Comparative study of Short term results between On-pump versus Off-pump CABG in Patients with Preoperative mild to moderate renal impairment

Background Coronary artery diseases are one of the leading causes of death around the world. Great efforts to diagnose, evaluate, prevent and decreasing morbidity and mortality had been done. CABG is one of the most effective ways for treatment of CAD when compared to PCI or medical treatment. On pump CABG is the basic and gold standard technique for CABG surgery. Yet there are some burdensome complications from the use of CPB so surgeons developed off pump technique to decrease these complications. Objective In this study we compared the early results of isolated CABG, using onpump and off-pump, in patients with preoperative mild to moderate elevation of serum creatinine. We examined if off-pump coronary revascularization offers a superior renal protection and less in post-operative complications when compared with conventional coronary revascularization with cardiopulmonary bypass. Methods This study was prospective cohort, observational study, conducted in post open heart ICU at Ain Shams university hospitals, 6th October insurance hospital and National Heart Institute during the period between October 2018 and April 2019. We enrolled 1st 100 consecutive adult patients scheduled for isolated CABG surgery (with a median sternotomy) with or without cardiopulmonary bypass pump. The patients are allocated in 2 groups where 50 patients in each group (group A – On pump – ONCAB- conventional surgery) and (group B – Off pump –OPCAB – beating heart) after obtaining their written informed consent without cross over between both groups. Results In this study, we found that postoperative AKI among both study group was relatively common defined by AKIN criteria and there was significant difference between the incidences of postoperative AKI among both study groups. It was higher in ONCAB group than OPCAB group (52%, 30% respectively) with (p-value = 0.025). According to AKIN classification for complicated cases with postoperative renal impairment; there were 32% among ONCAB group had AKIN stage 1 renal impairment versus 22% among OPCAB group had the same stage. While, there were 6% versus 2% had AKIN stage 2 renal impairment among ONCAB group versus OPCAB group respectively. Also there were 14% versus 6% had AKIN stage 3 renal impairment among ONCAB group versus OPCAB group respectively. The need for dialysis was much greater in the ONCAB group 20% versus 8% in the OPCAB group with significant p-value (0.029). Early mortality was significantly higher in ONCAB group about 11 cases (22%) VS 4 cases (8%) in OPCAB group with p-value 0.033. Also there was statistically significant difference between ONCAB group and OPCAB group according to drainage amount (p-value 0.028), re-exploration for bleeding (p-value 0.018), mean ICU stay (p-value 0.027) and mean hospital stay (p-value 0.009). Conclusion The off pump CABG is superior and gives more renal protection in patients with preoperative mild to moderate renal impairment. It is also reducing the early mortality and morbidity in these patients.

MIDCAB vs OPCAB for severe coronary artery disease: a comparative study

Background/Introduction MIDCAB (minimally invasive direct coronary artery bypass surgery) ± PCI/DES was compared to classical “off pump” coronary artery bypass surgery (OPCAB) for the treatment of severe coronary artery disease. Purpose We hypothesized that MIDCAB is associated with reduced perioperative morbidity and mortality. Methods Preoperative and postoperative clinical data were collected prospectively in 329 consecutive patients with severe coronary artery disease undergoing either a MIDCAB procedure ± PCI/DES (MIDCAB group), n=118 patients, or classical OPCAB (OPCAB group), n=211 patients, at our institution from January 2017 to July 2019. A matched analysis using the EuroSCORE II (81 patients per group) was done. Results The median of EuroSCORE II was 1.05 in both groups, p=1. All MIDCAB patients underwent a left-sided mini-thoracotomy and received a single LIMA-LAD graft, OPCAB patients received median 3 distal anastomoses, p<0.001. Operative time was shorter in MIDCAB patients, 160min vs. 240min, p<0.001. Maximum postoperative Troponin levels were lower in MIDCAB compared to OPCAB, 105 μg/l vs. 260 μg/l, p<0.001. Intubation time was shorter in MIDCAB, 7.0 h vs. 9.3 h, p=0.04, as was ICU time, p=0.02. Chest tube drainage after 24 hours was lower in MIDCAB patients, 405 mL vs. 555 mL, p<0.001. Transfusions of blood, platelets and fresh frozen plasma were rarely needed. Transfusion of erythrocytes were more common in OPCAB, 19%, vs. MIDCAB, 2.5%, p=0.001. A transient neurological deficit showed one (1.2%) patient in the OPCAB group, non in MIDCAB, p=0.3. A hybrid procedure was performed in 18 MIDCAB patients (22%) and 5 OPCAB patients (6.2%). In-hospital mortality was 0% in the MIDCAB group, and 1.2% in OPCAB patients, p=0.3. Conclusions MIDCAB is a good and safe option to treat severe coronary artery disease. MIDCAB is not only less invasive, but associated with reduced perioperative risk compared to standard OPCAB surgery even if a hybrid procedure is needed. Funding Acknowledgement Type of funding source: None

