Human cytokine responses to coronary artery bypass grafting with and without cardiopulmonary bypass

Sex-differences in outcome after off-pump coronary artery bypass grafting is age-dependent; data from the Netherlands Heart Registration

Background

Women are known to have worse outcome after coronary artery bypass grafting (CABG) than men. Studies have shown that off-pump coronary artery bypass grafting (OPCAB) might benefit higher-risk patients, and therefore might also benefit women. We aimed to determine differences in early and late outcomes between sexes after OPCAB.

Methods

Data from all patients undergoing OPCAB, between 2013 through 2021 was retrieved from the Netherlands Heart Registration (NHR) database. Primary outcomes were early mortality, morbidity and late survival. We divided the population into subgroups based on age (aged ≥70 years or < 70 years) and sex.

Results

This study included 8,487 men and 2,170 women (total = 10,657). Female patients received fewer anastomoses (mean (SD)) women 2.38 (1.17) vs men 2.68 (1.23), p < 0.001) and total arterial revascularization was performed less frequently in women than in men (21.3 % versus 29.5 % respectively, p < 0.001).In the subgroup of patients <70 years, early mortality was 1.7 % in women and 0.6 % in men (p < 0.001). Survival rate at 5 years was 88.4 % in women and 91.1 % in men (p < 0.001). Female sex was associated with worse late survival in the subgroup <70 years (HR (95 % CI) 1.42 (1.10-1.83) p = 0.008).

Conclusions

Sex-differences in outcome after CABG persists in OPCAB surgery. However, these differences are solely present in the younger subgroup. In our data, women undergoing OPCAB surgery seem to be treated differently during surgery as compared to their male counter parts, further research is needed to analyze this finding.

The effect of off-pump coronary bypass graft surgery on subfoveal choroidal thickness, ganglion cell complex, and retinal nerve fiber layer thickness

Background

Cardiac surgery has been associated with adverse ocular events. Off-pump coronary artery bypass graft surgery evades the systemic inflammatory response seen in extracorporeal circulation and is superior to on-pump surgery with regard to end-organ dysfunction and neurological outcomes.

Objectives

To determine the effects of off-pump (without extracorporeal circulation) coronary artery bypass graft surgery on choroidal thickness, ganglion cell complex, and the retinal nerve fiber layer.

Design

Prospective, longitudinal study.

Methods

Patients who underwent off-pump surgery were examined preoperatively and postoperatively at 1 week and 6 weeks after surgery. Choroidal thickness, ganglion cell complex, and the retinal nerve fiber layer measurements were recorded, and the effects of off-pump coronary artery bypass on these parameters were assessed.

Results

A total of 44 eyes of 44 patients were included in the study. There was a statistically significant increase in subfoveal choroidal thickness from 252.84 ± 56.24 µm preoperatively to 273.82 ± 39.76 µm at 1 week and 301.97 ± 44.83 µm at 6 weeks after off-pump coronary artery bypass graft surgery (p = 0.044; p ⩽ 0.001). Ganglion cell complex and retinal nerve fiber measurements showed no significant difference compared to preoperative values.

Conclusion

Off-pump coronary artery bypass graft surgery showed no negative effects on ganglion cell complex and retinal nerve fiber measurements. A significant increase in subfoveal choroidal thickness was seen after off-pump surgery, which might be advantageous in patients who are at high risk or have preexisting ocular diseases that are affected by the choroid.

Review of Postoperative Care for Heart Transplant Recipients

The early postoperative management strategies after heart transplantation include optimizing the function of the denervated heart, correcting the causes of hemodynamic instability, and initiating and maintaining immunosuppressive therapy, allograft rejection surveillance, and prophylaxis against infections caused by immunosuppression. The course of postoperative support is influenced by the quality of allograft myocardial protection prior to implantation and reperfusion, donor-recipient heart size matching, surgical technique of orthotopic heart transplantation, and patient factors (eg, preoperative condition, immunologic compatibility, postoperative vasomotor tone, severity and reversibility of pulmonary vascular hypertension, pulmonary function, mediastinal blood loss, and end-organ perfusion). This review provides an overview of the early postoperative care of recipients and includes a brief description of the surgical techniques for orthotopic heart transplantation.

Impact of Chronic Lymphocytic Leukemia on Outcomes and Readmissions following Cardiac Operations

BACKGROUND

Outcomes of cardiac operations in patients with chronic lymphocytic leukemia (CLL) have been examined in limited series. The present study aimed to assess the impact of CLL on clinical outcomes and resource utilization following cardiac operations in a nationally representative cohort.

METHODS

All adult patients undergoing elective coronary artery bypass grafting, valve repair or valve replacement were identified utilizing the 2010-2017 Nationwide Readmissions Database. Patients were stratified by history of CLL. Incidence of in-hospital mortality, perioperative complications, blood transfusions and readmission within 90 days were examined. We subsequently performed 3:1 nearest neighbor matching between CLL and non-CLL patients for all primary and secondary outcomes of interest.

RESULTS

Of an estimated 1,250,882 patients undergoing cardiac operations, 0.23% had a diagnosis of CLL. Among 11,237 propensity matched patients, those with CLL had similar rates of in-hospital mortality (3.8 vs 2.6%, P=0.08) and perioperative complications (33.4 vs 33.6%, P=0.92) compared to their non-CLL counterparts. Although the incidence of infection was comparable (8.5 vs 9.4%, P=0.38), CLL patients did require blood transfusions more frequently (33.7 vs 28.4%, P=0.003) than others. Furthermore, CLL patients were more likely to be readmitted with respiratory etiologies contributing significantly to re-hospitalization.

