On-pump Beating Heart Technique Research Articles

Beating Heart Pulmonary Valve Replacement: Technique of Pulmonary Valve Replacement with a Biological Valve

Pulmonary valve replacement is traditionally performed using cardioplegia in order to induce cardiac arrest during the operation. However, the induction of cardiac arrest is known to be associated with several postoperative complications. Therefore, over the years new cardioprotective techniques have been introduced: one of which is the on-pump beating heart technique. The technique of pulmonary valve replacement on a beating heart could be efficacious in reducing the incidence of cardiac dysfunction or injury which can be associated with the use of cardioplegia. Such as the avoidance of aortic cross-clamping observed in the beating heart technique may be linked with lower risks of stroke and other aortic complications. Therefore, the technique that we present combines the advantages of operating on a beating heart and being on-pump in the context of complex re-do operations of the pulmonary valve.

On-pump beating-heart technique for managing a ruptured left coronary artery aneurysm.

We present the case of an 86-year-old woman with a ruptured left coronary artery aneurysm associated with coronary-pulmonary artery fistula. She was transferred to our hospital with complaints of chest discomfort. Echocardiography revealed cardiac tamponade, and subsequently, a bloody pericardial effusion was drained. Coronary angiography and computed tomography revealed a ruptured left coronary artery aneurysm originating from a branch of the proximal left anterior descending artery and a coronary-pulmonary artery fistula. In the emergency operation, under cardiopulmonary bypass, the inlet and outlet vessels were ligated, and the aneurysm was closed without arresting the heart. By utilizing cardiopulmonary bypass, the pulmonary trunk was easily decompressed, and dissection around the aneurysm and identification of the inlet and outlet vessels was facilitated without cardiac arrest. Thus, to conclude, an on-pump beating-heart technique should be considered in such cases.

Outcomes of urgent coronary artery bypass grafting in patients who have recently recovered from COVID-19 infection, with a median follow-up period of twelve months: our experience

BackgroundThe Coronavirus disease 2019 (COVID-19) was declared a worldwide pandemic in 2020 by the World Health Organization (WHO). Certain individuals are at higher risk, (age > 65 years, pre-existing lung or heart conditions, diabetes and obesity) especially those requiring cardiac surgery, including Coronary Artery Bypass Grafting (CABG). Here we present a case series of 11 patients, operated between April 2020 and April 2022, all of whom had recently recovered from COVID-19, who presented with unstable angina, and therefore required urgent Coronary Artery Bypass Grafting (CABG). Similar cases reported in the past, have had a high morbidity and mortality rate.Case presentationThe study included 11 males, and their age varied between 53 and 68 years (median of 65 years). They were either partially or fully vaccinated. All of them had a history of recent mild COVID-19 infection. The European system for cardiac operative risk evaluation, EuroSCORE II in-hospital mortality risk at admission, varied between 1.48% and 5.12%. Six out of 11 patients (54.55%) had a recent Acute Coronary Syndrome (ACS) which is associated with a higher risk and poor prognosis. All of them underwent urgent CABG (10 of them, 90.91% cases, using the off-pump technique and one patient had to be converted to the on-pump beating heart surgery technique during surgery). Ten of the 11 patients were operated using the off-pump technique, and there was one death (9.09%). All surviving patients made an uneventful recovery and have been followed up with a median follow-up period of 12 months.ConclusionsPrevious studies on a similar group of patients have resulted in high morbidity and mortality. A conscious effort was made to perform all surgeries off-pump, thereby eliminating the inflammatory effects and other hazards of cardiopulmonary bypass in this case series, with only one out of 11 (9.09%) being converted to the on-pump beating heart technique due to the hemodynamic instability faced during surgery. Our findings show a mortality rate of 9.09%, with the surviving patients doing well at a median follow-up period of 12 months, suggesting that it is a safe procedure in this patient subset.

