solution for 10 or 20 min in each group. After gas insufflation, the incised coronary artery was repaired, then, the coronary was reperfused. Perfusion-fixation was done for observation of the coronary endothelium by scanning electron microscopy. The adverse effect on the endothelium was graded as follows: grade 1, appeared normal; grade 2, few blood cells deposited; grade 3, many blood cells deposited; grade 4, few endothelial cells delaminated with blood cells deposited; grade 5, many endothelial cells delaminated with blood cells deposited. Results: Non-elastic looping caused much more endothelial tears than elastic looping (P<0.00001). Non-humidified gas blowing for 20 min caused more endothelial cell damage than humidified gas blowing (P=0.00005). Non-humidified gas blowing for 10 min caused less damage than for 20 min (P=0.00326), but still caused more damage than humidified gas blowing (P=0.00253). Heparin and dipyridamole-added humidification reduced coronary endothelial area mottled by the deposited cells when compared with simple humidification (P=0.00120). Conclusions: Coronary snaring resulted in coronary endothelial injury, which was ameliorated by using elastic sutures instead of non-elastic sutures. Non-humidified gas insufflation made blood cells deposited and endothelial cells delaminated with time. Humidified gas insufflation attenuated these adverse effects. Heparin and dipyridamole-added humidification had potential advantage in terms of reducing deposited blood cells on the endothelium over simple humidification.     

Propensity case-matched analysis of off-pump coronary artery bypass grafting in patients with atheromatous aortic disease

OBJECTIVE: Atheromatous aortic disease is a risk factor for excessive mortality and stroke in patients undergoing coronary artery bypass grafting. Outcomes of off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass in patients with severe atheromatous aortic disease were compared by propensity case-match methods. METHODS: Routine intraoperative transesophageal echocardiography identified 985 patients undergoing isolated coronary artery bypass grafting with severe atheromatous disease in the aortic arch or ascending aorta. Off-pump coronary artery bypass grafting was performed in 281 patients (28.5%). Propensity matched-pairs analysis was used to match patients undergoing off-pump coronary artery bypass grafting (n = 245) with patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. RESULTS: Univariate analysis revealed decreased hospital mortality (16/245, 6.5% vs 28/245, 11.4%; P =.058) and stroke prevalence (4/245, 1.6% vs 14/245, 5.7%; P =.03) in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass. Freedom from any postoperative complication was higher in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass (226/245, 92.2% vs 196/245, 80.0%; P <.001). Multivariable analysis of preoperative risk factors showed that increased hospital mortality was associated with coronary artery bypass grafting with cardiopulmonary bypass (odds ratio = 2.7; P =.01), fewer grafts (P =.05), acute myocardial infarction (odds ratio = 11.5; P <.001), chronic obstructive pulmonary disease (odds ratio = 2.4; P =.03), previous cardiac surgery (odds ratio = 10.2, P =.05), and peripheral vascular disease (odds ratio = 2.1; P =.05). Cardiopulmonary bypass was the only independent risk factor for stroke (odds ratio = 3.6, P =.03). At 36 months' follow-up, comparable survival was observed in the off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass groups (74% vs 72%). Multivariable analysis revealed that renal disease (P <.001), advanced age (P <.001), previous myocardial infarction (P =.03), and lower number of grafts (P =.02) were independent risks for late mortality. CONCLUSIONS: Patients with severe atherosclerotic aortic disease who undergo off-pump coronary artery bypass grafting have a significantly lower prevalence of hospital mortality, perioperative stroke, and overall complications than matched patients who underwent coronary artery bypass grafting with cardiopulmonary bypass. Routine intraoperative transesophageal echocardiography identifies severe atheromatous aortic disease and directs the choice of surgical technique.     

