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

Perioperative Hyper-coagulation and Thrombosis: Cost Analysis After Congenital Heart Surgery

Thrombosis, a major adverse event of congenital heart surgery, has been associated with poor outcomes. We hypothesized that in CHD patients undergoing cardiac surgery, increased perioperative use of pro-coagulant products may be associated with postoperative thrombosis in the setting of hyperfibrinogenemia, leading to greater hospital and blood product costs. Single-center retrospective study. Data from Boston Children's Hospital's electronic health record database was used in this study. All patients undergoing congenital heart surgery between 2015 and 2018 with postoperative fibrinogen levels above 400 mg/dl were reviewed. Of 334 patients with high plasma fibrinogen levels, 28 (8.4%) developed postoperative thrombosis (median age: one year, 59% male). In our cohort, 25 (7%) demonstrated evidence of baseline hypercoagulability by one or more panel test results. Thrombosis was associated with greater hospital and blood product costs, longer ventilation times, and longer hospital and ICU length of stays. Preoperative hypercoagulable state (odds ratio: 2.58, 95% CI [1.07, 9.99], p = 0.002), postoperative red blood cell transfusion (odds ratio: 1.007, 95% CI [1.000, 1.015], p = 0.04), and single ventricle physiology (univariate odds ratio: 2.94, 95% CI [1.09, 7.89], p = 0.03) were predictors of postoperative thrombosis. Preoperative hypercoagulable state and intraoperative platelet transfusion were predictors of hospital cost. Thrombosis was associated with worse in-hospital outcomes and higher costs. Preoperative hypercoagulable state and postoperative red blood cell transfusion were significant predictors of thrombosis. Risk prediction models that can guide thrombosis prevention are needed to improve outcomes of patients undergoing congenital heart surgery.

Preoperative ultrasound-guided bilateral thoracic erector spinae plane block within an enhanced recovery program is associated with decreased intraoperative lactate levels in cardiac surgery

INTRODUCTION

In the perioperative period, regional analgesia techniques may play an increasingly important role in "Enhanced Recovery After Surgery (ERAS)" programs, as they can facilitate recovery. We hypothesized that Erector Spinae Plane (ESP) block could improve regional perfusion, thereby limiting blood lactate increase. Therefore, we aimed to evaluate the effect of ESP block on intraoperative blood lactate levels in patients scheduled for elective on-pump cardiac surgery with ERAS protocol.

METHODS

A total of 68 adult patients scheduled for on-pump cardiac surgery were included. All patients were randomized to the ESP group and the non-ESP group. Blood lactate analyses were performed at intraoperative five-time points. C-Reactive protein (CRP) values were also measured.

RESULTS

Blood lactate values were significantly lower in the ESP group than in the Non-ESP group, at the end of CPB [1.78 (1.23-2.78) mmol L-1 to 2.63 (1.70-3.12) mmol L-1] and during the sternal closure period [1.78 (1.27-2.42) mmol L-1 to 2.40 (2.14-2.80) mmol L-1] (p = 0.039, p = 0.009). In addition, CRP values were significantly lower in the ESP group in the postoperative period [0.048 (0.036-0.105) g L-1 to 0.090 (0.049-0.154) g L-1] (p = 0.035).

CONCLUSIONS

This study showed that preoperative bilateral single-shot ESP block significantly reduces intraoperative final blood lactate and postoperative CRP values. We consider that these results are related to the attenuation of intraoperative hypoperfusion and the alleviation of surgery-related postoperative inflammation. ERAS programs aim to achieve the rapid recovery of patients, a decrease in inflammation, and high-quality analgesia with less opioid consumption. Therefore, our results also prove that it is easier to reach the primary goals of ERAS programs with the application of ESP block in cardiac surgery.

Mass intraoperative endothelial glycocalyx shedding affects postoperative systemic inflammation response

BACGROUND

Off-pump coronary artery bypass graft (OPCABG) has a high incidence of postoperative systemic inflammation response syndrome (SIRS), and perioperative endothelial glycocalyx layer (EGL) disruption can be one of the predisposing factors. We hypothesized that EGL shedding happened earlier in OPCABG which can influence on postoperative SIRS, and sevoflurane might preserve EGL better than propofol.

METHODS

We randomly allocated 50 patients undergoing OPCABG to receive either sevoflurane-sufentanil or propofol-sufentanil anesthesia. Plasma syndecan-1, heparan sulfate (HS), atrial natriuretic peptide (ANP), IL-6, and cardiac troponin I (cTnI) were measured. Blood samples were collected at 6 timepoints: induction (T1), before grafting (T2), after grafting(T3), surgery done (T4), postoperative day1 (POD1,T5) and POD2 (T6). SIRS criteria and sequential organ failure assessment (SOFA) score were examined.

RESULTS

There were neither differences of syndecan-1, HS, IL-6 nor of SIRS criteria or SOFA score between the sevoflurane and propofol groups. All patients were pooled as a single group for further statistical analyses, plasma syndecan-1 (P < 0.001) and IL-6 (P < 0.001) increased significantly as a function of time; syndecan-1 increasing correlated significantly with the duration of coronary graft anastomosis (r = 0.329, P = 0.026). Syndecan-1(T3) correlated significantly with ANP(T3) (r = 0.0.354, P = 0.016) and IL-6 (T5) (r = 0.570, P < 0.001). The maximum value of IL-6 correlated significantly with SIRS (r = 0.378, P = 0.010), the maximum value of SOFA score (r = 0.399, P = 0.006) and ICU days (r = 0.306, P = 0.039). The maximum value of SOFA score correlated significantly with the occurrence of SIRS (r = 0.568, P < 0.001) and ICU days (r = 0.338, P = 0.022).

CONCLUSIONS

OPCABG intraoperative early EGL shedding caused of grafts anastomosis greatly affected postoperative SIRS and SOFA score, sevoflurane did not clinically preserve EGL better.

TRIAL REGISTRATION

ChiCTR-IOR-17012535. Registered on 01/09/2017.

The Role of Immune Cells Driving Electropathology and Atrial Fibrillation

Atrial fibrillation (AF) is the most common progressive cardiac arrhythmia worldwide and entails serious complications including stroke and heart failure. Despite decades of clinical research, the current treatment of AF is suboptimal. This is due to a lack of knowledge on the mechanistic root causes of AF. Prevailing theories indicate a key role for molecular and structural changes in driving electrical conduction abnormalities in the atria and as such triggering AF. Emerging evidence indicates the role of the altered atrial and systemic immune landscape in driving this so-called electropathology. Immune cells and immune markers play a central role in immune remodeling by exhibiting dual facets. While the activation and recruitment of immune cells contribute to maintaining atrial stability, the excessive activation and pronounced expression of immune markers can foster AF. This review delineates shifts in cardiac composition and the distribution of immune cells in the context of cardiac health and disease, especially AF. A comprehensive exploration of the functions of diverse immune cell types in AF and other cardiac diseases is essential to unravel the intricacies of immune remodeling. Usltimately, we delve into clinical evidence showcasing immune modifications in both the atrial and systemic domains among AF patients, aiming to elucidate immune markers for therapy and diagnostics.

T-cell lymphopenia is associated with an increased infecting risk in children after cardiopulmonary bypass

BACKGROUND

children who undergo CPB operations are at an elevated risk of infection due to immunosuppression. This study aims to investigate the association between lymphopenia following CPB and early postoperative infection in children.

METHODS

A retrospective analysis including 41 children under 2 years old underwent CPB. Among them, 9 subjects had an early postoperative infection, and 32 subjects were period-matched without infection. Inflammatory cytokines, serum CRP and PCT values were measured in plasma, additionally, circulating total leucocyte and lymphocyte subpopulations were counted.

RESULTS

Infected subjects exhibited significantly higher levels of inflammatory cytokines, including IL-6, IL-8, IL-10, IL-1β and TNF-α, than non-infected subjects after CPB. Additionally, lower absolute number of lymphocyte and their subpopulations CD3+ T cells, CD4+ T-helper cells and CD8+cytotoxic T-cells, were observed in infected subjects. The impairment of T-cells Immune was found to be associated with higher levels of inflammatory cytokines IL-10. The ROC demonstrated that the absolute number of CD3+ T-cells <1934/ul, CD4+ T helper cells <1203/ul and CD8+cytotoxic T-cells <327/ul were associated with early postoperative infection.

CONCLUSION

Higher levels of inflammatory cytokines resulted in T-cells lymphopenia after CPB, which significantly increasing the risk of postoperative infection in infants and young children.