Retrospective assessment of the early and medium outcomes of on-pump beating-heart versus off-pump CABG in patients with moderate left ventricular dysfunction (LVEF)

Aim: To compare the early and medium outcomes of on-pump beating-heart (OPBH) coronary artery bypass grafting (CABG) and off-pump CABG (OPCABG) in patients with left ventricular ejection fraction (LVEF) between 30% and 40%. Material & Methods: This study was conducted as a retrospective observation over a period of 1 year at the Department of Cardiothoracic and Vascular Surgery, Indira Gandhi Institute of medical Sciences, Patna, Bihar, India.130 patients were selected for this study. All patients were divided into 2 groups, according to the revascularization method: OPCABG group and OPBH group. Results: LVEF before discharge significantly improved from 34.39 ± 4.21 to 44.27 ± 7.29 in the OPBH group and from 34.27±4.61 to 42.66 ± 8.20in the OPCABG group (P<0.001). All survival patients have been echocardiographically examined after 6 months which showed a significant higher early postoperative LVEF in the OPBH group than in the OPCABG group (45.28 ± 6.10 versus 44.42 ± 7.08%, respectively; P=0.002). Conclusion: The OPBH technique was a safe and an acceptable alternative for surgical revascularization in patients with moderate left ventricular dysfunction which provided better midterm MACE-free survival compared with OPCABG.

Experience of post-infarction left ventricular aneurysm reconstruction with on-pump beating heart technique

Aim. To evaluate the results of surgical treatment of post-infarction left ventricular aneurysms with on-pump beating heart technique. 
 Methods. In our center from April, 2009 to January, 2014 169 patients had reconstruction of the left ventricle with on-pump beating heart technique. Among the patients 159 were males (94.1%) and 10 of them were females (5.9%), average age 53.8±8.9 years (39 to 72 years). Angina pectoris class I (according to the classification of Canadian Heart Association) was established in 7 (4.1%) patients, class II - in 49 (29.0%), class III - in 107 (63.3%), class IV - in 4 (2.4%), unstable angina in 2 (1.2%) patients. Chronic heart failure class I (according to New York Heart association functional classification) was diagnosed in 5 (3.0%) patients, class II in 37 (21.9%), class III in 124 (73.4%), class IV in 3 (1.8%) patients. Average ejection fraction of the left ventricle was 38.6±7.9% (25 to 67%). Mitral valve insufficiency stage 2-3 was revealed in 23 (13.6%) patients. 
 Results. Endoventriculoplasty of the left ventricle by Dor's technique was performed in 49 (29.0%) patients, auto-septoplasty of the left ventricle - 59 (34.9%) patients, linear repair in 40 (23.7%) patients. Combined surgical interventions were performed in 21 (12.4%) patients. In-hospital lethality was 2.4% (n=4). 
 Conclusion. Left ventricular reconstruction with on-pump beating heart technique without cardioplegic arest is effective and safe; the method allows performing remodelling of the left ventricle and reaching the target volume parameters.

On-pump beating-heart coronary artery bypass grafting: a literature review

Coronary artery bypass grafting techniques have been unchangeable for many years, whereas development and enhancement of myocardial protection methods in coronary bypass grafting for patients with ischemic heart disease are still actual issues of current coronary surgery. Coronary artery bypass grafting techniques include the traditional/conventional technique with cardiopulmonary bypass, aortic cross-clamping and cardioplegia, off-pump and on-pump beating heart coronary artery bypass grafting. Coronary artery bypass grafting with cardiopulmonary bypass and cardioplegia remains the most common method of coronary revascularization. However the cardiac arrest inevitably leads to global cardiac ischemia, and current cardioplegias do not prevent ischemic damage to the myocardium in all cases, especially in high-risk surgical patients. Off-pump coronary artery bypass grafting allows preventing global myocardial ischemia (due to the constant native coronary blood-flow) and avoiding possible negative consequences of cardiopulmonary bypass use. The main limitations of this technique are associated with high risk of hemodynamic instability due to low cardiac output and systolic output caused by target arteries exposition. On-pump beating heart technique is a reasonable compromise between conventional on-pump coronary artery bypass grafting, cardioplegia and off-pump procedure. It is a safe and effective technique with outcomes that are equivalent or superior to the outcomes reported for conventional coronary artery bypass grafting in patients with unstable hemodynamics, low left ventricular ejection fraction and in high-risk patients. The literature review presents the results of on-pump beating heart coronary artery bypass grafting.

