Cytokines in myocardial injury: impact on cardiac surgical approach

Tapping into Nature's Arsenal: Harnessing the Potential of Natural Antioxidants for Human Health and Disease Prevention

Numerous natural antioxidants commonly found in our daily diet have demonstrated significant benefits for human health and various diseases by counteracting the impact of reactive oxygen and nitrogen species. Their chemical properties enable a range of biological actions, including antihypertensive, antimicrobial, anti-inflammatory, anti-fibrotic, and anticancer effects. Despite promising outcomes from preclinical studies, ongoing debate persists regarding their reproducibility in human clinical models. This controversy largely stems from a lack of understanding of the pharmacokinetic properties of these compounds, coupled with the predominant focus on monotherapies in research, neglecting potential synergistic effects arising from combining different antioxidants. This study aims to provide an updated overview of natural antioxidants, operating under the hypothesis that a multitherapeutic approach surpasses monotherapy in efficacy. Additionally, this study underscores the importance of integrating these antioxidants into the daily diet, as they have the potential to prevent the onset and progression of various diseases. To reinforce this perspective, clinical findings pertaining to the treatment and prevention of non-alcoholic fatty liver disease and conditions associated with ischemia and reperfusion phenomena, including myocardial infarction, postoperative atrial fibrillation, and stroke, are presented as key references.

Colchicine in atrial fibrillation: are old trees in bloom?

Colchicine is a widely used drug that was originally used to treat gout and rheumatic diseases. In recent years, colchicine has shown high potential in the cardiovascular field. Atrial fibrillation (AF) is a cardiovascular disease with a high incidence. One of the most frequent complications following cardiovascular surgery is postoperative atrial fibrillation (POAF), which affects patient health and disease burden. This article reviews the research status of colchicine in AF and summarizes the relevant progress.

Antioxidant activity in off and on-pump coronary artery bypass grafting and valve replacement surgery

OBJECTIVES

Cardiac surgeries initiate oxidative stress, increasing organ dysfunction development and mortality. The present study investigated the superoxide dismutase (SOD) activity, as an antioxidant enzyme, in patients undergoing coronary artery bypass (CABG) and heart valve replacement surgeries.

METHODS

A prospective study was performed on patients with proven coronary artery disease (CAD) or valvular heart disease (VHD) candidates for on- or off-pump CABG and valve replacement surgery. Serum SOD activity was measured preoperatively, at 24 h postoperatively, and at the time of discharge. In addition, echocardiography was performed before surgery and at discharge.

RESULTS

A total of 48, 51, and 47 patients were enrolled in the on-pump, off-pump CABG, and valve replacement groups, respectively. Baseline serum SOD activity showed no significant association with BMI, age, and blood pressure in either CAD or VHD patients. The SOD values decreased at the 24 h postoperative time and then increased at the time of discharge in all groups, except for a slight decrease in the on-pump group. The changes in serum SOD values were not significantly different for the three surgical groups.

CONCLUSIONS

The serum SOD activities fell significantly after CABG and valve replacement surgery. Further investigation is emphasized for the role of SOD in oxidative stress after cardiac surgery.

Early and Long-Term Outcomes after On-Pump and Off-Pump Coronary-Artery Bypass Grafting in Patients with Severe Left Ventricular Dysfunction and a Giant Left Ventricle

Introduction: No previous studies comparing the outcomes between off-pump coronary artery bypass grafting (off-pump CABG, OPCAB) and on-pump CABG (ONCAB) have been performed in patients with severe left ventricular dysfunction (LVD) and a giant left ventricle. We aimed to investigate whether such patients could benefit from OPCAB. Methods: From January 2011 to January 2021, a total of 98 patients with severe LVD and a giant left ventricle underwent isolated CABG (ONCAB 46, OPCAB 52) in Wuhan Union Hospital. The clinical data were collected retrospectively and propensity score matching was performed to adjust baseline characteristics. Results: After propensity matching, the two groups were comparable in baseline variables. The OPCAB group had a higher rate of incomplete revascularization than the ONCAB group (25.0% vs. 9.1%; p = 0.047). The 30-day mortality was similar between the matched groups (4.5% vs. 4.5%; p = 1.000) but the OPCAB group had a lower risk of postoperative IABP usage (9.1% vs. 25.0%; p = 0.047) and renal insufficiency (11.4% vs. 29.5%; p = 0.034). The long-term probability of survival (log-rank test, p = 0.450) was similar between the two groups but the OPCAB group had a lower probability of major adverse cardiovascular events (log-rank test, p = 0.038). Conclusions: For patients with severe LVD and a giant left ventricle, OPCAB reduced early postoperative complications while sacrificing long-term quality of life compared to those having ONCAB.

Monocyte Metabolism and Function in Patients Undergoing Cardiac Surgery

Objective

Cardiopulmonary bypass (CPB) can lead to systemic inflammation, which is associated with higher morbidity. Therefore, we investigated the metabolism of isolated blood monocytes before and after CPB compared to healthy controls.

Methods

In this prospective, monocentric, observational study, we included 30 patients undergoing CPB and 20 controls. We isolated monocytes from heparinized blood and investigated their metabolism by using Seahorse technology before (t0), 4 h (t4), and 24 h (t24) after the start of the CPB. We also examined programmed cell death 1 ligand (PD-L1), PD-L2, V-domain Ig suppressor of T cell activation (VISTA), and human leukocyte antigen-DR isotype (HLA-DR) using fluorescence-activated cell sorting analysis. Additionally, we investigated plasma cytokine levels in patients without and after ex vivo stimulation.

Results

CPB-induced inflammatory responses are shown by significantly elevated plasma interleukin-6 levels in the CPB group compared to baseline and controls [t0: 0 ng/ml (95%CI 0-0 ng/ml); t4: 0.16 ng/ml (95%CI 0.1-0.197 ng/ml), p < 0.0001; t24: 0.11 ng/ml (95% CI 0.1-0.16 ng/ml), p < 0.0001, and controls: 0 ng/ml (95% CI 0-0 ng/ml)]. The cytokine release in the ex vivo stimulation is reduced for lipopolysaccharide stimulation at t4 [t0: 35.68 ng/ml (95% CI 22.17-46.57 ng/ml) vs. t4: 15.02 (95% CI 10.25-24.78 ng/ml), p < 0.0001]. Intracellular metabolism of monocytes after CPB showed a protracted shift to aerobic glycolysis [t0: 179.2 pmol/min (95% CI 138.0-205.1 pmol/min) vs. t24: 250.1 pmol/min (95% CI 94.8-300.2 pmol/min), p < 0.0001]. Additionally, we observed an altered metabolism in monocytes in patients undergoing cardiac surgery compared to controls even before any surgical procedure [t0: 179.2 pmol/min (95% CI 138.0-205.1) vs. controls 97.4 (95% CI 59.13-144.6 pmol/min), p = 0.0031].

Conclusion

After CPB, patients' monocytes show a shift in metabolism from oxidative phosphorylation to aerobic glycolysis, which is associated with energy-demanding and proinflammatory processes. This is the first study to show changes in monocyte immunometabolism in cardiac surgery. Monocytes of patients undergoing cardiac surgery were leaning toward aerobic glycolysis even before any surgical procedure was conducted. Leaving the question of the pathophysiological mechanisms for future studies to be investigated and paving the way for potential therapy approaches preventing inflammatory effects of CPB.