CONCLUSIONS

Patients with CLL generally have similar outcomes following cardiac operations but may more commonly require blood transfusion. Blood conserving interventions may be considered in this at-risk population to improve outcomes. Furthermore, interventions to mitigate readmission deserve further exploration.

Pleiotropic Effects of Acetylsalicylic Acid after Coronary Artery Bypass Grafting-Beyond Platelet Inhibition

Acetylsalicylic acid (ASA) is one of the most frequently used medications worldwide. Yet, the main indications for ASA are the atherosclerosis-based cardiovascular diseases, including coronary artery disease (CAD). Despite the increasing number of percutaneous procedures to treat CAD, coronary artery bypass grafting (CABG) remains the treatment of choice in patients with multivessel CAD and intermediate or high anatomical lesion complexity. Taking into account that CABG is a potent activator of inflammation, ASA is an important part in the postoperative therapy, not only due to ASA antiplatelet action, but also as an anti-inflammatory agent. Additional benefits of ASA after CABG include anticancerogenic, hypotensive, antiproliferative, anti-osteoporotic, and neuroprotective effects, which are especially important in patients after CABG, prone to hypertension, graft occlusion, atherosclerosis progression, and cognitive impairment. Here, we discuss the pleiotropic effects of ASA after CABG and provide insights into the mechanisms underlying the benefits of treatment with ASA, beyond platelet inhibition. Since some of ASA pleiotropic effects seem to increase the risk of bleeding, it could be considered a starting point to investigate whether the increase of the intensity of the treatment with ASA after CABG is beneficial for the CABG group of patients.

Ubiquinol supplementation in elderly patients undergoing aortic valve replacement: biochemical and clinical aspects

Epidemiological data show a rise in the mean age of patients affected by heart disease undergoing cardiac surgery. Senescent myocardium reduces the tolerance to ischemic stress and there are indications about age-associated deficit in post-operative cardiac performance. Coenzyme Q10 (CoQ10), and more specifically its reduced form ubiquinol (QH), improve several conditions related to bioenergetic deficit or increased exposure to oxidative stress. This trial (Eudra-CT 2009-015826-13) evaluated the clinical and biochemical effects of ubiquinol in 50 elderly patients affected by severe aortic stenosis undergoing aortic valve replacement and randomized to either placebo or 400 mg/day ubiquinol from 7 days before to 5 days after surgery. Plasma and cardiac tissue CoQ10 levels and oxidative status, circulating troponin I, CK-MB (primary endpoints), IL-6 and S100B were assessed. Moreover, main cardiac adverse effects, NYHA class, contractility and myocardial hypertrophy (secondary endpoints) were evaluated during a 6-month follow-up visit. Ubiquinol treatment counteracted the post-operative plasma CoQ10 decline (p<0.0001) and oxidation (p=0.038) and curbed the post-operative increase in troponin I (QH, 1.90 [1.47-2.48] ng/dL; placebo, 4.03 [2.45-6.63] ng/dL; p=0.007) related to cardiac surgery. Moreover, ubiquinol prevented the adverse outcomes that might have been associated with defective left ventricular ejection fraction recovery in elderly patients.

Differences of early immunological responses in on-pump versus off-pump cardiac surgery

INTRODUCTION

Cardiopulmonary bypass surgery is accompanied by an inflammatory response and pulmonary dysfunction that renders patients vulnerable to postoperative complications. The majority of studies investigating the inflammatory response in cardiopulmonary bypass focus on cytokine measurements. This study investigated the early response of peripheral blood cell types and early changes in lung tissue in on-pump versus off-pump cardiopulmonary bypass surgery.

METHODS

Landrace pigs were assigned to the following groups (n = 6 per group): 1. off-pump cardiopulmonary bypass, 2. conventional cardiopulmonary bypass, 3. heparin-coated cardiopulmonary bypass, 4. surface-reduced cardiopulmonary bypass, and 5. surface-reduced cardiopulmonary bypass plus lung perfusion. Surgery was performed under mild hyperthermia (32°C), with 90-minute ischemia and 180-minute reperfusion. Histological and flow cytometric analyses were performed.

RESULTS

Lung water content increased during reperfusion in heparin-coated (84.63 ± 2.99%) compared to conventional cardiopulmonary bypass (76.33 ± 4.56%, p = 0.04). Alveolar septal thickness increased during ischemia at heparin-coated (p < 0.01) and surface-reduced cardiopulmonary bypass plus lung perfusion (p = 0.05). Tumor necrosis factor expression increased significantly (p < 0.01) in peribronchial, perivascular, and peripheral lung areas in all on-pump groups, but not in off-pump cardiopulmonary bypass. The usage of heparin-coated cardiopulmonary bypass led to increased percentages of CD3⁺CD4⁺ (p = 0.03) and CD3⁺CD8⁺ (p = 0.01) T cells compared to an uncoated device. Natural killer and mature B lymphocytes decreased at conventional and surface-reduced cardiopulmonary bypass plus lung perfusion. Activated granulocytes and macrophages increased at conventional cardiopulmonary bypass and heparin-coated cardiopulmonary bypass.

CONCLUSION

Off-pump cardiopulmonary bypass induces less immunological response and lung injury than on-pump surgery. The reduction of cardiopulmonary bypass surface reduces the inflammatory immune response induced by cardiopulmonary bypass. Lung perfusion of surface-reduced cardiopulmonary bypass diminished the extravasation caused by surface reduction of the cardiopulmonary bypass.

A Comparison of Inflammatory Responses Between Robotically Enhanced Coronary Artery Bypass Grafting and Conventional Coronary Artery Bypass Grafting: Implications for Hybrid Revascularization

OBJECTIVE

The inflammatory response elicited by robotically enhanced coronary artery bypass grafting (r-CABG) has not been well described. When r-CABG is performed as part of hybrid coronary revascularization, the inflammatory milieu and the timing of percutaneous coronary intervention may affect the stent patency negatively in the short and long term. The goal of this study was to describe the extent and time course of cytokine release after r-CABG compared with conventional CABG (c-CABG) and to elucidate the optimal timing for r-CABG in the setting of hybrid coronary revascularization for a future study.