Outcome of Coronary Artery Bypass Graft with On-pump Beating-heart Technique

Background: This paper intends to evaluate the effects of on-pump beating-heart coronary artery bypass graft (CABG) in patients with coronary artery disease. Studies have shown that this surgical procedure can have acceptable results. Objectives: This study intends to share experiences and results of on-pump beating-heart CABG. Methods: We reported preliminary results related to mortality and morbidity in patients who underwent CABG in the period from 2015 to 2017 in Ghaem hospital, Mashhad, Iran. Results: 80 patients, in the period from 2015to 2017, underwent general anesthesia and on-pump beating-heart CABG surgery was done for them. The average number of grafts was 3.18± 0.474 and two patients died, unfortunately: one during surgery and one in ICU. There were no postoperative myocardial infarctions during the study. None of the patients reported kidney dysfunction. The average length of hospitalization was 4±1.11 days and the mean follow-up of the patients was 6 months. The average ejection fraction (EF) of patients was 43. 28± 9.58. Conclusion: In the last decade there has been a big challenge between using off-pump CABG and on-pump CABG, on-pump beating method could present acceptable and effective results.

Myocardial revascularization among patients with severe left ventricular dysfunction: a comparison between on-pump beating-heart and off-pump coronary artery bypass grafting

Objective: To evaluate the impacts of an on-pump beating-heart versus an off-pump coronary artery bypass grafting (CABG) technique for surgical revascularization on the early clinical outcomes in patients with a left ventricular ejection fraction (EF) of 35% or less. Methods: A total of 216 consecutive patients with an echocardiographic estimated EF of 35% or less who underwent non-emergency, primary, isolated CABG from January 2010 to December 2014 at Department of Cardiovascular Surgery, Zhongshan Hospital, Fudan University were included in this study and were divided into either an OBCAB group (patients who received on-pump beating-heart CABG surgery, n=88) or an OPCAB group (patients who received off-pump CABG surgery, n=128). The early clinical outcomes were investigated and compared. The outcomes were compared between groups by t-test, χ2 test or Fisher's exact test, when appropriate. Results: No significant differences emerged between the two groups in baseline characteristics of the entire cohort except for more patients with diabetes and a larger left ventricular endo-diastolic diameter in the OBCAB group. Patients in the OBCAB group compared to the OPCAB group had a similar in-hospital mortality (3.4% vs. 4.7%, P= 0.741). Mean EF, as measured preoperatively and early postoperatively (before discharge), significantly improved from (31.0±2.8)% to (35.6±2.9)% (t=10.61, P=0.000) in the OBCAB group and from (31.0±2.9)% to (34.8±3.3)% (t=9.68, P=0.000) in the OPCAB group, respectively. The improvement of mean LVEF in the OBCAB group was significantly higher than that in the OPCAB group ((4.7±0.2)% vs. (3.6±0.3)%, t=29.53, P=0.000). Patients in the OBCAB group compared to the OPCAB group had a significant higher early postoperative EF ((35.6±2.9)% vs.(34.8±3.3)%, t=1.892, P=0.034) but shared a similar baseline EF ((31.0±2.8)% vs. (31.0±2.9)%, t=0.012, P=0.930). Patients in the OBCAB group compared to the OPCAB group received a greater number of grafts and an increased amount of drainage during the first 24 h (3.7±0.8 vs. 2.8±0.6, t=9.442, P=0.000; (715±187) ml vs. (520±148) ml, t=8.544, P=0.000, respectively), without evidence of worse in-hospital mortality or major postoperative morbidity. Conclusion: The on-pump beating-heart technique may be an acceptable alternative to the off-pump technique for surgical revascularization in patients with an estimated EF of 35% or less.

On-pump beating versus arrested heart (conventional) revascularization in severe left ventricular dysfunction

BackgroundFor revascularization of myocardium, the on-pump beating heart technique has been successfully used in patients with either low or high risk. However, the use of this technique in patients with low ejection fraction is not well thoroughly evaluated. The aim of the work was to evaluate the on-pump beating heart technique in subjects with severe left ventricular dysfunction and to compare results with on-pump non-beating (conventional) technique. MethodsThe present study was held at Al-Azhar University Hospitals, Cairo, Egypt during the period from January 2014 till June 2016. The study included 200 patients who achieved the inclusion criteria. They were allocated either to on-pump beating heart (n = 84) or conventional group (n = 116). Patients were evaluated for in hospital mortality or major postoperative complications. ResultsOn-pump beating heart was found to be associated with low in hospital mortality, postoperative CK-MB, new myocardial infarction, renal dysfunction and need for hemodialysis. ConclusionsOn-pump beating heart technique was better than conventional technique for cardiac revascularization in patients with severe left ventricular dysfunction.

