Bile acid excess induces cardiomyopathy and metabolic dysfunctions in the heart

Facilitating a high-quality dietary pattern induces shared microbial responses linking diet quality, blood pressure, and microbial sterol metabolism in caregiver-child dyads

Low-resource individuals are at increased risk of obesity and cardiovascular disease (CVD), partially attributable to poor dietary patterns and dysfunctional microbiota. Dietary patterns in childhood play critical roles in physiological development and are shaped by caregivers, making caregiver-child dyads attractive targets for dietary interventions to reduce metabolic disease risk. Herein, we targeted low-resource caregiver-child dyads for a 10-week, randomized, controlled, multifaceted lifestyle intervention including: nutrition and physical activity education, produce harvesting, cooking demonstrations, nutrition counseling, and kinetic activites; to evaluate its effects on dietary patterns, CVD risk factors, and microbiome composition. Subjects in the lifestyle intervention group improved total diet quality, increased whole grain intake, decreased energy intake, and enhanced fecal elimination of the microbe-derived metabolite lithocholic acid (LCA) in contrast to control subjects. Microbiomes were highly personalized, similar within dyads, and altered by lifestyle intervention. Differential modeling of microbiome composition identified taxa associated with total diet quality, whole grain intake, and LCA elimination including recognized fiber-degrading bacteria such as Subdoligranulum, and bile acid metabolizing organisms like Bifidobacterium. Inclusion of taxa identified in diet and metabolite modeling within blood pressure models improved prediction accuracy of microbiome-blood pressure associations. Importantly, microbiota-blood pressure relationships were shared between dyads, implying shared host-microbiota responses to lifestyle intervention. Overall, these outcomes provide insight into mechanisms by which dietary interventions impact the gut-cardiovascular axis to reduce future CVD risk. Registered at clinicaltrials.gov: NCT05367674.

Biliary cirrhosis-induced cardiac abnormality in rats: Interaction between Farnesoid-X-activated receptors and the cardiac uncoupling proteins 2 and 3

OBJECTIVES

This study aimed to evaluate the relationship between Farnesoid-X-activated receptors (FXR) as nuclear regulators of the antioxidant defense system as well as cardiac mitochondrial carrier proteins of UCP2 and UCP3 in cardiac damage induced by cirrhosis.

MATERIALS AND METHODS

Twenty-two male Wistar rats (200-250 g) were randomly divided into 3 experimental groups, including a control group (n=6), a sham-operated group (n=8), and a bile duct ligated (BDL) group (n=8). Four weeks after surgical intervention, biochemical assessment (AST, ALT, GGT, LDH, and ALP), histological observation, and molecular evaluation (FXR, UCP2, UCP3, BNP, Caspase3, and GAPDH) using real-time RT-PCR were performed.

RESULTS

Compared with the sham-operation group, the BDL group showed a significant rise in liver enzymes of AST, ALT, GGT, LDH, and ALP. Defined fibrotic and necrotic bundles and thick reticulin fibers were also found in BDL liver tissue. Besides liver morphological alterations, left ventricles of BDL ones were also associated with defined cardiomyocyte hypertrophy, myofiber vacuolization, and clear pigmentation. Findings showed a significant up-regulation of cardiac Brain Natriuretic Peptide (BNP) along with marked down-regulation in hepatic FXR, cardiac FXR, and cardiac UCP2 and UCP3. However, the expression of caspase 3 in the cardiac tissue was not affected by BDL operation during 4 weeks.

CONCLUSION

Expression of FXR as an upstream regulator of cellular redox status, besides the non-enzymatic ROS buffering defense system of cardiac UCPs, has a pivotal role in the pathogenesis of cirrhotic-induced cardiac abnormality in rats.

Pathogenic Mechanisms Underlying Cirrhotic Cardiomyopathy

Cardiac dysfunction associated with cirrhosis in the absence of preexisting heart disease is a condition known as cirrhotic cardiomyopathy (CCM). Cardiac abnormalities consist of enlargement of cardiac chambers, attenuated systolic and diastolic contractile responses to stress stimuli, and repolarization changes. CCM may contribute to cardiovascular morbidity and mortality after liver transplantation and other major surgeries, and also to the pathogenesis of hepatorenal syndrome. The underlying mechanisms of CCM are poorly understood and as such medical therapy is an area of unmet medical need. The present review focuses on the pathogenic mechanisms responsible for development of CCM. The two major concurrent mechanistic pathways are the inflammatory phenotype due to portal hypertension, and protein/lipid synthetic/metabolic defects due to cirrhosis and liver insufficiency. The inflammatory phenotype arises from intestinal congestion due to portal hypertension, resulting in bacteria/endotoxin translocation into the systemic circulation. The cytokine storm associated with inflammation, particularly TNFα acting via NFκB depresses cardiac function. They also stimulate two evanescent gases, nitric oxide and carbon monoxide which produce cardiodepression by cGMP. Inflammation also stimulates the endocannabinoid CB-1 pathway. These systems inhibit the stimulatory beta-adrenergic contractile pathway. The liver insufficiency of cirrhosis is associated with defective synthesis or metabolism of several substances including proteins and lipids/lipoproteins. The protein defects including titin and collagen contribute to diastolic dysfunction. Other protein abnormalities such as a switch of myosin heavy chain isoforms result in systolic dysfunction. Lipid biochemical changes at the cardiac sarcolemmal plasma membrane result in increased cholesterol:phospholipid ratio and decreased membrane fluidity. Final common pathway changes involve abnormal cardiomyocyte intracellular ion kinetics, particularly calcium. In conclusion, cirrhotic cardiomyopathy is caused by two pathways of cellular and molecular dysfunction/damage due to hepatic insufficiency and portal hypertension.

The Role of Bile Acids in Cardiovascular Diseases: from Mechanisms to Clinical Implications

Bile acids (BAs), key regulators in the metabolic network, are not only involved in lipid digestion and absorption but also serve as potential therapeutic targets for metabolic disorders. Studies have shown that cardiac dysfunction is associated with abnormal BA metabolic pathways. As ligands for several nuclear receptors and membrane receptors, BAs systematically regulate the homeostasis of metabolism and participate in cardiovascular diseases (CVDs), such as myocardial infarction, diabetic cardiomyopathy, atherosclerosis, arrhythmia, and heart failure. However, the molecular mechanism by which BAs trigger CVDs remains controversial. Therefore, the regulation of BA signal transduction by modulating the synthesis and composition of BAs is an interesting and novel direction for potential therapies for CVDs. Here, we mainly summarized the metabolism of BAs and their role in cardiomyocytes and noncardiomyocytes in CVDs. Moreover, we comprehensively discussed the clinical prospects of BAs in CVDs and analyzed the clinical diagnostic and application value of BAs. The latest development prospects of BAs in the field of new drug development are also prospected. We aimed to elucidate the underlying mechanism of BAs treatment in CVDs, and the relationship between BAs and CVDs may provide new avenues for the prevention and treatment of these diseases.

