Combined cardioplegia delivery offers no advantage over antegradecardioplegia administration in coronary surgical patients with a preserved left ventricular function

The effects of antegrade and of combined antegrade and retrograde cardioplegia were compared in 101 patients undergoing elective coronary artery surgery. The patients were randomly allocated to two groups. antegrade cardioplegia was administered in 53 patients and combined cardioplegia in 43 patients. The patients of the two groups were similar in age, sex and left ventricular ejection fraction. Aortic clamping time and the number of coronary bypasses were equal in the groups. The ventricular septal temperature was measured continuously during cardioplegia administration, after each distal anastomosis accomplished, and continuously after aortic declamping. Serum CK-MB activities were serially measured for up to 3 days postoperatively. Electrocardiograms (ECG) were taken preoperatively, as well as on the first, second and eighth postoperative days. The left ventricular function was evaluated with a volume load test preoperatively and on the first postoperative morning. The two groups were similar with respect to myocardial cooling, response to volume loading, the number of patients with perioperative myocardial infarctions, cardiac arrhythmias or atrioventricular conduction blocks and clinical outcome. However, the CK-MB activities were lower in the antegrade group suggesting better myocardial protection in an unselected group of patients undergoing coronary artery bypass grafting.     

冷血心肌麻痹液温度对肌浆网Ca2+摄取和释放的影响

评价冷血心肌麻痹液（ＣＢＣ）温度对肌浆网（ＳＲ）Ｃａ２＋摄取和释放的影响。方法测定ＣＢＣ不同温度停搏１２０分钟和再灌注后心肌匀浆ＳＲ４５Ｃａ２＋摄取及钉红阻滞ＳＲＣａ２＋释放通道后ＳＲ４５Ｃａ２＋摄取的变化。结果停搏期１６℃和２０℃ＳＲ　４５Ｃａ２＋摄取降幅分别为１７．０９％和２１．１６％（Ｐ＜０．０５）;停搏期４、８、１２℃、再灌注后各组ＳＲ　４５Ｃａ２＋摄取与对照组差异均无显著意义（Ｐ＞０．０５）。ＳＲＣａ２＋释放通道阻滞后各组停搏和再灌注后ＳＲ摄４５Ｃａ２＋增幅差异无显著意义（Ｐ＞０．０５）。结论ＣＢＣ温度不同所表现的保护效果差异与ＳＲＣａ２＋摄入受损有关,ＳＲＣａ２＋释放不受影响。     

Warm blood cardioplegia in high risk patients

Objective: Despite overall good clinical results, cardiac surgery in high risk patients, such as those with poor left ventricular function or heavily hypertrophied myocardium, is still challenging. This study was designed to assess the efficacy of warm blood cardioplegia (WBC) in these two subgroups of patients. Methods: Fifty-two patients, with an ejection fraction less than 50%, who underwent surgical revascularization, and 36 patients, with marked left ventricular hypertrophy (LVH), who were operated on for aortic valve replacement (AVR), were consecutively studied. All of them received continuous retrograde ‘warm' blood cardioplegia. Results were assessed on clinical outcomes and compared with those predicted from a risk-stratifying index which has been previously validated in a large multicenter population-based study (Ontario score). Results: For cardiac revascularization, the rates of overall hospital mortality, Q-wave infarctions and inotropic use were respectively 5.8%, 9.6% and 21.1%, comparing favorably with those of the Ontario Group. For aortic valve replacement, the incidence of hospital mortality and Q-wave infarction was 2.8%. Conclusions: By virtue of the study design, these data cannot conclusively establish the superiority of warm blood cardioplegia over other methods of myocardial protection. However, they support the safety of this technique, and suggest that these subgroups of high risk patients might represent the elective indication for aerobic arrest.     

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。     

甲状腺激素T3增补于心脏停搏液中对心肌的保护作用

目的　探讨Ｔ３ 增补于停搏液中的心肌保护作用。方法　离体鼠心（ ｎ ＝ １６） 在改良的ＬａｎｇｅｎｄｏｒｆｆＮｅｅｌｙ 灌注模型上、３７ ℃下经历２０ 分钟预灌注、２０ 分钟停搏、３０ 分钟再灌注。结果　再灌注３０ 分钟时,左室功能指标（ＬＶＤＰｄｐ／ｄｔ）百分恢复率治疗组显著高于对照组（ Ｐ ＜０ ．０１）,心肌超氧化物歧化酶（ＳＯＤ） 治疗组显著高于对照组（ Ｐ＜ ０．０１）,过氧化脂质（ＬＰＯ） 治疗组显著低于对照组（ Ｐ ＜０．０５）;心肌酶（ＨＢＤＨ．ＬＤＨ）释放量再灌注期对应时点组间比较,治疗组显著低于对照组（ Ｐ＜ ０ ．０１） ;电镜观察心肌超微结构,治疗组显著优于对照组。结论　Ｔ３ 增补于心脏停搏液中可以显著地促进缺血后左室功能的恢复,显著减轻心肌缺血再灌注损伤,具有良好的心肌保护作用。     