Effect of open-heart operation involving cardiopulmonary bypass on myocardial endoplasmic reticulum stress

Objective To explore the myocardial endoplasmic reticulum stress (ERS) during the open heart surgery involving cardiopulmonary bypass (CPB), and whether the reduced ERS by beating-heart technique played an important role in the myocardial protection. Methods Forty patients with rheumatic heart disease undergoing MVR were randomly divided into 2 groups. The patients in the experimental group received operation on beating-heart, while under arrested heart in the control group. Right atrial myocardial samples were taken before and after CPB. The expressions levels of mRNA and protein of GRP78 and NF-κBp65 were detected using real-time PCR and Western blotting. Results After CPB, the expression levels of mRNA and protein of GRP78 were 2.31±0.44 and 0.096±0.024, those of NF-κBp65 were 2.89±0.93 and 0.129±0.034 respectively in the control group. In the experimental group, the expression levels of mRNA and protein of GRP78 were 1.56±0.29 and 0.061±0.021, and those of NF-κBp65 were 1.73±0.48 and 0.085±0.025. As compared with the baseline values, mRNA and protein levels of GRP78 and NF-κBp65 were increased after CPB. The increasing degrees of GRP78 and NF-κBp65 were significantly lower in the experimental group than in the control group (P=0.001, 0.002; P=0.001, 0.001). Conclusion ERS could be provocated during open-heart operation. The attenuated ERS, through NF-kappaB pathway, may play an important role in myocardial protection by on-pump beating-heart technique. Key words: Open-heart operation involving cardiopulmonary bypass; Beating heart surgery; Endoplasmic reticulum stress; Inflammatory reaction

Early clinical outcomes of on-pump beating-heart versus off-pump technique for surgical revascularization in patients with severe left ventricular dysfunction: the experience of a single center

BackgroundLimited experiences of applying an on-pump beating-heart technique for surgical revascularization in patients with severe left ventricular dysfunction have been reported. Which strategy, either off-pump coronary artery bypass grafting (CABG) or on-pump beating-heart CABG surgery, is the best strategy for surgical revascularization in patients with severe left ventricular dysfunction is still controversial. This single-center study aimed to evaluate the impacts of an on-pump beating-heart versus an off-pump technique for surgical revascularization on the early clinical outcomes in patients with a left ventricular ejection fraction (LVEF) of 35% or less to explore which technique would be more suitable for surgical revascularization in patients with severe left ventricular dysfunction.MethodsA total of 216 consecutive patients with an echocardiographic estimated LVEF of 35% or less who underwent non-emergency, primary, isolated CABG from January 2010 to December 2014 were included in this study and were divided into either an ONBEAT group (patients who received on-pump beating-heart CABG surgery, n = 88) or an OFF group (patients who received off-pump CABG surgery, n = 128). The early clinical outcomes were investigated and compared.ResultsPatients in the ONBEAT group compared to the OFF group had a significant higher early postoperative LVEF (35.6 ± 2.9 vs. 34.8 ± 3.3%, p = 0.034) but shared a similar baseline LVEF (31.0 ± 2.8 vs. 31.0 ± 2.9%, p = 0.930). Patients in the ONBEAT group compared to the OFF group received a greater number of grafts and an increased amount of drainage during the first 24 h (3.7 ± 0.8 vs. 2.8 ± 0.6, p <0.001; 715 ± 187 ml vs. 520 ± 148 ml, p <0.001, respectively), without evidence of worse in-hospital mortality or major postoperative morbidity. Additionally, logistic regression analysis showed that surgical technique (on-pump beating-heart CABG vs. off-pump CABG) had no independent influence on in-hospital mortality or major postoperative morbidity in patients with preoperative LVEF of 35% or less.ConclusionsThe on-pump beating-heart technique may be an acceptable alternative to the off-pump technique for surgical revascularization in patients with an estimated LVEF of 35% or less.