Comparison of Early Outcome of Off-pump and Conventional Coronary Artery Bypass Graft Surgery in Patients with Multivessel Coronary Artery Disease and Left Ventricular Dysfunction

Introduction: Left ventricular dysfunction is an important predictor of in-hospital mortality. Due to the theoretical and practical advantages to avoid the harmful effects of cardiopulmonary bypass (CPB), many cardiac surgeons are using Off-pump Coronary Artery Bypass (OPCAB)as an effective alternative to conventional CABG (CCAB) even in patients with reduced left ventricular (LV)ejection fraction. Objectives: This study performed in the National Institute of Cardiovascular Diseases (NICVD) evaluated the early outcomes of OPCAB in terms of mortality and major post-operative morbidities and compared them with that of CCAB in patients with multivessel coronary artery diseases and reduced left ventricular (LV) function. Methods: Total 120 patients with multivessel coronary artery disease with reduced left ventricular ejection fraction (d”50%)were allocated into two groups: a) 60 patients who underwent OPCAB and b) another 60 patients who underwent conventional CABG between January 2013 and December 2015. Pre-operative, peroperative and early post-operative variables were recorded, compiled and compared. Results: All risk factors and co-morbidities were homogenously distributed between the two groups. Majority of the patients had triple vessel disease. Nearly three-quarter (73.3%) of patients in OPCAB group and 80% in CCAB group received 3 grafts (p=0.470). The mean total operative time (268.5 ± 33.5vs. 296.3 ± 34.8minutes, p < 0.001), intubation times(8.6±0.3 vs. 12.3±0.5 hours, p<0.001), blood losses (377.8378 ± 45 ml vs. 602 ± 60 ml, p < 0.001); requirements for blood and blood products (689.7±21.1 vs. 1199.3±34.5ml, p < 0.0010),intensive care unit stays (31.7±0.9 hours versus 41.6±1.5 hours; p<0.001) and hospital stays (8.2 ± 0.2days vs.10.3 ± 0.3days, p < 0.001)were all significantly lower in the OPCAB group. Conclusion: OPCAB is a safe and effective operative revascularization procedure for patients with multivessel coronary artery disease and left ventricular dysfunction and is associated with reduced morbidity. However, a larger and omized trial with long-term followup may show the real benefits of OPCAB. Bangladesh Heart Journal 2020; 35(1) : 20-27

P312 Early changes of left ventricular myocardial work performance in patients undergoing coronary artery bypass surgery: off-pump vs. on-pump

Background Coronary-artery bypass grafting (CABG) without the use of cardio-pulmonary bypass (CPB) was introduced to avoid the potential damaging effects of fpreign surfaces. Nevertheless, the value of off-pump CABG (OPCAB) remains controversial. Regional myocardial work has been shown to reflect regional metabolic demand and provide a more comprehensive assessment of myocardial function. Recently a novel non-invasive method for assessing regional MW by LV pressure–strain loop analysis has been described. Purpose To detect changes of MW after CABG comparing off- and on-pump techniques. Methods We prospectively evaluated 93 patients undergoing CABG (50 on- vs. 43 off-pump). Patients underwent transthoracic echocardiography exams prior to and one week after surgery as well as concurrently systolic arterial blood pressure measurements at rest. Besides conventional echocardiography parameters, wemeasured global longitudinal strain (GLS), global work index (GWI) and global work efficiency (GWE). Results All patients survived surgery. Patients in the OPCAB group had significantly higher EuroSCORE II (3.3% vs. 1.1%, p &lt; 0.001). Preoperatively, OPCABgroup had significantly lower EF (50.1 vs. 55.7%, p = 0.004), lower GWI (1411 vs. 1650mmHg%, p = 0.039) and lower GWE (86.7 vs. 91.6%, p = 0.017). GLS did not differ significantly between off- and on-pump groupspreoperatively. However, postoperatively GLS, MWI, MWE and EF decreased significantly within the on-pump group (p &lt; 0.001, p &lt; 0.001, p &lt; 0.001 and p = 0.002, respectively). In the OPCAB group only GWI and GLSdecreased significantly (p = 0.028 and p = 0.017, respectively). Due to the fact, that mean differences between all pre- and postoperative values were higher in the on-pump group, no significant differences in systolic LV-function (sLVF) could be detected between on- and off-pump patients postoperatively. During the early postoperative phase, no correlation between GWI and GWE and clinical outcomes could be detected, onlylower preoperative-GWI values showed a weak correlation with the incidence of postoperative cardiogenic shock (r= -0.27, p = 0.029). Conclusion Despite having worse preoperative sLVF in the off-pump group determined by EF, GLS, GWI and GWE, the decrease in sLVF parameters was significantly higher in the on-pump group, leading to an equal distribution of LV-function parameters between off- and on-pump patients postoperatively. Our results suggest that off-pump CABG provides a better preservation of LV-function.