冷血停搏液对法洛四联症婴幼儿心肌代谢的影响

目的：通过临床应用，评价冷血停搏液对未成熟心肌代谢的影响。方法：50例行择期法洛四联症根治术病儿随机分为2组，对照组用10℃改良St.Thomas 1停搏液（CCP），试验组用冷血停搏液（BCP），阻断升主动脉前，开放升主动脉1，3，10min分别由冠状静脉窦和动脉同时取血测定血气，电解质，乳酸，丙二醛（MDA）等含量。结果：再灌注后BCP组心肌氧提取率，乳酸摄取率恢复较快（P＜0．05），再灌注各时点两组均出现钾离子释放和MDA升高；再灌注后BCP组钙离子摄取较低（P＜0．05），结论：冷血停搏液对再灌注后的离子平衡，氧化谢，糖代谢恢复优于冷晶体停搏液。     

Risk-adjusted analysis of long-term outcomes after on- versus off-pump coronary artery bypass grafting

 Open in a separate windowOBJECTIVESRecent data suggested that off-pump coronary artery bypass (OPCAB) may carry a higher risk for mortality in the long term when compared to on-pump coronary artery bypass (ONCAB). We, therefore, compared long-term survival and morbidity in patients undergoing ONCAB versus OPCAB in a large single-centre cohort.METHODSA total of 8981 patients undergoing isolated elective/urgent coronary artery bypass grafting between January 2009 and December 2019 were analysed. Patients were stratified into 2 groups (OPCAB n = 6649/ONCAB n = 2332). The primary end point was all-cause mortality. Secondary endpoints included repeat revascularization, stroke and myocardial infarction. To adjust for potential selection bias, 1:1 nearest neighbour propensity score (PS) matching was performed resulting in 1857 matched pairs. Moreover, sensitivity analysis was applied in the entire study cohort using multivariable- and PS-adjusted Cox regression analysis.RESULTSIn the PS-matched cohort, 10-year mortality was similar between study groups [OPCAB 36.4% vs ONCAB 35.8%: hazard ratio (HR) 0.99, 95% confidence interval (CI) 0.87–1.12; P = 0.84]. While 10-year outcomes of secondary endpoints did not differ significantly, risk of stroke (OPCAB 1.50% vs ONCAB 2.8%: HR 0.51, 95% CI 0.32–0.83; P = 0.006) and mortality (OPCAB 3.1% vs ONCAB 4.8%: HR 0.65, 95% CI 0.47–0.91; P = 0.011) at 1 year was lower in the OPCAB group. In the multivariable- and the PS-adjusted model, mortality at 10 years was not significantly different (OPCAB 34.1% vs ONCAB 35.7%: HR 0.97, 95% CI 0.87–1.08; P = 0.59 and HR 1.01, 95% CI 0.90–1.13; P = 0.91, respectively).CONCLUSIONSData do not provide evidence that elective/urgent OPCAB is associated with significantly higher risks of mortality, repeat revascularization, or myocardial infarction during late follow-up when compared to ONCAB. Patients undergoing OPCAB may benefit from reduced risks of stroke and mortality within the first year postoperatively.     

间断缺血心停搏在冠脉搭桥术中的应用

１９９２～１９９３年间为１８０例冠脉病变的病人施行冠脉搭桥术，全部病人均采用核甙抑制剂利多氟嗪预处理和低温（２８℃）间断缺血心停搏进行术中心肌保护。平均每例病人作冠状动脉端吻合３～４个，每个吻合口用９分钟，主动脉阻断累加时间约２５分钟，体外循环时间９０分钟，术后医院死亡率１．６％（３／１８０），无术后心梗发生。作者认为，冠脉搭桥术的术中心肌保护可采用核甙抑制剂和间断缺血心停搏方法，而不用心肌停搏液。     

冠状动脉旁路移植术同期瓣膜手术的经验

目的 探讨同期施行冠状动脉旁路移植术和瓣膜手术的方法,疗效及影响因素。方法 回顾分析１９９５～１９９８年间１５例冠状动脉旁路移植术时,同期行二尖瓣置换或成形、主动脉瓣置换、联合瓣膜置换、Ｂｅｎｔａｌｌ术。结果 瓣膜病病因中,风湿性８例,退行性４例,缺血性３例,手术病死率为６．７％（１／１５）‘４例发生低心输出量综合征,其中３例需行主动脉内球反博;５例二尖瓣成形术后,反流面积从６．５～１５．０ｃｍ＾     

