Bioactive Oxylipins in Infants and Children With Congenital Heart Disease Undergoing Pediatric Cardiopulmonary Bypass

Oxylipins Derived from PUFAs in Cardiometabolic Diseases: Mechanism of Actions and Possible Nutritional Interactions

Oxylipins are oxidized fatty acids, both saturated and unsaturated, formed through pathways that involve singlet oxygen or dioxygen-mediated oxygenation reactions and are primarily produced by enzyme families such as cyclooxygenases, lipoxygenases, and cytochrome P450. These lipid-based complex bioactive molecules are pivotal signal mediators, acting in a hormone-like manner in the pathophysiology of numerous diseases, especially cardiometabolic diseases via modulating plenty of mechanisms. It has been reported that omega-6 and omega-3 oxylipins are important novel biomarkers of cardiometabolic diseases. Moreover, collected literature has noted that diet and dietary components, especially fatty acids, can modulate these oxygenated lipid products since they are mainly derived from dietary omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) or linoleic acid and α-linolenic by elongation and desaturation pathways. This comprehensive review aims to examine their correlations to cardiometabolic diseases and how diets modulate oxylipins. Also, some aspects of developing new biomarkers and therapeutical utilization are detailed in this review.

Prediction of Vasoactive-Inotropic Score on Prolonged Mechanical Ventilation in Adult Congenital Heart Disease Patients After Surgical Treatment Combined with Coronary Artery Bypass Grafting

INTRODUCTION

This study aimed to investigate the predictive value of the vasoactive-inotropic score (VIS) at different time points for postoperative prolonged mechanical ventilation (PMV) in adult congenital heart disease patients undergoing surgical treatment combined with coronary artery bypass grafting.

METHODS

Patients were divided into two groups that developed PMV or not. The propensity score matching method was applied to reduce the effects of confounding factors between the two groups. VIS at different time points (VIS at the end of surgery, VIS6h, VIS12h, and VIS12h max) after surgery were recorded and calculated. The value of VIS in predicting PMV was analyzed by the receiver operating characteristic (ROC) curve, and multivariate logistic regression was used to analyze independent risk factors.

RESULTS

Among 250 patients, 52 were in the PMV group, and 198 were in the non-PMV group. PMV rate was 20.8%. After propensity score matching, 94 patients were matched in pairs. At each time point, the area under the ROC curve predicted by VIS for PMV was > 0.500, among which VIS at the end of surgery was the largest (0.805). The optimal cutoff point for VIS of 6.5 could predict PMV with 78.7% sensitivity and 72.3% specificity. VIS at the end of surgery was an independent risk factor for PMV (odds ratio=1.301, 95% confidence interval 1.091~1.551, P<0.01).

CONCLUSION

VIS at the end of surgery is an independent predictor for PMV in patients with adult congenital heart disease surgical treatment combined with coronary artery bypass grafting.

The association of vasoactive-inotropic score and surgical patients' outcomes: a systematic review and meta-analysis

BACKGROUND

The objective of this study is to conduct a systematic review and meta-analysis examining the relationship between the vasoactive-inotropic score (VIS) and patient outcomes in surgical settings.

METHODS

Two independent reviewers searched PubMed, Web of Science, EMBASE, Scopus, Cochrane Library, Google Scholar, and CNKI databases from November 2010, when the VIS was first published, to December 2022. Additional studies were identified through hand-searching the reference lists of included studies. Eligible studies were those published in English that evaluated the association between the VIS and short- or long-term patient outcomes in both pediatric and adult surgical patients. Meta-analysis was performed using RevMan Manager version 5.3, and quality assessment followed the Joanna Briggs Institute (JBI) Critical Appraisal Checklists.