Intermittent Fasting Enhances Right Ventricular Function in Preclinical Pulmonary Arterial Hypertension

Background Intermittent fasting (IF) confers pleiotropic cardiovascular benefits including restructuring of the gut microbiome and augmentation of cellular metabolism. Pulmonary arterial hypertension (PAH) is a rare and lethal disease characterized by right ventricular (RV) mitochondrial dysfunction and resultant lipotoxicity and microbiome dysbiosis. However, the effects of IF on RV function in PAH are unexplored. Therefore, we investigated how IF altered gut microbiota composition, RV function, and survival in the monocrotaline model of PAH. Methods and Results Male Sprague Dawley rats were randomly allocated into 3 groups: control, monocrotaline-ad libitum feeding, and monocrotaline-IF (every other day feeding). Echocardiography and invasive hemodynamics showed IF improved RV systolic and diastolic function despite no significant change in PAH severity. IF prevented premature mortality (30% mortality rate in monocrotaline-ad libitum versus 0% in monocrotaline-IF rats, P=0.04). IF decreased RV cardiomyocyte hypertrophy and reduced RV fibrosis. IF prevented RV lipid accrual on Oil Red O staining and ceramide accumulation as determined by metabolomics. IF mitigated the reduction in jejunum villi length and goblet cell abundance when compared with monocrotaline-ad libitum. The 16S ribosomal RNA gene sequencing demonstrated IF changed the gut microbiome. In particular, there was increased abundance of Lactobacillus in monocrotaline-IF rats. Metabolomics profiling revealed IF decreased RV levels of microbiome metabolites including bile acids, aromatic amino acid metabolites, and gamma-glutamylated amino acids. Conclusions IF directly enhanced RV function and restructured the gut microbiome. These results suggest IF may be a non-pharmacological approach to combat RV dysfunction, a currently untreatable and lethal consequence of PAH.

The gut-cardiovascular connection: new era for cardiovascular therapy

Our gut microbiome is constituted by trillions of microorganisms including bacteria, archaea and eukaryotic microbes. Nowadays, gut microbiome has been gradually recognized as a new organ system that systemically and biochemically interact with the host. Accumulating evidence suggests that the imbalanced gut microbiome contributes to the dysregulation of immune system and the disruption of cardiovascular homeostasis. Specific microbiome profiles and altered intestinal permeability are often observed in the pathophysiology of cardiovascular diseases. Gut-derived metabolites, toxins, peptides and immune cell-derived cytokines play pivotal roles in the induction of inflammation and the pathogenesis of dysfunction of heart and vasculature. Impaired crosstalk between gut microbiome and multiple organ systems, such as gut-vascular, heart-gut, gut-liver and brain-gut axes, are associated with higher cardiovascular risks. Medications and strategies that restore healthy gut microbiome might therefore represent novel therapeutic options to lower the incidence of cardiovascular and metabolic disorders.

Mechanistic insights into the pathophysiology of cirrhotic cardiomyopathy

Myocardial dysfunction in end stage cirrhotic liver disease, termed cirrhotic cardiomyopathy, is a long known, but little understood comorbidity seen in ∼50% of adults and children who present for liver transplantation. Structural, functional, hemodynamic and electrocardiographic aberrations that occur in the heart as a direct consequence of a damaged liver, is associated with multi-organ failure and increased mortality and morbidity in patients undergoing surgical procedures such as porto-systemic shunt placement and liver transplantation. Despite its clinical significance and rapid advances in science and pharmacotherapy, there is yet no specific treatment for this disease. This may be due to a lack of understanding of the pathogenesis and mechanisms behind how a cirrhotic liver causes cardiac pathology. This review will focus specifically on insights into the molecular mechanisms that drive this liver-heart interaction. Deeper understanding of the etio-pathogenesis of cirrhotic cardiomyopathy will allow us to design and test treatments that can be targeted to prevent and/or reverse this co-morbid consequence of liver failure and improve health care delivery and outcomes in patients with cirrhosis.

Redox-Dependent Effects in the Physiopathological Role of Bile Acids

Bile acids (BA) are recognized by their role in nutrient absorption. However, there is growing evidence that BA also have endocrine and metabolic functions. Besides, the steroidal-derived structure gives BA a toxic potential over the biological membrane. Thus, cholestatic disorders, characterized by elevated BA on the liver and serum, are a significant cause of liver transplant and extrahepatic complications, such as skeletal muscle, central nervous system (CNS), heart, and placenta. Further, the BA have an essential role in cellular damage, mediating processes such as membrane disruption, mitochondrial dysfunction, and the generation of reactive oxygen species (ROS) and oxidative stress. The purpose of this review is to describe the BA and their role on hepatic and extrahepatic complications in cholestatic diseases, focusing on the association between BA and the generation of oxidative stress that mediates tissue damage.

Intestinal-derived FGF15 protects against deleterious effects of vertical sleeve gastrectomy in mice

Bariatric surgeries such as the Vertical Sleeve Gastrectomy (VSG) are invasive but provide the most effective improvements in obesity and Type 2 diabetes. We hypothesized a potential role for the gut hormone Fibroblast-Growth Factor 15/19 which is increased after VSG and pharmacologically can improve energy homeostasis and glucose handling. We generated intestinal-specific FGF15 knockout (FGF15^INT-KO) mice which were maintained on high-fat diet. FGF15^INT-KO mice lost more weight after VSG as a result of increased lean tissue loss. FGF15^INT-KO mice also lost more bone density and bone marrow adipose tissue after VSG. The effect of VSG to improve glucose tolerance was also absent in FGF15^INT-KO. VSG resulted in increased plasma bile acid levels but were considerably higher in VSG-FGF15^INT-KO mice. These data point to an important role after VSG for intestinal FGF15 to protect the organism from deleterious effects of VSG potentially by limiting the increase in circulating bile acids.

The mechanisms that mediate the effects of weight loss surgeries such as vertical sleeve gastrectomy (VSG) are incompletely understood. Here the authors show that intestinal FGF15 is necessary to improve glucose tolerance and to prevent the loss of muscle and bone mass after VSG, potentially via protection against bile acid toxicity.