温血停搏液持续与间断灌注在冠状动脉搭桥术中的比较研究

目的 比较温血持续与间断灌注心脏停搏液在冠状动脉搭桥术中心肌保护效应。方法将30例冠状动脉搭桥手术随机分为温血持续灌注组（n=15）;温血间断灌注组（n=15）,灌注心脏停搏液,在常温体外循环下分别于切皮前、转流60min、停机6、12h采集动脉血,以ELISA法测定血浆心肌肌钙蛋白T（cTnT）浓度。分别取主动脉阻断前、开放后心肌组织,观察三磷酸腺苷（ATP）含量及心肌超微结构。结果 温血间断组 cTnT在停机6h时点比温血持续组有显著性差异（P<0.05）。两组术中60min、停机6hcTnT升高,停机24h逐渐恢复术前水平。两组ATP含量比主动脉阻断前有显著性差异（P<0.05）。温血间断组线粒体计分主动脉阻断开放后比主动脉阻断开放前有显著性差异（P<0.05）,温血持续组略升高（P<0.05）。结论 常温体外循环中温血持续灌注停搏液优于温血间断灌注停搏液的心肌保护作用。     

Continuous monitoring of myocardial acid–base status during intermittent warm blood cardioplegia

Objective: Intermittent warm blood cardioplegia (IWBC) is a well-established technique for myocardial protection during cardiac operations. According to standardized protocols, IWBC administration is currently performed every 15–20 min regardless of any individual variable and in the absence of any instrumental monitoring. We devised a new system for continuous measurement of the acid–base status of coronary sinus blood for on-line evaluation of myocardial oxygenation during IWBC. Methods: In 19 patients undergoing cardiac surgery for coronary artery bypass graft and/or valve surgery and receiving IWBC (34–37°C) by antegrade induction (3 min) and retrograde or antegrade maintenance (2 min) every 15 min, continuous monitoring of myocardial oxygenation and acid/base status was performed by means of a multiparameter PO₂, PCO₂, pH, and temperature sensor (Paratrend7 ®, Philips Medical System) inserted into the coronary sinus. Results: Mean cross-clamping time was 76±26 min; ischemic time was 13±0.2 min. pH decline was not linear, showing an initial fast decline, a point of flexus, and a progressive slow decline. After every ischemic period, the pH adaptation curve showed a complex pattern reaching step-by-step lower minimum levels (7.28±0.14 during the first ischemic period, to 7.16±0.19 during the third ischemic period – P=0.003). PO₂ decreased rapidly at 90% in 5.0±1.2 min after every reperfusion. During ischemia, PCO₂ increased steadily at 1.6±0.1 mmHg per minute, with progressively incomplete removal after successive reperfusion, and progressive increase of maximal level (42±12 mmHg during the first ischemic period, to 53±23 mmHg during the third ischemic period – P=0.05). Conclusions: Myocardial oxygen, carbon dioxide, and pH show marked changes after repeated IWBC. Myocardial ischemia is not completely reversed by standardized reperfusions, as reflected by steady deterioration of PCO₂ and pH after each reperfusion. Progressive increase of reperfusion durations or direct monitoring of myocardial oxygenation could be advisable in cases of prolonged cross-clamping time.     

心肌肌钙蛋白I评价冷氧合血停跳和心脏不停跳的心肌保护效果

目的：探讨冷氧合血停跳和心脏不停跳的心肌保护效果。方法：50例心内直视手术病人随机分为冷氧合血停跳组（I组）和心脏不停跳组（Ⅱ组），每组25例，分别于术前，术后多个时点采取中心静脉血，测定血肌肌钙蛋白I（cTnI),CK,CK-MB，缺血前后观察心肌超微结构变化。结果：术前两组的cTnI,CK和CK－MB均在正常范围内，开放主动脉后1小时至术后24小时达峰值，其后缓慢下降，术后24小时心脏不停跳组CK水平明显低于冷氧合血组（P＜0．05），各时点cTnI,CK-MB水平两组间无显著性差异（P＞0．05），心肌超微结构于体外循环后两组间或与术前比较均无显著性差异（P＞0．05），结论：cTnI，心肌酶，心肌超微结构的动态变化提示冷氧合血停跳液与心脏不停跳的心肌保护效果相同。     

