Activation of complement and leukocyte receptors during on- and off pump coronary artery bypass surgery

Improvement in radiologic findings over time is associated with increased survival in patients with viral ARDS requiring extracorporeal membrane oxygenation

INTRODUCTION

Acute respiratory distress syndrome (ARDS) requiring venovenous extracorporeal membrane oxygenation (VV ECMO) support is associated with chest radiograph changes commonly referred to as "drowning ECMO lung" ECMO lung presents as white-out of both lung fields, involving all lobes of the bilateral lungs. While the clinical significance of chest radiograph findings over time has been described in the general ARDS population, it has not been evaluated specifically in VV ECMO patients. This subpopulation suffers the most severe disease as well as the confounding effects of ECMO support.

MATERIALS AND METHODS

We identified 28 patients requiring VV ECMO cannulation for influenza-related ARDS between September 2009 and January 2018. Interpretation of chest X-ray images was divided into zones that correspond to anatomical lobes on computed tomography. Progression of radiologic injury was assessed by analysing the number of zones involved on the chest radiograph (X-ray) at days 1, 3, 7, 14, and 21 from cannulation and discharge. The primary endpoint was survival to hospital discharge.

RESULTS

The majority of patients had complete opacification on days 1, 3, and 7 after VV ECMO cannulation. Patients with persistent complete opacification on chest X-ray infiltrate by day 14, following cannulation had an increased mortality. Survival to hospital discharge was increased in patients demonstrating improvement in radiological findings at day 19 compared to patients without significant radiologic improvement (100% vs 53%, log-rank P = 0.003).

CONCLUSION

The evolution and recovery of lung injury reflected by serial chest X-ray imaging studies after influenza-related ARDS requiring VV ECMO support is associated with improved survival in this single centre, retrospective cohort.

Differences in Plasma Extracellular Vesicles of Different Origin in On-Pump Versus Off-Pump Cardiac Surgery

Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) causes a systemic inflammatory response that can worsen patient outcomes. Off-pump surgery has been associated with a reduced inflammatory response. The precise mechanisms and the role of extracellular vesicles (EVs) in this context are not fully understood. This study aimed to investigate the early immune response, including main T- and B-lymphocyte subsets, cytokine profiles, and plasma EVs, in patients undergoing off-pump (n = 18) and on-pump (n = 18) CABG. Thirty-six patients undergoing isolated CABG were enrolled in this randomized control study. Pre- and 24 h postoperative blood samples were analyzed for immune cell populations, cytokine levels, and plasma EV phenotyping. Off-pump CABG triggered a milder immune response than on-pump surgery. On-pump surgery led to greater changes in circulating EVs, particularly platelet- (CD62P+), endothelial- (CD31+), and B-cell-derived (CD19+), as well as platelet- and erythrocyte-derived aggregates (CD41+CD235a+). Levels of platelet-derived EVs, expressing both constitutional and activation markers (CD41+CD62P+) decreased in both groups of patients 24 h after surgery. On-pump cardiac procedures led to an increase in T-regulatory cell-derived EVs (CD73+CD39+), suggesting a potential mechanism for immune suppression compared to off-pump surgery. There were numerous correlations between EV levels and cytokine profiles following on-pump surgery, hinting at a close relationship. Leucocyte-derived EVs exhibited positive correlations with each other and with GRO but showed negative correlations with endothelial-derived EVs (CD90+ and CD31+). Additionally, CD73+ EVs demonstrated positive correlations with platelet counts and with erythrocyte-derived CD235a+ EVs. EV changes were significantly greater after on-pump surgery, highlighting a more pronounced response to this type of surgery and emphasizing the role of EVs as regulators of post-surgical inflammation.

Cardiopulmonary bypass and VA-ECMO induced immune dysfunction: common features and differences, a narrative review

Cardiopulmonary bypass (CPB) and veno-arterial extracorporeal membrane oxygenation are critical tools in contemporary cardiac surgery and intensive care, respectively. While these techniques share similar components, their application contexts differ, leading to distinct immune dysfunctions which could explain the higher incidence of nosocomial infections among ECMO patients compared to those undergoing CPB. This review explores the immune modifications induced by these techniques, comparing their similarities and differences, and discussing potential treatments to restore immune function and prevent infections. The immune response to CPB and ECMO involves both humoral and cellular components. The kinin system, complement system, and coagulation cascade are rapidly activated upon blood contact with the circuit surfaces, leading to the release of pro-inflammatory mediators. Ischemia-reperfusion injury and the release of damage-associated molecular patterns further exacerbate the inflammatory response. Cellular responses involve platelets, neutrophils, monocytes, dendritic cells, B and T lymphocytes, and myeloid-derived suppressor cells, all of which undergo phenotypic and functional alterations, contributing to immunoparesis. Strategies to mitigate immune dysfunctions include reducing the inflammatory response during CPB/ECMO and enhancing immune functions. Approaches such as off-pump surgery, corticosteroids, complement inhibitors, leukocyte-depleting filters, and mechanical ventilation during CPB have shown varying degrees of success in clinical trials. Immunonutrition, particularly arginine supplementation, has also been explored with mixed results. These strategies aim to balance the inflammatory response and support immune function, potentially reducing infection rates and improving outcomes. In conclusion, both CPB and ECMO trigger significant immune alterations that increase susceptibility to nosocomial infections. Addressing these immune dysfunctions through targeted interventions is essential to improving patient outcomes in cardiac surgery and critical care settings. Future research should focus on refining these strategies and developing new approaches to better manage the immune response in patients undergoing CPB and ECMO.

Inflammatory Progression in Patients Undergoing Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is identified as a novel therapeutic strategy that offers short-term support to the metabolism of the heart and lungs in humans. Recently, the clinical centers, which provide ECMO has increased rapidly worldwide. The indications for the use of ECMO in daily clinical practice were broadened dynamically. However, even with the widespread adoption of ECMO, it still remains significant morbidity and mortality, and the underlying mechanisms are still not elucidated. Notably, one of the vital complications during ECMO was proposed as the inflammatory progression within the extracorporeal circulation. via the development of inflammatory response, patients with ECMO may further suffer from systemic inflammatory response syndrome (SIRS), posing serious risks to human health. Recently, growing evidence confirmed that through exposure of blood into the ECMO circuit could lead to the stimulation of the immune system which also facilitated the inflammatory response and systemic impaired. In the current review, the pathological development of inflammatory progression in patients with ECMO is well-listed. Furthermore, the relationship between immune-related activation and the development of inflammation is also summarized, which may further help us to decide the therapeutic strategies in daily clinical practice.