Taming the Storm in the Heart: Exploring Different Therapeutic Choices Against Myocardial Inflammation in COVID-19

Mechanism of cardiac injury in COVID-19 is a serious problem and plays critical role in mediating the severity of the disease. However, the mechanistic insights of the induction of the inflammatory signal leading to cardiac injury was poorly understood. However, few recent studies have indicated the involvement of Toll-Like Receptors (TLRs) as the major 'culprit' behind eliciting the initial signal of 'cytokine storm'. As a result, TLRs are now considered as the therapeutic targets to develop efficacious therapeutics. Herein, we present an overall summary on the mechanistic insight of cardiac injury in COVID-19 patients and the therapeutic promises of TLR-targeted therapies.

Postoperative Atrial Fibrillation Following Cardiac Surgery: From Pathogenesis to Potential Therapies

Postoperative atrial fibrillation (POAF) is a major complication after cardiac surgery which can lead to high rates of morbidity and mortality, an enhanced length of hospital stay, and an increased cost of care. POAF is postulated to be a multifactorial phenomenon; however, some major pathogeneses have been proposed, including inflammatory pathways, oxidative stress, and autonomic dysfunction. Genetic studies also showed that inflammatory pathways, beta-1 adrenoreceptor variants, G protein-coupled receptor kinase 5 gene variants, and non-coding single-nucleotide polymorphisms in the 4q25 chromosomal locus are involved in this phenomenon. Moreover, several predisposing factors lead to the development of POAF, consisting of pre-, intra-, and postoperative contributors. The main predisposing factors comprise age, prior history of major cardiovascular risk factors, and ischemia-reperfusion injury during surgery. The management of POAF is based on the usual therapies used for non-surgical AF, including medications for either rate control or rhythm control in hemodynamically unstable patients. The perioperative administration of β-blockers and some antiarrhythmic agents has been recommended in major international guidelines. In addition, upstream therapies consisting of colchicine, magnesium, statins, and antioxidants have attenuated the incidence of POAF; however, some uncomfortable side effects developed in large randomized trials. The use of anticoagulation has also resulted in less mortality in patients with POAF at higher risk of thromboembolic events. Despite these recommendations, the actual regimen for the prevention of POAF remains controversial. In this review, we highlight the pathogenesis, predisposing factors, and potential therapeutic options for the management of patients at risk for or with POAF following cardiac surgery.

Interfering with long chain noncoding RNA ANRIL expression reduces heart failure in rats with diabetes by inhibiting myocardial oxidative stress

This study is performed to elucidate whether long-chain noncoding RNA ANRIL has an effect on diabetes, and further explore the mechanism of ANRIL in diabetes. The rat model of diabetes was established via intraperitoneal injection of streptozotocin. The modeled rats were grouped into normal, diabetes, siRNA-NC, and ANRIL siRNA groups. Besides, the expression of ANRIL, cardiac function, inflammatory factor levels, cardiomyocyte apoptosis, and levels of oxidative stress index were all determined. Upregulated ANRIL was found in myocardial tissue of diabetic rats. Downregulated ANRIL improved cardiac function index and the expression of inflammatory factors, improved the pathological state of myocardial tissue and myocardial remodeling, decreased myocardial collagen deposition area and cardiomyocyte apoptosis and reduced the oxidative level of myocardial tissue in diabetic rats. This present study suggests that upregulated ANRIL is found in myocardial tissue of diabetic rats. Additionally, silencing of ANRIL reduces myocardial injury in diabetes by inhibiting myocardial oxidative stress.

Involvement of IL-1β and IL-6 in antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in rats

PURPOSE

Evidence show that statins possess wide beneficial cardioprotective and anti-inflammatory effects; therefore, in the present experiment, we investigated the antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in isolated rat atria and the role of several inflammatory cytokines in this effect.

MATERIALS AND METHODS

Male rats were pretreated with either of atorvastatin (10 mg/kg) or vehicle, orally once daily for 6 weeks. After induction of anesthesia, we isolated the atria and after incubation with ouabain, time of onset of arrhythmia and asystole as well as atrial beating rate and contractile force were recorded. We also measured the atrial levels of IL-1β, IL-6, and TNF-α after the injection of ouabain to animals.

RESULTS

Pretreatment with atorvastatin significantly delayed the onset of arrhythmia and asystole compared with vehicle-treated group (p < .01, p < .001, respectively). Incubation of ouabain boosted both atrial beating rate and contractile force in vehicle-treated group (p < .05), while these responses in atorvastatin-treated group were not significant (p > .05). Injection of ouabain elevated the atrial levels of IL-1β, IL-6, and TNF-α, while pretreatment of animals with atorvastatin could reverse the ouabain-induced increase in atrial IL-1β and IL-6 (p < .01 and p < .05, respectively).

CONCLUSIONS

It is concluded that observed antiarrhythmic effects of atorvastatin might be attributed to modulation of some inflammatory cytokines, at least IL-1β and IL-6.

l-Carnitine and heart disease

Cardiovascular disease (CVD) is a key cause of deaths worldwide, comprising 15-17% of healthcare expenditure in developed countries. Current records estimate an annual global average of 30 million cardiac dysfunction cases, with a predicted escalation by two-three folds for the next 20-30years. Although β-blockers and angiotensin-converting-enzymes are commonly prescribed to control CVD risk, hepatotoxicity and hematological changes are frequent adverse events associated with these drugs. Search for alternatives identified endogenous cofactor l-carnitine, which is capable of promoting mitochondrial β-oxidation towards a balanced cardiac energy metabolism. l-Carnitine facilitates transport of long-chain fatty acids into the mitochondrial matrix, triggering cardioprotective effects through reduced oxidative stress, inflammation and necrosis of cardiac myocytes. Additionally, l-carnitine regulates calcium influx, endothelial integrity, intracellular enzyme release and membrane phospholipid content for sustained cellular homeostasis. Carnitine depletion, characterized by reduced expression of "organic cation transporter-2" gene, is a metabolic and autosomal recessive disorder that also frequently associates with CVD. Hence, exogenous carnitine administration through dietary and intravenous routes serves as a suitable protective strategy against ventricular dysfunction, ischemia-reperfusion injury, cardiac arrhythmia and toxic myocardial injury that prominently mark CVD. Additionally, carnitine reduces hypertension, hyperlipidemia, diabetic ketoacidosis, hyperglycemia, insulin-dependent diabetes mellitus, insulin resistance, obesity, etc. that enhance cardiovascular pathology. These favorable effects of l-carnitine have been evident in infants, juvenile, young, adult and aged patients of sudden and chronic heart failure as well. This review describes the mechanism of action, metabolism and pharmacokinetics of l-carnitine. It specifically emphasizes upon the beneficial role of l-carnitine in cardiomyopathy.