Clinical Outcome of CABG on Off-pump Beating Heart and On-pump Beating Heart: Experience in Ibrahim Cardiac Hospital & Research Institute (ICHRI)

Background: To avoid harmful effect of cardiopulmonary bypass (CPB) used in off-pump coronary artery bypass graft (CABG) surgery, cardiac surgeons are now inclined to on-pump beating heart surgery (ONBEAT). However, the superiority of ONBEAT over Off-pump has not yet been conclusively established. This study compares the outcomes between off-pump and on pump beating heart CABG surgery. Methods: A total 249 consecutive patients who underwent non-emergency, primary isolated CABG from January 2014 to December 2017 by a single surgeon were included. The selected patients were assigned to either OPCAB group (Patients who received Off-pump beating heart CABG surgery, n=193) or to ONBEAT group (patients who received On-pump beating heart CABG surgery, n=56). The clinical outcomes were investigated and compared. Result: Forty percent of the patients were in their 5th decade of life. A male predominance was also observed. The two study groups were almost identical in terms of age and sex (p=0.983 and p=0.153 respectively). None of the conventional risk factors of ischemic heart disease (smoking, diabetes, hypertension and dyslipidaemia) were any different between the study groups (p > 0.05). Cerebrovascular disease, recent MI, congestive heart failure and left main disease were significantly higher in the on-pump beating heart group compared to those in the off-pump beating heart group (p < 0.05). The left ventricular ejection fraction (LVEF) was significantly lower in the former group than that in the latter group (p= 0.007). Both groups required 3 grafts on an average. Two patients in the on-pump group required Intra-Aortic Balloon Pump (IABP) support as opposed to none in the off-pump group (p=0.050). The mean cardiopulmonary bypass (CPB) time was 105.8 ± 46.5 in the on-pump group. Fourteen patients (25%) from off-pump group needed urgent switching to on-pump group. Postoperative drainage in the first 24 hours was significantly voluminous in the on-pump group (p < 0.001). The incidence of pneumonia, respiratory failure, arrhythmia, renal failure requiring haemodialysis and perioperative MI were significantly higher in the on-pump group (p < 0.001, p < 0.001, p=0.037, p < 0.001 and p=0.050 respectively). The patients with prolonged mechanical ventilation were also more in the on-pump group. The left ventricular ejection fraction (LVEF) was much lower and Intensive Care Unit (ICU) stay was longer in the on-pump group compared to those in the off-pump group (p < 0.001). The incidence of in-hospital mortality was also higher in the former group (p=0.037). Conclusion: OPCAB was associated with lower operative morbidity compared to ONBEAT cardiac surgery. However, the increased morbidity in ONBEAT group might have been influenced by a sizable proportion of patients from OPCAB group being switched to ONBEAT group due to their haemodynamic deterioration and frequent ventricular fibrillation. But on-pump CABG can be performed safely on high risk patients. Use of cardiopulmonary bypass and elimination of cardioplegic arrest may be beneficial to hemodynamically unstable patients. Ibrahim Card Med J 2017; 7 (1&2): 15-22

Vascular Endothelial Dysfunction during Cardiac Surgery: On-Pump versus Off-Pump Coronary Surgery