IMPACT

Infection complications after cardiopulmonary bypass (CPB) in pediatric CHD patients are serious issues, identifing the infection from after CPB remains a challenging. CPB can release numerous inflammatory cytokines associated with T cells lymphopenia, which increases the risk of postoperative infection after surgery. Monitoring T cells lymphopenia maybe more beneficial to predict early postoperative infection than C-reactive protein and procalcitonin.

Health position paper and redox perspectives on reactive oxygen species as signals and targets of cardioprotection

The present review summarizes the beneficial and detrimental roles of reactive oxygen species in myocardial ischemia/reperfusion injury and cardioprotection. In the first part, the continued need for cardioprotection beyond that by rapid reperfusion of acute myocardial infarction is emphasized. Then, pathomechanisms of myocardial ischemia/reperfusion to the myocardium and the coronary circulation and the different modes of cell death in myocardial infarction are characterized. Different mechanical and pharmacological interventions to protect the ischemic/reperfused myocardium in elective percutaneous coronary interventions and coronary artery bypass grafting, in acute myocardial infarction and in cardiotoxicity from cancer therapy are detailed. The second part keeps the focus on ROS providing a comprehensive overview of molecular and cellular mechanisms involved in ischemia/reperfusion injury. Starting from mitochondria as the main sources and targets of ROS in ischemic/reperfused myocardium, a complex network of cellular and extracellular processes is discussed, including relationships with Ca2+ homeostasis, thiol group redox balance, hydrogen sulfide modulation, cross-talk with NAPDH oxidases, exosomes, cytokines and growth factors. While mechanistic insights are needed to improve our current therapeutic approaches, advancements in knowledge of ROS-mediated processes indicate that detrimental facets of oxidative stress are opposed by ROS requirement for physiological and protective reactions. This inevitable contrast is likely to underlie unsuccessful clinical trials and limits the development of novel cardioprotective interventions simply based upon ROS removal.

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

Patients undergoing coronary revascularization with extracorporeal circulation or cardiopulmonary bypass (CPB) may develop several biochemical changes in the microcirculation that lead to a systemic inflammatory response. Surgical incision, post-CPB reperfusion injury and blood contact with non-endothelial membranes can activate inflammatory signaling pathways that lead to the production and activation of inflammatory cells, with cytokine production and oxidative stress. This inflammatory storm can cause damage to vital organs, especially the heart, and thus lead to complications in the postoperative period. In addition to the organic pathophysiology during and after the period of exposure to extracorporeal circulation, this review addresses new perspectives for intraoperative treatment and management that may lead to a reduction in this inflammatory storm and thereby improve the prognosis and possibly reduce the mortality of these patients.

Comparison of the Efficacy of Atorvastatin and Rosuvastatin in Preventing Atrial Fibrillation after Coronary Artery Bypass Grafting: A Double-Blind Randomized Comparative Trial

Background

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by disorganized atrial activity and subsequent mechanical atrial failure. Postoperative AF is a frequent complication of coronary artery bypass grafting (CABG). Although there is evidence of decreased AF after CABG with statin usage, information is scarce regarding a direct comparison between atorvastatin and rosuvastatin. The present study was conducted to compare the efficacy of rosuvastatin and atorvastatin in preventing post-CABG AF.

Methods

The present double-blind randomized comparative clinical trial selected CABG candidates with stable ischemic heart disease or acute coronary syndromes. Atorvastatin (40 mg per day) or rosuvastatin (20 mg per day) was prescribed 1 week before surgery, and the outcomes were compared.

Results

Two-hundred patients, 100 cases in each group, completed the study. Twenty-five patients in each group were female, and the mean age was 59.30±8.42 years in the rosuvastatin group and 60.13±9.40 years in the atorvastatin group (P=0.513). The frequency of AF was 31% in the atorvastatin group and 27% in the rosuvastatin group (P=0.534). No significant differences existed between the groups concerning the length of hospital and ICU stay (P=0.333 and P=0.161) and in-hospital and 3-month mortality (P=0.315 and P=0.648). A subgroup analysis of only patients with stable ischemic heart disease could not detect a significant difference between the study groups in any of the investigated outcomes. Our logistic regression analysis showed an association only between age and the incidence of AF after CABG (OR, 1.12; 95% CI, 1.05 to 1.20; P<0.01).

Conclusion

Rosuvastatin and atorvastatin are similar concerning the prevention of post-CABG AF, but there is a need for future well-designed multicenter studies on this topic.

Microvascular dysfunction following cardiopulmonary bypass plays a central role in postoperative organ dysfunction

Despite significant advances in surgical technique and strategies for tissue/organ protection, cardiac surgery involving cardiopulmonary bypass is a profound stressor on the human body and is associated with numerous intraoperative and postoperative collateral effects across different tissues and organ systems. Of note, cardiopulmonary bypass has been shown to induce significant alterations in microvascular reactivity. This involves altered myogenic tone, altered microvascular responsiveness to many endogenous vasoactive agonists, and generalized endothelial dysfunction across multiple vascular beds. This review begins with a survey of in vitro studies that examine the cellular mechanisms of microvascular dysfunction following cardiac surgery involving cardiopulmonary bypass, with a focus on endothelial activation, weakened barrier integrity, altered cell surface receptor expression, and changes in the balance between vasoconstrictive and vasodilatory mediators. Microvascular dysfunction in turn influences postoperative organ dysfunction in complex, poorly understood ways. Hence the second part of this review will highlight in vivo studies examining the effects of cardiac surgery on critical organ systems, notably the heart, brain, renal system, and skin/peripheral tissue vasculature. Clinical implications and possible areas for intervention will be discussed throughout the review.

The Anti-Inflammatory and Antioxidant Effects of Propofol and Sevoflurane in Children With Cyanotic Congenital Heart Disease

OBJECTIVE

The authors aimed to compare the anti-inflammatory and antioxidant effects of propofol and sevoflurane in children with cyanotic congenital heart disease (CCHD) undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Single center, university hospital.

PARTICIPANTS

Children ages 1-10 years with CCHD undergoing elective cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Children were randomized to receive general anesthesia with either sevoflurane (group S) or propofol (group P). Systemic inflammatory response syndrome (SIRS) occurrence was assessed at the end of the surgery and at the sixth, 12th, and 24th postoperative hours. Blood samples were obtained at 4 times: after anesthesia induction (T0), after release of the aortic cross-clamp (T1), at the end of the surgery (T2), and at the postoperative 24th hour (T3). The serum levels of interleukin 6 and tumor necrosis factor alpha, and the total antioxidant status (TAS) and total oxidant status, were analyzed.

RESULTS

SIRS was more common in group S than in group P at all times (p = 0.020, p = 0.036, p = 0.004, p = 0.008). There were no significant differences between the groups in the mean tumor necrosis factor alpha and interleukin 6 levels at any time. The TAS level at T2 was higher in group P than group S (p = 0.036). The serum TAS level increased at T2 compared with T0 in group P, but it decreased in group S (p = 0.041).

CONCLUSION

The results showed that propofol provided a greater antioxidant effect and reduced SIRS postoperatively more than sevoflurane in children with CCHD undergoing cardiac surgery.

Effects of inflammation and oxidative stress on postoperative delirium in cardiac surgery

The past decade has witnessed unprecedented medical progress, which has translated into cardiac surgery being increasingly common and safe. However, complications such as postoperative delirium remain a major concern. Although the pathophysiological changes of delirium after cardiac surgery remain poorly understood, it is widely thought that inflammation and oxidative stress may be potential triggers of delirium. The development of delirium following cardiac surgery is associated with perioperative risk factors. Multiple interventions are being explored to prevent and treat delirium. Therefore, research on the potential role of biomarkers in delirium as well as identification of perioperative risk factors and pharmacological interventions are necessary to mitigate the development of delirium.