Assessment of the myocardial protective effect of antegrade warm blood cardioplegia by measuring the release of biochemical markers

vs 40.8 ± 12.6 IU/l, respectively (P = 0.0042). The serum Tn-T 12 h after CPB was significantly lower in the warm group than in the cold group, at 1.40 ± 0.71 ng/ml vs 2.06 ± 0.95 ng/ml, respectively (P = 0.049). In conclusion, intermittent antegrade warm blood cardioplegia showed effective myocardial protection in elective CABG. (Received for publication on Dec. 15, 1997; accepted on Sept. 11, 1998)     

Prospective randomized trial of single clamp technique versus intermittent ischaemic arrest: myocardial and neurological outcome

Objective: To explore the hypothesis that intermittent ischaemic arrest (IIA) provides better myocardial preservation but generates a larger number of cerebral microemboli (ME) and consequently a higher incidence of post-operative cerebral dysfunction compared with the single clamp technique (SCT). Methods: Ninety-one patients with stable angina undergoing elective CABG with no clinical evidence of aortic or cerebro-vascular or neurological disease were prospectively randomized to: IIA (n=43) or SCT with intermittent anterograde cold blood cardioplegia (n=48). Myocardial preservation was assessed by measuring serum CK-MB, Troponin-T (TnT) and Troponin-I (TnI) and from pre- and post-operative ECGs and left ventricular (LV) function by echocardiography. Intra-operative cerebral ME were counted by transcranial Doppler of the right middle cerebral artery. All patients completed the Luria Nebraska Neuropsychological Battery (LNNB) tests for motor, visual, reading, memory and intellectual processes the day before surgery and at 1 week and 6 months post-operatively. Serum levels of the neuro-specific protein S-100 were measured. Results: The two groups were comparable for age, sex, extent of coronary disease, previous myocardial infarction, diabetes, hypertension and number of arterial and venous grafts. The median number of ME detected per patient was 34 (range 4–208) and was similar in both groups. Protein S-100 levels remained normal and similar in both groups at all times except in one patient with SCT who had an operative stroke. LNNB scores were similarly depressed at 1 week and recovered in all cases at 6 months. There was no correlation between the number of ME and LNNB scores. Median peak TnI levels were 0.64 μg/l with IIA vs. 0.87 μg/l with SCT (P=NS) and TnT 0.8 μg/l vs. 1.08 μg/l (P<0.03). SCT was however associated with longer mean ischaemic (67.6±16.1 vs. 34.5±16.5 min, P<0.001) and mean bypass time (88.5±18.2 vs. 74.6±26.3min, P<0.004) than IIA. Four patients with SCT and none with IIA had ECG changes suggestive of MI (P=0.04). Conclusion: During elective CABG in patients with no clinical evidence of aortic or cerebro-vascular disease the incidence of peri-operative ME and post-operative neuropsychological disturbances are comparable with both techniques of myocardial preservation. Biochemical analysis suggests that IIA provides more effective myocardial preservation.     

Terminal warm blood cardioplegia improves the recovery of myocardial electrical activity. A retrospective and comparative study.

OBJECTIVE: The effect of terminal warm blood cardioplegia was analyzed in 191 patients undergoing either coronary artery bypass grafting (CABG) or prosthetic heart valve replacement between Jan. 1990 and Dec. 1995. METHODS: Patients were subdivided into 3 historical cohorts based on the method of myocardial protection: Group A (n = 106), multidose cold crystalloid glucose-potassium cardioplegia, alone; Group B (n = 37), cold crystalloid glucose-potassium cardioplegia plus terminal warm blood cardioplegia, Group C (n = 48), cardioplegia induction with cold crystalloid glucose-potassium cardioplegia, maintenance with multidose cold blood cardioplegia, and terminal warm blood cardioplegia. RESULTS: Of patients undergoing CABG, 5.6% of group A, 70.4% of group B, and 86.7% of group C spontaneously resumed sinus rhythm after aortic declamping, as did 9.1% of group A, 60.0% of group B, and 55.6% of group C of patients undergoing prosthetic heart valve replacement. The incidence of spontaneous recovery was significantly better in groups B and C than in group A (p < 0.05). Over 90% of patients without terminal warm blood cardioplegia developed ventricular fibrillation or tachycardia requiring electrical cardioversion (p < 0.05). Postoperatively, patients without terminal warm blood cardioplegia required temporary epicardial pacing more frequently than those with terminal warm blood cardioplegia (p < 0.05). In patients undergoing prosthetic heart valve replacement, groups B and C, the incidence of postoperative atrial fibrillation was significantly lower than in group A. CONCLUSION: Terminal warm blood cardioplegia thus promoted better postoperative electrophysiological cardiac recovery.     