DESIGN

Prospective, observational study.

SETTING

Tertiary-care center in a university hospital.

PARTICIPANTS

The study comprised patients scheduled to undergo r-CABG or c-CABG from October 2012 to November 2014.

INTERVENTIONS

Cytokine levels of interleukin (IL)-6, IL-8, IL-10; tumor necrosis factor-α; and C-reactive protein (CRP) were measured at the following time points: preprocedure; at the end of the procedure; and at 4, 8, 12, 24, and 48 hours after the procedure.

MEASUREMENTS AND MAIN RESULTS

Twenty-eight patients undergoing r-CABG and 10 patients undergoing c-CABG were enrolled. The levels of cytokines after r-CABG and c-CABG were compared using the mixed-effect linear regression model for longitudinal data. Cytokine release in the r-CABG group was comparatively less for IL-6, IL-10, tumor necrosis factor, and CRP levels. They all trended toward the baseline by the 48th hour in both groups, except CRP levels, which reached their peak at 48 hours in both groups.

CONCLUSIONS

The inflammatory response to r-CABG was blunted compared with that of c-CABG. The high CRP levels on the second postoperative day after r-CABG were a cause for concern in regard to percutaneous coronary intervention performed at that time period, but additional studies are necessary.

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.

Demonstration and Operative Influence of Low Prime Volume Closed Pump

Various improvements have been made in cardiopulmonary bypass (CPB) in the past few decades. We designed a new type of CPB to reduce the secretion of systemic inflammatory markers. We used a low prime volume pump (LPVP), completely closed CPB circuit and examined coagulant factors and inflammatory cytokines. In this study, we demonstrate the efficacy of LPVP using molecular biological data. Fourteen patients were randomized prospectively into two groups: Group L patients underwent LPVP ( n = 8) and Group N patients underwent normal prime volume CPB ( n = 6). We measured thrombin-antithrombin III complex (TAT), complement factor (C3a), and interleukin (IL)-10 levels at four time points. TAT (66.1 ± 15.1 ng·mL−1), C3a (1895 ± 282 ng·mL−1) and IL-10 (486 ± 114 pg·mL−1) levels in Group N were significantly higher than in Group L (TAT, 19.5 ± 4.4 ng·mL−1; IL-10, 105 ± 24.6 pg·mL−1; C3a, 1349 ± 369 ng·mL−1) immediately following CPB. LPVP demonstrated a lower systemic inflammatory response compared to normal prime volume CPB, as assessed using a molecular biological approach.

On pump coronary artery bypass graft surgery versus off pump coronary artery bypass graft surgery: a review

There are two basic ways of performing coronary artery bypass graft surgery (CABG): on pump CABG and off pump CABG. Off pump CABG is relatively a newer procedure to on-pump CABG and does not require the use of the cardiopulmonary bypass machine. On pump CABG is the more traditional method of performing bypass surgery. However its resultant inflammatory effects cause renal dysfunction, gastrointestinal distress and cardiac abnormalities which have forced the surgeons to look for alternatives to the procedure. An extensive literature search revealed that on pump CABG causes better revascularization as compared to off pump CABG while off pump CABG has a much lower post operative morbidity and mortality especially in high risk patients. We suggest that the technique used should depend on the ease of the surgeon doing the operation as both the methods seem almost equally efficient according to the review.

Antibiotics regulate the immune response in both presence and absence of lipopolysaccharide through modulation of Toll-like receptors, cytokine production and phagocytosis in vitro

The inflammatory response to pathogen-associated molecular patterns such as lipopolysaccharide (LPS) in sepsis is mediated via Toll-like receptors (TLRs). Since TLRs also trigger various immune functions, including phagocytosis, their modulation is a promising strategy in the treatment of sepsis. As antibiotics have immunomodulatory properties, this study examined the effect of commonly used classes of antibiotics on i) the expression of TLRs and cytokines and ii) the phagocytic activity under sepsis-like conditions in vitro. This was achieved by incubating THP-1 monocytes and peripheral blood mononuclear cells (PBMCs) obtained from patients after open-heart surgery with the addition of LPS and six key antibiotics (piperacillin, doxycycline, erythromycin, moxifloxacin or gentamicin). After 24h, mRNA levels of both cytokines (IL-1β, IL-6) and TLRs (1, 2, 4, and 6) were monitored and phagocytosis was determined following coincubation with Escherichia coli. Each antibiotic differentially regulated the gene expression of the investigated TLRs and cytokines in monocytes. Erythromycin, moxifloxacin and doxycyclin displayed the strongest effects and changed mRNA-levels of the investigated genes up to 5.6-fold. Consistent with this, antibiotics and, in particular, moxifloxacin, regulated the TLR-and cytokine expression in activated PBMCs obtained from patients after open-heart surgery. Furthermore, piperacillin, doxycyclin and moxifloxacin inhibited the phagocytic activity of monocytes. Our results suggest that antibiotics regulate the immune response by modulating TLR- and cytokine expression as well as phagocytosis under septic conditions. Moxifloxacin, doxycycline and erythromycin were shown to possess the strongest immunomodulatory effects and these antibiotic classes should be considered for future immunomodulatory studies in sepsis.

Comparison between preoperative administration of methylprednisolone with its administration before and during congenital heart surgery on serum levels of IL-6 and IL-10

Background

Steroid administration during cardiopulmonary bypass is considered to improve cardiopulmonary function by modulating inflammations caused by bypass.