RESULTS

A total of 58 studies comprising 29,920 patients were included in the systematic review, 34 of which were eligible for meta-analysis. Early postoperative VIS was found to be associated with prolonged mechanical ventilation (OR 5.20, 95% CI 3.78-7.16), mortality (OR 1.08, 95% CI 1.05-1.12), acute kidney injury (AKI) (OR 1.26, 95% CI 1.13-1.41), poor outcomes (OR 1.02, 95% CI 1.01-1.04), and length of stay (LOS) in the ICU (OR 3.50, 95% CI 2.25-5.44). The optimal cutoff value for the VIS as an outcome predictor varied between studies, ranging from 10 to 30.

CONCLUSION

Elevated early postoperative VIS is associated with various adverse outcomes, including acute kidney injury (AKI), mechanical ventilation duration, mortality, poor outcomes, and length of stay (LOS) in the ICU. Monitoring the VIS upon return to the Intensive Care Unit (ICU) could assist medical teams in risk stratification, targeted interventions, and parent counseling.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022359100.

Effect of cardiopulmonary bypass on plasma and erythrocytes oxylipins

BACKGROUND

Oxylipins, the oxidative metabolites of polyunsaturated fatty acids (PUFAs), serve as key mediators of oxidative stress, inflammatory responses, and vasoactive reactions in vivo. Our previous work has established that hemodialysis affects both long chain fatty acids (LCFAs) and oxylipins in plasma and erythrocytes to varying degrees, which may be responsible for excess cardiovascular complications in end-stage renal disease. In this study, we aimed to determine changes in blood oxylipins during cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery to identify novel biomarkers and potential metabolites of CPB-related complications. We tested the hypothesis that CPB would differentially affect plasma oxylipins and erythrocytes oxylipins.

METHODS

We conducted a prospective observational study of 12 patients undergoing elective cardiac surgery with expected CPB procedure. We collected venous and arterial blood samples before CPB, 15 and 45 min after the start of CPB, and 60 min after the end of CPB, respectively. Oxylipins profiling in plasma and erythrocytes was achieved using targeted HPLC-MS mass spectrometry.

RESULTS

Our results revealed that most venous plasma diols and hydroxy- oxylipins decreased after CPB initiation, with a continuous decline until the termination of CPB. Nevertheless, no statistically significant alterations were detected in erythrocytes oxylipins at all time points.

CONCLUSIONS

CPB decreases numerous diols and hydroxy oxylipins in blood plasma, whereas no changes in erythrocytes oxylipins are observed during this procedure in patients undergoing cardiac surgery. As lipid mediators primarily responsive to CPB, plasma diols and hydroxy oxylipins may serve as potential key biomarkers for CPB-related complications.

Crosstalk between adenosine receptors and CYP450-derived oxylipins in the modulation of cardiovascular, including coronary reactive hyperemic response