Effects of interventions targeting the systemic inflammatory response to cardiac surgery on clinical outcomes in adults

BACKGROUND

Organ injury is a common and severe complication of cardiac surgery that contributes to the majority of deaths. There are no effective treatment or prevention strategies. It has been suggested that innate immune system activation may have a causal role in organ injury. A wide range of organ protection interventions targeting the innate immune response have been evaluated in randomised controlled trials (RCTs) in adult cardiac surgery patients, with inconsistent results in terms of effectiveness.

OBJECTIVES

The aim of the review was to summarise the results of RCTs of organ protection interventions targeting the innate immune response in adult cardiac surgery. The review considered whether the interventions had a treatment effect on inflammation, important clinical outcomes, or both.

SEARCH METHODS

CENTRAL, MEDLINE, Embase, conference proceedings and two trial registers were searched on October 2022 together with reference checking to identify additional studies.

SELECTION CRITERIA

RCTs comparing organ protection interventions targeting the innate immune response versus placebo or no treatment in adult patients undergoing cardiac surgery where the treatment effect on innate immune activation and on clinical outcomes of interest were reported.

DATA COLLECTION AND ANALYSIS

Searches, study selection, quality assessment, and data extractions were performed independently by pairs of authors. The primary inflammation outcomes were peak IL-6 and IL-8 concentrations in blood post-surgery. The primary clinical outcome was in-hospital or 30-day mortality. Treatment effects were expressed as risk ratios (RR) and standardised mean difference (SMD) with 95% confidence intervals (CI). Meta-analyses were performed using random effects models, and heterogeneity was assessed using I2.

MAIN RESULTS

A total of 40,255 participants from 328 RCTs were included in the synthesis. The effects of treatments on IL-6 (SMD -0.77, 95% CI -0.97 to -0.58, I2 = 92%) and IL-8 (SMD -0.92, 95% CI -1.20 to -0.65, I2 = 91%) were unclear due to heterogeneity. Heterogeneity for inflammation outcomes persisted across multiple sensitivity and moderator analyses. The pooled treatment effect for in-hospital or 30-day mortality was RR 0.78, 95% CI 0.68 to 0.91, I2 = 0%, suggesting a significant clinical benefit. There was little or no treatment effect on mortality when analyses were restricted to studies at low risk of bias. Post hoc analyses failed to demonstrate consistent treatment effects on inflammation and clinical outcomes. Levels of certainty for pooled treatment effects on the primary outcomes were very low.

AUTHORS' CONCLUSIONS

A systematic review of RCTs of organ protection interventions targeting innate immune system activation did not resolve uncertainty as to the effectiveness of these treatments, or the role of innate immunity in organ injury following cardiac surgery.

Synthetic Material Abdominal Swabs Reduce Activation of Platelets and Leukocytes Compared to Cotton Materials

During surgical procedures, cotton abdominal swabs with their high absorptive capacity and malleability are used to retain organs and absorb blood or other body fluids. Such properties of the natural material cotton are advantageous for most operations, but in cardiopulmonary bypass (CPB) surgery, a high blood volume can accumulate in the thoracic cavity that is quickly retransfused via the heart-lung machine (HLM). This common practice is supposed to be safe due to the high anticoagulation. However, in vitro analyses showed that blood cells and plasma proteins were activated despite a high anticoagulation, which can propagate especially an inflammatory response in the patient. Thus, we investigated patients' blood during CPB surgery for inflammatory and coagulation-associated activation after contact to the HLM and either cotton or synthetic abdominal swabs. Contact with cotton significantly increased thrombocyte and neutrophil activation measured as β-thromboglobulin and PMN-elastase secretion, respectively, compared to synthetic abdominal swabs. Both inflammatory cytokines, interleukin (IL) 1β and IL6, were also significantly increased in the cotton over the synthetic patient group, while SDF-1α was significantly lower in the synthetic group. Our data show for the first time that cotton materials can activate platelets and leukocytes despite a high anticoagulation and that this activation is lower with synthetic materials. This additional activation due to the material on top of the activation exerted by the tissue contact that blood is exposed to during CPB surgery can propagate further reactions in patients after surgery, which poses a risk for this already vulnerable patient group.

Mitral valve surgery combined with on-pump versus off-pump myocardial revascularization: A prospective randomized analysis with midterm follow-up

BACKGROUND

The aim of the study was to compare results off-pump coronary artery bypass (OPCAB) combined mitral valve reconstruction (MVR) with standard on-pump approach.

METHODS

From January 2014 to December 2017, a total of 53 patients received a combined myocardial revascularization and MVR for multivessel coronary artery disease (CAD) complicated by severe ischemic mitral regurgitation (IMR). All the subjects were divided into two groups: group I: 27 patients, received OPCAB + MVR, and group II (control group): 26 patients with on-pump myocardial revascularization (ONCAB) + MVR.

RESULTS

The aortic cross-clamp (ACC) and cardio-pulmonary bypass (CPB) times were longer in group II, 47.0 (44.0; 55.0) vs 94.5 (89.75; 105.5) minutes, P < .05 and 70.0 (63.0; 77.0) vs 138.5 (127.0; 157.5) minutes, P < .05, respectively. Evaluation of major clinical events showed that the implementation of the off-pump stage of myocardial revascularization in patients with severe IMR did not lead to significant changes in the mortality and postoperative complications. Furthermore, its use did not affect the volume of blood loss and need for blood transfusion, the duration of mechanical ventilation, the need for inotropic therapy, as well as the duration of the patient's resuscitation and the total duration of hospitalization, with the one exception: the troponin-T level increase in the OPCAB + MVR group was less than in the ONCAB + MVR group.

CONCLUSION

OPCAB combined MVR in patients with CAD and severe IMR can be performed with shorter CPB and ACC times, and lower troponin-T level after surgery, without reducing the risk of surgical complications.

Acute kidney injury following on-pump or off-pump coronary artery bypass grafting in elderly patients: a retrospective propensity score matching analysis

Objectives

This single-centre, retrospective propensity score matching (PSM) study designed to study the impact of cardiopulmonary bypass (CPB) on postoperative acute kidney injury (AKI) and the relationship between AKI and long-term outcomes in elderly patients undergoing coronary artery bypass grafting (CABG).

Methods

After PSM, 466 pairs of patients (A group, on-pump; B group, off-pump) who were aged≥70 years undergoing first isolated CABG surgery from January 2012 to December 2016 entered the study. AKI was defined and classified according to the Acute Kidney Injury Network (AKIN) criteria. The incidence and severity of in-hospital AKI were compared. The impacts of AKI on the long-term outcomes including new onset of dialysis and mortality were analyzed.