Objectives

This study was performed to compare effectiveness of preoperative and intraoperative methylprednisolone (MP) to preoperative methylprednisolone alone in post bypass inflammatory (IL-6) and anti-inflammatory (IL-10) factors.

Patients and Methods

Fifty pediatric patients undergoing cardiopulmonary bypass surgery from August 2011 to 2012 in the cardiac surgery department of Imam Reza Hospital, the major center for CPB, in Mashhad, Iran were randomly assigned to receive preoperative and intraoperative MP (30 mg/kg, 4 hours before bypass and in bypass prime, number 25) or preoperative MP only (30 mg/kg, number 25). Before and after bypass, four and 24 hours after bypass, serum IL-6 and IL-10 were measured by ELISA.

Results

In both groups, no significant difference with variation of expression for IL-6 (inflammatory factor) and IL-10 (anti-inflammatory factor) in different times after bypass was observed.

Conclusions

No significant difference in reducing post bypass inflammation between preoperative steroid treatment and combined preoperative and intraoperative steroid administration reported and they had the same effects.

Circulação extracorpórea e complicações no período pós-operatório imediato de cirurgias cardíacas

OBJETIVO: Comparar a frequência de complicações apresentadas pelos pacientes, durante o pós-operatório imediato (POI), de cirurgias cardíacas de acordo com o tempo de circulação extra-corpórea (CEC). MÉTODOS: Estudo de natureza quantitativa, descritivo e correlacional com 83 pacientes adultos divididos em dois grupos de acordo com o tempo de CEC. RESULTADOS: Do total de pacientes, 44 (53%) tiveram o tempo de duração da CEC de até 85 minutos e 39 (47 %) tiveram o tempo acima de 85 minutos. As complicações foram comuns para ambos os grupos, sendo as mais frequentes dor e oligúria. No entanto, hemotórax, pneumotórax e infarto agudo do miocárdio ocorreram apenas no grupo com maior tempo de CEC. CONCLUSÃO: A maioria das complicações ocorridas no POI apresentou frequencia semelhante para os pacientes, independente do tempo de CEC.

A Transapical or Transluminal Approach to Aortic Valve Implantation Does Not Attenuate the Inflammatory Response

Background: Cardiopulmonary bypass (CPB) and cardiac surgery cause an inflammatory response, as measurable by an increase in the concentration of C-reactive protein (CRP), a nonspecific inflammation marker. Previous publications have demonstrated typical perioperative CRP concentration profiles in cases of uncomplicated aortic valve replacement (AVR) with CPB. A regression analysis for modifying factors showed that chronic disease (heart failure, diabetes, and pulmonary disease), along with obesity and sex, all tend to influence the CRP response. We analyzed the inflammatory response to aortic valve implantation (AVI) with interventional techniques, mainly transapical but also transfemoral and transaxillary approaches, in a retrospective case-control study design.Methods: Sixty-eight patients who underwent AVI by the transapical (59 patients), transfemoral (7 patients), or transaxillary (2 patients) approach were matched by age, sex, body mass index (BMI), and chronic-disease state (absence or presence of diabetes, pulmonary disease, and renal impairment) with 68 patients who underwent conventional AVR with CPB. We compared the 2 groups with respect to perioperative CRP concentration, EuroSCORE, and outcome data (time to extubation and 30-day mortality). All data were collected prospectively and analyzed retrospectively.Results: The 2 groupsthe study population (interventional) and the control population (conventional)were similar in age, sex distribution, BMI, and chronic-disease status. As expected, the study population had a significantly higher median EuroSCORE. The 2 groups had similar postoperative CRP profiles over time, but the interventional group had significantly higher peak concentrations on days 2, 3, and 4. The short-term outcomes, as assessed by ventilation time and 30-day mortality, were similar for the 2 groups.Conclusions: Using an interventional transcatheter approach to AVI (thereby eliminating CPB from the procedure and reducing surgical trauma) does not attenuate the patient's innate inflammatory response.

Immunosuppression following surgical and traumatic injury

Severe sepsis and organ failure are still the major causes of postoperative morbidity and mortality after major hepatobiliary pancreatic surgery. Despite recent progress in understanding the immune conditions of abdominal sepsis, the postoperative incidence of septic complications after major visceral surgery remains high. This review focuses on the clinical and immunological parameters that determine the risk of the development and lethal outcome of postoperative septic complication following major surgery and trauma. A review of the literature indicates that surgical and traumatic injury profoundly affects the innate and adaptive immune responses, and that a marked suppression in cell-mediated immunity following an excessive inflammatory response appears to be responsible for the increased susceptibility to subsequent sepsis. The innate and adaptive immune responses are initiated and modulated by pathogen-associated molecular-pattern molecules and by damage-associated molecular-pattern molecules through the pattern-recognition receptors. Suppression of cell-mediated immunity may be caused by multifaceted cytokine/inhibitor profiles in the circulation and other compartments of the host, excessive activation and dysregulated recruitment of polymorphonuclear neutrophils, induction of alternatively activated or regulatory macrophages that have anti-inflammatory properties, a shift in the T-helper (Th)1/Th2 balance toward Th2, appearance of regulatory T cells, which are potent suppressors of the innate and adaptive immune system, and lymphocyte apoptosis in patients with sepsis. Recent basic and clinical studies have elucidated the functional effects of surgical and traumatic injury on the immune system. The research studies of interest may in future aid in the selection of appropriate therapeutic protocols.

Coronary artery bypass grafting without full sternotomy

Coronary artery bypass grafting is performed without full sternotomy in selected patients because it is less invasive. Left internal thoracic artery-left anterior descending artery bypass (LITA-LAD bypass) via a small left anterior thoracotomy is a well established procedure, which achieves good graft patency with low mortality and morbidity rates. Multiple revascularization is possible with a limited lateral thoracotomy or L-figure approach. Axillary-coronary bypass and right gastroepiploic artery-right coronary artery bypass (RGEA-RCA bypass) are alternative methods, especially for redo surgery, in selected patients.