ON-PUMP BEATING HEART MYOCARDIAL REVASCULARIZATION FOR HIGH RISK PATIENTS

107 patients with mean ejection fraction 40,6±7,4% underwent on-pump-beating heart coronary revascularization and associated procedures. There were 76 men and 31 women, with a mean age of 68,9±7,8 years. Five patients required carotid endarterectomy and twelve patients required left ventricular aneurysm repair. 5 patients underwent carotid endarterectomy and 12 patients - left ventricular aneurysm repair. The mean number of graft/patient was 2,9±0,8. Postoperatively occurred the following complications: acute ischemic stroke - 1 (0.9%), acute heart failure - 1 (0.9%), respiratory failure - 2 (1.9%) and bleeding required surgical revision - 1 (0.9%). Hospital mortality rate was 0,9% (1 of the 107 patients). On-pump beating heart technique is a safe and efficient method for coronary artery bypass grafting and associated procedures (carotid endarterectomy, left ventricular aneurysm repair).

On-pump beating-heart technique is associated with lower morbidity and mortality following coronary artery bypass grafting: a meta-analysis.

A hybrid procedure of beating-heart coronary artery bypass grafting (CABG) with the concomitant use of cardiopulmonary bypass termed on-pump beating-heart CABG (ON-BH CABG) has emerged as an alternative for high-risk patient populations. Although several studies have reported the advantage of ON-BH CABG in high-risk patients, the clinical benefit of ON-BH CABG is still under discussion. Here, we performed a meta-analysis of the data derived from published studies comparing the clinical outcomes of ON-BH CABG with that of conventional arrested heart CABG. Medline, Embase and Scopus databases were searched for relevant publications up to March 2015. A systematic review of the published literature identified 14 published studies incorporating 2040 patients (884 ON-BH CABG and 1156 conventional CABG). Odds ratios (ORs) for binary variables or weighted mean difference for continuous variables were combined using the inverse variance method in a fixed-effects model. Study heterogeneity was tested using Cochran's Q test and the publication bias was assessed using Begg's and Egger's tests. The fixed-effects meta-analysis for early mortality showed that ON-BH CABG provided a 45% lower risk of early mortality compared with conventional CABG (OR 0.553; 95% confidence interval [CI] 0.376-0.815; P = 0.003). There was minimal heterogeneity in the included studies (P = 0.29) and no evidence of significant publication bias. A sensitivity analysis, including a random-effects meta-analysis (OR 0.552; 95% CI 0.356-0.856; P = 0.008) and a one-study-removed meta-analysis, supported the validity of the primary analysis for early mortality. There was significantly lower perioperative morbidity associated with ON-BH CABG, including myocardial infarction (OR 0.294; 95% CI 0.141-0.613; P = 0.001), renal failure (OR 0.362; 95% CI 0.209-0.626; P < 0. 001) and low output syndrome (OR 0.330; 95% CI 0.197-0.551; P < 0.001) with no significant heterogeneity. In conclusion, current evidence from comparative studies indicates that ON-BH CABG is associated with significantly lower early morbidity and mortality. The ON-BH CABG could be an attractive planned alternative for high-risk patient populations.

Off-pump or on-pump beating heart: which technique offers better outcomes following coronary revascularization?

A best evidence topic was written according to a structured protocol. The question addressed was whether on-pump beating heart coronary artery bypass (BH-ONCAB) surgery has a different outcome profile in comparison to off-pump coronary artery bypass (OPCAB). A total of 205 papers were found by systematic search of which 7 provided the largest and most recent outcome analysis comparing BH-ONCAB with OPCAB, and represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results were tabulated. Reported outcome measures included mortality, stroke, myocardial infarction, renal failure, myocardial damage, change in ejection fraction, number of bypass grafts and completeness of revascularization. With the exception of one study that favoured the off-pump technique, our review did not demonstrate a statistically significant difference in terms of mortality between the groups. We did not identify a statistically significant difference in any reported morbidity outcomes. However, there was a trend towards better outcomes for the on-pump beating heart technique, despite a higher risk profile in terms of age, ejection fraction and burden of coronary disease in this group. Consistent statistically significant differences between the groups were the mean number of grafts performed and the completeness of revascularization, both of which were higher with the on-pump beating heart technique. Limitations to the current evidence include the finding that most of the current data arise from specialist off-pump surgeons or centres that would usually only carry out BH-ONCAB in the higher risk patients where the added safety of cardiopulmonary bypass is desired.