Results

The two PSM groups had similar baseline and procedure except whether the CPB was used or not. In hospital and 30-day mortality was of no difference(χ2 = 0.051, p = 0.821). AKI of any severity occurred in 40.3% of all patients, with stage 1 accounting for most cases. No difference regarding the incidence and severity of AKI could be found: AKIN stage 1: 139 (29.8%) vs 131 (28.1%); AKIN stage 2: 40 (8.6%) vs 35 (7.5%); AKIN stage 3: 18 (3.9%) vs 13 (2.8%), (u = 0.543, p = 0.532). No difference was observed in the in-hospital new onset of dialysis (χ2 = 0.312, P = 0.576). The use of CPB was not found to influence long-term new onset of dialysis (χ2 = 0.14, p = 0.708) and mortality (χ2 = 0.099, p = 0.753). Comparing with non-AKI patients, AKI patients were associated with an increased rates of new onset of dialysis (χ2 = 8.153, p = 0.004) and mortality (χ2 = 6.277, p = 0.012) during the follow-up. Multivariable logistic regression manifested that the HR for long-term new onset of dialysis and mortality in AKI patients vs. non-AKI patients was 1.83 and 1.31 respectively (95%CI 1.12–2.86, p = 0.007; 95%CI 1.17–2.58, p = 0.015). The HR for long-term new onset of dialysis and mortality in on-pump group vs. off-pump group was 1.07 and 1.11 respectively (95%CI 1.03–1.23, p = 0.661; 95%CI 1.09–1.64, p = 0.702).

Conclusions

For elderly CABG patients, AKI was common, but deterioration of dialysis was a seldom incidence. Comparing with on-pump, off-pump did not decrease the rates or severity of AKI, long-term new onset of dialysis or mortality. AKI was associated with an increased long-term new onset of dialysis and decreased long-term survival.

Extracorporeal life support and systemic inflammation

Extracorporeal life support (ECLS) encompasses a wide range of extracorporeal modalities that offer short- and intermediate-term mechanical support to the failing heart or lung. Apart from the daily use of cardiopulmonary bypass (CPB) in the operating room, there has been a resurgence of interest and utilization of veno-arterial and veno-venous extracorporeal membrane oxygenation (VA- and VV-ECMO, respectively) and extracorporeal carbon dioxide removal (ECCO₂R) in recent years. This might be attributed to the advancement in technology, nonetheless the morbidity and mortality associated with the clinical application of this technology is still significant. The initiation of ECLS triggers a systemic inflammatory response, which involves the activation of the coagulation cascade, complement systems, endothelial cells, leukocytes, and platelets, thus potentially contributing to morbidity and mortality. This is due to the release of cytokines and other biomarkers of inflammation, which have been associated with multiorgan dysfunction. On the other hand, ECLS can be utilized as a therapy to halt the inflammatory response associated with critical illness and ICU therapeutic intervention, such as facilitating ultra-protective mechanical ventilation. In addition to addressing the impact on outcome of the relationship between inflammation and ECLS, two different but complementary pathophysiological perspectives will be developed in this review: ECLS as the cause of inflammation and ECLS as the treatment of inflammation. This framework may be useful in guiding the development of novel therapeutic strategies to improve the outcome of critical illness.

Off-Pump versus Conventional Coronary Artery Bypass Grafting: A Meta-Analysis and Consensus Statement from the 2004 ISMICS Consensus Conference

Background

The purpose of this evidence-based consensus statement is to systematically review and meta-analyze the randomized and nonrandomized evidence comparing off-pump (OPCAB) to conventional coronary artery bypass (CCAB) surgery and to provide consensus on the role of OPCAB in low- and high-risk surgical patients.

Methods and Results

This consensus conference was conducted according to the American College of Cardiology (ACC)/American Heart Association (AHA) standards for development of clinical practice guidelines. The Steering Committee collated all published studies of OPCAB versus CCAB through May 2004 and developed six questions central to controversies surrounding OPCAB surgery in mortality, morbidity, and resource utilization. For mixed-risk patient populations, meta-analysis of 37 randomized clinical trials (3,369 patients, Level A) reported across a total of 53 papers, and two meta-analyses of nonrandomized trials (Level B) comparing OPCAB versus CCAB were identified. For high-risk patient populations, we performed a meta-analysis of 3 randomized and 42 nonrandomized trials (26,349 patients, Level B).

Conclusion

Meta-analysis of Level A and B evidence provided the basis for the following consensus statements in patients undergoing surgical myocardial revascularization: (1) OPCAB should be considered a safe alternative to CCAB with respect to risk of mortality [Class I, Level A]; (2) With appropriate use of modern stabilizers, heart positioning devices, and adequate surgeon experience, similar completeness of revascularization and graft patency can be achieved [Class IIa, Level A]; (3) OPCAB is recommended to reduce perioperative morbidity [Class I, Level A]; (4) OPCAB may be recommended to minimize midterm cognitive dysfunction [Class IIa, Level A]; (5) OPCAB should be considered as an equivalent alternative to CCAB in regard to quality of life [Class I, Level A]; (6) OPCAB is recommended to reduce the duration of ventilation, ICU and hospital stay, and resource utilization [Class I, Level A]; (7) OPCAB should be considered in high-risk patients to reduce perioperative mortality, morbidity, and resource utilization [Class IIa, Level B].

Feasibility and efficacy of simultaneous off-pump coronary artery bypass grafting and esophagectomy in elderly patients

INTRODUCTION

To analyze the outcomes of off-pump coronary artery bypass grafting (OPCABG) and esophagectomy simultaneously for patients with coronary artery disease (CAD) and coexisting esophageal cancer.

METHODS

Twenty-two patients with CAD and coexisting esophageal cancer underwent combined surgical interventions were subjected to the study. OPCABG was performed first, followed by esophagectomy. All the corresponding data including clinicopathological characteristics and postoperative outcomes were all investigated.

RESULTS

All the combined procedures were performed successfully. The average number of grafts was 2.36. Tumors were located at the middle third of the esophagus in 5 patients, at the lower third of the esophagus in 8 patients, at the esophageal gastric junction (EGJ) in 9 patients, respectively. The operations were carried out through a left lateral thoracotomy approach in 21 patients while a median sternotomy and left lateral thoracotomy approach was used in 1 patient for his condition rapidly worsened. Postoperatively, pneumonia occurred in 4 patients (18.2%). During the follow-up, three patients died of cancer metastasis /recurrence (6, 18, 37 months) and one died of pneumonia (1 month). The cumulative 5 years survival rate is 52.9%.