Renal and Cerebral Hypoxia and Inflammation During Cardiopulmonary Bypass

Cardiac surgery-associated acute kidney injury and brain injury remain common despite ongoing efforts to improve both the equipment and procedures deployed during cardiopulmonary bypass (CPB). The pathophysiology of injury of the kidney and brain during CPB is not completely understood. Nevertheless, renal (particularly in the medulla) and cerebral hypoxia and inflammation likely play critical roles. Multiple practical factors, including depth and mode of anesthesia, hemodilution, pump flow, and arterial pressure can influence oxygenation of the brain and kidney during CPB. Critically, these factors may have differential effects on these two vital organs. Systemic inflammatory pathways are activated during CPB through activation of the complement system, coagulation pathways, leukocytes, and the release of inflammatory cytokines. Local inflammation in the brain and kidney may be aggravated by ischemia (and thus hypoxia) and reperfusion (and thus oxidative stress) and activation of resident and infiltrating inflammatory cells. Various strategies, including manipulating perfusion conditions and administration of pharmacotherapies, could potentially be deployed to avoid or attenuate hypoxia and inflammation during CPB. Regarding manipulating perfusion conditions, based on experimental and clinical data, increasing standard pump flow and arterial pressure during CPB appears to offer the best hope to avoid hypoxia and injury, at least in the kidney. Pharmacological approaches, including use of anti-inflammatory agents such as dexmedetomidine and erythropoietin, have shown promise in preclinical models but have not been adequately tested in human trials. However, evidence for beneficial effects of corticosteroids on renal and neurological outcomes is lacking. © 2021 American Physiological Society. Compr Physiol 11:1-36, 2021.

High dose supplementation of selenium in left ventricular assist device implant surgery - a double-blinded, randomized controlled, pilot trial

BACKGROUND

Systemic inflammation and oxidative stress remain the main cause of complications in heart failure patients receiving a left ventricular assist device (LVAD). Selenoproteins are a cornerstone of antioxidant defense mechanisms for improving inflammatory conditions.

METHODS

We conducted a monocentric double-blinded, randomized pilot trial. Patients scheduled for LVAD implantation were randomized to receive 300μg of selenium the evening before surgery orally, followed by high-dose intravenous selenium supplementation (3000μg after anesthesia induction, 1000 μg upon intensive care unit (ICU) admission, and 1000μg daily at ICU for a maximum of 14 days), or placebo. The main outcomes of this pilot study were feasibility and effectiveness in restoring serum selenium concentrations.

RESULTS

20 out of 21 randomized patients were included in the analysis. The average recruitment rate was 1.5 patients/month (0-3). The average duration of study intervention was 12.6 days (7-14) with a 97.7% dose compliance. No patient received open-label selenium. The supplementation strategy was effective in compensating low serum selenium concentration (before surgery: control: 63.5±11.9μg/L vs. intervention: 65.8±16.5μg/L, ICU admission: control: 49.0±9.8μg/L vs. intervention: 144.2±45.4μg/L). Comparing to the control group, the serum selenium concentrations in the intervention group were significantly higher during the observation period (baseline: mean of placebo (MoP):63.1 vs. mean of selenium (MoS):64.0; ICU admission: MoP:49.0 vs. MoS:144.6; day 1:MoP:44.9 vs. MoS: 102.4; day 3: MoP:43.6 vs. MoS:100.4; day 5: MoP:48.5 vs. MoS:114.7; day 7: MoP:44.4 vs.MoS:118.3; day 13:MoP:48.0 vs. MoS:131.0).

CONCLUSIONS

Selenium supplementation in patients receiving LVAD-implantation is feasible and effective to compensate a selenium deficiency. This article is protected by copyright. All rights reserved.

Can acute-phase response biomarkers differentiate infection from inflammation postpediatric cardiac surgery?

Background:

Infection is a common serious complication postpediatric cardiac surgery. Diagnosis of infection after cardiopulmonary bypass (CPB) is difficult in the presence of surgical stress, hemodynamic instability, and inflammatory reaction.

Aim:

The purpose of this study is to investigate the value of available inflammatory biomarkers and its validity to differentiate infection from inflammation postpediatric cardiac surgery and to find the trend and the change in the level of these biomarkers shortly after cardiac surgery.

Methods:

We conducted a prospective study that included all children who underwent cardiac surgery in Prince Sultan Cardiac Centre-Qassim from November 2013 to October 2015. C-reactive protein, erythrocyte sedimentation rate, white blood cell count, and neutrophil count were measured for all patients presurgery, 4 consecutive days postsurgery, and predischarge. Patients were divided into two groups (the infected and the noninfected group). We compared the level of biomarkers between both groups. Then, we further analyzed the effects of CPB and preoperative steroid on postoperative inflammatory biomarker levels. Collected data were then reviewed and analyzed.

Results:

There were 134 pediatric cardiac patients included during the study period. Group 1 (bacterial negative culture group) had 125 cases and Group 2 (bacterial positive culture group) had nine cases. We found no statistically significant difference in inflammatory biomarker elevation between both groups. Only Group 2 had higher (RACHS) Risk adjustment for congenital heart surgery score, more ventilator days, and more drop in platelet count on the 2^nd and 3^rd postoperative days in comparison with the noninfected group 1. Both groups of patients who were in on and off CPB had the same level of inflammatory biomarkers with no significant differences. Giving corticosteroid preoperatively did not affect the trend of biomarker elevation and made no difference when it was compared to the group of patients who did not receive corticosteroid before surgery.

Conclusion:

Common inflammatory biomarkers cannot differentiate between infection and inflammation within the first 5 days postpediatric cardiac surgery as these reflect the inflammatory process rather than infection. Trend is more important than single reading.

Evaluation of acute kidney injury with oxidative stress biomarkers and Renal Resistive Index after cardiac surgery

BACKGROUND

We investigated whether cardiopulmonary bypass (CPB) related oxidative stress mediated glycocalyx degradation can cause an increase in renal resistive index (RRI) or postoperative AKI. Additionally, to evaluate whether RRI and early postoperative serum cystatin C levels could improve the prediction sensitivity of acute kidney injury (AKI).

METHODS

Forty-two patients undergoing cardiac surgery were included in this prospective observational study. RRI was measured pre-operatively and in the cardiac intensive care unit. Blood samples were collected for analyzing of cellular injury biomarkers at preoperative and postoperative second hours. We determined areas under the receiver operating characteristic curve (AUC) and odds ratios for postoperative biomarkers and RRI to predict AKI.

RESULTS

While postoperative cystatin C level (AUC: 0.902, 95% CI = 0.79-1.00, p < .001) and RRI (AUC: 0.748, 95% CI = 0.56-0.93, p = .023) have diagnostic and predictive value in the prediction of AKI, we could not identify any relation between products of oxidative stress and the glycocalyx degradation and AKI.

CONCLUSION

These data suggest that CPB leads to structural and oxidative changes at the protein level and the integrity of glycocalyx is disturbing, but these changes are not specific to kidney injury. Our data suggest that serum cystatin C level and RRI could be used as an early biomarker for postoperative AKI after cardiac surgery.

Optimising risk factors for atrial fibrillation post-cardiac surgery

Postoperative atrial fibrillation (POAF) is an ongoing complication following cardiac surgery, with an incidence of 15%-60%. It is associated with substantial mortality and morbidity, as well increased hospital stays and healthcare costs. The pathogenesis is not fully understood, but the literature suggests that POAF occurs when transient, postoperative triggers act on vulnerable atrial tissue produced by preoperative, procedure-induced and postoperative processes such as inflammation, oxidative stress, autonomic dysfunction and electrophysiological remodelling of the atrial tissues. This sets the stage for arrhythmogenic mechanisms, such as ectopic firing secondary to triggered activity and re-entry mechanisms generating POAF. Preoperative factors include advanced age, sex, ethnicity, cardiovascular risk factors, preoperative drugs, electrocardiogram and echocardiogram abnormalities. Procedural factors include: the use of cardiopulmonary bypass and aortic cross clamp, type of cardiac surgery, use of hypothermia, left ventricular venting, bicaval cannulation and exclusion of the left atrial appendage. Postoperative factors include postoperative drugs, electrolyte and fluid balance and infection. This review explores the pathogenesis of POAF and the contribution of these perioperative factors in the development of POAF. Patients can be risk stratified for targeted treatment and prophylaxis, and how these factors can be attenuated to improve POAF outcomes following cardiac surgery.

Comparison of Del Nido Cardioplegia and Blood Cardioplegia in Terms of Development of Postoperative Atrial Fibrillation in Patients Undergoing Isolated Coronary Artery Bypass Grafting

Objective

Del Nido cardioplegia (DNC) has been used in pediatric cardiac surgery for many years with a single dose application and its usage in adult cardiac surgery has been increasing in recent years, with results being published. In this study, we aimed to investigate the effect of DNC on the development of postoperative atrial fibrillation (PoAF).

Methods

In this retrospective observational comparative study, 255 patients who underwent isolated on-pump coronary artery bypass grafting, between January 2019 and November 2019, were enrolled. The patients were divided into two groups: DNC (n=132) and blood cardioplegia (BC) (n=123). Intraoperative and postoperative data were evaluated and compared in terms of the development of PoAF.