Involvement of Inflammatory Cytokines in Antiarrhythmic Effects of Clofibrate in Ouabain-Induced Arrhythmia in Isolated Rat Atria

Considering the cardioprotective and anti-inflammatory properties of clofibrate, the aim of the present experiment was to investigate the involvement of local and systemic inflammatory cytokines in possible antiarrhythmic effects of clofibrate in ouabain-induced arrhythmia in rats. Rats were orally treated with clofibrate (300 mg/kg), and ouabain (0.56 mg/kg) was administered to animals intraperitoneally. After induction of anesthesia, the atria were isolated and the onset of arrhythmia and asystole was recorded. The levels of inflammatory cytokines in atria were also measured. Clofibrate significantly postponed the onset of arrhythmia and asystole when compared to control group (P ≤ 0.05 and P ≤ 0.01, resp.). While ouabain significantly increased the atrial beating rate in control group (P ≤ 0.05), same treatment did not show similar effect in clofibrate-treated group (P > 0.05). Injection of ouabain significantly increased the atrial and systemic levels of all studied inflammatory cytokines (P ≤ 0.05). Pretreatment with clofibrate could attenuate the ouabain-induced elevation of IL-6 and TNF-α in atria (P ≤ 0.01 and P ≤ 0.05, resp.), as well as ouabain-induced increase in IL-6 in plasma (P ≤ 0.05). Based on our findings, clofibrate may possess antiarrhythmic properties through mitigating the local and systemic inflammatory factors including IL-6 and TNF-α.

Inflammation, oxidative stress and postoperative atrial fibrillation in cardiac surgery

Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery that occurs in up to 60% of patients. POAF is associated with increased risk of cardiovascular mortality, stroke and other arrhythmias that can impact on early and long term clinical outcomes and health economics. Many factors such as disease-induced cardiac remodelling, operative trauma, changes in atrial pressure and chemical stimulation and reflex sympathetic/parasympathetic activation have been implicated in the development of POAF. There is mounting evidence to support a major role for inflammation and oxidative stress in the pathogenesis of POAF. Both are consequences of using cardiopulmonary bypass and reperfusion following ischaemic cardioplegic arrest. Subsequently, several anti-inflammatory and antioxidant drugs have been tested in an attempt to reduce the incidence of POAF. However, prevention remains suboptimal and thus far none of the tested drugs has provided sufficient efficacy to be widely introduced in clinical practice. A better understanding of the cellular and molecular mechanisms responsible for the onset and persistence of POAF is needed to develop more effective prediction and interventions.

Relationship between Nadir Hematocrit during Cardiopulmonary Bypass and Postoperative Hyperglycemia in Nondiabetic Patients

<p><b>Background:</b> Hyperglycemia is common after cardiac surgery in both diabetic and nondiabetic patients and is associated with increased morbidity and mortality. Association between nadir hematocrit levels on cardiopulmonary bypass (CPB) and postoperative hyperglycemia is not clear. This study was carried out to determine the relationship between nadir hematocrit during CPB and postoperative hyperglycemia in nondiabetic patients.</p><p><b>Methods:</b> Records of 200 nondiabetic patients undergoing coronary artery bypass grafting operation were retrospectively reviewed. In the first analysis, patients were divided into two subgroups according to the presence or absence of hyperglycemia. Further analysis was made after dividing the patients into 3 subgroups according to nadir hematocrit levels on CPB (less than 20%; 20% to 25%; greater than or equal to 25%).</p><p><b>Results:</b> Compared to patients without hyperglycemia, patients with postoperative hyperglycemia had significantly lower preoperative hematocrit levels (p = 0.004) and were associated with lower nadir hematocrit levels during CPB (p= 0.002). Peak intensive care unit blood glucose levels and number of blood transfusions were significantly higher in patients with nadir hematocrit levels less than 20. (p<0.001 and p<0.001 respectively). Logistic regression analysis demonstrated that nadir hematocrit levels less than 20% (OR 2.9, p=0.009) and allogenic blood transfusion (OR 1.5, p=0.003) were independently associated with postoperative hyperglycemia.</p><p><b>Conclusions:</b> Nadir hematocrit levels on CPB less than 20% and allogenic blood transfusions were independently associated with postoperative hyperglycemia in nondiabetic patients. Patients with a nadir hematocrit levels less than 20 % during CPB should be closely monitored for hyperglycemia in the perioperative period.</p>

Lung inflammatory response syndrome after cardiac-operations and treatment of lornoxicam

The majority of patients survive after extracorporeal circulation without any clinically apparent deleterious effects. However, disturbances exist in various degrees sometimes, which indicate the harmful effects of cardiopulmonary bypass (CPB) in the body. Several factors during extracorporeal circulation either mechanical dependent (exposure of blood to non-biological area) or mechanical independent (surgical wounds, ischemia and reperfusion, alteration in body temperature, release of endotoxins) have been shown to trigger the inflammatory reaction of the body. The complement activation, the release of cytokines, the leukocyte activation and accumulation as well as the production of several "mediators" such as oxygen free radicals, metabolites of arachidonic acid, platelet activating factors (PAF), nitric acid, and endothelin. The investigation continues today on the three metabolites of lornoxicam (the hydroxylated metabolite and two other metabolites of unknown chemical composition) to search for potential new pharmacological properties and activities.

Heme Oxygenase-1 and Acute Kidney Injury following Cardiac Surgery

BACKGROUND

Intraoperative hemolysis and inflammation are associated with acute kidney injury (AKI) following cardiac surgery. Plasma-free hemoglobin induces heme oxygenase-1 (HO-1) expression. HO-1 degrades heme but increases in experimental models of AKI. This study tested the hypothesis that plasma HO-1 concentrations are associated with intraoperative hemolysis and are increased in patients that develop AKI following cardiac surgery.

METHODS

We measured plasma HO-1, free hemoglobin, and inflammatory markers in 74 patients undergoing cardiopulmonary bypass (CPB). AKI was defined as an increase in serum creatinine concentration of 50% or 0.3 mg/dl within 72 h of surgery.

RESULTS

Twenty-eight percent of patients developed AKI. HO-1 concentrations increased from 4.2 ± 0.2 ng/ml at baseline to 6.6 ± 0.5 ng/ml on postoperative day (POD) 1 (p < 0.001). POD1 HO-1 concentrations were 3.1 ng/ml higher (95% CI 1.1-5.1) in AKI patients, as was the change in HO-1 from baseline to POD1 (4.4 ± 1.3 ng/ml in AKI patients vs. 1.5 ± 0.3 ng/ml in no-AKI patients, p = 0.006). HO-1 concentrations remained elevated in AKI patients even after controlling for AKI risk factors and preoperative drug therapy. Peak-free hemoglobin concentrations correlated with peak HO-1 concentrations on POD1 in patients that developed AKI (p = 0.02). Duration of CPB and post-CPB IL-6 and IL-10 concentrations were also associated with increased HO-1 on POD1.

CONCLUSION

Plasma HO-1 is increased in patients that develop AKI, and CPB duration, hemolysis, and inflammation are associated with increased HO-1 concentrations following cardiac surgery. Strategies that alter hemolysis and HO-1 expression during cardiac surgery may affect risk for AKI.