CONCLUSIONS

The combined procedure of OPCABG and esophagectomy is a safe and effective treatment option for patients with severe CAD and esophageal cancer.

Pathway-related modules involved in the application of sevoflurane or propofol in off-pump coronary artery bypass graft surgery

Off-pump coronary artery bypass graft (CABG) surgery has recently emerged as a means to avoid the sequelae of extracorporeal circulation, including the whole-body inflammatory response, coagulation disorders and multiple organ dysfunction. At present, gas anesthesia, sevoflurane and intravenous anesthesia and propofol have been widely used during the CABG. To further understand the underlying mechanisms of these anesthetics on the gene level, the present study conducted pathway-related module analysis based on a co-expression network. This was performed in order to identify significant pathways in coronary artery disease patients who had undergone off-pump CABG surgery before and after applying sevoflurane or propofol. A total of 269 and 129 differentially expressed genes were obtained in the sevoflurane and propofol groups, respectively. In total, eight and seven pathways (P<0.05) in the sevoflurane and propofol groups were separately obtained via Kyoto Encyclopedia of Genes and Genome pathway analysis. Finally, eight and seven pathway-related modules in the sevoflurane and propofol groups were obtained, respectively. Furthermore, the mean degree of complement and coagulation cascades pathway-related module in both of the groups was the highest. It was predicted that during the CABG, the anesthetics might activate the complement and coagulation systems in order to possess some cardioprotective properties.

The inflammatory response to extracorporeal membrane oxygenation (ECMO): a review of the pathophysiology

Extracorporeal membrane oxygenation (ECMO) is a technology capable of providing short-term mechanical support to the heart, lungs or both. Over the last decade, the number of centres offering ECMO has grown rapidly. At the same time, the indications for its use have also been broadened. In part, this trend has been supported by advances in circuit design and in cannulation techniques. Despite the widespread adoption of extracorporeal life support techniques, the use of ECMO remains associated with significant morbidity and mortality. A complication witnessed during ECMO is the inflammatory response to extracorporeal circulation. This reaction shares similarities with the systemic inflammatory response syndrome (SIRS) and has been well-documented in relation to cardiopulmonary bypass. The exposure of a patient’s blood to the non-endothelialised surface of the ECMO circuit results in the widespread activation of the innate immune system; if unchecked this may result in inflammation and organ injury. Here, we review the pathophysiology of the inflammatory response to ECMO, highlighting the complex interactions between arms of the innate immune response, the endothelium and coagulation. An understanding of the processes involved may guide the design of therapies and strategies aimed at ameliorating inflammation during ECMO. Likewise, an appreciation of the potentially deleterious inflammatory effects of ECMO may assist those weighing the risks and benefits of therapy.

The intraoperative effect of pentoxifylline on the inflammatory process and leukocytes in cardiac surgery patients undergoing cardiopulmonary bypass

Background: Inflammation plays a pivotal role in the pathogenesis of organ dysfunction after cardiopulmonary bypass (CPB). The aim of this study was to investigate whether pentoxifylline (PTX) has effects on the inflammatory process and leukocytes in cardiac surgery patients undergoing CPB.

Material and methods: A double-blind, prospective, randomized, placebo-controlled study was undertaken to assess the effect of PTX on leukocyte counts, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP) levels in 60 patients undergoing CPB for elective coronary artery bypass grafting. In 30 patients, 200 mg of PTX was added to 500 mL NaCl and perfused for 180 min after induction of anaesthesia and also 100 mg of PTX was added to the warm cardioplegic solution; another 30 patients received saline solution as placebo.

Results: All measurements were performed before PTX infusion (T0), after induction of anaesthesia (T1), 30 min after weaning from CPB (T2), and 6 hours (T3) and 24 hours postoperatively (T4). PTX did not change the percentage of eosinophils, basophils, neutrophils, monocytes, or lymphocytes, or CRP levels. In the control group, however, total leukocyte count and IL-6 level at T3 and T4 period were significantly higher than the study group. The progressive increment in TNF-α level observed at each period was also significantly prominent in the control group.

Conclusion: CPB-related whole body inflammatory response could be partially inhibited by intraoperative PTX administration. This effect of PTX would be helpful in preventing the well-known complications of CPB-induced systemic inflammation.

Preoperative Prophylactic Intraaortic Balloon Pump Reduces the Incidence of Postoperative Acute Kidney Injury and Short-Term Death of High-Risk Patients Undergoing Coronary Artery Bypass Grafting: A Meta-Analysis of 17 Studies

This meta-analysis investigated the effects of preoperative prophylactic intraaortic balloon pump placement on postoperative renal function and short-term death of high-risk patients undergoing coronary artery bypass grafting. We found that preoperative prophylactic intraaortic balloon pump support reduced the incidence of coronary artery bypass grafting-associated acute kidney injury and short-term death and dramatically decreased the incidence of postoperative renal replacement therapy by 82% compared with high-risk patients without the procedure. This is the first meta-analysis to demonstrate significant beneficial effects of preoperative prophylactic intraaortic balloon pump on renal function in high-risk patients undergoing coronary artery bypass grafting.

Off-pump coronary artery bypass grafting improves short-term outcomes in high-risk patients compared with on-pump coronary artery bypass grafting: Meta-analysis

OBJECTIVES

To assess the benefits and risks of off-pump coronary artery bypass (OPCAB) versus coronary artery bypass grafting (CABG) through a meta-analysis of randomized controlled trials (RCTs), and to investigate the relationship between outcomes and patient risk profile.

METHODS

PubMed, Embase, the Cumulative Index of Nursing and Allied Health Literature, Scopus, Web of Science, Cochrane Library, and major conference proceedings databases were searched for RCTs comparing OPCAB and CABG and reporting short-term (≤ 30 days) outcomes. Endpoints assessed were all-cause mortality, myocardial infarction (MI), and cerebral stroke.

RESULTS

The meta-analysis included 100 studies, with a total of 19,192 subjects. There was no difference between the 2 techniques with respect to all-cause mortality and MI (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.71-1.09; P = .25; I(2) = 0% and OR, 0.90; 95% CI, 0.77-1.05; P = .19; I(2) = 0%, respectively). OPCAB was associated with a significant 28% reduction in the odds of cerebral stroke (OR, 0.72; 95% CI, 0.56-0.92; P = .009; I(2) = 0%). A significant relationship between patient risk profile and benefits from OPCAB was found in terms of all-cause mortality (P < .01), MI (P < .01), and cerebral stroke (P < .01).