Results

We found that the development of PoAF and the length of hospital stay remain significantly higher in the BC group (P=0.044, P<0.001, respectively). In addition, the aortic cross-clamp time and the cardioplegia volume delivered were significantly lower in the DNC group (P=0.042, P<0.001, respectively). In multivariate logistic regression analysis, only higher cardioplegia volume was determined as an independent predictor for PoAF development (OR 1.001; 95% CI 1.000-1.001; P=0.033). We did not found difference between groups in terms of troponin T, inotropic drug support, need for intraaortic balloon pump and mortality.

Conclusion

This study showed that DNC can be used safely in adult coronary bypass surgery and PoAF development effect is reduced.

Association between cardioplegia and postoperative atrial fibrillation in coronary surgery

OBJECTIVE

The aim of this multicenter study was to evaluated whether cold or warm cardioplegia are associated with postoperative atrial fibrillation (POAF) and the prognostic role of the latter on early stroke and neurological mortality.

METHOD

This was a retrospective analysis of prospective collected data from 9 cardiac centers in Italy and the United States including patients undergoing surgery between 2010 and 2018. From the 9 institutional databases, 17,231 patients underwent isolated CABG on-pump, using either warm cardioplegia (n = 7730) or cold cardioplegia (n = 9501); among the latter group blood and crystalloid cardioplegia were used in 691 and 8810 patients, respectively. After matching, two pairs of 4162 patients (overall cohort 8324) were analyzed.

RESULTS

In matched population, the rate of POAF was 18% (1472 cases), 15% (608) in warm group versus 21% (864) in cold group (p < 0.001). Multivariable analysis confirmed that cold cardioplegia was associated with higher rate of POAF, along with age, hypercholesterolemia, LVEF, reoperation, preoperative IABP, previous stroke, cardiopulmonary and cross-clamp. Moreover, cold cardioplegia as well as POAF increased the rate of postoperative stroke as well as early mortality and neurological mortality Propensity-weighted cohort included 11,830 (70%) patients out of 17,231. After adjustment, both cold blood and cold crystalloid cardioplegia negatively influenced POAF, stroke and neurological mortality.

CONCLUSIONS

Warm cardioplegia may reduce the rate of POAF in CABG patients with respect to cold cardioplegia, either blood or crystalloid. This has a prognostic impact on postoperative stroke and neurological mortality.

Cardioprotective Effect of Anesthetics: Translating Science to Practice

Cardiovascular diseases are the number one cause of mortality in the world, particularly among the aging population. Major adverse cardiac events are also a major contributor to perioperative complications, affecting 2.6% of noncardiac surgeries and up to 18% of cardiac surgeries. Cardioprotective effects of volatile anesthetics and certain intravenous anesthetics have been well-documented in preclinical studies; however, their clinical application has yielded conflicting results in terms of their efficacy. Therefore, better understanding of the underlying mechanisms and developing effective ways to translate these insights into clinical practice remain significant challenges and unmet needs in the area. Several recent reviews have focused on mechanistic dissection of anesthetic-mediated cardioprotection. The present review focuses on recent clinical trials investigating the cardioprotective effects of anesthetics in the past five years. In addition to highlighting the main outcomes of these trials, the authors provide their perspectives about the current gap in the field and potential directions for future investigations.

Best practice in cardiac anesthesia during the COVID-19 pandemic: Practical recommendations

The COVID-19 outbreak has influenced the entire health care system, including cardiac surgery. In this review, the authors reveal practical aspects that are important during the COVID-19 pandemic with regards to the safe delivery of cardiac anesthesia. Timing for operations of the cardio-vascular system may be well programmed in most cases. Hence, the level of priorities must be defined for any single patient. The postponement of surgery may be convenient for most cases, if it is made in the best interest of the patient. The preanesthetic evaluation should be attentive of the respiratory history of the patient. Cardiac anesthesia always implies some respiratory monitoring; hence the existing clinical situation of the patient's respiratory system should be clear. In case of emergency surgery, the patient should be treated as if they potentially have or are at risk for the virus. In the case of a COVID-19 confirmed or suspected patient, attention must be made to preserve operating room and team integrity. The machineries are to be draped with plastic to simplify the disinfection after the operation. Perioperative management of suspected or confirmed COVID-19 patients must strictly follow the most relevant international guidelines. This review article has synthesized the common aspects present in the most important of these.

General Anesthetics on Immune System Cytokines: A Narrative Review Article

Context

According to the previous studies, general anesthesia influences the immune system. Evaluating such impacts on the immune system helps to improve the management of anesthesia.

Evidence Acquisition

The current review aimed to summarize the literature related to the effects of general anesthesia agents on the cytokines. Google Scholar, PubMed, and ISI/Web of Sciences databases were searched using the following keywords: cytokine, general anesthesia, immune response, intravenous anesthetics, volatile anesthetics, opioids, benzodiazepines, and controlled ventilation.

Results

Long-term administration of general anesthesia drugs, due to their effects on cytokines, can lead to disease progression in patients with immune deficiency. Due to the conflicting results of various studies and the increasing number of patients with immune deficiency, the choice of the appropriate general anesthesia agents facilitates achieving the more favorable function of the cytokines.

Conclusions

It seems that the effect of general anesthesia on the immune system in healthy patients and short-term surgeries is not considerable and changes in the immune system are related to surgical trauma, particularly in major surgery.

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.

B Lymphocytes and Macrophages in the Perivascular Adipose Tissue Are Associated With Coronary Atherosclerosis: An Autopsy Study

Background

Macrophages and T lymphocytes in the perivascular adipose tissue (PvAT) were previously linked to coronary artery disease. However, the role of these cells and B lymphocytes in the human PvAT adjacent to unstable atherosclerotic plaques has not been investigated. Moreover, previous studies were inconclusive on whether PvAT inflammation was restricted to the surroundings of the atheroma plaque.

Methods and Results

Coronary arteries were freshly dissected with the surrounding PvAT. Atherosclerotic plaques were classified according to the internationally accepted anatomopathological criteria. Immune cells in the PvAT were detected using immunohistochemistry and then quantified. We used linear and logistic regressions with robust standard errors, adjusted for possible confounding factors. In 246 atherosclerotic plaques (205 stable and 41 unstable plaques) from 82 participants (mean age=69.0±14.4 years; 50% men), the percentage of arterial obstruction was positively correlated with the densities of CD68⁺ macrophages (P=0.003) and CD20⁺ B lymphocytes (P=0.03) in the periplaque PvAT. The number of cells was greater in the periplaque PvAT than in the distal PvAT (macrophages, P<0.001; B lymphocytes, P=0.04). In addition, the density of macrophages in the periplaque PvAT was greater in the presence of unstable plaques (P=0.03) and was also greater near unstable plaques than in the distal PvAT (P=0.001). CD3⁺ T lymphocytes were not associated with percentage of obstruction and stable/unstable plaque composition.

Conclusions

The density of CD20⁺ B lymphocytes and CD68⁺ macrophages in periplaque PvAT was increased with plaque size, and the CD68⁺ macrophages were greater near unstable atherosclerotic plaques than near stable lesions. This inflammation was more intense in the periplaque PvAT than in the PvAT distal to the atherosclerotic plaques.

Blood cytokine expression correlates with early multi-organ damage in a mouse model of moderate hypothermia with circulatory arrest using cardiopulmonary bypass

Cardiopulmonary bypass (CPB) with moderate hypothermic cardiac arrest (MHCA) is essential for prolonged complex procedures in cardiac surgery and is associated with postoperative complications. Although cytokine release provoked through MHCA under CPB plays a pivotal role in postoperative organ damage, the pathomechanisms are unclear. Here, we investigated the cytokine release pattern and histological organ damage after MHCA using a recently described mouse CPB model. Eight BALB/c mice underwent 60 minutes of circulatory arrest under CPB, were successively rewarmed and reperfused. Blood cytokine concentrations and liver and kidney function parameters were measured and histological changes to these organs were compared to control animals. Our results showed a marked increase in proinflammatory cytokines and histological changes in the kidney, lung, and liver after CPB. Furthermore, clinical chemistry showed signs of hemolysis and acute kidney injury. These results suggest early onset of solid organ injury which correlates with increased leukocyte infiltration. A better understanding of the interplay between pro-inflammatory cytokine activation and solid organ injury in this model of CBP with MHCA will inform strategies to reduce organ damage during cardiac surgeries in the clinic.