The warm versus cold perfusion controversy: a clinical comparative study

To evaluate the effects of temperature on myocardial and total body protection, we analyzed 129 consecutive patients who underwent coronary artery bypass grafting, valve replacement, or both, with continuous cardioplegia (Cp). The patients were assigned to three groups: group I (n = 37) normothermic cardiopulmonary bypass (CPB) (37°C) and warm (37°C) Cp, group II (n = 49) normothermic CPB and cold (4°C) Cp and group III (n = 43) hypothermic (28°C) CPB and cold Cp. Comparison of groups I and II showed similar serum levels of creatine kinase (CK) and its myocardialspecific isoenzyme on the first postoperative day, a similar rate of perioperative myocardial infarction, postoperative need for intra-aortic balloon pump, postoperative need for inotropic support and mortality. Comparison of groups I and III showed similar serum levels of CK, amylase, lactate dehydrogenase and creatinine on the first postoperative day, a similar complication rate and mortality rate. However, normothermic CPB resulted in a shorter bypass time (83 ± 4 vs 98 ± 7 min, P<0.05) and interval until extubation (25.0 ± 3.8 vs 40.3 ± 7.4 h, P<0.05). In conclusion, there are no differences concerning myocardial protection, however, warm CPB shortens the perfusion time and postoperative course.     

合并甲状腺功能低下病人的冠状动脉旁路移植术

目的 探讨冠心病(CAD)合并甲状腺功能低下(甲低)病人的冠状动脉旁路移植术(CABG)围术期外科处理的临床效果.方法 2002年9月至2009年6月,1347例CABG中21例(A组)合并甲低需要甲状腺激素替代治疗,男6例,女15例;平均(60.4±14.2)岁.体外循环下手术4例(包括心脏停跳手术1例),非体外循环下CABG 17例.术前均口服左旋甲状腺素,FT3、FT4、TSH、TT3、TT4明显改善后手术.同期对照20例甲状腺功能正常CABG者(B组),其中4例体外循环下CABG.观察两组术前、术中、术后甲状腺功能指标以及近端吻合时血流动力学指标.结果 围术期应用放射免疫法甲状腺激素水平检测,非体外循环下手术者,A组17例FT3术前及术中水平为[(1.39±0.36)pg/ml对(1.29±0.32)pg/ml]、B组16例为[(2.28±0.36)pg/ml对(2.19±0.34)pg/ml];体外循环下手术者,A组4例FT3术前及术中水平为[(1.53±0.51)pg/ml对(0.85±0.40)pg/ml]、B组4例为[(2.08±0.24)pg/ml对(1.96±0.26)pg/ml].A、B两组术中心排指数[(2.7±1.4)L·min-1·m-2对(2.8±1.5)L·min-1·m-2,P=0.53].A组1例重度甲低病人体外循环下心脏停跳手术后因心脏复跳困难死亡,20例生存者均为心脏不停跳方式手术者,其中17例为非体外循环手术,术后随访2～30个月均有心功能改善,射血分数(EF)由术前0.48±0.17增加至术后0.55±0.21.B组均生存.两组间术中血流动力学、手术预后、住院时间[(12.2±4.7)天对(10.1±3.9)天]、呼吸机辅助[(17.6±9.1)h对(15.1±13.7)h],差异无统计学意义.结论 冠心病合并甲低病人,术前准备充分,采用心脏不停跳手术方式较安全,非体外循环下手术对病人FT3激素水平影响较小;围术期甲状腺素治疗是关键;重度甲低病人体外循环下手术风险大.