Exercise Training Attenuates Cirrhotic Cardiomyopathy

Cirrhotic cardiomyopathy is a condition where liver cirrhosis is associated with cardiac dysfunction. Triggers and blockers of cirrhotic cardiomyopathy are poorly understood, which might compromise the prognosis of chronic liver disease patients. We tested whether exercise training would reduce liver damage induced by thioacetamide and prevent liver cirrhosis-associated cardiomyopathy. Wistar rats were divided into three groups: control, thioacetamide (TAA), or TAA plus exercise. Thioacetamide increased liver weight and serum alanine aminotransferase and aspartate aminotransferase levels. Also, TAA treatment was involved with hepatic nodule formation, fibrotic septa, inflammatory infiltration, and hepatocyte necrosis. The exercise group presented with a reduction in liver injury status. We found that liver injury was associated with disordered cardiac hypertrophy as well as diastolic and systolic dysfunction. Exercise training attenuated cirrhosis-associated cardiac remodeling and diastolic dysfunction and prevented systolic impairment. These results provided insights that exercise training can mitigate cirrhotic cardiomyopathy phenotype. Graphical Abstract Exercise training attenuated liver injury as well as cirrhosis-associated cardiac remodeling and diastolic dysfunction and prevented systolic impairment.

Bile Acids, Liver Cirrhosis, and Extrahepatic Vascular Dysfunction

The bile acid pool with its individual bile acids (BA) is modulated in the enterohepatic circulation by the liver as the primary site of synthesis, the motility of the gallbladder and of the intestinal tract, as well as by bacterial enzymes in the intestine. The nuclear receptor farnesoid X receptor (FXR) and Gpbar1 (TGR5) are important set screws in this process. Bile acids have a vasodilatory effect, at least according to in vitro studies. The present review examines the question of the extent to which the increase in bile acids in plasma could be responsible for the hyperdynamic circulatory disturbance of liver cirrhosis and whether modulation of the bile acid pool, for example, via administration of ursodeoxycholic acid (UDCA) or via modulation of the dysbiosis present in liver cirrhosis could influence the hemodynamic disorder of liver cirrhosis. According to our analysis, the evidence for this is limited. Long-term studies on this question are lacking.

Chenodeoxycholic and deoxycholic acids induced positive inotropic and negative chronotropic effects on rat heart

Bile acids are endogenous amphiphilic steroids from the metabolites of cholesterol. Studies showed that they might contribute to the pathogenesis of cardiopathy in cholestatic liver diseases. Chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA) is associated with colon cancer, gallstones, and gastrointestinal disorders. However, little information is available regarding their cardiac effects. Here, we reported that CDCA (100 μM) and DCA (100 μM) significantly increased the left ventricular developed pressure of the isolated rat hearts to 122.3 ± 5.6% and 145.1 ± 13.7%, and the maximal rate of the pressure development rising and descending (± dP/dtmax) to 103.4 ± 17.6% and 124.4 ± 37.7% of the basal levels, respectively. They decreased the heart rate and prolonged the RR, QRS, and QT intervals of Langendorff-perfused hearts in a concentration-dependent manner. Moreover, CDCA and DCA increased the developed tension of left ventricular muscle and the cytosolic Ca2+ concentrations in left ventricular myocytes; these functions positively coordinated with their inotropic effects on hearts. Additionally, CDCA (150 μM) and DCA (100 μM) decreased the sinoatrial node beating rate to 80.6 ± 3.0% and 79.7 ± 0.9% of the basal rate (334.2 ± 10.7 bpm), respectively. These results were consistent with their chronotropic effects. In conclusion, CDCA and DCA induced positive inotropic effects by elevating the Ca2+ in left ventricular myocytes. They exerted negative chronotropic effects by lowering the pace of the sinoatrial node in rat heart. These results indicated that the potential role of bile acids in cardiopathy related to cholestasis.

Microbiota and Metabolites as Factors Influencing Blood Pressure Regulation

The study of microbes has rapidly expanded in recent years due to a surge in our understanding that humans host a plethora of commensal microbes, which reside in their bodies and depending upon their composition, contribute to either normal physiology or pathophysiology. This article provides a general foundation for learning about host-commensal microbial interactions as an emerging area of research. The article is divided into two sections. The first section is dedicated to introducing commensal microbiota and its known effects on the host. The second section is on metabolites, which are biochemicals that the host and the microbes use for bi-directional communication with each other. Together, the sections review what is known about how microbes interact with the host to impact cardiovascular physiology, especially blood pressure regulation. © 2021 American Physiological Society. Compr Physiol 11:1731-1757, 2021.

Interplay of cardiovascular mediators, oxidative stress and inflammation in liver disease and its complications

The liver is a crucial metabolic organ that has a key role in maintaining immune and endocrine homeostasis. Accumulating evidence suggests that chronic liver disease might promote the development of various cardiac disorders (such as arrhythmias and cardiomyopathy) and circulatory complications (including systemic, splanchnic and pulmonary complications), which can eventually culminate in clinical conditions ranging from portal and pulmonary hypertension to pulmonary, cardiac and renal failure, ascites and encephalopathy. Liver diseases can affect cardiovascular function during the early stages of disease progression. The development of cardiovascular diseases in patients with chronic liver failure is associated with increased morbidity and mortality, and cardiovascular complications can in turn affect liver function and liver disease progression. Furthermore, numerous infectious, inflammatory, metabolic and genetic diseases, as well as alcohol abuse can also influence both hepatic and cardiovascular outcomes. In this Review, we highlight how chronic liver diseases and associated cardiovascular effects can influence different organ pathologies. Furthermore, we explore the potential roles of inflammation, oxidative stress, vasoactive mediator imbalance, dysregulated endocannabinoid and autonomic nervous systems and endothelial dysfunction in mediating the complex interplay between the liver and the systemic vasculature that results in the development of the extrahepatic complications of chronic liver disease. The roles of ageing, sex, the gut microbiome and organ transplantation in this complex interplay are also discussed.

Overview of bile acid signaling in the cardiovascular system

Bile acids (BAs) are classically known to play a vital role in the metabolism of lipids and in absorption. It is now well established that BAs act as signaling molecules, activating different receptors (such as farnesoid X receptor, vitamin D receptor, Takeda G-protein-coupled receptor 5, sphingosine-1-phosphate, muscarinic receptors, and big potassium channels) and participating in the regulation of energy homeostasis and lipid and glucose metabolism. In addition, increased BAs can impair cardiovascular function in liver cirrhosis. Approximately 50% of patients with cirrhosis develop cirrhotic cardiomyopathy. Exposure to high concentrations of hydrophobic BAs has been shown to be related to adverse effects with respect to vascular tension, endothelial function, arrhythmias, coronary atherosclerotic heart disease, and heart failure. The BAs in the serum BA pool have relevant through their hydrophobicity, and the lipophilic BAs are more harmful to the heart. Interestingly, ursodeoxycholic acid is a hydrophilic BA, and it is used as a therapeutic drug to reverse and protect the harmful cardiac effects caused by hydrophobic elevated BAs. In order to elucidate the mechanism of BAs and cardiovascular function, abundant experiments have been conducted in vitro and in vivo. The aim of this review was to explore the mechanism of BAs in the cardiovascular system.