On-pump beating-heart versus conventional coronary artery bypass grafting for revascularization in patients with severe left ventricular dysfunction: early outcomes

We sought to evaluate the effects of on-pump beating-heart versus conventional coronary artery bypass grafting techniques requiring cardioplegic arrest in patients with coronary artery disease with left ventricular dysfunction. We report the early outcomes associated with survival, morbidity and improvement of left ventricular function in patients with low ejection fraction who underwent coronary artery bypass grafting between August 2009 and June 2012. Patients were separated into 2 groups: group I underwent conventional coronary artery bypass grafting and group II underwent an on-pump beating-heart technique without cardioplegic arrest. In all, 131 patients underwent coronary artery bypass grafting: 66 in group I and 65 in group II. Left ventricular ejection fraction was 26.6% ± 3.5% in group I and 27.7% ± 4.7% in group II. Left ventricular end diastolic diameter was 65.6 ± 3.6 mm in group I and 64.1 ± 3.2 mm in group II. There was a significant reduction in mortality in the conventional and on-pump beating-heart groups (p < 0.001). Perioperative myocardial infarction and low cardiac output syndrome were higher in group I than group II (both p < 0.05). Improvement of left ventricular function after the surgical procedure was better in group II than group I. The on-pump beating-heart technique is the preferred method for myocardial revascularization in patients with left ventricular dysfunction. This technique may be an acceptable alternative to the conventional technique owing to lower postoperative mortality and morbidity.

Mitral valve and coronary artery bypass surgeries 13 years after pneumonectomy for lung cancer : case report

We successfully performed coronary artery bypass grafting and mitral valve replacement in a 72-year-old man who had undergone a left pneumonectomy 13 years previously due to a malignant mass. The patient was admitted to our clinic with symptoms of dyspnoea, palpitations, chest pain and fatigue. He was diagnosed with mitral valve disease and two-vessel coronary artery disease, as seen from echocardiography and catheterisation studies. Conventional cardiopulmonary bypass grafting was performed following sternotomy. The patient's heart was completely displaced to the left hemithorax. Saphenous vein grafts were harvested. Distal anastomoses were performed with the use of the on-pump beatingheart technique without cross clamping. Afterwards a cross clamping was placed and a left atriotomy was performed. The mitral valve was severely calcific. A mitral valve replacement was performed using number 27 mechanical valve after the valve had been excised. The patient's postoperative course was uneventful. Cardiac contractility was seen to be normal and the mitral valve was functioning on echocardiography done in the second postoperative month.

One-Stage Complete Removal of Intracardiac Leiomyomatosis without Cardiac Arrest

We present here a woman with an intracardiac leiomyoma originating from uterine leiomyomatosis. The tumor was completely removed in a one-stage procedure using cardiopulmonary bypass without cardiac arrest. Most one-stage operations were performed with total circulation arrest; however, using of on-pump beating-heart technique when removing the intracardiac mass has seldom been reported in detail. The patient was asymptomatic with no evidence of recurrence on 13-month follow-up.

Right Atrial Myxoma and Severe Left Ventricular Dysfunction: Which Explanations? Which Management?

A 57 year-old woman with a large right atrial myxoma underwent emergency surgical resection in our institute. It is known that surgical management of such tumours is difficult regarding venous cannulation and embolic risk, but in our patient, the surgery was more challenging because of the severe left ventricular dysfunction. Thus, we aim on the one hand, to discuss the association between the left ventricular dysfunction and the right atrial myxoma, and, on the other hand, to describe the on-pump beating heart technique we used to remove this mass.