The effect of electroacupuncture on postoperative immunoinflammatory response in patients undergoing supratentorial craniotomy

The aim of this study was to explore the effect of electroacupuncture (EA) on immune function in patients undergoing supratentorial craniotomy. We also examined whether point specificity in EA was present. The study involved 29 patients undergoing craniotomy. The patients were divided into three groups: a control (C, n=10), an EA (A, n=9) and a sham acupoints group (S, n=10). Blood samples were collected at the following time points: before anesthesia (T0), 4 h after the induction of anesthesia (T1), 1 day post-surgery (T2) and 2 days post-surgery (T3) to determine the levels of tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), interleukin-10 (IL-10), immunoglobulin M (IgM), IgA and IgG. Data were analyzed using SPSS 13.0 software. When comparing the levels of cytokines following surgery, we observed that the peripheral blood IL-8 levels in groups A and S were increased significantly compared with those of group C at 1 and 2 days after surgery. When comparing immunoglobulin levels after surgery, we established that the peripheral blood IgA levels in group C had decreased significantly compared to those of group A and group S 4 h after induction of anesthesia and 1 day after surgery. However, there was no significant difference between group A and group S. Compared with simple general anesthesia, acupuncture combined with anesthesia partially reduces immune suppression in the perioperative periods under the same conditions as the simple general anesthesia. Point specificity in EA was not present.

Epicardial ganglionated plexus stimulation decreases postoperative inflammatory response in humans

BACKGROUND

Surgical cardiac revascularization produces a high degree of systemic inflammation and the secretion of several cytokines. Intensive postoperative inflammation may increase the incidence of postoperative atrial fibrillation and favor organ dysfunctions. No data documenting the anti-inflammatory properties of epicardial vagal ganglionated plexus stimulation are available.

OBJECTIVE

To verify the feasibility and safety of postoperative inferior vena cava-inferior atrial ganglionated plexus (IVC-IAGP) burst stimulation and the effectiveness of this approach in reducing serum levels of inflammatory cytokines.

METHODS

In 27 patients who were candidates for off-pump surgical revascularization, the IVC-IAGP was located during surgery, a temporary wire was inserted, and a negative atrioventricular node dromotropic effect was obtained in 20 patients on applying high-frequency burst stimulation. In 5 patients atrial fibrillation or phrenic nerve stimulation was induced, and the remaining 15 patients served as the experimental group. Twenty additional patients underwent off-pump surgical revascularization without IVC-IAGP stimulation and served as the control group. On arrival in the intensive care unit, the experimental group underwent IVC-IAGP stimulation for 6 hours. Blood samples were collected at different times.

RESULTS

The serum levels of cytokines were not statistically different at baseline and on arrival in the intensive care unit between the groups, while they proved statistically different after 6 hours of stimulation: interleukin-6 (EG: 121 ± 71 pg/mL vs CG: 280 ± 194 pg/mL; P = .004), tumor necrosis factor-α (EG: 2.68 ± 1.81 pg/mL vs CG: 5.87 ± 3.48 pg/mL; P = .003), vascular endothelial growth factor (EG: 93 ± 43 pg/mL vs CG: 177 ± 86 pg/mL; P = .002), and epidermal growth factor (EG: 79 ± 48 pg/mL vs CG: 138 ± 76 pg/mL; P = .012).

CONCLUSIONS

Prolonged burst IVC-IAGP stimulation after surgical revascularization appears to be feasible and safe and significantly reduces inflammatory cytokines in the postoperative period.

Endothelial activation after coronary artery bypass surgery: comparison between on-pump and off-pump techniques

BACKGROUND

The effects of off-pump coronary artery bypass (OPCAB) surgery on endothelial cell activation are poorly understood. Endothelial cell adhesion molecules (CAMs) are expressed and released when the endothelium is activated. We compared plasma CAMs (E-selectin, ICAM-1 and VCAM-1) and HUVEC expression of the same CAMs when exposed to plasma taken before, during and after OPCAB or on-pump coronary surgery (CABG).

METHODS

Patients undergoing first time CABG (n=10) or OPCAB (n=10) had 6 blood samples taken before surgery and up to 24h post-operatively. Plasma samples were assayed for E-selectin, ICAM-1 and VCAM-1. The same plasma samples were exposed to HUVEC cultures and cell-surface expression of E-selectin, ICAM-1 and VCAM-1 measured. Data are expressed as mean+/-SEM of n subjects.

RESULTS

Plasma E-selectin was unchanged. Plasma ICAM-1 and VCAM-1 were elevated 24h post-operatively in both groups (P<0.01), with no differences between the groups. Twenty-four hours post-OPCAB plasma increased basal and IL-1beta induced expression of endothelial VCAM-1 by 133+/-16% and 140+/-27% (P<0.05), respectively. Plasma taken 3h post-CABG decreased endothelial VCAM-1 expression by 76+/-10% (P<0.05). Peri-operative plasma had no effect on endothelial expression of E-selectin or ICAM-1 in either group.

CONCLUSIONS

OPCAB and CABG with CPB appear to generate qualitatively different inflammatory responses with respect to endothelial activation, which may have clinical implications.

High postoperative interleukin-8 levels related to atrial fibrillation in patients undergoing coronary artery bypass surgery

BACKGROUND

Atrial fibrillation (AF) is the most frequently encountered postoperative arrhythmic complication after coronary artery bypass graft (CABG). There is increasing evidence to support the influence of inflammation in the pathogenesis of AF. The aim of the present study was to investigate the relation of postoperative new AF and systemic inflammatory changes after CABG.

METHODS

A total of 113 CABG patients were recruited in the present study. Holter data from 24-hour electrocardiography were collected from 1 day before the operation to postoperative day 2 (POD2). AF was registered as positive if any AF event occurred. Serum cytokine, including interleukin (IL)-6, IL-8, and IL-10 were analyzed before and after surgery.

RESULTS

The overall incidences of postoperative AF and sustained AF were 36.3% and 31.9%, respectively. Patients with postoperative AF had longer respiratory treatment, intensive care unit treatment, and inotropic medication periods. Similar concentrations of serum IL-6 were found after surgery in patients with and without AF. The concentrations of serum IL-8 was significantly higher at 2 hours and on POD1 and POD2 in patients with postoperative AF. The concentration of serum IL-10 was significantly higher on POD1 in patients with postoperative AF.

CONCLUSIONS

Postoperative AF in CABG patients is associated with a more complicated postoperative outcome. Higher concentrations of serum IL-8 in CABG patients with postoperative AF suggested that an influence of inflammation in the pathogenesis postoperative AF after open heart surgery.

Analysis of inflammatory response and utility of N-terminal pro brain-type natriuretic peptide in cardiac surgery with extracorporeal circulation

OBJECTIVES

Cardiac surgery with cardiopulmonary bypass (CPB) elicits an inflammatory response. During and after cardiac surgery, we examined the pattern of cytokine release of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-alpha, to investigate inflammatory response. We analyzed N-terminal pro brain-type natriuretic peptide (NT-proBNP) as a marker of ventricular function.

METHODS

Consecutive patients (n = 58) undergoing elective cardiac surgery with extra-corporeal circulation were recruited into the study. Blood samples for analysis of the biochemical markers were taken at seven time points for cytokines and TNF, and three for Nt-proBNP.