[Fast track in cardiac surgery]

Fast track in cardiac surgery is not well defined. In the past early or immediate extubation was used as a marker. After cardiac surgery this parameter is not sufficient. In addition to cardiorespiratory stability, circulatory and haemostatic homeostasis are also required. Therefore the current Fast Track concept includes a period of intensive monitoring of the patient postoperatively to establish stability. Thereafter intensive care medicine should not be required. Evolving new surgical concepts in combination with appropriate anaesthesiologic management will lead to wide application of fast track cardiac surgery in the future.

TNF-alpha inhibits toll-like receptor 4 expression on monocytic cells via tristetraprolin during cardiopulmonary bypass

Toll-like receptor 4 (TLR4) plays a major role in regulating the innate immune response, which is related to postoperative complications. Although inflammatory capacity and TNF-alpha synthesis were altered on monocytes after cardiopulmonary bypass (CPB), whether the CPB and the CPB-induced TNF-alpha affect TLR4 expression on monocytes have not yet clarified. We speculate that the changing of TNF-alpha level during CPB may be involved in monocytic TLR4 expression. As previous report, our enzyme-linked immunosorbent assay showed that CPB elevated the plasma level of TNF-alpha, whereas off-pump cardiac surgery does not. Flow cytometry reported decreased levels of monocytic TLR4 in patients undergoing CPB but not undergoing off-pump cardiac surgery. To elucidate whether the CPB-induced TNF-alpha is related to TLR4 down-regulation, we used human monocytic THP-1 cells. Actinomycin D chase experiments demonstrated that TNF-alpha decreased TLR4 expression and TLR4 mRNA stability on THP-1. Confocal microscopy and real-time polymerase chain reaction showed that TNF-alpha induced intracellular tristetraprolin (TTP) expression. Transfection with TTP siRNA reversed the down-regulation of TLR4 in TNF-alpha-stimulated THP-1. Treatment with ERK1/2 inhibitor and SAPK/JNK inhibitor decreased TNF-alpha-induced TTP expression. Immunoprecipitation and Western blot analysis showed that the TNF-alpha-mediated activation of TTP might be inhibited by p38 mitogen-activated protein kinase inhibitor and by PD98059. We also demonstrated in clinical samples with confocal microscopy and flow cytometry that CPB led to an elevation of TTP in monocytes. In conclusion, CPB and TNF-alpha decrease TLR4 expression on monocytes; TTP expression and mitogen-activated protein kinase-signaling pathways play critical roles in CPB- and TNF-alpha-mediated decreases of TLR4 on monocytes. Our results suggest that using TTP to control cytokine message decay rate may be a promising approach for controlling system inflammation and preventing post-CPB complications.

Serum concentrations of procalcitonin after cardiac surgery

BACKGROUND AND AIM

Monitoring of complications in patients undergoing cardiac surgery may be difficult because cardiopulmonary bypass (CPB) can lead to a systemic inflammatory response syndrome because of exposure of blood to nonphysiological surfaces. The purpose of the study was to establish the baseline levels of procalcitonin (PCT) after cardiac surgery in our population in order to analyze a possible induction of the inflammatory response that might interfere with the diagnosis of infection by PCT.

METHODS

Serum samples from patients undergoing coronary artery bypass grafting or valve replacement were collected at the time of admission to intensive care unit, after surgery as well as in the first and second postoperative days. Patients were followed for the development of postoperative complications. PCT levels were measured by immunoluminometric assay.

RESULTS

The mean PCT values were significantly higher in the first postoperative day in all the groups except the control group. No increased PCT levels were found related neither to duration of CPB, nor to time of aortic clamping. Only patients who presented complications had significantly increased PCT values immediately after surgery (p = 0.004), in the first postoperative day (p < 0.0001), and in the second postoperative day (p < 0.0001) with respect to those who recovered uneventfully.

CONCLUSIONS

A slight and transient increase in PCT levels was observed in the first postoperative day after cardiac surgery. Significant elevation of PCT was only observed when complications were present.

[Thoracic aortic surgery with circulatory arrest and cold cerebral perfusion]

BACKGROUND

This study was undertaken to identify pre- and perioperative risk factors to mortality and permanent neurological dysfunction (PND) and temporary neurological dysfunction (TND) in a large patient cohort, all operated under moderate hypothermic circulatory arrest (HCA) and selective antegrade cerebral perfusion (SACP) in a single centre.

PATIENT AND METHODS

Between November 1999 and March 2006, 319 patients at a median age of 65 years (range 21-86, 201 male) underwent elective aortic arch surgery with moderate HCA at 25 degrees C and additional SACP at 14 degrees C. Sixty-nine had additional coronary artery bypass grafts or valve procedures. Ninety-four (29%) had total arch repair. Statistical analysis was carried out to determine the risk factors for 30-day mortality as well as for TND and PND.

RESULTS

Overall mortality was 7.8% (15% in cases with repeat surgery vs 4.8% in nonrepeats, P=0.002). Twenty-seven (8.5%) suffered from PND, and six (22%) died during hospital stay (P=0.004). There was TND detected in 32 patients (10%). Stepwise logistic regression revealed age (P=0.001, OR 1.09/year), repeat surgery (P=0.008, OR 5.04), preoperative neurological events (P=0.004, OR 3.44), CAD (P=0.051, OR 3.58), and cardiopulmonary bypass duration (P<0.001, OR 1.01/min) as risk factors for mortality. The PND was associated with preoperative renal insufficiency (P=0.026, OR 3.34) and operation duration (P<0.001, OR 1.01/min), whereas TND occurred in patients with coronary artery disease (P=0.04, OR 2.41), and prolonged cardiopulmonary bypass duration (P=0.05, OR 1.01/min).