Irradiation of the kidneys causes pathologic remodeling in the nontargeted heart: A role for the immune system

Cardiac disease is a frequent and significant adverse event associated with radiotherapy for cancer. Identifying the underlying mechanism responsible for radiation injury to the heart will allow interventions to be developed. In the present study, we tested if local kidney irradiation results in remodeling of the shielded, nontargeted heart. One kidney, two kidneys, or the total body of male WAG and Dahl SS rats were irradiated with 10 Gy of X-rays. Local kidney irradiation resulted in systemic hypertension, increased BUN, infiltration of T lymphocytes, natural killer cells, and macrophages into the renal cortex and medulla, and renal fibrosis. Local irradiation of kidneys in WAG rats resulted in remodeling in the nontargeted heart after 120 days, manifested by perivascular fibrosis and increased interventricular septal thickness, but was not seen in Dahl SS rats due to a high baseline level of fibrosis in the sham-irradiated animals. Genetic depletion of T cells mitigated the nephropathy after local kidney irradiation, indicating a role for the immune system in mediating this outcome. Local kidney irradiation resulted in a cascade of pro-inflammatory cytokines and low-molecular weight metabolites into the circulation associated with transmission of signals resulting in pathologic remodeling in the nontargeted heart. A new model is proposed whereby radiation-induced cardiac remodeling in susceptible animals is indirect, with lower hemi body organs such as the kidney exporting factors into the circulation that cause remodeling outside of the irradiated field in the shielded, nontargeted heart. This nontargeted effect appears to be mediated, in part, by the immune system.

Gastrointestinal Mechanisms Underlying the Cardiovascular Effect of Metformin

Metformin, the most widely prescribed drug therapy for type 2 diabetes, has pleiotropic benefits, in addition to its capacity to lower elevated blood glucose levels, including mitigation of cardiovascular risk. The mechanisms underlying the latter remain unclear. Mechanistic studies have, hitherto, focused on the direct effects of metformin on the heart and vasculature. It is now appreciated that effects in the gastrointestinal tract are important to glucose-lowering by metformin. Gastrointestinal actions of metformin also have major implications for cardiovascular function. This review summarizes the gastrointestinal mechanisms underlying the action of metformin and their potential relevance to cardiovascular benefits.

Impaired myosin isoform shift and calcium transients contribute to cellular pathogenesis of rat cirrhotic cardiomyopathy

BACKGROUND & AIMS

Cirrhotic cardiomyopathy is a recently recognized entity, but detailed cellular and molecular mechanisms remain unclarified. We aimed to elucidate the role of myosin heavy chain isoform shifts and their relation to calcium transients in the contractile kinetics of cirrhotic rats.

METHODS

Cirrhosis was induced in male Lewis Brown-Norway rats by bile duct ligation (BDL). Myosin heavy chain (MHC) isoform distribution was evaluated by gel electrophoresis. Contractile force, Ca²⁺ transients and cell shortening were studied at varied frequency and extracellular [Ca²⁺ ]. T-tubular integrity was analysed by power spectrum analysis of images of myocytes stained with di-8-ANEPPS.

RESULTS

Compared with sham controls, the phenotypes of cirrhotic rats were as follows: (a) alpha-myosin heavy chain shifted to beta-MHC isoform; (b) mild loss of T-tubular integrity in myocytes; (c) a reduced maximum and rate of rise of the Ca²⁺ transient (max F/F_o ); (d) a reduction in both the rate of rise and fall of contraction; (e) decreased maximal force-generating capacity; (f) loss of the inotropic effect of increased stimulus frequency; (g) unchanged sensitivity of force development to varied extracellular [Ca²⁺ ] and (h) increased spontaneous diastolic sarcomere length fluctuations.

CONCLUSION

Cardiomyocytes and ventricular trabeculae in a cirrhotic rat model showed features of typical heart failure including systolic and diastolic prolongation, impaired force-frequency relation and decreased force-generating capacity. Impaired myosin isoform shift and calcium transients are important contributory mechanisms underlying the pathogenesis of the heart failure phenotype seen in cirrhosis.

Impact of Intraoperative Norepinephrine Support on Living Donor Liver Transplantation Outcomes: A Retrospective Cohort Study of 430 Children

Norepinephrine (NE) is often administered during the perioperative period of liver transplantation to address hemodynamic instability and to improve organ perfusion and oxygen supply. However, its role and safety profile have yet to be evaluated in pediatric living donor liver transplantation (LDLT). We hypothesized that intraoperative NE infusion might affect pediatric LDLT outcomes. A retrospective study of 430 pediatric patients (median [interquartile range] age, 7 [6.10] months; 189 [43.9%] female) receiving LDLT between 2014 and 2016 at Renji Hospital was conducted. We evaluated patient survival among recipients who received intraoperative NE infusion (NE group, 85 recipients) and those that did not (non-NE group, 345 recipients). The number of children aged over 24 months and weighing more than 10 kg in NE group was more than that in non-NE group. And children in NE group had longer operative time, longer anhepatic phase time and more fluid infusion. After multivariate regression analysis and propensity score regression adjusting for confounding factors to determine the influence of intraoperative NE infusion on patient survival, the NE group had a 169% more probability of dying. Although there was no difference in mean arterial pressure changes relative to the baseline between the two groups, we did observe increased heart rates in NE group compared with those of the non-NE group at anhepatic phase (P=0.025), neohepatic phase (P=0.012) and operation end phase (P=0.017) of the operation. In conclusion, intraoperative NE infusion was associated with a poorer prognosis for pediatric LDLT recipients. Therefore, we recommend the application of NE during pediatric LDLT should be carefully re-considered.

Teneligliptin Promotes Bile Acid Synthesis and Attenuates Lipid Accumulation in Obese Mice by Targeting the KLF15-Fgf15 Pathway

Bile acids (BAs) play essential physiological roles not only by facilitating the absorption and transport of nutrients but also by acting as a complex molecular signaling system. Reduced levels of BAs have been observed in obesity and other metabolic disorders. In the present study, we explored the effect of the dipeptidyl peptidase-4 (DPP-4) inhibitor teneligliptin on BA synthesis, both in vitro and in vivo. In our in vivo experiments, we found that teneligliptin increased the liver, ileal, and serum BA concentrations in mice undergoing teneligliptin treatment for 10 weeks. We further found that in mice fed a high-fat diet, teneligliptin prevented an increase in markers of obesity (body weight, total cholesterol, total triglyceride, adipocyte size) while increasing the total serum and ileal levels of BA. Mechanistically, teneligliptin increased BA synthesis through the alternative synthesis pathway, as the levels of both 7α-hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1) along with downstream oxysterol 7α-hydroxylase (CYP7B1) but not sterol 12α-hydroxylase (CYP8B1) were increased. Importantly, teneligliptin suppressed the expression of the BA synthesis inhibitory factor Fgf15, which was mediated through phosphatidylinositol 3-kinase (PI3K)/AKT/Krüppel-like factor 15 (KLF15) signaling. Inhibition of KLF15 abolished this effect. Together, our results provide evidence of the potential benefit of teneligliptin in the treatment of metabolic disorders via increased BA production.