RESULTS

All markers increased significantly after CPB. IL-6 and IL-8 levels were higher in men. IL-8 was related to a need for inotropic support. IL-6 was related to the time of CPB (P = 0.004), aortic clamping (P = 0.013), length of stay in intensive care unit (ICU) (P = 0.004) and mechanical ventilation for more than 12 h (P = 0.006). The levels of NT-proBNP were higher in cases of ventricular dysfunction (P = 0.003) and functional class III/IV (P = 0.001). The postoperative values were related to age (P < 0.05), creatinine values (P < 0.001), mechanical ventilation time (P < 0.001) and stay in the ICU (P = 0.001).

CONCLUSION

Our data indicate a relationship between cytokine levels and sex, time of CPB and aortic clamping, The increase of cytokines correlates with a need for inotropic support, mechanical ventilation and length of stay in ICU. We confirmed the predictive role, and its utility in the risk stratification of the NT-proBNP, and its importance in early diagnosis of postoperative ventricular dysfunction.

Influence of dextran-70 on systemic inflammatory response and myocardial ischaemia-reperfusion following cardiac operations

Introduction

Experimental studies have demonstrated that dextran-70 reduces the leukocyte–endothelium interaction, but clinical evidence is still lacking. Our objective was to justify the anti-inflammatory effect of dextran-70 following cardiac operations.

Methods

Forty patients undergoing coronary bypass surgery (n = 32) or aortic valve replacement (n = 8) were enrolled in this prospective, randomized, double-blind study. Two groups were formed. In group A (n = 20), dextran-70 infusion was administered at a dose of 7.5 ml/kg before the initiation of cardiopulmonary bypass and at a dose of 12.5 ml/kg after the cessation of cardiopulmonary bypass. Group B served as a control with identical amounts of gelatin infusion (n = 20). The plasma concentration of procalcitonin, C-reactive protein, IL 6, IL 6r, IL 8, IL 10, soluble endothelial leukocyte adhesion molecule-1, soluble intercellular adhesion molecule-1, cardiac troponin-I and various haemodynamic parameters were measured in the perioperative period. Multivariate methods were used for statistical analysis.

Results

In group A, lower peak (median) plasma levels of procalcitonin (0.2 versus 1.4, p < 0.001), IL 8 (5.6 versus 94.8, p < 0.001), IL 10 (47.2 versus 209.7, p = 0.001), endothelial leukocyte adhesion molecule-1 (88.5 versus 130.6, p = 0.033), intercellular adhesion molecule-1 (806.7 versus 1,375.7, P = 0.001) and troponin-I (0.22 versus 0.66, p = 0.018) were found. There was no significant difference in IL 6, IL-6r and C-reactive protein values between groups. Higher figures of the cardiac index (p = 0.010) along with reduced systemic vascular resistance (p = 0.005) were noted in group A.

Conclusion

Our investigation demonstrated that the use of dextran-70 reduces the systemic inflammatory response and cardiac troponin-I release following cardiac operation.

Trial registration number

ISRCTN38289094.

Prevention of atrial fibrillation following cardiac surgery: basis for a novel therapeutic strategy based on non-hypoxic myocardial preconditioning

Atrial fibrillation is the most common complication of cardiac surgical procedures performed with cardiopulmonary bypass. It contributes to increased hospital length of stay and treatment costs. At present, preventive strategies offer only suboptimal benefits, despite improvements in anesthesia, surgical technique, and medical therapy. The pathogenesis of postoperative atrial fibrillation is considered to be multifactorial. However oxidative stress is a major contributory factor representing the unavoidable consequences of ischemia/reperfusion cycle occurring in this setting. Considerable evidence suggests the involvement of reactive oxygen species (ROS) in the pathogenic mechanism of this arrhythmia. Interestingly, the deleterious consequences of high ROS exposure, such as inflammation, cell death (apoptosis/necrosis) or fibrosis, may be abrogated by a myocardial preconditioning process caused by previous exposure to moderate ROS concentration known to trigger survival response mechanisms. The latter condition may be created by n-3 PUFA supplementation that could give rise to an adaptive response characterized by increased expression of myocardial antioxidant enzymes and/or anti-apoptotic pathways. In addition, a further reinforcement of myocardial antioxidant defenses could be obtained through vitamins C and E supplementation, an intervention also known to diminish enzymatic ROS production. Based on this paradigm, this review presents clinical and experimental evidence supporting the pathophysiological and molecular basis for a novel therapeutic approach aimed to diminish the incidence of postoperative atrial fibrillation through a non-hypoxic preconditioning plus a reinforcement of the antioxidant defense system in the myocardial tissue.

Inflammatory response and cardioprotection during open-heart surgery: the importance of anaesthetics

Open-heart surgery triggers an inflammatory response that is largely the result of surgical trauma, cardiopulmonary bypass, and organ reperfusion injury (e.g. heart). The heart sustains injury triggered by ischaemia and reperfusion and also as a result of the effects of systemic inflammatory mediators. In addition, the heart itself is a source of inflammatory mediators and reactive oxygen species that are likely to contribute to the impairment of cardiac pump function. Formulating strategies to protect the heart during open heart surgery by attenuating reperfusion injury and systemic inflammatory response is essential to reduce morbidity. Although many anaesthetic drugs have cardioprotective actions, the diversity of the proposed mechanisms for protection (e.g. attenuating Ca(2+) overload, anti-inflammatory and antioxidant effects, pre- and post-conditioning-like protection) may have contributed to the slow adoption of anaesthetics as cardioprotective agents during open heart surgery. Clinical trials have suggested at least some cardioprotective effects of volatile anaesthetics. Whether these benefits are relevant in terms of morbidity and mortality is unclear and needs further investigation. This review describes the main mediators of myocardial injury during open heart surgery, explores available evidence of anaesthetics induced cardioprotection and addresses the efforts made to translate bench work into clinical practice.

Effect of cardiopulmonary bypass on cytokine network and myocardial cytokine production

BACKGROUND

In addition to the well-investigated proinflammatory cytokine expression, there is an ever increasing interest in the field of anti-inflammatory response to cardiopulmonary bypass (CPB). Evidence suggests that myocardium serves as an important source of cytokines during reperfusion and application of CPB. The effect of coronary artery bypass graft (CABG) without CPB on myocardial cytokine production has not as yet been investigated.

HYPOTHESIS

Cardiopulmonary bypass can cause long-term disturbance in pro- and anti-inflammatory cytokine balance, which may impede a patient's recovery following surgery. Therefore, the effect of CPB on the balance of the pro-/anti-inflammatory cytokines network and myocardial cytokine outflow was assessed throughout a longer period after surgery.

METHODS

Twenty patients were scheduled for CABG with CPB and 10 had off-pump surgery. Blood samples were taken before, during, and over the first week following surgery. Coronary sinus blood samples were collected during surgery. The ratio of pro- and anti-inflammatory cytokines was calculated and the cytokine concentration of peripheral and coronary sinus blood were compared in both groups.

RESULTS

Pro-/anti-inflammatory cytokine ratio decreased early after CPB followed by a delayed and marked increase. A more balanced ratio was present following off-pump surgery. Coronary sinus levels of certain cytokines exceeded the concentration of systemic blood in the course of CPB but not during off-pump operation.

CONCLUSION

Patients show pro-inflammatory predominant cytokine balance at a later stage after CPB in contrast to those without CPB. The heart produces a remarkable amount of cytokines only in the course of surgery with CPB.