冠状动脉旁路移植术围术期心肌肌钙蛋白I动态变化

目的　观察心肌肌钙蛋白I(cTnI)和CK -MB在冠状动脉旁路移植术 (CABG)围术期变化 ,以判断心肌损伤状况。方法　 19例CABG病人 ,其中 3例同时行左室室壁瘤切除。平均体外循环时间12 1min ,阻断升主动脉 5 6min。灌注冷血停跳液保护心肌 ,平均每例搭桥 3 2支。围术期 2 0个时间点取静脉血标本 ,留血浆测cTnI和CK MB。术前及术后第 7d作标准 12导联心电图 (ECG)。结果　cTnI术前 5例升高者 ,停机后全部升高 ,第 8h达高峰 ,术后第 7d有 7例 (36 8% )仍高于正常 ;CK MB阻断升主动脉前正常 ,停机后升高 ,第 6h达高峰 ,术后第 2d全部恢复正常 ;2例发生围术期心梗 (PMI)者 ,整个围术期cTnI高于无PMI者 ;cTnI阻断升主动脉前已升高者 ,术后升高更显著。结论　cTnI与CK MB在CABG术后变化规律相似 ,但cTnI高于正常的持续时间长于CK MB ,有利于回顾性诊断 ;若阻断升主动脉前cTnI已升高 ,术后水平更高 ;cTnI诊断心肌损伤敏感性高于CK -MB。     

缺血预处理与温-冷-温技术在冠状动脉旁路移植术中对心肌的保护作用

目的通过监测血浆肌酸激酶同工酶(CK-MB)、心肌肌钙蛋白I(cTnI) 的水平,评价三种不同的心肌保护方法在冠状动脉旁路移植术(CABG)中的应用. 方法将36例均为稳定型心绞痛、3支血管病变、首次施行CABG患者随机分成3组缺血预处理组、温血组、对照组, 观察临床结果和术后应用血管活性药情况,并于转流前、术毕、术后6～12 、24 、72小时和第6天分别抽静脉血测定 CK-MB、cTnI. 结果缺血预处理组和温血组的自动复跳率均为100%,明显高于对照组(58%); cTnI 和CK-MB的水平从术后6～12小时开始升高(P<0.05),在24小时达到峰值,在术后第6天恢复.与对照组比较缺血预处理组和温血组在术后6～12、24、72小时时cTnI 和CK-MB的水平明显低(P<0.01). 结论多次短时间的缺血预处理和"温-冷-温"技术在低危CABG患者中较常规方法更有利于对缺血心肌的保护.     

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)     

不同温度下停搏液对成熟与未成熟心肌的保护作用

目的:观察不同温度下停搏液对成熟与未成熟心肌的保护作用.方法:使用Langendorff离体心脏灌注模型,分别比较St.Thomas No Ⅱ停搏液在15℃、30℃时对成年大白兔(3～4月)和幼兔(3～4周)的心肌保护效果.结果:30℃时,未成熟心肌的冠脉流量恢复率与15℃相比明显下降(P<0.01),心肌肌酸激酶(CK)及乳酸脱氢酶(LDH)漏出率、细胞内N_a~ 、C_a~( )含量明显增加(P<0.01);而成熟心肌30℃与15℃相比各指标无明显差异(P>0.05).且未成熟心肌超微结构15℃时的病理改变较成熟心肌明显.结论:St.Thomas No Ⅱ停搏液对兔未成熟心肌的保护效果不如成熟心肌;低温可增强未成熟心肌的保护效果.     

Off Pump coronary artery revascularization via left thoracotomy —Early results

Background There are very few studies in literature, which have reported primary revascularization of the coronaries via a thoracotomy incision. We hereby present our initial experiences using this approach to off pump coronary revascularization. Patients and Methods 27 patients with coronary artery disease were selected for surgical revascularization via the thoracotomy approach. The left chest is entered through the 5^th intercostal space, and the left internal mammary artery (LIMA) pedicle is harvested under direct vision. The radial artery or saphenous vein is harvested simultaneously depending on the availability and suitability of the conduits. Using standard off pump techniques, the LIMA is anastomosed to the Left Anterior Descending Artery (LAD) followed by other distal anastomoses. Results Complete revascularization was achieved in all patients. The average number of grafts were 2.40. The mean blood loss during the first 6 hours was 380 ± 169 ml. None of the patients needed emergency conversion to cardiopulmonary bypass / sternotomy. Post operatively 4 patients had on table extubation. 1 patient was re-explored due to bleeding from the thoracotomy. There was no peri-operative Myocardial infarction and the mortality was nil. The average hospital stay was 6.4 ± 1 days. Conclusion Based on our initial experience, this approach appears to be safe and practical in selected cases. It is well tolerated hemodynamically, with minimal postoperative morbidity.     