Living Donor Liver Transplantation in Children: Perioperative Risk Factors and a Nomogram for Prediction of Survival

BACKGROUND

Living donor liver transplantation (LDLT) in children has achieved promising outcomes during the past few decades. However, it still poses various challenges. This study aimed to analyze perioperative risk factors for postoperative death in pediatric LDLT.

METHODS

We retrospectively analyzed medical records of pediatric patients who underwent LDLT surgery from January 1, 2014, to December 31, 2016, in our hospital. Predictors of mortality following LDLT were analyzed in 430 children. Cox regression and Kaplan-Meier curve analysis were used for covariates selection. A nomogram was developed to estimate overall survival probability. The performance of the nomogram was assessed using calibration curve, decision curve analysis, and time-dependent receiver operating characteristic curve.

RESULTS

Among the 430 patients in this cohort (median [interquartile range] age, 7 [6.10] mo; 189 [43.9%] female; 391 [90.9%] biliary atresia), the overall survival was 91.4% (95% confidence interval, 89.2-94.4), and most of the death events (36/37) happened within 6 months after the surgery. Multivariate analysis indicated that the Pediatric End-stage Liver Disease score, neutrophil lymphocyte ratio, graft-to-recipient weight ratio, and intraoperative norepinephrine infusion were independent prognostic factors. A novel nomogram was developed based on these prognostic factors. The C index for the final model was 0.764 (95% confidence interval, 0.701-0.819). Decision curve analysis and time-dependent receiver operating characteristic curve suggested that this novel nomogram performed well at predicting mortality of pediatric LDLT.

CONCLUSIONS

We identified several perioperative risk factors for mortality of pediatric LDLT. And the newly developed nomogram can be a convenient individualized tool in estimating the prognosis of pediatric LDLT.

Effects of ablation and activation of Nrf2 on bile acid homeostasis in male mice

The role of nuclear factor erythroid 2-related factor 2 (Nrf2) in bile acid (BA) homeostasis remains controversial. In this study, activation of Nrf2 was achieved either pharmacologically by CDDO-imidazolide (CDDO-Im) or genetically through a "gene dose-response" model consisting of Nrf2-null, wild-type (WT), Keap1-knockdown (Keap1-KD), and Keap1-hepatocyte knockout (Keap1-HKO) mice. In WT mice, CDDO-Im increased bile flow and decreased hepatic BAs, which was associated with a down-regulation of the canalicular BA efflux transporter Bsep and an increase in biliary BA excretion. In contrast, hepatic Bsep and biliary BA excretion were not altered in Keap1-KD or Keap1-HKO mice, suggesting that Nrf2 is not important for regulating Bsep or BA-dependent bile flow. In contrast, hepatic Mrp2 and Mrp3 were up-regulated by both pharmacological and genetic activations of Nrf2. Furthermore, ileal BA transporters (Asbt and Ostβ) and cholesterol transporters (Abcg5 and Abcg8) were down-regulated by both pharmacological and genetic activations of Nrf2, suggesting a role of Nrf2 in intestinal absorption of BAs and cholesterol. In Nrf2-null mice, CDDO-Im down-regulated hepatic BA uptake transporters (Ntcp, Oatp1a1, and Oatp1b2), leading to a 39-fold increase of serum BAs. To conclude, the present study demonstrates that activation of Nrf2 in mice up-regulates Mrp2 and Mrp3 in the liver and down-regulates BA and cholesterol transporters in the intestine.

Nonalcoholic fatty liver disease and cardiovascular disease phenotypes

Nonalcoholic fatty liver disease is increasingly recognized as a major global health problem. Intertwined with diabetes, metabolic syndrome, and obesity, nonalcoholic fatty liver disease embraces a spectrum of liver conditions spanning from steatosis to inflammation, fibrosis, and liver failure. Compared with the general population, the prevalence of cardiovascular disease is higher among nonalcoholic fatty liver disease patients, in whom comprehensive cardiovascular risk assessment is highly desirable. Preclinical effects of nonalcoholic fatty liver disease on the heart include both metabolic and structural changes eventually preceding overt myocardial dysfunction. Particularly, nonalcoholic fatty liver disease is associated with enhanced atherosclerosis, heart muscle disease, valvular heart disease, and arrhythmias, with endothelial dysfunction, inflammation, metabolic dysregulation, and oxidative stress playing in the background. In this topical review, we aimed to summarize current evidence on the epidemiology of nonalcoholic fatty liver disease, discuss the pathophysiological links between nonalcoholic fatty liver disease and cardiovascular disease, illustrate nonalcoholic fatty liver disease-related cardiovascular phenotypes, and finally provide a glimpse on the relationship between nonalcoholic fatty liver disease and cardiac steatosis, mitochondrial (dys)function, and cardiovascular autonomic dysfunction.

Thermodynamic interference with bile acid demicelleization reduces systemic entry and injury during cholestasis

Bile acids (BA), with their large hydrophobic steroid nucleus and polar groups are amphipathic molecules. In bile, these exist as micelles above their critical micellar concentration (CMC). In blood at low concentrations, these exist as monomers, initiating cellular signals. This micellar to monomer transition may involve complex thermodynamic interactions between bile salts alone or with phospholipids, i.e. mixed micelles and the aqueous environment. We therefore went on to test if therapeutically relevant changes in temperature could influence micellar behavior of bile salts, and in turn whether this affected the biological responses in cells, and in vivo. Sodium taurocholate (STC) belongs to a major class of bile salts. STC has a CMC in the 5–8 mM range and its infusion into the pancreatic duct is commonly used to study pancreatitis. We thus studied micellar breakdown of STC using isothermal titration calorimetry (ITC), dynamic light scattering and cryogenic transmission electron microscopy. Under conditions relevant to the in vivo environment (pH 7.4, Na 0.15 M), ITC showed STC to have a U shaped reduction in micellar breakdown between 37 °C and 15 °C with a nadir at 25 °C approaching ≈90% inhibition. This temperature dependence paralleled pancreatic acinar injury induced by monomeric STC. Mixed micelles of STC and 1-palmitoyl, 2-oleyl phosphatidylcholine, a phospholipid present in high proportions in bile, behaved similarly, with ≈75% reduction in micellar breakdown at 25 °C compared to 37 °C. In vivo pancreatic cooling to 25 °C reduced the increase in circulating BAs after infusion of 120 mM (5%) STC into the pancreatic duct, and duct ligation. Lower BA levels were associated with improved cardiac function, reduced myocardial damage, shock, lung injury and improved survival independent of pancreatic injury. Thus micellar breakdown of bile salts is essential for their entry into the systemic circulation, and thermodynamic interference with this may reduce their systemic entry and consequent injury during cholestasis, such as from biliary pancreatitis.