CONCLUSIONS

OPCAB is associated with a significant reduction in the odds of cerebral stroke compared with conventional CABG. In addition, benefits of OPCAB in terms of death, MI, and cerebral stroke are significantly related to patient risk profile, suggesting that OPCAB should be strongly considered in high-risk patients.

Differential impact on acute kidney injury incidence between on- and off pump coronary artery bypass grafting in octogenarians

INTRODUCTION

Acute kidney injury (AKI) following surgical myocardial revascularization is associated with high mortality and morbidity. The aim of this study was to evaluate the risk of acute kidney injury in a population of very old patients following different surgical techniques.

PATIENTS AND METHODS

A retrospective study of 310 consecutive patients aged 78 to 93 years, mean 80.5±2.2, who underwent surgery at one cardiac surgery centre. Based on the surgical technique used the patients were divided into: Group I. CABG (n=134) - surgical myocardial revascularization using extracorporeal circulation and arterial and venous grafts. Group II. OPCABG (n=55) - surgical revascularization without extracorporeal circulation but using arterial and venous grafts. Group III. NOTOUCH (n=121) - no handling with the ascending aorta was performed at all.

RESULTS

A statistically insignificant renoprotective trend was found in patients who underwent surgery without extracorporeal circulation regardless of technique. Comparing groups II and III vs. group I, a significantly poorer renal functioning (median difference in creatinine was 10.0 (32.9) vs 17.5 (35.0), P=0.05) was shown for patients in group I.

CONCLUSION

Surgical myocardial revascularization without extracorporeal circulation in very old patients is safe. The results of this study show a renoprotective trend.

Cancer in heart disease patients: what are the limitations in the treatment strategy?

Cardiovascular disease and cancer are leading causes of morbidity and mortality, and can both be present in one patient. In patients with simultaneous disease, the most threatening disease should be treated first. This is usually heart disease, but this can pose specific problems. If percutaneous coronary intervention is preferred, bleeding and thrombotic tendencies have to be taken into account in the subsequent treatment of the malignancy. With coronary artery bypass grafting, the advantages and disadvantages of one- or two-stage procedures, and the use of extracorporeal circulation have to be balanced. Development of heart disease after treatment of malignancy could be due to radiotherapy and chemotherapy. The effects of these cancer treatments have to be taken into account for the treatment options of the heart disease and the postoperative prognosis.

Risk of stroke with percutaneous coronary intervention compared with on-pump and off-pump coronary artery bypass graft surgery: Evidence from a comprehensive network meta-analysis

BACKGROUND

Although some trials have reported that on-pump coronary artery bypass graft (CABG) surgery may be associated with higher rates of stroke than percutaneous coronary intervention (PCI), whether stroke is more common after off-pump CABG compared with PCI is unknown. We therefore sought to determine whether off-pump CABG is associated with an increased risk of stroke compared with PCI by means of network meta-analysis.

METHODS

Randomized controlled trials (RCTs) comparing CABG vs PCI were searched through MEDLINE, EMBASE, Cochrane databases, and proceedings of international meetings.

RESULTS

Eighty-three RCTs with 22,729 patients randomized to on-pump CABG (n = 10,957), off-pump CABG (n = 7,119), or PCI (n = 4,653) were analyzed. Thirty-day rates of stroke were significantly lower in patients treated with PCI compared with either off-pump CABG (odds ratio [OR]; 0.39, 95% CI, 0.19-0.83) or on-pump CABG (OR, 0.26; 95% CI, 0.12-0.47). Compared with on-pump CABG, off-pump CABG was associated with significantly lower 30-day risk of stroke (OR, 0.67; 95% CI, 0.41-0.95). However, in sensitivity analyses restricted to high-quality studies, studies with more than either 100 or 1,000 patients, or studies with protocol definition or adjudication of stroke by a clinical events committee, the precision of the point estimate for the 30-day risk of stroke between off-pump vs on-pump CABG was markedly reduced.

CONCLUSIONS

Percutaneous coronary intervention is associated with lower 30-day rates of stroke than both off-pump and on-pump CABG. Further studies are required to determine whether the risk of stroke is reduced with off-pump CABG compared with on-pump CABG.

CD62L (L-selectin) shedding for assessment of perioperative immune sensitivity in patients undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVE

To investigate the suitability of blood granulocyte and monocyte sensitivity, as measured by the quantity of different agonists required to induce CD62L shedding, for assessment of perioperative immune changes in patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

Patients scheduled for aortocoronary bypass grafting or for valve surgery were included in this prospective observational study. Blood samples were drawn before anesthesia induction, directly after surgery and 48 hours after anesthesia induction. We determined the concentration of two different inflammatory stimuli--lipoteichoic acid (LTA) and tumor necrosis factor alpha (TNF)--required to induce shedding of 50% of surface CD62L from blood granulocytes and monocytes. In parallel monocyte surface human leukocyte antigen (HLA)-DR, and plasma interleukin (IL)-8, soluble (s)CD62L, soluble (s)Toll-like receptor (TLR)-2 and ADAM17 quantification were used to illustrate perioperative immunomodulation.

RESULTS

25 patients were enrolled. Blood granulocytes and monocytes showed decreased sensitivity to the TLR 2/6 agonist Staphylococcus aureus LTA immediately after surgery (p = 0.001 and p = 0.004 respectively). In contrast, granulocytes (p = 0.01), but not monocytes (p = 0.057) displayed a decreased postoperative sensitivity to TNF. We confirmed the presence of a systemic inflammatory response and a decreased immune sensitivity in the post-surgical period by measuring significant increases in the perioperative plasma concentration of IL-8 (p ≤ 0.001) and sTLR (p = 0.004), and decreases in monocyte HLA-DR (p<0.001), plasma sCD62L (p ≤ 0.001). In contrast, ADAM17 plasma levels did not show significant differences over the observation period (p = 0.401).

CONCLUSIONS

Monitoring granulocyte and monocyte sensitivity using the "CD62L shedding assay" in the perioperative period in cardiac surgical patients treated with the use of cardiopulmonary bypass reveals common changes in sensitivity to TLR2/6 ligands and to TNF stimulus. Further long-term follow-up studies will address the predictive value of these observations for clinical purposes.

Surgical management of coronary artery disease associated with malignancy

Surgical management of patients with combined coronary artery disease and malignancy remains a challenge. In this review the time of surgical intervention, whether to treat the malignancy or the coronary artery disease first, and which bypass technique should be used during myocardial revascularization are reviewed to determine the most optimal strategy to manage patients who require coronary surgical revascularization and present with an underlying malignancy.