Background: Cardiac surgery often causes ischemia and development of a systemic inflammatory response syndrome, which impairs vascular barrier function, normally maintained by the endothelial cell line and the endothelial glycocalyx (EG). The EG normally covers and protects healthy endothelial cells throughout the vasculature. The aim of the present study was to assess the disruption of the cellular part of the microvascular barrier by determining parameters of endothelial cell activation known to influence and reflect cell-cell junctional integrity. Particular attention was placed on angiopoietins and their important effects on endothelial gap junctions. Furthermore, comparative measurements were undertaken in patients undergoing on- and off-pump cardiac surgery, the latter group presumably experiencing less ischemic stress. Methods: 30 patients undergoing elective coronary artery bypass surgery were assigned to the conventional coronary artery bypass (CCAB) group (n = 15) or the off-pump coronary artery bypass grafting (OPCAB) group (n = 15). Blood samples were obtained for measuring angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), vascular endothelial (VE)-cadherin, and endocan at various time points. Results: There were significant increases in all measured parameters in both study groups versus the respective basal values. Maximal increases were as follows: Ang-1: CCAB +220%, OPCAB +166%, p < 0.05 each; Ang-2: CCAB +150%, OPCAB +20%, p < 0.05 each; VE-cadherin: CCAB +87%, OPCAB +66%, p < 0.05 each; endocan: CCAB +323%, OPCAB +72%, p < 0.05 each. Conclusion: The present study demonstrates the activation of endothelial cells, shedding of cell-cell contacts and a potential intrinsic counterregulation by Ang-1 and endocan in patients undergoing major cardiac surgery. Quantitatively greater deviations of parameters in the CCAB than in the OPCAB group suggest a relation between the occurrence of ischemia/reperfusion and the extent of endothelial activation.

Minimally invasive direct coronary artery bypass versus off-pump coronary surgery through sternotomy

Introduction Although it is not a new technique, minimally invasive direct coronary artery bypass (MIDCAB) is employed only by a few surgeons in the UK. We compared our experience with MIDCAB with that of single vessel off-pump coronary artery bypass (OPCAB) graft surgery through a standard median sternotomy. Methods Patients who underwent either MIDCAB or OPCAB between April 2008 and July 2011 were reviewed. Exclusion criteria included patients with an ejection fraction of <0.5 or previous cardiac surgery. Data were obtained retrospectively from our prospective database, medical records and through general practitioners. Results Overall, 74 patients were analysed in the MIDCAB group and 78 in the OPCAB group. Their demographics and EuroSCORE (European System for Cardiac Operative Risk Evaluation) values were comparable (p>0.05). There was no statistically significant difference in the two groups in terms of mortality, recurrent myocardial infarction, postoperative stroke, wound infection, atrial fibrillation or need for reintervention. The MIDCAB group had six conversions to a sternotomy. Eight patients in each group required blood transfusion, with the average transfusion being 1.8 units in the MIDCAB group and 3.2 units in the OPCAB group. The mean duration of ventilation and intensive care unit stay was 5.0 hours and 38.4 hours in the MIDCAB group and 5.4 and 47.8 hours in the OPCAB group. The mean hospital stay was significantly reduced in the MIDCAB population (6.1 vs 8.5 days, p<0.05). Conclusions MIDCAB can be performed safely in appropriately selected patients with outcomes comparable with OPCAB. The potential benefits include shorter hospital stay, reduced need for blood transfusion and faster recovery.

Effect of Cardiopulmonary Bypass on Regional Antibiotic Penetration into Lung Tissue

ABSTRACTThe use of cardiopulmonary bypass (CPB) during cardiac surgery causes regional ventilation-perfusion mismatch, contributing to regional disturbances in antibiotic penetration into lung tissue. Ventilation-perfusion mismatch is associated with postoperative pneumonia, a frequent and devastating complication after cardiac surgery. In this prospective clinical animal study, we performedin vivomicrodialysis to determine the effect of CPB on regional penetration of levofloxacin (LVX) into lung tissue. Six pigs underwent surgery with CPB (CPB group), and another six pigs underwent surgery without CPB (off-pump coronary artery bypass grafting; OPCAB group). LVX (750 mg) was administered intravenously to all pigs immediately after surgery. For regional measurements of LVX in pulmonary concentrations, microdialysis probes were inserted in both lungs of each pig. Pigs were placed in the right lateral position. Time versus concentration profiles of unbound LVX were measured in the upper and lower lung tissue and plasma in all pigs. In all pigs, maximum concentrations (Cmax) of LVX were significantly lower in the upper lung than in the lower lung (OPCAB,P= 0.035; CPB,P< 0.001). MedianCmaxof LVX showed a significant difference in the upper versus lower lung in the CPB group (P< 0.05). No significant difference was found in the medianCmaxof LVX in the upper and the lower lung in the OPCAB group (P= 0.32). Our data indicate that CPB affects perioperative regional antibiotic penetration into lung tissue. Common clinical antibiotic dosing schemes should be reevaluated in patients undergoing coronary artery bypass grafting with CPB.