CONCLUSION

Thoracic aortic surgery including aortic arch using HCA and SACP can be performed with excellent results in elective patients, especially those without previous surgery. Nevertheless PND is associated with high hospital mortality. Neurological complications seem to be strongly associated with general atherosclerotic changes as well as the extent of surgery.

Understanding the inflammatory response to cardiac surgery

The systemic inflammatory response to cardiac surgery is common, and resultant impairment of multiple organ function is generally mild or subclinical due to physiological reserve within organ systems. Unfortunately, the changing profile of patients referred for surgery suggests that the systemic inflammatory response may prominently influence surgical outcome in the future. Older, co-morbid patients with more limited physiological reserve are being referred for complex lengthy procedures, and paediatric surgery has witnessed a shift to earlier complex primary correction or palliation involving long cardiopulmonary bypass times or a period of suboptimal organ perfusion using circulatory arrest or low flow cardiopulmonary bypass. Unique to cardiac surgery is the predictability of the inflammatory response, but prophylactic therapies have not translated into clinical benefit, which the preconditioning phenomenon may address.

Differences of peripheral inflammatory markers between mild cognitive impairment and Alzheimer's disease

Multiple pathogenic factors may contribute to the pathophysiology of Alzheimer's disease (AD). Peripheral markers have been used to assess biochemical alterations associated with AD and mild cognitive impairment (MCI) involved in its pathophysiology. The present study was conducted to evaluate inflammatory peripheral markers in elderly patients with MCI, patients with AD and normal elderly subjects. We measured plasma levels of different cytokines (IL-6, TNF-alpha and IFN-alpha) and platelet levels of cyclooxigenase-2 (COX-2) from 34 patients with MCI, 45 patients with AD and 28 age-matched control subjects. MCI and AD patients showed similarities in TNF-alpha and COX-2 levels, and differences in IL-6 and INF-alpha. Whereas augmented IL-6 levels have been found in AD patients, a significant increase in INF-alpha has been detected only in patients with MCI possibly associated with the depression stage frequently found in cognitive impairment. In conclusion, inflammatory response may be an early factor in AD development and these changes in circulating markers are possibly related to the progression of MCI to AD.

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.

On-Pump Beating-Heart Coronary Artery Bypass: A Propensity Matched Analysis

BACKGROUND

It remains unclear how cardioplegic arrest affects surgical results after coronary artery bypass grafting surgery (CABG). This study compares early outcomes after on-pump beating-heart CABG and conventional CABG.

METHODS

From 2002 to 2005, 114 patients underwent on-pump beating-heart CABG. Multivariate logistic regression revealed five characteristics according to which technique is liable to be used: history of cerebral infarction, urgent or emergent operation, lower ejection fraction, preoperative creatine kinase, and lower number of diseased vessels. The early clinical outcome for these patients was compared against 114 conventional CABG patients, matched using a propensity score constructed with these five significant variables and with two nonsignificant variables: history of diabetes mellitus and hypertension.

RESULTS

On-pump beating-heart CABG significantly reduced the duration of operation and cardiopulmonary bypass, total blood loss, and peak creatine kinase (p < 0.05). The number of patients requiring additional intra-aortic balloon pump support was significantly lower in the on-pump beating-heart CABG group (2 versus 13, p < 0.01). No patients required percutaneous cardiopulmonary support after on-pump beating-heart CABG, whereas 4 patients needed it after conventional CABG. Complete revascularization was significantly lower (42.1% versus 77.2%, p < 0.0001), but in-hospital mortality was less in the on-pump beating-heart CABG group (2.6% versus 9.6%, p < 0.05). No significant difference was found in morbidity including stroke, renal failure, mediastinitis, and prolonged ventilation.

CONCLUSIONS

On-pump beating-heart CABG can be performed safely, including on high-risk patients. Use of cardiopulmonary bypass and the elimination of cardioplegic arrest may be of most benefit to hemodynamically unstable patients.

Deleterious effects of cardiopulmonary bypass in coronary artery surgery and scientific interpretation of off-pump's logic

Cardiopulmonary bypass (CPB) has been suggested to be a cause of complex systemic inflammatory response that significantly contributes to several adverse postoperative complications. In the last few years, off-pump coronary artery bypass grafting (OPCAB) has gained widespread attention as an alternative technique to conventional on-pump coronary artery bypass grafting (ONCAB). However, a degree of uncertainty regarding the relative merits of ONCAB and OPCAB continues to be a significant issue. Surgeons supporting off-pump surgery, state that the avoidance of the CPB leads to significantly reduced myocardial ischemia-reperfusion injury, postoperative systemic inflammatory response and other biological derangements, a feature that may improve the clinical outcomes. However, perfection in perioperative care, surgical technique and methods of attenuating the untoward effects of CPB has resulted in better clinical outcome of ONCAB as well. Possible reasons of these controversial opinions are that high-quality studies have not comprehensively examined relevant patient outcomes and have enrolled a limited range of patients. Some studies may have been too small to detect clinically important differences in patient outcomes between these two modalities. We present a review of the available scientific interpretation of the literature on OPCAB with regard to safety, hemodynamic changes, inflammation, myocardial preservation and oxidative stress. We also sought to determine from different reported retrospective and randomized control studies, the initial and the long-term benefits of this approach, despite the substantial learning curve associated with OPCAB.