Off-pump versus on-pump coronary artery bypass grafting for ischaemic heart disease

BACKGROUND

Coronary artery bypass grafting (CABG) is performed both without and with cardiopulmonary bypass, referred to as off-pump and on-pump CABG respectively. However, the preferable technique is unclear.

OBJECTIVES

To assess the benefits and harms of off-pump versus on-pump CABG in patients with ischaemic heart disease.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 1, 2011), MEDLINE (OVID, 1950 to February 2011), EMBASE (OVID, 1980 to February 2011), Science Citation Index Expanded on ISI Web of Science (1970 to February 2011) and CINAHL (EBSCOhost, 1981 to February 2011) on 2 February 2011. No language restrictions were applied.

SELECTION CRITERIA

Randomised clinical trials of off-pump versus on-pump CABG irrespective of language, publication status and blinding were selected for inclusion.

DATA COLLECTION AND ANALYSIS

For statistical analysis of dichotomous data risk ratio (RR) and for continuous data mean difference (MD) with 95% confidence intervals (CI) were used. Trial sequential analysis (TSA) was used for analysis to assess the risk of random error due to sparse data and to multiple updating of accumulating data.

MAIN RESULTS

Eighty-six trials (10,716 participants) were included. Ten trials (4,950 participants) were considered to be low risk of bias. Pooled analysis of all trials showed that off-pump CABG increased all-cause mortality compared with on-pump CABG (189/5,180 (3.7%) versus 160/5144 (3.1%); RR 1.24, 95% CI 1.01 to 1.53; P =.04). In the trials at low risk of bias the effect was more pronounced (154/2,485 (6.2%) versus 113/2,465 (4.6%), RR 1.35,95% CI 1.07 to 1.70; P =.01). TSA showed that the risk of random error on the result was unlikely. Off-pump CABG resulted in fewer distal anastomoses (MD -0.28; 95% CI -0.40 to -0.16, P <.00001). No significant differences in myocardial infarction, stroke, renal insufficiency, or coronary re-intervention were observed. Off-pump CABG reduced post-operative atrial fibrillation compared with on-pump CABG, however, in trials at low risk of bias, the estimated effect was not significantly different.

AUTHORS' CONCLUSIONS

Our systematic review did not demonstrate any significant benefit of off-pump compared with on-pump CABG regarding mortality, stroke, or myocardial infarction. In contrast, we observed better long-term survival in the group of patients undergoing on-pump CABG with the use of cardiopulmonary bypass and cardioplegic arrest. Based on the current evidence, on-pump CABG should continue to be the standard surgical treatment. However, off-pump CABG may be acceptable when there are contraindications for cannulation of the aorta and cardiopulmonary bypass. Further randomised clinical trials should address the optimal treatment in such patients.

The cellular and molecular origin of reactive oxygen species generation during myocardial ischemia and reperfusion

Myocardial ischemia-reperfusion injury is an important cause of impaired heart function in the early postoperative period subsequent to cardiac surgery. Reactive oxygen species (ROS) generation increases during both ischemia and reperfusion and it plays a central role in the pathophysiology of intraoperative myocardial injury. Unfortunately, the cellular source of these ROS during ischemia and reperfusion is often poorly defined. Similarly, individual ROS members tend to be grouped together as free radicals with a uniform reactivity towards biomolecules and with deleterious effects collectively ascribed under the vague umbrella of oxidative stress. This review aims to clarify the identity, origin, and progression of ROS during myocardial ischemia and reperfusion. Additionally, this review aims to describe the biochemical reactions and cellular processes that are initiated by specific ROS that work in concert to ultimately yield the clinical manifestations of myocardial ischemia-reperfusion. Lastly, this review provides an overview of several key cardioprotective strategies that target myocardial ischemia-reperfusion injury from the perspective of ROS generation. This overview is illustrated with example clinical studies that have attempted to translate these strategies to reduce the severity of ischemia-reperfusion injury during coronary artery bypass grafting surgery.

Off-pump coronary artery bypass surgery and acute kidney injury: a meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVES

Off-pump coronary artery bypass grafting (CABG) has been advocated to cause less inflammation, morbidity, and mortality than the more traditional on-pump technique. This meta-analysis compares these two surgical techniques with respect to causing acute kidney injury (AKI).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study searched for randomized controlled trials in MEDLINE and abstracts from the proceedings of scientific meetings through February 2010. Included were trials comparing off-pump to on-pump CABG that reported the incidence of AKI, as defined by a mixture of criteria including biochemical parameter/urine output/dialysis requirement. Mortality was evaluated among the studies that reported kidney-related outcomes. For primary and subgroup analyses, fixed-effect meta-analyses of odds ratios (OR) were performed.

RESULTS

In 22 identified trials (4819 patients), the weighted incidence of AKI in the on-pump CABG group was 4.0% (95% confidence interval [CI] 1.8%, 8.5%), dialysis requirement 2.4% (95% CI 1.6%, 3.7%), and mortality 2.6% (95% CI 1.6%, 4.0%). By meta-analysis, off-pump CABG was associated with a 40% lower odds of postoperative AKI (OR 0.60; 95% CI 0.43, 0.84; P = 0.003) and a nonsignificant 33% lower odds for dialysis requirement (OR 0.67; 95% CI 0.40, 1.12; P = 0.12). Within the selected trials, off-pump CABG was not associated with a significant decrease in mortality.

CONCLUSIONS

Off-pump CABG may be associated with a lower incidence of postoperative AKI but may not affect dialysis requirement, a serious complication of cardiac surgery. However, the different definitions of AKI used in individual trials and methodological concerns preclude definitive conclusions.

Markers of cardiovascular risk are not changed by increased whole-grain intake: the WHOLEheart study, a randomised, controlled dietary intervention

Recommendations for whole-grain (WG) intake are based on observational studies showing that higher WG consumption is associated with reduced CVD risk. No large-scale, randomised, controlled dietary intervention studies have investigated the effects on CVD risk markers of substituting WG in place of refined grains in the diets of non-WG consumers. A total of 316 participants (aged 18-65 years; BMI>25 kg/m2) consuming < 30 g WG/d were randomly assigned to three groups: control (no dietary change), intervention 1 (60 g WG/d for 16 weeks) and intervention 2 (60 g WG/d for 8 weeks followed by 120 g WG/d for 8 weeks). Markers of CVD risk, measured at 0 (baseline), 8 and 16 weeks, were: BMI, percentage body fat, waist circumference; fasting plasma lipid profile, glucose and insulin; and indicators of inflammatory, coagulation, and endothelial function. Differences between study groups were compared using a random intercepts model with time and WG intake as factors. Although reported WG intake was significantly increased among intervention groups, and demonstrated good participant compliance, there were no significant differences in any markers of CVD risk between groups. A period of 4 months may be insufficient to change the lifelong disease trajectory associated with CVD. The lack of impact of increasing WG consumption on CVD risk markers implies that public health messages may need to be clarified to consider the source of WG and/or other diet and lifestyle factors linked to the benefits of whole-grain consumption seen in observational studies.