Vitamin C to Improve Organ Dysfunction in Cardiac Surgery Patients-Review and Pragmatic Approach

The pleiotropic biochemical and antioxidant functions of vitamin C have sparked recent interest in its application in intensive care. Vitamin C protects important organ systems (cardiovascular, neurologic and renal systems) during inflammation and oxidative stress. It also influences coagulation and inflammation; its application might prevent organ damage. The current evidence of vitamin C's effect on pathophysiological reactions during various acute stress events (such as sepsis, shock, trauma, burn and ischemia-reperfusion injury) questions whether the application of vitamin C might be especially beneficial for cardiac surgery patients who are routinely exposed to ischemia/reperfusion and subsequent inflammation, systematically affecting different organ systems. This review covers current knowledge about the role of vitamin C in cardiac surgery patients with focus on its influence on organ dysfunctions. The relationships between vitamin C and clinical health outcomes are reviewed with special emphasis on its application in cardiac surgery. Additionally, this review pragmatically discusses evidence on the administration of vitamin C in every day clinical practice, tackling the issues of safety, monitoring, dosage, and appropriate application strategy.

Hydrogen-rich solution attenuates myocardial injury caused by cardiopulmonary bypass in rats via the Janus-activated kinase 2/signal transducer and activator of transcription 3 signaling pathway

The incidence of complications and mortality following open-heart surgery with cardiopulmonary bypass (CPB) is associated with the severity of the myocardial injury that occurs during surgery. Hydrogen-rich solution (HRS) may prevent antioxidant stress and inhibit apoptosis and inflammation. The present study was designed to investigate the effects of HRS on CPB-induced myocardial injury, and to investigate its potential regulation of the Janus-activated kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway. The HRS treatment resulted in the significant upregulation of malonyl dialdehyde (MDA) and myeloperoxidase (MPO), whilesuperoxide dismutase (SOD) levels were significantly downregulated, compared with the Sham group (P<0.05). Additionally, HRS treatment improved myocardial injury, and decreased the expression levels of cardiac troponins, heart-type fatty acid binding protein, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, MDA and MPO, and increased SOD release in CPB rats (P<0.05). Additionally, in the CPB group without the HRS treatment, the expression levels of B-cell lymphoma (Bcl)-2, JAK2, phospho-JAK2 (p-JAK2), STAT3 and phospho-STAT3 (p-STAT3) were significantly decreased, and Bax was significantly increased, compared with the Sham group (P<0.05). By contrast, compared with the CPB group, the expression levels of B-cell lymphoma 2 (Bcl-2), JAK2, phosphorylated (p)-JAK2, STAT3 and p-STAT3 in the HRS group were significantly increased, and Bcl-2-associated X protein expression was significantly decreased (P<0.05). In JAK2 knockdown experiments using siRNA, HRS treatment following hypoxia/reoxygenation also significantly increased the viability of myocardial cells, decreased the rate of myocardial cell apoptosis, elevated the levels of SOD and suppressed the release of MDA and lactate dehydrogenase in the control siRNA and CPB groups (P<0.05). Furthermore, JAK2 siRNA attenuated these protective effects of HRS (P<0.05 vs. control siRNA, HRS and CPB groups). Additionally, the results demonstrated that the HRS treatment significantly increased the expression levels of p-JAK2, p-STAT3 and Bcl-2 in myocardial cells following hypoxia and decreased Bax expression in the control siRNA and CPB groups (P<0.05). In addition, JAK2 siRNA was determined to attenuate these effects of HRS (P<0.05 vs. control siRNA, HRS and CPB groups). Taken together, these results indicated that HRS may alleviate CPB-induced myocardial injury, inhibit myocardial cell apoptosis and protect myocardial cells through regulation of the JAK2/STAT3 signaling pathway.

Hydrogen‑rich solution against myocardial injury and aquaporin expression via the PI3K/Akt signaling pathway during cardiopulmonary bypass in rats

Myocardial ischemia, hypoxia and reperfusion injury are induced by aortic occlusion, cardiac arrest and resuscitation during cardiopulmonary bypass (CPB), which can severely affect cardiac function. The aim of the present study was to investigate the effects of hydrogen-rich solution (HRS) and aquaporin (AQP) on cardiopulmonary bypass (CPB)-induced myocardial injury, and determine the mechanism of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Sprague Dawley rats were divided into a sham operation group, a CPB surgery group and a HRS group. A CPB model was established, and the hemodynamic parameters were determined at the termination of CPB. The myocardial tissues were observed by hematoxylin and eosin, and Masson staining. The levels of myocardial injury markers [adult cardiac troponin I (cTnI), lactate dehydrogenase (LDH), creatine kinase MB (CK-MB) and brain natriuretic peptide (BNP)], inflammatory factors [interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α)] and oxidative stress indicators [superoxide dismutase (SOD), malondialdehyde (MDA) and myeloperoxidase (MPO)] were determined by ELISA. Furthermore, H9C2 cells were treated with HRS following hypoxia/reoxygenation. Cell viability and cell apoptosis were investigated. The expression of apoptosis regulator Bcl-2 (Bcl-2), apoptosis regulator Bax (Bax), caspase 3, AQP-1, AQP-4, phosphorylated (p)-Akt, heme oxygenase 1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) were investigated using western blotting and quantitative-polymerase chain reaction of tissues and cells. Following CPB, myocardial cell arrangement was disordered, myocardial injury markers (cTnI, LDH, CK-MB and BNP), inflammatory cytokines (IL-1β, IL-6 and TNF-α) and MDA levels were significantly increased compared with the sham group; whereas the SOD levels were significantly downregulated following CPB compared with the sham group. HRS attenuated myocardial injury, reduced the expression levels of cTnI, LDH, CK-MB, BNP, IL-1β, IL-6, TNF-α, MDA and MPO, and increased SOD release. Levels of Bcl-2, AQP-1, AQP-4, p-Akt, HO-1 and Nrf2 were significantly increased following HRS; whereas Bax and caspase-3 expression levels were significantly reduced following CPB. HRS treatment significantly increased the viability of myocardial cells, reduced the rate of myocardial cell apoptosis and the release of MDA and LDH compared with the CPB group. A PI3K inhibitor (LY294002) was revealed to reverse the protective effect of HRS treatment. HRS was demonstrated to attenuate CPB-induced myocardial injury, suppress AQP-1 and AQP-4 expression following CPB treatment and protect myocardial cells via the PI3K/Akt signaling pathway.

Hemolysis and Inflammatory Response to Extracorporeal Circulation during On-Pump CABG: Comparison between Roller and Centrifugal Pump Systems

Objective

To compare the perioperative incidence rates of hemolysis and inflammatory response in patients undergoing coronary artery bypass grafting with the two main types of cardiopulmonary bypass, centrifugal and roller pumps, and establish correlations among hemolytic and inflammatory changes.

Methods

This was a prospective, randomized trial of 60 patients assigned to either roller pump (G1, n=30) or centrifugal pump (G2, n=30) bypass. Markers of hemolysis (serum haptoglobin, lactate dehydrogenase [LDH]) and inflammation (interleukin [IL]1ß, IL-6, and TNF-α) were measured and analyzed.

Results

There was no significant between-group difference in the variables of interest. In G1, there was a positive association with IL-6 and TNF-α (P<0.01 and P<0.05, respectively). In G2, there was a positive association with LDH in the postoperative period (P<0.5). At 24h post-cardiopulmonary bypass, there were positive associations between LDH and IL-1ß (P<0.05), LDH and TNF-α (P<0.01), haptoglobin and TNF-α (P<0.05), and LDH and TNF-α (P<0.01) in G1, and between LDH and IL-6 (P<0.01), LDH and TNF-α (P<0.01), and LDH and IL-6 (P<0.01) in G2.

Conclusion

There were no significant between-group differences in markers of hemolysis or inflammation. IL-6 and TNF-α were positively associated with duration of cardiopulmonary bypass in G1, while LDH was positively associated with duration of cardiopulmonary bypass in G2. The rate of significant associations between markers of hemolysis and inflammation was higher in the roller pump group (G1).

Registration number

ReBEC (RBR-92b9dg).

A randomized controlled trial comparing the myocardial protective effects of isoflurane with propofol in patients undergoing elective coronary artery bypass surgery on cardiopulmonary bypass, assessed by changes in N-terminal brain natriuretic peptide

Objective:

The objective of the study is to compare the myocardial protective effects of isoflurane with propofol in patients undergoing elective coronary artery bypass surgery on cardiopulmonary bypass (CPB), the cardio protection been assessed by changes in N-terminal brain natriuretic peptide (NT proBNP).