Knockout of farnesoid X receptor aggravates process of diabetic cardiomyopathy

Previous studies have shown that FXR is involved in glycolipid metabolism, tissue inflammation and regeneration in organs such as the liver, intestines and kidneys. Although FXR has been reported in cardiac tissue, its function in diabetic cardiomyopathy has not been reported. Here, we successfully constructed a diabetic mouse model of FXR^-/- and evaluated the effects of FXR knockout on cardiac function in mice by measuring various indicators. We demonstrated that blood glucose levels in diabetic mice are significantly elevated in the case of FXR knockout. Our findings from cardiac ultrasound and tissue HE staining supported that FXR knockout aggravates diabetic cardiomyopathy. Masson staining of myocardial tissue and quantitative detection of α-SMA by qPCR suggest that FXR knockout exacerbates cardiac fibrosis in diabetic cardiomyopathy. Combined with the results of Oil Red staining and quantitative detection of triglycerides in fresh tissue blocks, we hypothesized that FXR knockout aggravates diabetes-induced cardiac lipid accumulation. Altogether our results revealed a role of the FXR in the diabetic cardiomyopathy, suggesting a possible novel target for the treatment of diabetic cardiomyopathy.

Bile Acid and Cholesterol Metabolism in Atherosclerotic Cardiovascular Disease and Therapy

Dysregulation of lipid metabolism is a major factor contributing to atherosclerotic cardiovascular disease (ACVD), which is the number one cause of death in western countries. The liver plays a central role in maintaining whole body cholesterol homeostasis via catabolism of cholesterol to bile acids, as well as biliary cholesterol excretion. The liver synthesizes lipoproteins that transport dietary cholesterol and fats to muscle and adipose tissue, directs reverse cholesterol transport of excess cholesterol from extrahepatic tissues and macrophages to the liver to convert to bile acids, and thus, protects against metabolism-related nonalcoholic fatty liver disease (NAFLD) and ACVD. Liver fibrosis/nonalcoholic steatohepatitis increases the risk and prevalence of cardiovascular disease morbidity and mortality. Bile acids are signaling molecules and metabolic regulators that activate farnesoid X receptor and G protein-coupled bile acid receptor-1 to regulate lipid, glucose, and energy metabolism. The bidirectional regulation of bile acids and the gut microbiota determine the rate of bile acid synthesis, the bile acid pool size, and the composition of the circulating bile acid pool. The liver-intestine-heart axis regulates lipid metabolism, inflammation, and the pathogenesis of metabolic diseases such as ACVD, NAFLD, diabetes, and obesity. This review focuses on the roles of liver-to-intestine, liver-to-heart and intestine-to-heart axes in cholesterol, lipoprotein, and bile acid metabolism; signaling in heart health and ACVD; and drug therapies for atherosclerosis.

Role of bile acids in the diagnosis and progression of liver cirrhosis: A prospective observational study

The accumulation of toxic bile acids (BAs) is closely related to liver injury, inflammation and tumorigenesis. The aim of the present study was to determine the role of the serum BA spectrum in the diagnosis and progression of liver cirrhosis. This was a prospective observational study involving patients with chronic hepatitis (n=23), liver cirrhosis (n=101), and cirrhosis complicated with hepatocellular carcinoma (CC-HCC; n=56). The 6-month survival of cirrhotic patients was recorded after blood collection. Comparisons of serum total BAs and individual BAs between different groups were performed using the Mann-Whitney U or Kruskal-Wallis tests. Correlation analysis was conducted by Spearman's correlation. Diagnosis and prediction analyses were performed using receiver operating characteristic curves. Survival was analyzed using the Kaplan-Meier method and multivariable Cox regression analysis. The concentrations of total BAs, glycocholic acid (GCA), glycochenodeoxycholic acid (GCDCA), taurocholic acid (TCA), taurochenoxycholic acid and tauroursodeoxycholic acid (TUDCA) were increased significantly in patients with early cirrhosis compared to patients with chronic hepatitis (P<0.05) and were associated with the diagnosis of cirrhosis (P=0.049, 0.004, 0.002, 0.003, 0.010 and 0.009, respectively). The levels of total BAs, primary conjugated BAs, and TUDCA increased as liver cirrhosis progressed (P<0.05). Serum total BAs, GCA, GCDCA, and TCA predicted the 6-month survival of patients with liver cirrhosis (P=0.0003, 0.005, 0.002, and 0.010 respectively). Based on multivariate Cox regression analysis, the level of total BAs was an independent predictor of mortality in cirrhotic patients (hazard ratios, 4.046; 95% CI, 1.620-10.108; P=0.003). In the early-stage cirrhosis group, the concentrations of total BAs and primary conjugated BAs were significantly elevated in patients with CC-HCC compared with patients with cirrhosis alone. In conclusion, total and individual BAs, especially primary conjugated BAs, are effective non-invasive markers in the diagnosis and prognosis of liver cirrhosis, and may be potential indicators in the occurrence of hepatocellular carcinoma in patients with early cirrhosis.

Living Donor Liver Transplantation in Biliary Atresia Children with Pulmonary Hypertension

OBJECTIVE

Though living donor liver transplantation (LDLT) is commonly performed for pediatric patients with biliary atresia (BA), pulmonary hypertension (PH) is seldom encountered or reported previously. The aim of this study is mainly to identify the prevalence of PH in pediatric patients undergoing liver transplantation and assess whether PH significantly augment the operative risk and evaluate the outcomes in this series of patients.

DESIGN

Retrospectively cohort study.

SETTING

Renji hospital, Shanghai, China.

PARTICIPANTS

This study comprised 161 pediatric patients undergoing LDLT.

INTERVENTIONS

Patient diagnosed of PH in preoperative examination was compared to those without PH in intra- or post- operative complications or outcomes.

MEASUREMENTS AND MAIN RESULTS

We collected clinical records of LDLT surgery for pediatric patients during the year of 2016 in our hospital. Results suggested that pediatric patients undergoing LDLT had a substantial number of PH with a prevalence of 16.1% in this study. No significant difference was identified between two groups of patients regarding intraoperative outcomes and postoperative complications and mortality.

CONCLUSION

LDLT is a safe procedure in a selected group of BA patients with PH, however, further long-term clinical investigations and mechanical researches are needed.