Myocardial revascularization using on-pump beating heart among patients with left ventricular dysfunction

ObjectivesOn-pump beating heart technique for myocardial revascularization has been used successfully among both low and high risk patients. Its application among low ejection fraction patients is limited. The aim of our study is to evaluate this technique among patients with low ejection fraction and to compare results with off-pump bypass technique.MethodsThis retrospective study includes 137 patients with ejection fraction below 0.35 who underwent isolated coronary artery bypass surgery. 39 patients underwent myocardial revascularization using on-pump beating heart (ONCAB/BH), while 98 patients had off-pump beating heart (OPCAB). Different preoperative, operative and postoperative variables were evaluated among both groups.ResultsPatients profiles and risk factors were similar among both groups, except for the number of patients undergoing redo CABG which was significantly higher among ONCAB/BH (13% vs 3%; p = 0.025). Ejection fraction (EF) varied from 10-34%. The mean EF for patients who underwent ONCAB/BH was 28 ± 6 in comparison to 26 ± 5 for OPCAB patients (P = 0.093). Predicted risk for surgery according to EuroSCORE was similar among both groups (P = 0.443). The number of grafts performed per patient was significantly more among patients who underwent ONCAB/BH (2.2 ± 0.7 Vs 1.7 ± 0.7; P = 0.002). Completeness of revascularization was significantly greater in the ONCAB/BH patients (72% Vs 46%, P = 0.015). The incidence of hospital mortality and combined major morbidity was more among ONCAB/BH in comparison to OPCAB, but the difference was not significant. However, the incidence of blood loss, ventricular arrythmias, inotropic support, ICU, hospital stay and blood transfusion were significantly greater among patients who underwent ONCAB/BH.ConclusionsOn-pump beating heart technique can be used in myocardial revascularization among patients with left ventricular dysfunction. The technique was found to be associated with better myocardial revascularization when compared with OPCAB technique. However, the incidence of morbidity and mortality was more than OPCAB.

Myocardial Infarction in Coronary Bypass Surgery Using On-Pump, Beating Heart Technique with Pressure-and Volume-Controlled Coronary Perfusion

Even with the current aerobic techniques in myocardial protection, perioperative myocardial infarction can still occur. In this study, we sought to find out whether there is a method-specific mechanism of ischemic injury in coronary bypass surgery using an on-pump beating heart technique. For this reason, we investigated localization and the extent of myocardial infarction in correlation to the severity of coronary artery stenosis. We discuss strategies for reduction of infarction incidence. 34 patients, who after isolated coronary bypass procedure developed non-Q or Q wave infarction were selected for the study. In 12 of 34 patients (group A) beating heart technique and in 22 of 34 patients (group B) cardioplegic arrest was used for myocardial protection. The study was conducted retrospectively and included patients with stable, unstable, and postinfarction angina without preoperative enzymatic evidence of ischemic injury and with technically noncomplicated coronary bypass grafting. Excluded from the study were emergency and redo procedures. In group A, in all instances, the left anterior descending artery was grafted as the last vessel and while distal anastomoses were constructed, coronary perfusion was maintained by using a perfusion catheter. Most patients in both groups had triple-vessel disease (10 of 12 patients group A; 17 of 22 patients group B), all patients received complete revascularization; 7 of 12 patients in group A and 5 of 22 patients in group B had significant or critical left main stem stenosis. In group A, 11 infarctions occurred in LAD-(12 stenotic), 1 in CX-(11 stenotic), and 1 in RCA-(11 stenotic) supply area, four were Q wave infarctions. In group B, eight infarctions occurred in LAD (22 stenotic), four in CX (17 stenotic), and 14 in RCA (20 stenotic) supply area, eight were Q wave infarctions. In group A, the infarction incidence in the LAD area was 10-times higher than in CX and RCA areas. In group B, the infarction incidence in the RCA area was 2- and 3-times higher than in the LAD and CX areas, respectively. In both groups no correlation between infarction incidence and severity of stenosis was observed. Using an on-pump beating heart technique, higher coronary perfusion pressures, avoidance of extreme upward retraction of the heart during revascularization of the CX-branch, as well as choosing the revascularization of the LAD as the first vessel, could possibly contribute to better myocardial protection. In hearts arrested with cardioplegic solution, the right ventricle is probably more susceptible to ischemic injury, especially when RCA is poorly collateralized. For adequate protection, choosing the revascularization of the RCA as the first vessel with immediate repeated cardioplegia via a RCA graft, higher perfusion pressures and antegrade with retrograde cardioplegia delivery, may be advantageous.