Cell Salvage Alters the Systemic Inflammatory Response After Off-Pump Coronary Artery Bypass Grafting Surgery

BACKGROUND

Retransfused cardiotomy suction blood contains elevated inflammatory markers and is a bypass independent source of inflammatory mediators. We hypothesized that, during off-pump coronary artery bypass (OPCAB) grafting surgery, avoiding retransfusion of unwashed cardiotomy suction blood would beneficially alter both urinary and plasma cytokine concentrations and be renoprotective.

METHODS

Thirty-seven OPCAB surgery patients were randomly allocated to control (retransfusion of unwashed shed blood) and treatment (retransfusion of washed shed blood or discarding of unwashed blood) groups. Over 72 hours we measured plasma (tumor necrosis factor-alpha [TNF-alpha], interleukin-8, interleukin-6, interleukin-10, TNF soluble receptor-2, and interleukin-1 receptor antagonist) and urinary TNF soluble receptor-2 and interleukin-1 receptor antagonist and markers of renal injury and dysfunction (N-acetyl beta D glucosaminidase and alpha1-microglobulin).

RESULTS

We demonstrated elevated proinflammatory cytokines in cardiotomy suction blood, which were effectively eliminated by cell salvage. After retransfusion, in comparison with controls, the treatment group had reduced plasma TNF soluble receptor-2. As compared with controls, treatment group patients also demonstrated significantly reduced levels of the urinary anti-inflammatory cytokine TNF soluble receptor-2. There were no between group differences in markers of renal injury or dysfunction.

CONCLUSIONS

We have demonstrated that the management of shed mediastinal blood alters perioperative, systemic, plasma and urinary cytokine homeostasis at OPCAB surgery but does not impact on subclinical renal injury or dysfunction in this low risk group of patients.

Patterns of Postoperative Systemic Vascular Resistance in a Randomized Trial of Conventional On-Pump Versus Off-Pump Coronary Artery Bypass Graft Surgery

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) is associated with a less intense systemic inflammatory response according to biochemical markers. We studied systemic vascular resistance (SVR) as a physiologic response to systemic inflammatory response to determine any differences between OPCAB and on-pump coronary artery bypass grafting (ONCAB) in a prospective randomized trial.

METHODS

One hundred consecutive patients were randomized to OPCAB or ONCAB, 50 in each group. Antifibrinolytics and steroids were not used. All protocols were identical except for cardiopulmonary bypass. Temperature, SVR index, cardiac index, and blood pressure were measured continuously for the first 24 hours postoperatively. All patients were reviewed at 30 days.

RESULTS

There was no 30-day mortality, no stroke, and no acute renal failure. Mean temperature peaked at 37.5 degrees C at 12 hours (p = 0.700 between groups). Mean SVR index fell to 1,900 dyne x cm(-5) x m(-2) at 12 to 18 hours; 42% of OPCAB and 32% of ONCAB patients developed very low SVR index (<1,500 dyne x cm(-5) x m(-2)). The incidence of high SVR (>2,500 dyne x cm(-5) x m(-2)) fell from 20% to 2% by 12 to 18 hours. The extent and pattern of SVR index responses were similar in both groups (p = 0.840). Mean cardiac index peaked at 3.0 L x min(-1) x m(-2), 12 to 18 hours postoperatively (p = 0.815 between groups); 84% of OPCAB and 90% of ONCAB had cardiac index greater than 2.2 L x min(-1) x m(-2) at all times. Only 10% of patients required vasopressors. Blood pressure responses were also similar (p = 0.314).

CONCLUSIONS

The incidence of low SVR, and patterns of SVR changes were similar in ONCAB and OPCAB, and were clinically unimportant as few patients required vasopressor support. Cardiac outputs and clinical outcomes were excellent in both groups.

Higher Levels of Serum Cytokines and Myocardial Tissue Markers During On-Pump Versus Off-Pump Coronary Artery Bypass Surgery

Increased Troponin I levels and pro-inflammatory cytokines have been reported in most patients undergoing cardiac surgery, ascribed to the type and extent of surgery, reperfusion injury, and the method of myocardial protection. We investigated their levels in patients undergoing on-pump (CCAB) or off-pump (OPCAB) coronary artery bypass surgery and whether these correlated with the extent of myocardial injury. One hundred twenty patients were prospectively randomized to undergo OPCAB (n = 60) or CCAB (n = 60). Hemodynamic and respiratory data, as well as serum CK-MB mass fraction, Troponin I, and interleukin (IL)-6, IL-8, and IL-10 levels, were collected perioperatively. Demographic, hemodynamic, and respiratory parameters were similar between the two groups. Troponin I was significantly lower in the OPCAB than in the CCAB group, either at the end of ischemia, end of surgery, 6-hour and 24-hour postoperatively (4 +/- 3, 5 +/- 3, 7 +/- 5, and 8 +/- 3 microg/L, vs. 19 +/- 18, 27 +/- 19, 28 +/- 13.5, and 33 +/- 8.5 microg/L, respectively, p < 0.05). Serum cytokine levels in the OPCAB patients were lower compared to the CCAB group at the end of surgery (32 +/- 35, 25 +/- 30, and 40 +/- 30 pg/ml for IL-6, IL-8, and IL-10 vs. 230 +/- 30, 140 +/- 70, and 125 +/- 50 pg/ml, respectively, p < 0.05). Plasma IL-6 levels correlated with the Troponin I levels at the end of surgery in both groups (r = 0.45, p = 0.01). Thus, OPCAB surgery is associated with reduced levels of Troponin I and activation of cytokines, compared to those in the CCAB group. High levels of these factors could correlate with myocardial damage during coronary artery bypass surgery. This finding warrants further laboratory and clinical confirmation in the future.