Methodology and Design:

This study is designed as a participant blinded, prospective randomized clinical trial.

Setting:

Christian Medical College Hospital, Vellore, India.

Participants:

Patients undergoing elective coronary artery bypass surgery on CPB.

Intervention:

Anesthesia was maintained with 0.8–1.2 end tidal concentrations of isoflurane in the isoflurane group and in the propofol group, anesthesia was maintained with propofol infusion as described by Roberts et al.

Measurements:

Hemodynamic data were recorded at frequent intervals during the surgery and up to 24 h in the Intensive Care Unit (ICU). The other variables that were measured include duration of mechanical ventilation, dose and duration of inotropes in ICU, (inotrope score), duration of ICU stay, NT proBNP levels before induction and 24 h postoperatively, creatine kinase-MB levels in the immediate postoperative, first and second day.

Results:

Mean heart rate was significantly higher in propofol group during sternotomy, (P = 0.021). Propofol group had a significantly more number of patients requiring nitroglycerine in the prebypass period (P = 0.01). The increase in NT proBNP from preoperative to postoperative value was lesser in the isoflurane group compared to propofol even though the difference was not statistically significant. The requirement of phenylephrine to maintain mean arterial pressure within 20% of baseline, mechanical ventilation duration, inotrope use, duration of ICU stay and hospital stay were found to be similar in both groups.

Conclusion:

Propofol exhibit comparable myocardial protective effect like that of isoflurane in patients undergoing coronary artery bypass graft surgery. Considering the unproven mortality benefit of isoflurane and the improved awareness of green OT concept, propofol may be the ideal alternative to volatile anesthetics, at least in patients with good left ventricular function.

The spectrum of myocardial homeostasis mechanisms in the settings of cardiac surgery procedures (Review)

Classic cardiac surgery, determined through the function of cardiopulmonary bypass machine and myocardial cardioplegic arrest, represents the most controlled scenario for cardiomyocyte homeostatic disturbances due to systemic inflammatory response and myocardial reperfusion injury. An increasing number of studies have demonstrated that myocardial cell homeostasis in cardiac surgery procedures is a sequence of molecularly interrelated and overlapping mechanisms in the form of apoptosis, autophagy and necrosis, which are activated by a plethora of induced inflammatory mediators and gene-related signaling pathways. In this study, we outline the molecular mechanisms of the cardiomyocyte adaptive homeostatic process and the associated clinical implications, in the settings of classic cardiac surgery procedures.

New and revisited approaches to preserving the reperfused myocardium

Early coronary artery reperfusion improves outcomes for patients with ST-segment elevation myocardial infarction (STEMI), but morbidity and mortality after STEMI remain unacceptably high. The primary deficits seen in these patients include inadequate pump function, owing to rapid infarction of muscle in the first few hours of treatment, and adverse remodelling of the heart in the months that follow. Given that attempts to further reduce myocardial infarct size beyond early reperfusion in clinical trials have so far been disappointing, effective therapies are still needed to protect the reperfused myocardium. In this Review, we discuss several approaches to preserving the reperfused heart, such as therapies that target the mechanisms involved in mitochondrial bioenergetics, pyroptosis, and autophagy, as well as treatments that harness the cardioprotective properties of inhaled anaesthetic agents. We also discuss potential therapies focused on correcting the no-reflow phenomenon and its effect on healing and adverse left ventricular remodelling.

Lactate Elevation During and After Major Cardiac Surgery in Adults: A Review of Etiology, Prognostic Value, and Management

Elevated lactate is a common occurrence after cardiac surgery. This review summarizes the literature on the complex etiology of lactate elevation during and after cardiac surgery, including considerations of oxygen delivery, oxygen utilization, increased metabolism, lactate clearance, medications and fluids, and postoperative complications. Second, the association between lactate and a variety of outcomes are described, and the prognostic role of lactate is critically assessed. Despite the fact that elevated lactate is strongly associated with many important outcomes, including postoperative complications, length of stay, and mortality, little is known about the optimal management of postoperative patients with lactate elevations. This review ends with an assessment of the limited literature on this subject.

Acute-phase proteins and oxidative stress in patients undergoing coronary artery bypass graft: comparison of cardioplegia strategy

Introduction

Several strategies are still being introduced to cardiac surgery techniques to reduce the signs of the inflammatory response and oxidative stress. Many efforts have been made to develop the best possible method for myocardial protection.

Aim

To assess the effect of the cardioplegia strategy on the systemic inflammatory response and oxidative stress.

Material and methods

A group of 238 consecutive, elective on-pump coronary artery bypass graft patients (CABG; 183 men, aged 64.6 ±8.1 years) were prospectively studied. Patients were enrolled in two groups: with warm blood cardioplegia (n = 124) and with cold crystalloid cardioplegia (n = 114). In each group, pre- and postoperative levels of plasma C-reactive protein, fibrinogen, interleukin 6 and 8-iso-prostaglandin F_2α (8-iso-PGF_2α) were measured.

Results

All studied markers significantly increased 18–36 h following CABG and then decreased in 5–7 postoperative days but remained above baseline levels. No differences in terms of studied markers and clinical outcomes were noted for the different types of cardioplegia. Regression analysis showed a significant correlation between preoperative level of oxidative stress measured by 8-iso-PGF_2α and postoperative myocardial infarction as well as in-hospital cardiovascular death (p = 0.047 and p = 0.041 respectively).

Conclusions

This study extends previous reports by showing that the type of cardioplegia does not affect the systemic inflammatory response or oxidative stress, which are associated with the CABG procedure. It might be speculated that preoperative screening of oxidative stress could be helpful in identifying patients at increased risk of an unfavorable course after CABG.

A Role for Photobiomodulation in the Prevention of Myocardial Ischemic Reperfusion Injury: A Systematic Review and Potential Molecular Mechanisms

Myocardial ischemia reperfusion injury is a negative pathophysiological event that may result in cardiac cell apoptosis and is a result of coronary revascularization and cardiac intervention procedures. The resulting loss of cardiomyocyte cells and the formation of scar tissue, leads to impaired heart function, a major prognostic determinant of long-term cardiac outcomes. Photobiomodulation is a novel cardiac intervention that has displayed therapeutic effects in reducing myocardial ischemia reperfusion related myocardial injury in animal models. A growing body of evidence supporting the use of photobiomodulation in myocardial infarct models has implicated multiple molecular interactions. A systematic review was conducted to identify the strength of the evidence for the therapeutic effect of photobiomodulation and to summarise the current evidence as to its mechanisms. Photobiomodulation in animal models showed consistently positive effects over a range of wavelengths and application parameters, with reductions in total infarct size (up to 76%), decreases in inflammation and scarring, and increases in tissue repair. Multiple molecular pathways were identified, including modulation of inflammatory cytokines, signalling molecules, transcription factors, enzymes and antioxidants. Current evidence regarding the use of photobiomodulation in acute and planned cardiac intervention is at an early stage but is sufficient to inform on clinical trials.

Attenuated recovery of contractile function in aging hearts following global ischemia/reperfusion: Role of extracellular HSP27 and TLR4

BACKGROUND

While cardiac functional recovery is attenuated in the elderly following cardiac surgery with obligatory global myocardial ischemia/reperfusion (I/R), the underlying mechanism remains incompletely understood. We observed previously that human and mouse myocardium releases heat shock protein (HSP) 27 during global I/R. Extracellular HSP27 induces myocardial inflammatory response and plays a role in post-ischemic cardiac dysfunction in adult mouse hearts.

OBJECTIVE

This study was to determine the role of extracellular HSP27 and Toll-like receptor 4 (TLR4) in the attenuated functional recovery in aging mouse hearts following global I/R.

METHODS AND RESULTS

Hearts isolated from aging (18-24 months) and adult (4-6 months) mice were subjected to ex vivo global I/R. Augmented release of HSP27 in aging hearts is associated with greater production of cytokines (TNF-α and IL-1β) and worse functional recovery. Anti-HSP27 suppressed the inflammatory response and markedly improved functional recovery in aging hearts. Perfusion of recombinant HSP27 to aging hearts resulted in greater cytokine production and more severe contractile depression in comparison to adult hearts. TLR4 deficiency abolished cytokine production and functional injury in aging hearts exposed to recombinant HSP27. Interestingly, aging hearts had higher TLR4 protein levels and displayed enhanced TLR4-mediated NF-κB activation following HSP27 stimulation or I/R.