Biocompatibility of Heparin-Coated Cardiopulmonary Bypass Circuits in Coronary Patients With Left Ventricular Dysfunction Is Superior to PMEA-Coated Circuits

BACKGROUND

Several coating techniques for extracorporeal circulation have been developed to diminish the systemic inflammatory response during cardiopulmonary bypass (CPB). The aim of this study was to evaluate the clinical effectiveness and biocompatibility of heparin-coated and poly-2-methoxyethylacrylate (PMEA)-coated CPB circuits on coronary patients with left ventricular systolic dysfunction.

METHODS

Thirty-six patients who underwent elective coronary artery bypass grafting were divided into two equal groups: group H (n = 18), heparin-coated; group P (n = 18), PMEA coated. Clinical outcomes, hematologic variables, cardiac enzymes, malondialdehyde (MDA), and acute phase inflammatory response (including myeloperoxidase (MPO), catalase, hsCRP, and IL-8) were analyzed perioperatively.

RESULTS

Demographic, CPB, and clinical outcome data were similar for both groups. Plasma fibrinogen, total protein, albumin, and platelet count decreased, neutrophil count, MDA, IL-8, MPO, and catalase levels increased during CPB. During CPB, MPO and catalase values were significantly higher in group P (p = 0.02 and p = 0.01) and postoperative MDA concentration was lower in group H (p = 0.03). Platelet counts were better preserved in group H during and after CPB but neutrophil count and IL-8 level did not differ between the groups. Postoperative total protein, albumin, and fibrinogen levels were higher in group H (p < 0.05). The postoperative first day levels of troponin-I, CK-MB, and CRP increased in both groups without any significant differences between the groups.

CONCLUSIONS

Heparin-coated circuit provided better suppression of perioperative inflammatory markers and exhibited more favorable effects on hematologic variables than PMEA-coated circuit.

Interleukin-10 and its role in clinical immunoparalysis following pediatric cardiac surgery

OBJECTIVE

A systemic insult is associated with subsequent hyporesponsiveness to endotoxin (as measured by ex vivo tumor necrosis factor [TNF]-alpha production) and an increased risk of late nosocomial infection in some patients. When combined with low monocyte surface major histocompatibility complex class II expression, this state of altered host defense is now commonly referred to as immunoparalysis. This study was undertaken to delineate the relationship between observed levels of the anti-inflammatory cytokine interleukin-10, common genetic polymorphisms that influence these levels, and the occurrence and severity of endotoxin hyporesponsiveness in children following elective cardiac surgery requiring cardiopulmonary bypass.

DESIGN

A prospective observational clinical study.

SETTING

A tertiary pediatric cardiac center.

PATIENTS

Thirty-six infants and children <2 yrs of age undergoing elective cardiac surgery requiring cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We investigated the production of TNF-alpha, interleukin-6, interleukin-8, interleukin-1 receptor antagonist, and interleukin-10 in whole blood in response to lipopolysaccharide (Neisseria meningitides 10 ng/mL) in samples drawn before, during, and up to 48 hrs after surgery. Patients were genotyped for the -1082, -819, and -592 interleukin-10 promoter polymorphisms. Whole blood cytokine response to lipopolysaccharide was reduced postoperatively to </=50% of preoperative levels for all cytokines measured. Stimulated cytokine production was lowest in cases with the highest postoperative plasma interleukin-10 levels, which were in turn associated with the GCC haplotype. Those patients in whom the whole blood response to endotoxin was maintained (TNF-alpha >100 pg/mL) over the first 48 hrs were more likely to have an uncomplicated short stay (odds ratio 4.7, 95% confidence interval 1-22).

CONCLUSIONS

Immediately following cardiac surgery, many children become relatively refractory to lipopolysaccharide stimulation. This immunoparalysis appears to be related in part to high circulating levels of interleukin-10 and places these patients at increased risk of postoperative complications. Interleukin-10 genotype may be a risk factor for immunoparalysis.

The acute cardioprotective effect of glucocorticoid in myocardial ischemia–reperfusion injury occurring during cardiopulmonary bypass

The purpose of this study was to evaluate the acute cardioprotective effect of high-dose methylprednisolone (25 mg/kg) in the controlled in vivo model of myocardial ischemia-reperfusion injury occurring during cardiopulmonary bypass. Forty nondiabetic male patients with three-vessel disease undergoing first-time bypass surgery were enrolled for this double-blind prospective study. Patients were randomized to be given 25 mg/kg methylprednisolone (Group I) and saline (Group II) 1 h before cardiopulmonary bypass. The levels of cardiac troponin-I (cTnI) were used as a marker of myocardial tissue damage in myocardial ischemia-reperfusion injury. The cTnI levels were measured before surgery, at the second hour after cardiopulmonary bypass, at the 6th and 24th hours, and 5th day postoperatively. There was no significant difference between the two groups in respect to the duration of ischemia and reperfusion. The preoperative cTnI levels were 0.22+/-0.29 ng/ml in Group I and 0.23+/-0.28 ng/ml in Group II. cTnI levels increased to 2.40+/-1.0 ng/ml in Group I and 3.19+/-0.88 ng/ml in Group II at the 2nd hour after cardiopulmonary bypass. When the differences between T1 and T0 level that showed the amount of troponin release occurring due to ischemia-repefusion injury was calculated and then compared, there was a significant difference between Groups I and II (P=0.024). The cTnI levels measured at 6 h after CPB were 1.98+/-0.63 ng/ml in Group I and 2.75+/-1.15 ng/ml in Group II (P=0.049). cTnI levels decreased to 0.22+/-0.10 ng/ml in Group I and 0.49+/-0.25 ng/ml in Group II on the postoperative day 5 (P=0.0001). Univalent regression analysis showed that preoperative high-dose corticosteroid usage decreased the troponin release in about 12% and this effect was statistically significant (R2=0.12, P<0.05). A single dose of intravenous methylpredisolone (25 mg/kg) given 1 h before ischemia reduced myocardial ischemia-reperfusion injury. These results demonstrated that the acute cardioprotective effect of corticosteroids has much potential in the future for reducing ischemia-reperfusion injury occurring during cardiopulmonary bypass when it is inevitable.

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.

Cytokine response in lower extremity ischaemia/reperfusion

We studied the local and systemic concentrations of pro-inflammatory cytokines produced during acute lower extremity ischaemia and following reperfusion in 19 patients undergoing thromboembolectomy of the femoral artery. Blood samples were taken from the femoral vein (local response) and radial artery (systemic response) in the ischaemic (baseline) phase, and 2, 12 and 24 h post-reperfusion. Associated lung injury was measured by the alveolar-arterial (A-a) oxygen gradient and post-reperfusion femoral vein plasma concentrations of creatinine kinase and lactic dehydrogenase were also measured. Local and systemic concentrations of interleukin (IL)-2 receptor and IL-6 (but not IL-1 beta) increased significantly after reperfusion. IL-8 concentration increased significantly in the radial artery. The high and progressively increasing concentration of IL-6 in the femoral vein suggests local production. The parallel increase in creatinine kinase concentration and A-a oxygen gradient indicates that IL-6 plays an important role in acute arterial occlusion and reperfusion injury.