An update on cirrhotic cardiomyopathy

Cirrhosis with portal hypertension and related complications are associated with a high mortality. Excess of circulating vasodilators and cardiodepressive substances lead to a hyperdynamic circulation with changed myocardial structure and function. The entity cirrhotic cardiomyopathy seems to be involved in different aspects of hepatic decompensation, which focuses on new targets of treatment. Areas covered: This review deals with contemporary aspects of cirrhotic cardiomyopathy, and the literature search was undertaken by PubMed with 'cirrhotic' and 'cardiomyopathies' as MeSH Terms. Cirrhotic cardiomyopathy is defined as the presence of systolic and diastolic dysfunction and electrophysiological abnormalities. The diagnosis is based on contemporary Doppler/Echocardiography measurements or quantitative magnetic resonance imaging. Cirrhotic cardiomyopathy is independent of the etiology of the liver disease but related to severity and survival. Expert commentary: The outcome of invasive procedures and liver transplantation is influenced by the presence of cardiac dysfunction. Therefore, a cautious cardiac evaluation should be included in the patient evaluation prior to liver transplantation. Liver transplantation ameliorates most of the abnormalities seen in cirrhotic cardiomyopathy, but no specific treatment can yet be recommended.

Rosuvastatin improves the FGF19 analogue NGM282-associated lipid changes in patients with non-alcoholic steatohepatitis

BACKGROUND

NGM282, an engineered analogue of the gut hormone FGF19, improves hepatic steatosis and fibrosis biomarkers in patients with non-alcoholic steatohepatitis (NASH). However, NGM282 increases serum cholesterol levels by inhibiting CYP7A1, which encodes the rate-limiting enzyme in the conversion of cholesterol to bile acids. Herein, we investigate whether administration of a statin can manage the cholesterol increase seen in patients with NASH receiving treatment with NGM282.

METHODS

In this phase II, open-label, multicenter study, patients with biopsy-confirmed NASH were treated with subcutaneous NGM282 once daily for 12 weeks. After 2 weeks, rosuvastatin was added in stepwise, biweekly incremental doses to a maximum of 40 mg daily. Both drugs were continued until the end of treatment at week 12. We evaluated plasma lipids, lipoprotein particles and liver fat content.

RESULTS

In 66 patients who received NGM282 0.3 mg (n = 23), NGM282 1 mg (n = 21), or NGM282 3 mg (n = 22), circulating cholesterol increased from baseline at week 2. Initiation of rosuvastatin resulted in rapid decline in plasma levels of total cholesterol and low-density lipoprotein cholesterol. At week 12, reductions from baseline in total cholesterol levels of up to 18% (p <0.001), low-density lipoprotein cholesterol of up to 28% (p <0.001), triglycerides of up to 34% (p <0.001) and an increase in high-density lipoprotein cholesterol of up to 16% (p <0.001), with similar changes in lipoprotein particles, were observed in these patients. Robust decreases from baseline in 7alpha-hydroxy-4-cholesten-3-one (p <0.001) and liver fat content (p <0.001) were also observed. Rosuvastatin was safe and well-tolerated when co-administered with NGM282 in patients with NASH.

CONCLUSIONS

In this multicenter study, NGM282-associated elevation of cholesterol was effectively managed with rosuvastatin. Co-administration of rosuvastatin with NGM282 may be a reasonable strategy to optimize the cardiovascular risk profile in patients with NASH.

LAY SUMMARY

Non-alcoholic steatohepatitis (NASH) represents a large and growing public health concern with no approved therapy. NGM282, an engineered analogue of the gut hormone FGF19, reduces liver fat, liver injury and inflammation in patients with NASH. However, NGM282 increases cholesterol levels. Here we show that co-administration of a statin can manage the cholesterol increase seen in patients with NASH receiving treatment with NGM282, producing a favorable overall lipid profile.

A novel network-based approach for discovering dynamic metabolic biomarkers in cardiovascular disease

Metabolic biomarkers may play an important role in the diagnosis, prognostication and assessment of response to pharmacological therapy in complex diseases. The process of discovering new metabolic biomarkers is a non-trivial task which involves a number of bioanalytical processing steps coupled with a computational approach for the search, prioritization and verification of new biomarker candidates. Kinetic analysis provides an additional dimension of complexity in time-series data, allowing for a more precise interpretation of biomarker dynamics in terms of molecular interaction and pathway modulation. A novel network-based computational strategy for the discovery of putative dynamic biomarker candidates is presented, enabling the identification and verification of unexpected metabolic signatures in complex diseases such as myocardial infarction. The novelty of the proposed method lies in combining metabolic time-series data into a superimposed graph representation, highlighting the strength of the underlying kinetic interaction of preselected analytes. Using this approach, we were able to confirm known metabolic signatures and also identify new candidates such as carnosine and glycocholic acid, and pathways that have been previously associated with cardiovascular or related diseases. This computational strategy may serve as a complementary tool for the discovery of dynamic metabolic or proteomic biomarkers in the field of clinical medicine.

Overview of Bile Acids Signaling and Perspective on the Signal of Ursodeoxycholic Acid, the Most Hydrophilic Bile Acid, in the Heart

Bile acids (BA) are classically known as an important agent in lipid absorption and cholesterol metabolism. Nowadays, their role in glucose regulation and energy homeostasis are widely reported. BAs are involved in various cellular signaling pathways, such as protein kinase cascades, cyclic AMP (cAMP) synthesis, and calcium mobilization. They are ligands for several nuclear hormone receptors, including farnesoid X-receptor (FXR). Recently, BAs have been shown to bind to muscarinic receptor and Takeda G-protein-coupled receptor 5 (TGR5), both G-protein-coupled receptor (GPCR), independent of the nuclear hormone receptors. Moreover, BA signals have also been elucidated in other nonclassical BA pathways, such as sphingosine-1-posphate and BK (large conductance calcium- and voltage activated potassium) channels. Hydrophobic BAs have been proven to affect heart rate and its contraction. Elevated BAs are associated with arrhythmias in adults and fetal heart, and altered ratios of primary and secondary bile acid are reported in chronic heart failure patients. Meanwhile, in patients with liver cirrhosis, cardiac dysfunction has been strongly linked to the increase in serum bile acid concentrations. In contrast, the most hydrophilic BA, known as ursodeoxycholic acid (UDCA), has been found to be beneficial in improving peripheral blood flow in chronic heart failure patients and in protecting the heart against reperfusion injury. This review provides an overview of BA signaling, with the main emphasis on past and present perspectives on UDCA signals in the heart.