CONCLUSION

Extracellular HSP27 and TLR4 jointly enhance the inflammatory response and hamper functional recovery following I/R in aging hearts. The enhanced inflammatory response to global I/R and attenuated post-ischemic functional recovery in aging hearts is due, at least in part, to augmented myocardial release of HSP27 and elevated myocardial TLR4 levels.

Preoperative values of inflammatory markers predict clinical outcomes in patients after CABG, regardless of the use of cardiopulmonary bypass

Objective

The impact of systemic inflammation on clinical outcomes after CABG surgery is still controversial. In this study, we evaluated the impact of the markers of inflammation, endothelial damage and platelet activation on clinical outcomes after on- and off-pump CABG.

Methods

A group of 191 consecutive on- and off-pump CABG patients were prospectively studied. Blood samples were drawn before surgery, 18–36 h after the procedure and 5–7 days postoperatively and analyzed for 8-iso-prostaglandin F_2α (8-iso-PGF_2α), asymmetric dimethylarginine (ADMA) and β-thromboglobulin (β-TG). White blood count and C-reactive protein were measured twice, first before and then during the first 18–36 h after CABG. The primary clinical end-points were: low cardiac output syndrome (LCOS), postoperative myocardial infarction (PMI) and in-hospital cardiovascular death.

Results

Elevation of 8-iso-PGF_2α, ADMA and β-TG before surgery was associated with an increased risk of morbidity and mortality after CABG. There were no differences in analyzed markers and clinical outcomes between the on- and off-pump groups. Even during the uncomplicated postoperative course the inflammatory response was enhanced and still remained higher than baseline 5–7 days after surgery.

Conclusion

Links between preoperative 8-iso-PGF_2α, ADMA and β-TG and unfavorable early post-CABG outcomes suggest that these markers could be useful in identifying patients with increased risk of LCOS, PMI and in-hospital cardiovascular death following elective CABG.

Effects of Low-dose Selenium on the Inflammatory Response in Coronary Artery Bypass Graft Surgery: A Clinical Trial

Background

Coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) triggers an inflammatory reaction, leading to the development of myocardial damage and dysfunction. It is suggested that selenium (Se), an essential trace element, has a protective role against oxidative stress. Decreased intraoperative Se levels might be an independent predictive factor for postoperative multiorgan failure. In spite of its proposed advantages, however, the optimal timing and dosage are not well known.

Objectives

To determine whether 600 µg of intravenous Se administration before induction of anesthesia for CABG surgery could attenuate inflammatory reactions in an Iranian population.

Methods

This randomized triple-blind clinical trial took place in the department of cardiac surgery of an academic hospital affiliated with Guilan University of Medical Sciences (GUMS) from May 2015 to September 2015. Eighty-eight eligible patients scheduled for elective on-pump CABG surgery were divided into two groups using randomized fixed quadripartite blocks. They received either an intravenous bolus of 600 µg Se before induction of anesthesia, or normal saline as a placebo. We had four measurement time-points: just before induction of anesthesia (T0), immediately after the end of CPB (T1), 24 hours after surgery (T2), and 48 hours after surgery (T3). Interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) serum levels were measured using the enzyme-linked immunosorbent assay (ELISA).

Results

Data from a total of 81 patients were analyzed: group S (n = 41) and group C (n = 40). There was no significant difference between the two groups with regard to baseline characteristics. In both groups, CPB caused markedly increased IL-6, TNF-α, and CRP plasma concentrations compared with baseline (P = 0.0001). However, the pattern of changes was not significantly different between group S (P = 0.068) and group C (P = 0.26). The IL-6 and TNF-α change trends were significant in each group (P=0.0001). However, comparing the two groups showed no significant difference. With regard to IL-6, there was no significant difference between the two groups at the time-points of T1 (P = 0.34), T2 (P = 0.17), and T3 (P = 0.056), and the same was found for TNF-α at T1 (P = 0.34), T2 (P = 0.17), and T3 (P = 0.056). With regard to CRP, the trend of the changes was significant in each group (P = 0.0001). However, comparing two groups showed a borderline significant difference between them at T1 (P = 0.039), but not at T2 (P = 0.075) or T3 (P = 0.11).

Conclusions

This study revealed that the administration of 600 μg of intravenous Se immediately before induction of anesthesia was safe, but when compared to a placebo, no predominant clinical effects or modifications in the systemic inflammatory response induced by on-pump CABG were observed.

The Role of Levosimendan in Patients with Decreased Left Ventricular Function Undergoing Cardiac Surgery

The postoperative low cardiac output is one of the most important complications following cardiac surgery and is associated with increased morbidity and mortality. The condition requires inotropic support to achieve adequate hemodynamic status and tissue perfusion. While catecholamines are utilised as a standard therapy in cardiac surgery, their use is limited due to increased oxygen consumption. Levosimendan is calcium sensitising inodilatator expressing positive inotropic effect by binding with cardiac troponin C without increasing oxygen demand. Furthermore, the drug opens potassium ATP (KATP) channels in cardiac mitochondria and in the vascular muscle cells, showing cardioprotective and vasodilator properties, respectively. In the past decade, levosimendan demonstrated promising results in treating patients with reduced left ventricular function when administered in peri- or post- operative settings. In addition, pre-operative use of levosimendan in patients with severely reduced left ventricular ejection fraction may reduce the requirements for postoperative inotropic support, mechanical support, duration of intensive care unit stay as well as hospital stay and a decrease in post-operative mortality. However, larger studies are needed to clarify clinical advantages of levosimendan versus conventional inotropes.

A comparison of minimally invasive and standard aortic valve replacement

OBJECTIVE

The study objective was to compare aortic valve replacement through a right anterior minithoracotomy with aortic valve replacement through a median sternotomy.

METHODS

With propensity score matching, we selected 211 patients after aortic valve replacement through a right anterior minithoracotomy and 211 patients after aortic valve replacement who underwent operation between January 2010 and December 2013. Perioperative outcomes were analyzed, and multivariable logistic regression analysis of risk factors of postoperative morbidity was performed.

RESULTS

For propensity score-matched patients, hospital mortality was 1.0% in the aortic valve replacement through a right anterior minithoracotomy group and 1.4% in the aortic valve replacement group (P = 1.000). Stroke occurred in 0.5% versus 1.4% (P = .615), myocardial infarction occurred in 1.4% versus 1.9% (P = 1.000), and new onset of atrial fibrillation occurred in 12.8% versus 24.2% (P = .003) of patients in the aortic valve replacement through a right anterior minithoracotomy and aortic valve replacement groups, respectively. Postoperative drainage was 353.5 ± 248.6 mL versus 544.3 ± 324.5 mL (P < .001) and blood transfusion was required for 48.8% versus 67.3% (P < .001) of patients in the aortic valve replacement through a right anterior minithoracotomy and aortic valve replacement groups, respectively. Mediastinitis occurred in 2.8% of patients after aortic valve replacement and in 0.0% of patients after aortic valve replacement through a right anterior minithoracotomy surgery (P = .040). Intensive care unit stay (1.3 ± 1.2 days vs 2.6 ± 2.6 days) and hospital stay (5.7 ± 1.6 days vs 8.7 ± 4.4 days) were statistically significantly shorter in the aortic valve replacement through a right anterior minithoracotomy group. Aortic valve replacement through a right anterior minithoracotomy surgery resulted in reduced postoperative morbidity (odds ratio, 0.4; P < .001) and postoperative bleeding and blood transfusion requirements (odds ratio, 0.4; P < .001).

CONCLUSIONS

Aortic valve replacement through a right anterior minithoracotomy surgery resulted in a reduced infection rate, diminished postoperative bleeding and blood transfusion requirements, reduced occurrence of new onset of atrial fibrillation, and shorter intensive care unit and hospital stays.

Protective Effect of Creatine Elevation against Ischaemia Reperfusion Injury Is Retained in the Presence of Co-Morbidities and during Cardioplegia

Aims

Ischaemic heart disease is most prevalent in the ageing population and often exists with other comorbidities; however the majority of laboratory research uses young, healthy animal models. Several recent workshops and focus meetings have highlighted the importance of using clinically relevant models to help aid translation to realistic patient populations. We have previously shown that mice over-expressing the creatine transporter (CrT-OE) have elevated intracellular creatine levels and are protected against ischaemia-reperfusion injury. Here we test whether elevating intracellular creatine levels retains a cardioprotective effect in the presence of common comorbidities and whether it is additive to protection afforded by hypothermic cardioplegia.