Pharmacologic preconditioning of JTE-607, a novel cytokine inhibitor, attenuates ischemia-reperfusion injury in the myocardium

BACKGROUND

Myocardial ischemia-reperfusion injury is a main cause of postoperative cardiac dysfunction, and a burst of proinflammatory cytokines, such as tumor necrosis factor alpha, interleukin 1 beta, interleukin 6, and interleukin 8, plays a pivotal role. Recently, JTE-607 has been reported as a potent inhibitor of the multiple inflammatory cytokines in the endotoxin shock mouse model. In this study we proved the hypothesis that JTE-607 might attenuate myocardial ischemia-reperfusion injury in a rat model.

METHODS

The isolated rat hearts in the JTE-607 preconditioning group (J group, n = 8) or control group (C group, n = 8) were subjected to warm ischemia (37 degrees C) for 30 minutes, followed by 60 minutes of reperfusion with the Langendorff perfusion system.

RESULTS

Left ventricular developed pressure and maximum dp/dt after reperfusion were significantly improved in the J group than in the C group (P <.01). Creatine phosphokinase leakage is significantly lower in the J group (P <.05). Moreover, the tissue cytokine levels, such as tumor necrosis factor alpha, interleukin 6, and interleukin 8, in the myocardium were significantly lower in the J group than in the C group (P <.05).

CONCLUSION

These results suggested that the pharmacologic preconditioning of JTE-607 inhibits a burst of endogenous cytokines in the myocardium, resulting in the improvement of cardiac function after ischemia-reperfusion injury. Thus JTE-607 might be a novel therapeutic strategy for the protection of postoperative cardiac dysfunction in cardiac surgery.

Importance of pulmonary artery perfusion in cardiac surgery

OBJECTIVE

To investigate the importance of pulmonary artery perfusion in cardiac surgery.

DESIGN

Prospective randomized study.

SETTING

University hospital.

PARTICIPANTS

Patients undergoing cardiac surgery.

INTERVENTIONS

Patients in whom the cross-clamp was applied only to the aorta were defined as group 1 (n = 11) and patients in whom the cross-clamp was applied to both the aorta and pulmonary artery were defined as group 2 (n = 11).

MEASUREMENT AND RESULTS

Tissue samples obtained from the lower lobe of the left lung before CPB, 20 minutes after cross-clamping, and 20 minutes after declamping were examined under light and electron microscopes. Electron microscopic examination revealed changes in the blood-air barrier, epithelial cells, pneumocytes, and basal membrane were more prominent in group 2. Changes in the leukocyte, neutrophil, and lymphocyte counts of blood samples obtained from the right atrium and right superior pulmonary vein before CPB and 5, 30, 60, and 90 minutes after the removal of clamp were also investigated. The transpulmonary difference was statistically significant at 5 and 30 minutes after declamping in group 1. In group 2, transpulmonary differences continued to be significant at 5, 30, 60, and 90 minutes after declamping. There was no difference between groups in terms of PaO(2)/F(I)O(2) ratio before CPB (group 1: 342.0 +/- 80.0 mmHg, group 2: 349.0 +/- 67.0 mmHg); however, a statistically significant difference was found between the groups 2 hours after declamping (group 1: 418.0 +/- 87.0 mmHg and group 2: 290.0 +/- 110.0 mmHg; p = 0.007).

CONCLUSION

Pulmonary artery perfusion was found to be important in cardiac surgery.

Monocyte activation markers during cardiopulmonary bypass

Extracorporeal support during cardiac surgery initiates an inflammatory response, causing damage to cardiac, pulmonary and renal tissue [Post Pump Syndrome (PPS)]. This is accompanied by a neutrophil leucocytosis and lymphopenia, but less is known about the role of monocytes and markers of monocyte activity. We studied 19 patients undergoing cardiac surgery, obtaining blood samples from the aortic root (AR) and from the coronary sinus ( < s) before the cardiopulmonary bypass (CPB), 1 min after release of the aortic crossclamp and 10 min after weaning from CPB (periods 1, 2 and 3). Leucocyte count, monocyte count and HLA-DR, CD15, CD11b and CD62L activation markers were measured. In samples obtained from the coronary sinus (CS), HLA-DR, expressed as a percentage of the monocyte count, decreased between periods 1, 2 and 3 by 78%, 66% and 43%, respectively. A similar change was observed in samples from the AR. Conversely, CD62L increased in the CS samples (55%, 68% and 73%), but revealed a lesser increase in the AR samples (51%, 68% and 63%). The other markers showed little change throughout the procedure. Reduced immunological competence could result from the decrease in HLA-DR counts. Increases in CD62L sensitizes monocytes to the tethering effects of endothelial integrins and might contribute to the atherosclerotic process.

Significance of assessment of serum cardiac troponin I and interleukin-8 in scorpion envenomed children

In the present study, 41 children in Upper Egypt were admitted to Pediatric Intensive Care Unit, Assiut University Hospital, for scorpion envenomation. They were compared with 15 apparently healthy children of matching age as controls. The victims and controls were subjected to complete clinical examination, full blood count and arterial blood gases analysis. According to severity of scorpion envenomation, 17 children had manifestations of severe envenomation and clinical signs of toxic myocarditis (severe cases), 14 children had moderate manifestations of envenomation without clinical evidence of carditis (moderate cases) and 10 cases showing only mild symptoms of envenomation (mild cases). The serum levels of cardiac troponin I (cTnI) and interleukin-8 (IL-8) beside the enzymatic activities of creatine phosphokinase (CPK), CPK-isoenzyme-MB (CPK-MB) and lactate dehydrogenase (LDH) were determined once for mild cases and controls on admission and twice for severe and moderate cases on admission and after 24. Electrocardiography and measurements of echocardiographic (Echo) of % fractional shortening of left ventricule (% SF), left ventricular ejection fraction (LVEF) and cardiac chambers dilatation were done for severe and moderate cases. All the envenomed victims showed significantly higher mean values of CPK, CPK-MB, LDH, and IL-8 on admission in comparison to control group. cTnI was not detectable in the sera of control group as well as patients of mild envenomation. The mean values of CPK, CPK-MB, LDH, and IL-8 were significantly higher in severe cases while only IL-8 and CPK-MB were significantly higher in moderate cases in comparison with mild cases. The mean values of IL-8, cTnI, CPK, CPK-MB and LDH were significantly higher in severe cases both on admission and on follow-up comparing with moderate cases. The case fatality rate was 12.5% and all were from severe cases with toxic myocarditis. The non-survivors victims showed significant higher mean values of only cTnI on admission and both cTnI and IL-8 on follow up in comparison to the survivors. Significant reduction of % SF and LVEF were noticed among the non-survivors in comparison to survivors. The cTnI showed 100% specificity and sensitivity for diagnosis of myocardial injury in relation to Echo finding in the envenomed victims. In severe cases, cTnI was positively correlated with IL-8 while negatively correlated with %SF and LVEF. In conclusion, cTnI is a specific marker for diagnosis of myocardial injury in scorpion envenomation while other biochemical markers did not show such specificity. Also, IL-8 may be involved in the pathogenesis of myocardial injury of scorpion envenomation. Both cTnI and IL-8 may be useful to forecast the fatal outcome in scorpion envenomation.