Off-Pump versus On-Pump Coronary Artery Bypass Procedures: Postoperative Renal Complications in an Asian Population

Introduction: Diabetes and habitual smoking cause advanced coronary artery disease (CAD) in Asian patients at a younger age. No definite data exist as to whether off-pump (OPCAB) is better than conventional on-pump coronary artery bypass grafting (CCAB) in terms of postoperative renal complications. Thus, we aimed to compare the renal outcomes of on-pump and off-pump coronary artery bypass grafting (CABG) on our patients, which constituted a predominantly Asian population. Materials and Methods: A cohort of 395 patients following CCAB were compared with 293 patients who underwent OPCAB. Baseline demographics, comorbidities, intraoperative data, intensive care unit stay, number of grafts, New York Heart Association (NYHA) score, American Society of Anesthesiologists (ASA) score, EuroSCORE risk assessment model, and postoperative complications particularly renal, were collected and analysed. Results: The off-pump group consisted of significantly older patients with higher Canadian Cardiovascular Society (CCS) and ASA scores. Additionally, the off-pump group involved a significantly greater number of smokers and chronic obstructive pulmonary disease (COPD) patients. Other demographic parameters were not different between the groups. Postoperative investigations showed a significantly elevated serum creatinine (100.3 ± 42.5 vs 127.6 ± 114.2 μmol/L; off-pump vs on-pump; P = 0.039) and urea levels (5.9 ± 3.1 vs 10.6 ± 15.6 mg/dL; off-pump vs on-pump; P = 0.006) in the on-pump group. Moreover, there was a high tendency towards a higher rate of renal dysfunction associated death in this group. Conclusions: OPCAB is a safe and equally efficient operative method compared to CCAB, and has a significant lower risk for postoperative renal complications as a treatment modality for surgical coronary revascularisation. Key words: Cardiopulmonary bypass, Renal dysfunction

The long pentraxin 3 in cardiac surgery: Distinct responses in “on-pump” and “off-pump” patients

OBJECTIVE

Pentraxin 3 (PTX3) is a newly identified acute phase reactant with non-redundant functions in innate immunity. The purpose of this study was to assess the kinetics of release of PTX3 in cardiac surgical patients, operated on either with or without the use of cardiopulmonary bypass (CPB).

DESIGN

Thirty-four patients, seventeen in each group, were randomly assigned to CABG surgery performed either with ("on-pump") or without ("off-pump") CPB. Blood samples were collected both during and after the operation up to the 7(th) day.

RESULTS

In patients operated on with the use of CPB, PTX3 levels increased throughout the operation. Compared to baseline levels the highest PTX3 value (p<0.000) was attained on the 1(st) postoperative day in both "on-pump" and "off-pump" patients. In contrast to CPB patients, however, PTX3 levels in the latter group declined slowly, remaining elevated as long as the 3(rd) postoperative day (p<0.042).

CONCLUSIONS

Operations performed with the use of CPB are associated with a more pronounced release of PTX3 immediately after operation.

Peripheral blood monocyte activation during coronary artery bypass grafting with or without cardiopulmonary bypass

OBJECTIVE

The aim of this prospective, randomized study was to investigate the impact of coronary artery bypass grafting (CABG) on peripheral monocytes and to evaluate the additional effect of cardiopulmonary bypass (CPB).

DESIGN

Twenty patients admitted for elective CABG were randomized to either on-pump (ONCAB, n = 9) or off-pump (OFFCAB, n = 11) surgery and blood samples were drawn before, during and 24 h after the operation. The total number of monocytes and the proportion of the more mature CD16+/CD14+ monocytes were measured. Expression of activation markers (CD11b, CD35 and CD62L) and oxidative burst were determined using flow cytometry on both resting and in vitro stimulated cells. Serum concentrations of soluble CD14 and monocytes/macrophage chemotactic protein 1 (MCP-1) were analysed.

RESULTS

During surgery there was a selective decrease in the proportion of CD16+/CD14+ monocytes compared to total monocytes. These had returned to preoperative values 24 h after surgery while the total number of monocytes had increased more than 100%. Intracellular production of oxygen free radical H2O2 was increased in the ONCAB group during surgery compared to OFFCAB. Monocyte expression and in vitro mobilization of complement receptors, CD11b and CD35, were similar in both study groups during and after surgery as was the expression of CD62L. Serum levels of MCP-1 decreased during surgery as did soluble CD14, both with increased levels again the day after surgery.

CONCLUSION

It is concluded that the circulating monocyte population is activated during and as a consequence of CABG. There were few apparent additional effects of CPB found in this study. In this setting the inflammation caused by the surgery procedure per se probably surpasses the impact of the CPB on circulating blood monocytes.

Inflammatory response and platelet activation after off-pump coronary artery bypass surgery

BACKGROUND

Cardiac surgery induces a systemic inflammatory activation and alterations in the hemostatic cascade. The responses contribute to postoperative complications but may also have protective effects. We investigated the relationship between inflammation, hemostasis and bleeding after off-pump coronary artery bypass surgery (OPCAB).

METHODS

Ten OPCAB patients were included in a prospective descriptive study. Selected markers of inflammation (IL-6, IL-8, PMN-elastase, C3a, and SC5b-9), and hemostasis (platelet count, ss-thromboglobulin, anti-thrombin, D-dimer and fibrinogen) were measured before and immediately after surgery. Postoperative bleeding was registered.

RESULTS

Inflammatory variables did not alter significantly during surgery while ss-thromboglobulin concentrations increased and anti-thrombin and fibrinogen decreased. There were significant postoperative correlations between PMN-elastase and ss-thromboglobulin (r=0.82, p=0.004), between PMN-elastase and fibrinogen (r=0.69, p=0.03) and between C3a and ss-thromboglobulin (r=0.71, p=0.02). In addition, there were significant inverse correlations between postoperative bleeding and pre- and postoperative fibrinogen levels (r=-0.76, p=0.011 and r=-0.84, p=0.002 respectively), between bleeding and postoperative ss-thromboglobulin levels (r=-0.66, p=0.04) and between bleeding and postoperative PMN-elastase (r=-0.75, p=0.01).