Adenosine is a ubiquitous endogenous nucleoside or autacoid that affects the cardiovascular system through the activation of four G-protein coupled receptors: adenosine A₁ receptor (A₁AR), adenosine A_2A receptor (A_2AAR), adenosine A_2B receptor (A_2BAR), and adenosine A₃ receptor (A₃AR). With the rapid generation of this nucleoside from cellular metabolism and the widespread distribution of its four G-protein coupled receptors in almost all organs and tissues of the body, this autacoid induces multiple physiological as well as pathological effects, not only regulating the cardiovascular system but also the central nervous system, peripheral vascular system, and immune system. Mounting evidence shows the role of CYP450-enzymes in cardiovascular physiology and pathology, and the genetic polymorphisms in CYP450s can increase susceptibility to cardiovascular diseases (CVDs). One of the most important physiological roles of CYP450-epoxygenases (CYP450-2C & CYP2J2) is the metabolism of arachidonic acid (AA) and linoleic acid (LA) into epoxyeicosatrienoic acids (EETs) and epoxyoctadecaenoic acid (EpOMEs) which generally involve in vasodilation. Like an increase in coronary reactive hyperemia (CRH), an increase in anti-inflammation, and cardioprotective effects. Moreover, the genetic polymorphisms in CYP450-epoxygenases will change the beneficial cardiovascular effects of metabolites or oxylipins into detrimental effects. The soluble epoxide hydrolase (sEH) is another crucial enzyme ubiquitously expressed in all living organisms and almost all organs and tissues. However, in contrast to CYP450-epoxygenases, sEH converts EETs into dihydroxyeicosatrienoic acid (DHETs), EpOMEs into dihydroxyoctadecaenoic acid (DiHOMEs), and others and reverses the beneficial effects of epoxy-fatty acids leading to vasoconstriction, reducing CRH, increase in pro-inflammation, increase in pro-thrombotic and become less cardioprotective. Therefore, polymorphisms in the sEH gene (Ephx2) cause the enzyme to become overactive, making it more vulnerable to CVDs, including hypertension. Besides the sEH, ω-hydroxylases (CYP450-4A11 & CYP450-4F2) derived metabolites from AA, ω terminal-hydroxyeicosatetraenoic acids (19-, 20-HETE), lipoxygenase-derived mid-chain hydroxyeicosatetraenoic acids (5-, 11-, 12-, 15-HETEs), and the cyclooxygenase-derived prostanoids (prostaglandins: PGD₂, PGF_2α; thromboxane: Txs, oxylipins) are involved in vasoconstriction, hypertension, reduction in CRH, pro-inflammation and cardiac toxicity. Interestingly, the interactions of adenosine receptors (A_2AAR, A₁AR) with CYP450-epoxygenases, ω-hydroxylases, sEH, and their derived metabolites or oxygenated polyunsaturated fatty acids (PUFAs or oxylipins) is shown in the regulation of the cardiovascular functions. In addition, much evidence demonstrates polymorphisms in CYP450-epoxygenases, ω-hydroxylases, and sEH genes (Ephx2) and adenosine receptor genes (ADORA1 & ADORA2) in the human population with the susceptibility to CVDs, including hypertension. CVDs are the number one cause of death globally, coronary artery disease (CAD) was the leading cause of death in the US in 2019, and hypertension is one of the most potent causes of CVDs. This review summarizes the articles related to the crosstalk between adenosine receptors and CYP450-derived oxylipins in vascular, including the CRH response in regular salt-diet fed and high salt-diet fed mice with the correlation of heart perfusate/plasma oxylipins. By using A_2AAR^-/-, A₁AR^-/-, eNOS^-/-, sEH^-/- or Ephx2^-/-, vascular sEH-overexpressed (Tie2-sEH Tr), vascular CYP2J2-overexpressed (Tie2-CYP2J2 Tr), and wild-type (WT) mice. This review article also summarizes the role of pro-and anti-inflammatory oxylipins in cardiovascular function/dysfunction in mice and humans. Therefore, more studies are needed better to understand the crosstalk between the adenosine receptors and eicosanoids to develop diagnostic and therapeutic tools by using plasma oxylipins profiles in CVDs, including hypertensive cases in the future.

A Review of Oxylipins in Alzheimer's Disease and Related Dementias (ADRD): Potential Therapeutic Targets for the Modulation of Vascular Tone and Inflammation

There is now a convincing body of evidence from observational studies that the majority of modifiable Alzheimer's disease and related dementia (ADRD) risk factors are vascular in nature. In addition, the co-existence of cerebrovascular disease with AD is more common than AD alone, and conditions resulting in brain ischemia likely promote detrimental effects of AD pathology. Oxylipins are a class of bioactive lipid mediators derived from the oxidation of long-chain polyunsaturated fatty acids (PUFAs) which act as modulators of both vascular tone and inflammation. In vascular cognitive impairment (VCI), there is emerging evidence that oxylipins may have both protective and detrimental effects on brain structure, cognitive performance, and disease progression. In this review, we focus on oxylipin relationships with vascular and inflammatory risk factors in human studies and animal models pertinent to ADRD. In addition, we discuss future research directions with the potential to impact the trajectory of ADRD risk and disease progression.