Short- and Long-Term Outcomes in Octogenarian Patients Undergoing Off-Pump Coronary Artery Bypass Grafting Compared with On-Pump Coronary Artery Bypass Grafting

Objective Coronary artery bypass grafting (CAB) on elderly patients presenting with multivessel coronary artery disease has become routine in modern day operating rooms. The aim of our study was to compare short- and long-term outcomes in octogenarian patients undergoing off-pump CAB (OPCAB) versus on-pump CAB (ONCAB). Methods A propensity-adjusted, retrospective review of patients older than 80 years who underwent primary CAB from January 1996 to September 2008 at our institution's hospitals was performed. Nine hundred thirty-seven patients were divided into two groups: OPCAB (n = 540) or ONCAB (n = 397). A propensity score was calculated based on 29 preoperative risk factors to adjust for selection bias when comparing the groups for differences in death, stroke, myocardial infarction incidence, and their composite (major adverse cardiac events). Long-term survival status was determined by cross-referencing patient records with the Social Security Death Index. Logistic regression analysis and Cox proportional hazards analysis were used to determine group differences in short- and long-term survival, respectively, adjusted for the propensity score. Kaplan-Meier curves were fit to estimate 10-year survival. Results The mean age (OPCAB: 82.9 ± 2.8 years vs ONCAB: 82.3 ± 2.4, P = 0.003) and male sex (OPCAB: 292/540, 54.1% vs ONCAB: 220/397, 55.4%, P = 0.68) were clinically similar between groups. Although the ejection fraction (OPCAB: 52.1 ± 12.5% vs ONCAB: 50.6 ± 13.1, P = 0.10) were similar between groups, the mean number of distal anastomoses [OPCAB: 2.7 ± 1.0 (median 3) vs ONCAB: 3.4 ± 0.9 (median 3), P < 0.001] were less in the OPCAB group. The median postoperative length of stay was 7 days for OPCAB group and 6 for the ONCAB group (P = 0.31). The Society of Thoracic Surgery predicted risk of in-hospital mortality was similar for OPCAB (5.4%) and ONCAB (5.3%) patients (P = 0.81). However, observed in-hospital mortality was improved for patients in the OPCAB group (OPCAB: 15/540, 2.8% vs ONCAB: 37/397, 9.3%, P = 0.007). Ten-year survival was similar between groups (OPCAB: 28.8% vs ONCAB: 26.3%, P = 0.22). Conclusions In this series, OPCAB reduced the incidence of in-hospital mortality compared with ONCAB. Long-term mortality was similar between groups.

Activation of Coagulation and Fibrinolysis after Off-Pump Coronary Artery Bypass Grafting with or without Endotracheal General Anesthesia

Objective In this study, we measured the activity of coagulation and fibrinolysis and clarified the presence of certain differences between off-pump coronary artery bypass grafting (OPCAB) cases and awake off-pump coronary artery bypass grafting (AOCAB) cases to evaluate whether AOCAB is actually safe from the viewpoint of coagulability. Methods 8 underwent OPCAB and 6 underwent AOCAB. The following factors inducing coagulation and fibrinolysis were measured for upto 5 days after the operation: platelet counts, prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin degeneration products, D-dimer, thrombin-antithrombin III complex (TAT), α2-plasmin inhibitor-plasmin complex, prothrombin fragment 1, 2 (F1+2), thrombomodulin, β-thromboglobulin (β-TG), and platelet factor-4. Results At 5 days after the operation, fibrin degeneration products, D-dimer, α2–plasmin inhibitor-plasmin complex, and F1 + 2 levels of the OPCAB group were significantly higher compared with their baseline values and those of the AOCAB group. At 5 days after the operation, thrombin-antithrombin III complex levels of the OPCAB group were significantly higher than those of the AOCAB group. Fibrinogen levels of the OPCAB group were significantly higher than their baseline values at 3 days after the operation (POD3) and 5 days after the operation (POD5). Conclusions In this study, the hypercoagulable state at POD5 was suggested in the patients in the OPCAB group, but not in those in the AOCAB group. Further study is necessary to confirm these results, and future studies would evaluate the potential benefit of AOCAB procedure from the viewpoint of perioperative coagulability.