Total arterial coronary revascularization - Single or double inlet system?

Background The study assessed the graft flow to the coronary arteries during coronary artery bypass grafting in 175 patients receiving a composite single or double mammary grafts. Methods 128 patients with single inlet and 47 with double inlet composite arterial grafts were evaluated. In on pump — prior to, and following release of aortic cross clamp-and in off pump settings, graft blood flow was measured using an ultrasonic Transit Time Volume flowmeter. Results On pump, unrestricted blood flow was lower in single inlet than in double inlet grafts (119.9 ± 6.9 ml/min versus 161.0 ± 14.0ml/min (P=0.0042). There was also significantly less blood flow through the single inlet system when the heart was beating (74.7 ± 3.7 ml/min versus 98.0 ± 8.1 ml/min (P=0.0018)). We also found that patients operated on pump had larger graft flow than patients operated off pump (85.6 ± 4.6 ml/min versus 69.5 ± 3.8ml/min (P = 0.042)). Gender and number of anastomoses to the coronary arteries, were not predictive for graft flow. Conclusions Double inlet arterial graft systems supply the heart with larger graft flow than single inlet arterial graft systems. This benefit was obtained at the price of a longer duration of the operation, corresponding to the time it takes to harvest the right ITA.     

Re-dosing of del Nido cardioplegia in adult cardiac surgery requiring prolonged aortic cross-clamp

Open in a separate window OBJECTIVESFew data exist on the use of del Nido cardioplegia in adults, specifically during operations requiring prolonged aortic cross-clamp. In this pilot study, we evaluate outcomes of patients undergoing surgery with cross-clamp time >3 h based on re-dosing strategy, using either full dose (FD; 1:4 blood to crystalloid ratio) or dilute (4:1 blood to crystalloid ratio) solution.METHODSConsecutive adult patients (>18 years) undergoing cardiac surgery from 2012 to 2018 with cross-clamp time >3 h were reviewed. Patients were excluded if del Nido cardioplegia was not used. Patients were categorized into FD or dilute groups based on re-dosing solution. Propensity score matching was used to control for baseline differences between groups. The primary endpoint was in-hospital mortality. Other outcomes examined included: postoperative mechanical support, arrhythmia, stroke, dialysis and cardiac function.RESULTSIncluded for analysis were 173 patients (115 male) with median age of 63.8 (interquartile range 53.9–73.1). Major comorbidities included diabetes (45), cerebrovascular disease (34), hypertension (131), atrial fibrillation (52) and previous cardiac surgery (83). There were 108 patients (62%) who received FD re-dosing, while 65 (38%) received dilute. A greater proportion of patients in the dilute group received retrograde delivery, for both induction (32/108 vs 39/65, P < 0.001) and re-dose (50/108 vs 53/65, P < 0.001). After propensity score matching, in-hospital mortality was not different between groups (6/48 vs 1/48, P = 0.131). There were no differences in rates of postoperative mechanical circulatory support, stroke, left ventricular ejection fraction or right ventricle dysfunction.CONCLUSIONSDel Nido cardioplegia has been used in complex cardiac surgery requiring prolonged cross-clamp. Re-dosing can be performed with either FD or dilute del Nido solution with no statistical difference in outcomes.     

Influence of aprotinin on early graft thrombosis in patients undergoing myocardial revascularization

One hundred sixty-five patients undergoing primary myocardial revascularization were prospectivelyentered into a randomized, double-blind, placebo-controlled study, in a single institution, in order to determine the influence of high- and low-dose aprotinin application on early coronary artery bypass graft patency. All patients were operated on by the same team and the three treatment groups were comparable in all demographic data and surgical variables. Postoperative chest tube drainage and transfusion requirements were significantly reduced in patients receiving high or low doses of aprotinin. In all patients vein and internal mammary artery graft patency was assessed by control coronary angiograms 4 to 15 days (median 8.2 days) postoperatively. In the high-dose aprotinin group, 140 of 142 vein grafts and in the low-dose aprotinin group all of the 128 vein grafts were patent compared with 138 of 139 in the placebo group. The difference was not statistically significant (P> 0.05). All pedicled internal mammary artery grafts were patent in the three treatment groups. The prevalence of perioperative myocardial infarction was evaluated by serial creatine kinase-myocardial band (CK-MB) isoenzyme measurements and by electrocardiographic recordings. No additional changes that could be attributed to aprotinin were observed. In conclusion, these results suggest that perioperative myocardial infraction secondary to aprotinin-induced native coronary artery or conduit thrombosis is not increased by aprotinin in patients undergoing primary myocardial revascularization.