Circulating Cytokines, Chemokines, and Stress Hormones are Increased in Patients with Organ Dysfunction Following Liver Resection

BACKGROUND

Humoral mediators are potentially involved in the pathogenesis of postoperative complications following surgery. The aim of the present study is to evaluate the postoperative responses of circulating cytokines, chemokines, and stress hormones following liver resection, and their effects on postoperative infectious complications and organ dysfunction.

PATIENTS AND METHODS

Perioperative plasma concentrations of interleukin (IL)-6, IL-10, IL-4, IL-8, macrophage chemoattractant protein (MCP)-1, cortisol, macrophage migration inhibitory factor (MIF), and leptin were measured by immunoassays in 128 consecutive patients undergoing liver resection.

RESULTS

Forty-three patients had postoperative infection and 11 had infection-related organ dysfunction. Plasma levels of all mediators except for IL-4 increased postoperatively. Postoperative levels of IL-6, IL-10, IL-8, MCP-1, cortisol, and leptin were significantly higher in patients with organ dysfunction than in those without organ dysfunction (P < 0.05). However, postoperative MIF levels were not affected by postoperative infection or organ dysfunction. Plasma levels of IL-6, IL-10, IL-8, and MCP-1 were positively correlated with operation time (P < 0.0001) or blood loss (P < 0.0001), and higher in patients with jaundiced liver (P < 0.05). In univariate logistic regression analyses, elevated IL-6, IL-10, IL-8, and MCP-1, advanced age, large volume of blood loss, long operation time, long hepatic ischemia time, and major liver resection were significantly correlated with postoperative infection (P < 0.05). In multivariate analyses, IL-6 and IL-10 were significant predisposing factors for postoperative infection (P < 0.05), and blood loss and IL-6 for organ dysfunction (P < 0.01).

CONCLUSIONS

These results suggest that IL-6, IL-10, IL-8, MCP-1, cortisol, and leptin are released after liver resection in response to surgical stress and correlated with postoperative infection and organ dysfunction, and that of these circulating mediators, IL-6 and IL-10, have a close relationship to the complications.

Comparison of inflammatory responses after off-pump and on-pump coronary surgery using surface modifying additives circuit

BACKGROUND

Cardiac surgery is followed by various degrees of inflammation, which have harmful consequences. Because of the central role of extracorporeal circulation (EC), off-pump coronary bypass surgery is deemed preferable. Do different modalities of EC challenge this view?

METHODS

Four groups of similar patients underwent coronary surgery: (group 1) on-pump, EC with closed surface modifying additives (SMA) circuit and no pump suckers (n = 20); (group 2) on-pump, EC with open SMA circuit and pump suckers (n = 20); (group 3) off-pump (beating heart) and heparin 3 mg/kg (n = 20); (group 4) off-pump (beating heart) and heparin 1 mg/kg (n = 20). Interleukins (IL)-6, IL-8, IL-10, myeloperoxidase, elastase, and terminal complex of the complement (TCC) were analyzed at various times: at induction (time I); after heparin (time II); after complete revascularization (time III); after protamine (time IV); and 24 hours later (time V).

RESULTS

The TCC was significantly higher in groups 1 and 2 at time III. The pattern of IL-6 was the same for the four groups. No significant difference in myeloperoxydase content was noted; however, elastase was significantly higher in the two EC (on-pump) groups.

CONCLUSIONS

Except for the complement system and elastase, on-pump surgery with SMA-coated circuits did not elicit any greater inflammatory response than off-pump surgery.

Modulation of systemic inflammatory response after cardiac surgery

Cardiac surgery and cardiopulmonary bypass initiate a systemic inflammatory response largely determined by blood contact with foreign surfaces and the activation of complement. It is generally accepted that cardiopulmonary bypass initiates a whole-body inflammatory reaction. The magnitude of this inflammatory reaction varies, but the persistence of any degree of inflammation may be considered potentially harmful to the cardiac patient. The development of strategies to control the inflammatory response following cardiac surgery is currently the focus of considerable research efforts. Diverse techniques including maintenance of hemodynamic stability, minimization of exposure to cardiopulmonary bypass circuitry, and pharmacologic and immunomodulatory agents have been examined in clinical studies. This article briefly reviews the current concepts of the systemic inflammatory response following cardiac surgery, and the various therapeutic strategies being used to modulate this response.

Expression of CD97 and Adhesion Molecules on Circulating Leukocytes in Patients Undergoing Coronary Artery Bypass Surgery

OBJECTIVE

Leukocyte activation is thought to be responsible for the adverse effects and postoperative complications following cardiopulmonary bypass (CPB). A novel cell surface molecule, CD97, is a sensitive marker of leukocyte and primary lymphocyte activation. The present study aimed to determine the activation of different leukocyte subsets by comparing the expression of CD97 and adhesion molecules (CD11, CD18) in patients receiving coronary surgery with or without CPB.

METHODS

30 patients were enrolled and scheduled for coronary bypass surgery under CPB (20 patients, group A) and with off-pump (OP) operation (10 patients, group B). Blood samples were taken before and during surgery, and over the following first week.

RESULTS

Here, we report an early decrease in CD97 expression of granulocytes (PMN) and monocytes (MC) followed by an intensive increase reaching the maximum on postoperative days 2 and 3 in patients operated with CPB. The rate of active CD97-positive lymphocytes showed a marked, gradual increase until postoperative day 3 and remained elevated up to day 7 after CPB. OP surgery resulted in moderate alteration in the presence of CD97 on PMN, MC and lymphocytes. The expression of adhesion molecules was similar to CD97 in all leukocyte subsets.

CONCLUSION

The findings about CD97 expression suggest considerable leukocyte activation following coronary bypass with CPB compared to OP surgery. The collected data show that the lymphocytes are highly activated and involved in leukocyte sequestration after CPB. Moreover, the importance of CD97 in CPB-related inflammatory response can be stated.