Methods and Results

CrT-OE mice and wild-type controls were subjected to transverse aortic constriction for two weeks to induce compensated left ventricular hypertrophy (LVH). Hearts were retrogradely perfused in Langendorff mode for 15 minutes, followed by 20 minutes ischaemia and 30 minutes reperfusion. CrT-OE hearts exhibited significantly improved functional recovery (Rate pressure product) during reperfusion compared to WT littermates (76% of baseline vs. 59%, respectively, P = 0.02). Aged CrT-OE mouse hearts (78±5 weeks) also had enhanced recovery following 15 minutes ischaemia (104% of baseline vs. 67%, P = 0.0007). The cardioprotective effect of hypothermic high K⁺ cardioplegic arrest, as used during cardiac surgery and donor heart transplant, was further enhanced in prolonged ischaemia (90 minutes) in CrT-OE Langendorff perfused mouse hearts (76% of baseline vs. 55% of baseline as seen in WT hearts, P = 0.02).

Conclusions

These observations in clinically relevant models further support the development of modulators of intracellular creatine content as a translatable strategy for cardiac protection against ischaemia-reperfusion injury.

Impairment of the Vascular KATP Channel Imposes Fatal Susceptibility to Experimental Diabetes Due to Multi-Organ Injuries

The vascular isoform of ATP-sensitive K(+) (KATP ) channels regulates blood flow to all organs. The KATP channel is strongly inhibited by reactive oxygen and carbonyl species produced in diabetic tissue inflammation. To address how such channel inhibition impacts vascular regulation as well as tissue viability, we performed studies in experimental diabetic mice. Strikingly, we found that knockout of the Kcnj8 encoding Kir6.1 subunit (Kcnj8-KO) caused mice to be fatally susceptible to diabetes. Organ perfusion studies suggested that the lack of this vascular K(+) channel handicapped activity-dependent vasodilation, leading to hypoperfusion, tissue hypoxia, and multi-organ failure. Morphologically, Kcnj8-KO mice showed greater inflammatory cell infiltration, higher levels of expression of inflammation indicator proteins, more severe cell apoptosis, and worse tissue disruptions. These were observed in the kidney, liver, and heart under diabetic condition in parallel comparison to tissues from WT mice. Patch clamping and molecular studies showed that the KATP channel was S-glutathionylated in experimental diabetes contributing to the inhibition of channel activity as well as the reduced arterial responses to vasodilators. These results suggest that the vascular KATP channel is organ protective in diabetic condition, and since the channel is suppressed by diabetic oxidative stress, therapeutical interventions to the maintenance of functional KATP channels may help to lower or prevent diabetic organ dysfunction.

Effect of dexmedetomidine on myocardial ischemia-reperfusion injury

Cardiopulmonary bypass (CPB) is associated with a marked systemic inflammatory response. Although dexmedetomidine (Dex) is routinely used in cardiac surgery, the effect in reducing the inflammatory response in coronary artery bypass graft surgery (CABG) with CPB remains unclear. In this study, Dex was administered at a loading dose of 0.5 μg/kg for 10 min, followed by a continuous infusion of 0.5 μg/kg per hour until the completion of CABG with CPB. The levels of inflammatory cytokines in the serum, including tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-6, IL-8 and IL-10, were measured to explore the inflammatory regulating function of Dex. In addition, troponin-I (cTnI) and creatine kinase (CK-MB) levels were studied to explore the myocardial protection provided by Dex. In this study, we showed Dex inhibited the increase in cTnI and CK-MB, attenuated the production of pro-inflammatory cytokines TNF-alpha, IL-6 and IL-8, and promoted anti-inflammatory cytokine IL-10 production. These findings demonstrate that Dex regulates anti-inflammatory as well as myocardial protection potential in CABG with CPB.

Pulmonary Protection Strategies in Cardiac Surgery: Are We Making Any Progress?

Pulmonary dysfunction is a common complication of cardiac surgery. The mechanisms involved in the development of pulmonary dysfunction are multifactorial and can be related to the activation of inflammatory and oxidative stress pathways. Clinical manifestation varies from mild atelectasis to severe respiratory failure. Managing pulmonary dysfunction postcardiac surgery is a multistep process that starts before surgery and continues during both the operative and postoperative phases. Different pulmonary protection strategies have evolved over the years; however, the wide acceptance and clinical application of such techniques remain hindered by the poor level of evidence or the sample size of the studies. A better understanding of available modalities and/or combinations can result in the development of customised strategies for the different cohorts of patients with the potential to hence maximise patients and institutes benefits.

Interaction of MIF Family Proteins in Myocardial Ischemia/Reperfusion Damage and Their Influence on Clinical Outcome of Cardiac Surgery Patients

AIMS

Cardiac surgery involves myocardial ischemia/reperfusion (I/R) with potentially deleterious consequences. Macrophage migration inhibitory factor (MIF) is a stress-regulating chemokine-like cytokine that protects against I/R damage, but functional links with its homolog, d-dopachrome tautomerase (MIF-2), and the circulating soluble receptor CD74 (sCD74) are unknown. In this study, we investigate the role of MIF, MIF-2, sCD74, and MIF genotypes in patients scheduled for elective single or complex surgical procedures such as coronary artery bypass grafting or valve replacement.

RESULTS

MIF and MIF-2 levels significantly increased intraoperatively, whereas measured sCD74 decreased correspondingly. Circulating sCD74/MIF complexes were detectable in 50% of patients and enhanced MIF antioxidant activity. Intraoperative MIF levels were independently associated with a reduced risk for the development of atrial fibrillation (AF) (odds ratio 0.99 [0.98-1.00]; p=0.007). Circulating levels of MIF-2, but not MIF, were associated with an increased frequency of organ dysfunction and predicted the occurrence of AF (area under the curve [AUC]=0.663; p=0.041) and pneumonia (AUC=0.708; p=0.040). Patients with a high-expression MIF genotype exhibited a reduced incidence of organ dysfunction compared with patients with low-expression MIF genotypes (3 vs. 25; p=0.042).

INNOVATION

The current study comprehensively highlights the kinetics and clinical relevance of MIF family proteins and the MIF genotype in cardiac surgery patients.

CONCLUSION

Our findings suggest that increased MIF levels during cardiac surgery feature organ-protective properties during myocardial I/R, while the soluble MIF receptor, sCD74, may enhance MIF antioxidant activity. In contrast, high MIF-2 levels are predictive of the development of organ dysfunction. Importantly, we provide first evidence for a gene-phenotype relationship between variant MIF alleles and clinical outcome in cardiac surgery patients.

Desflurane preconditioning protects human umbilical vein endothelial cells against anoxia/reoxygenation by upregulating NLRP12 and inhibiting non-canonical nuclear factor-κB signaling

Volatile anesthetics modulate endothelial cell apoptosis and inhibit nuclear factor-κB (NF-κB) signaling. In this study, we aimed to assess whether desflurane preconditioning protects human umbilical vein endothelial cells (HUVECs) agaist anoxia/reoxygenation (A/R) injury. HUVECs were pre-conditioned with desflurane (1.0 MAC) for 30 min, followed by a 15-min washout, then exposed to 60 min anoxia and 60 min reoxygenation (A/R), and incubated with 10 ng/ml tumor necrosis factor (TNF)-α for 60 min. HUVEC viability and apoptosis were measured by MTT assay and annexin V staining, and immunoblot analysis was used to measure the levels of Smac and cellular inhibitor of apoptosis 1 (cIAP1). NF-κB activation was assessed using the NF-κB signaling pathway real‑time PCR array, and the levels of NF-κB inducing kinase (NIK), p52, IκB kinase (IKK)α, p100, RelB and NLR family, pyrin domain containing 12 (NLRP12) were assessed by immunoblot analysis. Desflurane preconditioning attenuated the effects of A/R and/or A/R plus TNF-α on cell viability, decreasing the levels of Smac and enhancing the levels of of cIAP1 (P<0.05). Preconditioning with desflurane also enhanced the mRNA levels of interleukin (IL)-10 and NLRP12 in the cells exposed to A/R by 2.40- and 2.16‑fold, respectively. The HUVECs exposed to A/R had greater levels of NIK and p100 and reduced levels of p52 and IKKα. Desflurance preconditioning further increased p100 levels, decreased the level of NIK, further decreased p52 levels and further reduced IKKα levels. A/R in combination with TNF-α increased the NIK, IKKα, p100 and RelB levels, and this increase was significantly attenuated by desflurance preconditioning (all P<0.05). Desflurane preconditioning enhanced HUVEC survival and protected the cells against A/R injury, and our results suggested that this process involved the upregulation of NLRP12 and the inhibition of non-canonical NF-κB signaling.