CONCLUSIONS

The results give further evidence for an association between the inflammatory response and hemostasis after cardiac surgery.

Clinical outcomes in randomized trials of off- vs. on-pump coronary artery bypass surgery: systematic review with meta-analyses and trial sequential analyses

AIMS

To assess the clinical outcomes of off- vs. on-pump coronary artery bypass surgery in randomized trials.

METHODS AND RESULTS

We searched electronic databases and bibliographies until June 2007. Trials were assessed for risk of bias. Outcome measures were all-cause mortality, myocardial infarction, stroke, atrial fibrillation, and renewed coronary revascularization at maximum follow-up. We applied trial sequential analysis to estimate the strength of evidence. We found 66 randomized trials. There was no statistically significant differences regarding mortality [relative risk (RR) 0.98; 95% confidence interval (CI) 0.66-1.44], myocardial infarction (RR 0.95; 95% CI 0.65-1.37), or renewed coronary revascularization (RR 1.34; 95% CI 0.83-2.18). We found a significant reduced risk of atrial fibrillation (RR 0.69; 95% CI 0.57-0.83) and stroke (RR 0.53; 95% CI 0.31-0.91) in off-pump patients. However, when continuity correction for zero-event trials was included, the reduction in stroke became insignificant (RR 0.62; 95% CI 0.32-1.19). Trial sequential analysis demonstrated overwhelming evidence supporting that off-pump bypass surgery reduces atrial fibrillation.

CONCLUSION

Off-pump surgery reduces the risks of postoperative atrial fibrillation compared with on-pump surgery. For death, myocardial infarction, stroke, and renewed coronary revascularization, the evidence is still weak and more low-bias risk trials are needed.

Current Status of Off-Pump Coronary Artery Bypass Surgery

The expanding indications for angioplasty coupled with the successful short and mid-term results of randomized controlled trials of drug-eluting stents have already had an unquestionable impact on the practice of coronary revascularization operations. However, coronary artery bypass grafting remains a major mode of therapy for coronary artery disease. It is likely that surgery will continue to be preferred for more complex subsets and that surgeons will have to continue to maintain good results in patients with more complex problems. Concerns regarding morbidity associated with conventional surgical myocardial revascularization on cardiopulmonary bypass have led to a resurgence of interest in off-pump bypass surgery during the last decade, with the expectation that it would be safer if cardiopulmonary bypass could be avoided. This review summarizes the impact of off-pump bypass surgery in reducing the morbidity and mortality associated with conventional coronary artery bypass on cardiopulmonary bypass by evaluating the current best-available evidence from randomized controlled trials and meta-analyses comparing off-pump surgery with conventional bypass grafting.

Complement activity and pharmacological inhibition in cardiovascular disease

While complement is the most important component of humoral autoimmunity, and inflammation plays a key role in atherosclerosis, relatively few studies have looked at complement implications in atherosclerosis and its complications. C-reactive protein is a marker of inflammation and is also involved in atherosclerosis; it activates complement and colocalizes with activated complement proteins within the infarcting myocardium and the active atherosclerotic plaques. As new agents capable of modulating complement activity are being developed, new targets for the management of atherosclerosis are emerging that are related to autoimmunity and inflammation. The present paper reviews the putative roles of the various complement activation pathways in the development of atherosclerosis, in ST segment elevation and non-ST segment elevation acute coronary syndromes, and in coronary artery bypass graft surgery. It also provides a perspective on new therapeutic interventions being developed to modulate complement activity. These interventions include the C1 esterase inhibitor, which may be consumed in some inflammatory states resulting in the loss of one of the mechanisms inhibiting activation of the classical and lectin pathways; TP10, a recombinant protein of the soluble complement receptor type 1 (sCR1) which inhibits the C3 and C5 convertases of the common pathway by binding C3b and C4b; a truncated version of the soluble complement receptor type 1 CRI lacking the C4b binding site which selectively inhibits the alternative pathway; and pexelizumab, a monoclonal antibody selectively blocking C5 to prevent the activation of the terminal pathway that is involved in excessive inflammation and autoimmune responses.

Impact of off-pump coronary artery bypass surgery on systemic inflammation: current best available evidence

The systemic inflammatory response after coronary artery bypass grafting using cardiopulmonary bypass (CPB) contributes substantially to postoperative organ dysfunction and coagulation disorders. Important features of this inflammatory reaction include the activation of complement and leukocytes, the release of proinflammatory cytokines, alterations in the metabolism of nitric oxide, and an increase in the production of oxygen-free radicals, which in some cases may lead to oxidant stress injury. Several strategies including the use of steroids, use of aprotinin, heparin-coated CPB circuits, and hemofiltration have been reported to reduce the inflammatory reaction induced by CPB and its consequences. A more radical and effective way of counteracting the effects of the inflammatory reaction and oxidative stress may be the omission of CPB itself. The development and application of off-pump coronary artery bypass (OPCAB) technology has largely been driven by this theme of avoiding systemic inflammatory reaction to decrease the incidence and/or severity of adverse outcomes. This review article discusses the influence of cardiopulmonary bypass on systemic inflammation and attempts to evaluate the current best available evidence on the impact of OPCAB on systemic inflammation.

Secretory phospholipase A2 activity and release kinetics of vascular tissue remodelling biomarkers after coronary artery bypass grafting with and without cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) has long been recognised as a main cause of a postoperative complex systemic inflammatory response after coronary artery bypass grafting (CABG).

METHODS

We determined the kinetics of peripheral blood release of the novel inflammatory biomarkers secretory phospholipase A(2) (sPLA(2)), matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) during the first 6 days following surgery in 16 patients undergoing CABG with (on-pump, n=9) or without (off-pump, n=7) CPB. Kinetic curves for these markers were compared to those of the well-known inflammatory parameters C-reactive protein (CRP) and fibrinogen.

RESULTS

sPLA(2) activity exhibited a maximum value on day 2, then decreased until day 6 for both groups and in a similar manner as CRP levels. On the other hand, elevation of plasma levels of both MMP-9 and TIMP-1 occurred as early as on day 1 and remained at this level until day 6. No significant difference in kinetic characteristics (peak value, area under the curve, initial slope) between CABG with and without CPB was observed.

CONCLUSIONS

These data show that the off- and on-pump groups did not show significantly different kinetics for the releases of all biomarkers studied, including sPLA(2) and biomarkers of the MMP-TIMP network. The off-pump procedure may therefore lead to global surgical trauma as important as CPB in terms of the systemic inflammatory process and matrix proteolysis pathway activation.