Association Between Hyperoxemia and Increased Cell-Free Plasma Hemoglobin During Cardiopulmonary Bypass in Infants and Children

OBJECTIVES

To determine potential risk factors for severe hemolysis during pediatric cardiopulmonary bypass and examine whether supraphysiologic levels of oxygen and cardiopulmonary bypass duration are associated with hemolysis.

DESIGN

Prospective observational study.

SETTING

Cardiac ICU in a university-affiliated children's hospital.

PATIENTS

Greater than 1 month to less than 18 years old patients undergoing cardiopulmonary bypass for cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma samples from 100 patients to assess cell-free plasma hemoglobin levels were obtained at start cardiopulmonary bypass, at the end of cardiopulmonary bypass, and 2 and 24 hours after reperfusion. Arterial blood gas samples were obtained before and every 30 minutes during cardiopulmonary bypass. Patient demographics and laboratory data were collected from the electronic medical record. Plasma hemoglobin levels peaked at the end of cardiopulmonary bypass and haptoglobin levels continued to fall throughout all time points. There were 44 patients with severe hemolysis (change in cell-free plasma hemoglobin > 50 mg/dL). Younger age (odds ratio/sd 0.45 [95% CI, 0.25-0.81]) and higher mean Pao2 × cardiopulmonary bypass duration (31.11 [1.46-664.64]) were identified as risk factors for severe hemolysis in multivariable analysis. Severe hemolysis was associated with longer hospital and ICU lengths of stay as well as acute kidney injury.

CONCLUSIONS

We observed younger age and the exposure to both oxygen and duration of cardiopulmonary bypass as risk factors for hemolysis. Oxygen delivery through the cardiopulmonary bypass circuit is an easily modifiable risk factor. Its role in the production of reactive oxygen species that could alter the erythrocyte membrane deserves further examination in larger prospective studies.

Oxoeicosanoid receptor inhibition alleviates acute myocardial infarction through activation of BCAT1

5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is an arachidonic acid metabolite produced along with leukotrienes via the 5-lipoxygenase pathway. Metabolomics studies have shown that 5-oxo-ETE level is elevated in the serum in acute myocardial infarction (AMI). The actions of 5-oxo-ETE are mediated by the highly selective oxoeicosanoid receptor (OXE-R). Moreover, increased OXE-R content was verified in AMI patients and mice. However, the precise role of OXE-R in AMI is unclear. In the present study, we demonstrate that 5-oxo-ETE triggered myocardial injury in mice. Pathway enrichment analysis identified branched chain amino acid transaminase 1/2 (BCAT1/2) as potential mediators of this effect. Western blot and immunohistochemical analyses showed that BCAT1/BCAT2 expression was significantly reduced by AMI in vitro and in vivo, while pharmacologic inhibition of BCAT1/BCAT2 accelerated myocardial injury. Conversely, heart-specific overexpression of BCAT1/BCAT2 in mice protected against ischemic myocardial injury. Treatment with the selective OXE-R inhibitor Gue1654 alleviated coronary artery ligation-induced ischemic myocardial injury in mice and oxygen/glucose deprivation-induced injury in cardiomyocytes through activation of BCAT1, while inhibiting OXE-R suppressed protein kinase C-ε (PKC-ε)/nuclear factor κB (NF-κB) signaling and cardiomyocyte apoptosis. Overall, our study confirmed a novel target OXE-R for the treatment of AMI based on metabolomics, and targeting OXE-R may represent unrecognized therapeutic intervention for cardiovascular diseases through activation of BCAT1.

The Year in Review: Anesthesia for Congenital Heart Disease 2019

This review focuses on the literature published from January 2019 to February 2020 that is of interest to anesthesiologists taking care of children and adults with congenital heart disease. Five themes are addressed during this time period, and 59 peer-reviewed articles are discussed.