Systematic organ protection in coronary artery surgery with or without cardiopulmonary bypass

Coronary artery bypass grafting with cardiopulmonary bypass (CPB) is known to be associated with a systemic inflammatory response, which contributes to the development of postoperative complications including multiple organ dysfunction. Off-pump coronary surgery has been shown to attenuate the inflammatory injury compared to the conventional approach, thereby reducing the incidence of postoperative cardiopulmonary, renal, or neurological dysfunction. It is believed that off-pump experience may greatly impact on improving the outcome of coronary surgery in certain high-risk patients. Moreover, a better understanding of the underlying mechanism would also help to improve our current CPB management. Accumulating evidence to date indicates that a balance between pro- and antiinflammatory responses is crucial in limiting the extent of such systemic inflammatory injury following surgical myocardial revascularization.

Differential effects of aprotinin and tranexamic acid on endotoxin desensitization of blood cells induced by circulation through an isolated extracorporeal circuit

OBJECTIVE

To compare the effects of aprotinin and tranexamic acid on blood cytokine secretion induced by the circulation of blood through an isolated extracorporeal circuit.

DESIGN

Prospective, placebo-controlled study.

SETTING

University hospital.

PARTICIPANTS

Healthy volunteers (n = 18).

INTERVENTIONS

Blood (400 mL) first was drawn from volunteers, then circulated through an isolated extracorporeal circuit. Three groups were compared depending on the addition or not of an antifibrinolytic agent in the circuit (control group [n = 8], tranexamic group [n = 5], aprotinin group [n = 5]). Samples for measurement were taken before and at different time points after the start of circulation through the extracorporeal circuit. Cytokine (tumor necrosis factor-alpha, interleukin [IL]-6, IL-8, and IL-10) concentrations in the plasma and in the supernatant of lipopolysaccharide-stimulated whole blood cell cultures were analyzed.

MEASUREMENTS AND MAIN RESULTS

In the control and tranexamic acid groups, tumor necrosis factor-alpha, IL-6, and IL-10 secretion by whole blood cell cultures were rapidly decreased, whereas IL-8 secretion was unaffected. In the aprotinin group, IL-8 secretion was also decreased (p < 0.05).

CONCLUSION

These results show that aprotinin, but not tranexamic acid, modulates the inflammatory response by reducing the IL-8 secretion of blood cells activated by contact with foreign surfaces.

Off-pump coronary artery surgery

Cardiopulmonary bypass has several associated deleterious effects that include a systemic inflammatory response, coagulopathy, central nervous system complications and a variable degree of end-organ damage. The recent upsurge in interest in "beating-heart" surgery attempts to avoid these deleterious effects. Advances in surgical technique, such as the use of intracoronary shunts and the Octopus retractor, have made beating-heart surgery a reality. The challenges for the anaesthetist are greater than for coronary artery surgery using cardiopulmonary bypass, and whilst some advantages are proven, such as the lack of the inflammatory response and the decreased need for blood or blood products, others have yet to be proved and there is a need for further research. The advantages and disadvantages need to be evaluated in randomised studies in order to confirm the safety and efficacy of these new techniques in terms of long-term graft patency and decreased morbidity.

The systemic factor: the comparative roles of cardiopulmonary bypass and off-pump surgery in the genesis of patient injury during and following cardiac surgery

There is compelling evidence that off-pump coronary artery bypass operations are associated with reduced circulating levels of inflammatory mediators. Whereas complement activation and release of acute-phase reactants such as interleukin-6 are still expected to occur as consequences of a nonbypass-related general surgical trauma, a major feature of off-pump surgery seems to be a decreased production of interleukin-8, which may have important practical implications because of the participation of this cytokine in neutrophil trafficking and myocardial injury. The scarcity of carefully controlled, randomized trials precludes firm conclusions regarding the extent to which these biological changes translate into meaningful improvements in clinical outcomes. The problem is further complicated by the fact that the adverse effects of cardiopulmonary bypass largely depend on a genetically controlled balance between proinflammatory and antiinflammatory mediators. Currently, it is still impossible to predict, in a given patient, the side toward which this balance will be shifted. Nevertheless, accumulating experience identifies patient subgroups who may greatly benefit from avoiding extracorporeal circulation. These subsets include patients with severe extracardiac comorbidities (in particular, renal failure) and, possibly, patients with advanced left ventricular dysfunction, who may poorly tolerate superimposed, bypass-related, inflammatory tissue injuries.

High-dose cimetidine reduces proinflammatory reaction after cardiac surgery with cardiopulmonary bypass

BACKGROUND

Cimetidine, which is usually used for gastric ulcer, enhances cellular immunity. The effect of cimetidine on perioperative proinflammatory response after cardiac surgery with cardiopulmonary bypass was investigated.

METHODS

Elective coronary artery bypass graft cases in which CPB was performed were placed randomly in a cimetidine (C) group (n = 20) or a no-treatment (N) group (n = 20). The time course of plasma levels of neutrophil elastase, interleukin (IL)-6 and IL-8, leukocyte counts, lymphocyte recovery ratio, C-reactive protein, creatine-kinase-MB, and oxygenation index were analyzed.

RESULTS

The plasma levels of neutrophil elastase and IL-8 were inhibited in the C groups at 2 hours after CPB termination. In a comparison of the two groups, the C group demonstrated higher lymphocyte recovery ratio and lower C-reactive protein on postoperative day 5 and shorter intubation time. No intergroup differences were observed in IL-6, leukocyte counts, creatine-kinase-MB levels, or oxygenation index.

CONCLUSIONS

Cimetidine may reduce surgical stress and augment the immune system after cardiac surgery with cardiopulmonary bypass.

Intraoperative metabolic monitoring of the heart: I. Clinical assessment of coronary sinus metabolites

Numerous clinical studies have corroborated the ability of intraoperative sampling of coronary sinus blood to measure changes in myocardial metabolism induced by ischemia and reperfusion. Among other changes, cardiac arrest induces a period of obligate myocardial lactate production that persists for an indeterminate amount of time after reperfusion. Coronary sinus lactate assays have been established as a standard method to compare various myocardial protection strategies. Current methodology requires detailed sample processing, precluding real-time feedback in the operating room. Newer devices hold promise in allowing the online assessment of myocardial metabolism; however, these methods await precise validation.

Off-Pump Coronary Artery Bypass Surgery: Revival of an Old Technique

The ability to perform surgical procedures on the heart was one of the greatest accomplishments of the 20th century. What was once considered an impossible task has become a routine in daily clinical activity. The in troduction of extracorporeal circulation and myocardial protection strategies opened the doors to what was considered by most an insurmountable barrier— unhin dered access to the coronary circulation and intracar diac structures. In the United States, approximately 85% of coronary artery bypass graft procedures are performed with the use of cardiopulmonary bypass (CPB). CPB was and remains the gold standard for this type of cardiac surgical intervention. Over the years, investigators have struggled to find ways of lessening or eliminating the adverse physiologic effects of CPB. These efforts have focused on pharmacologic interven tion, monitoring procedures, blood gas management, and temperature management. Another way of avoid ing these effects is inherently obvious — eliminate the main source of the problem.