TGR5 activation induces cytoprotective changes in the heart and improves myocardial adaptability to physiologic, inotropic, and pressure-induced stress in mice

INTRODUCTION

Administration of cholic acid, or its synthetic derivative, 6-alpha-ethyl-23(S)-methylcholic acid (INT-777), activates the membrane GPCR, TGR5, influences whole body metabolism, reduces atherosclerosis, and benefits the cardiovascular physiology in mice. Direct effects of TGR5 agonists, and the role for TGR5, on myocardial cell biology and stress response are unknown.

METHODS

Mice were fed chow supplemented with 0.5% cholic acid (CA) or 0.025% INT-777, a specific TGR5 agonist, or regular chow for 3 weeks. Anthropometric, biochemical, physiologic (electrocardiography and echocardiography), and molecular analysis was performed at baseline. CA and INT-777 fed mice were challenged with acute exercise-induced stress, acute catecholamine-induced stress, and hemodynamic stress induced by transverse aortic constriction (TAC) for a period of 8 weeks. In separate experiments, mice born with constitutive deletion of TGR5 in cardiomyocytes (CM-TGR5^del ) were exposed to exercise, inotropic, and TAC-induced stress.

RESULTS

Administration of CA and INT-777 supplemented diets upregulated TGR5 expression and activated Akt, PKA, and ERK1/2 in the heart. CA and INT-777 fed mice showed improved exercise tolerance, improved sensitivity to catecholamine and attenuation in pathologic remodeling of the heart under hemodynamic stress. In contrast, CM-TGR5^del showed poor response to exercise and catecholamine challenge as well as higher mortality and signs of accelerated cardiomyopathy under hemodynamic stress.

CONCLUSIONS

Bile acids, specifically TGR5 agonists, induce cytoprotective changes in the heart and improve myocardial response to physiologic, inotropic, and hemodynamic stress in mice. TGR5 plays a critical role in myocardial adaptability, and TGR5 activation may represent a potentially attractive treatment option in heart failure.

Combined effects of FH (E404D) and ACOX2 (R409H) cause metabolic defects in primary cardiac malignant tumor

Primary malignant cardiac tumors (PMCTs) are extremely rare. The apparent immunity of the heart to invasive cancer has attracted considerable interest given the continuously rising incidence of cancer in other organs. This study aims to determine the conditions that could result in cardiac carcinoma and expand our understanding of cardiac tumor occurrence. We report two cases: a male (Patient-1) with primary cardiac malignant fibrous histiocytoma (MFH) and a female (Patient-2) with primary cardiac angiosarcoma. Merged genome-wide analyses of aCGH, Exome sequencing, and RNA-sequencing were performed on Patient-1 using peripheral blood, carcinoma tissue, and samples of adjacent normal tissue. Only whole-transcriptome analysis was carried out on Patient-2, due to insufficient quantities of sample from Patient-2. We identified a novel inherited loss of functional mutation of FH (Glu404Asp), a recurrent somatic hotspot mutation of PIK3CA (His1047Arg) and a somatic duplication in copy number of HIF1A. FH (E404D) severely compromised FH enzyme activity and lead to decreased protein expression in cardiac tumor tissues. We previously reported a functional mutation ACOX2 (R409H), which is potentially associated with decreased β-oxidation of fatty acids in the cardiac tumor tissue. Results of transcriptome analyses on two patients further revealed that the RNA expression of genes in the TCA cycle and beta-oxidation were uniformly downregulated. In this study, combined effects of FH (E404D) and ACOX2 (R409H) on metabolic switch from fatty acids to glucose were remarkably distinct, which might be an essential precondition to trigger the occurrence of PMCTs and mimic the Warburg effect, a hallmark of cancer metabolism.

Pediatric cirrhotic cardiomyopathy: Impact on liver transplant outcomes

In adults, cirrhotic cardiomyopathy (CCM) has a significant incidence and impact on liver transplantation. For pediatric liver transplantation (pLT), data on liver-induced cardiac changes are scarce, and in particular, the comparison between cirrhotic and noncirrhotic liver disease has not been investigated. We retrospectively evaluated cardiac changes associated with CCM by echocardiography and 12-lead electrocardiogram in 198 pLT-candidates (median age 4.1 years) 4.2 before and 12 months after pLT. Results were correlated with the stage of liver fibrosis and cholestasis before transplantation. The left ventricular end-diastolic diameter (LVIDd) z score, left ventricular mass z score, and left ventricular mass index were significantly higher in cirrhotic patients (-0.10 versus 0.98, P < 0.001; -1.55 versus -0.42, P = 0.001; 78.99 versus 125.64 g/m² , P = 0.001, respectively) compared with children with noncirrhotic liver disease. Pathological z scores (>2SDS) for the LVIDd occurred more frequently in cirrhotic patients compared with patients with noncirrhotic liver disease (31/169 versus 1/29; P = 0.03) and were significantly associated with cholestasis. All observed cardiac changes were reversible 1 year after pLT. Pathological LVIDd z scores correlated highly with intensive care unit (ICU) stay (9.6 days versus 17.1 days, respectively, P = 0.002) but not with patient survival pre-LT or post-LT. In contrast to other studies, prolonged QTc time was not associated with liver cirrhosis in our patients. In conclusion, CCM-associated cardiac changes in pLT candidates with cirrhotic liver disease are frequent, mild, and associated with cholestasis and reversible after pLT. They may impact peritransplant care and posttransplant hospitalization time. Further prospective evaluation is warranted. In particular, for QTc time prolongation etiological factors, possible protective effects of ursodeoxycholic acid treatment and the use as a screening parameter for CCM should be verified. Liver Transplantation 24 820-830 2018 AASLD.

Total bile acid levels are associated with left atrial volume and cardiac output in patients with cirrhosis

BACKGROUND AND AIMS

Bile acids (BAs) are potent signaling molecules involved in the regulation of several metabolic and functional aspects of cardiovascular homeostasis. BA pool alteration in cirrhosis may contribute toward the development of hemodynamic and cardiac disturbances. We aimed to investigate the association between total BA levels and echocardiographic and biochemical markers of cardiac dysfunction in cirrhotic patients.

METHODS

Cirrhotic patients were enrolled prospectively in this hypothesis-generating study and evaluated for cardiac and hemodynamic dysfunction through clinical, echocardiographic, and biochemical means. Associations between total serum BA concentrations and markers of systolic or diastolic dysfunction and the presence of cirrhotic cardiomyopathy were tested through univariate and multivariate analyses.

RESULTS

Fifty-eight patients with cirrhosis were assessed in this monocentric study. 49 (85%) patients had decompensated cirrhosis according to the Child class. The median total BA level was 45 µmol/l. There was no correlation between BA levels and the etiology of cirrhosis (P=0.2), current alcohol use (P=0.8), sex (P=0.1), smoking status (P=0.2), age, or BMI. Systolic and diastolic dysfunction were rare in the cohort. Total BA levels associated with several echocardiographic parameters of the hyperdynamic syndrome in univariate analysis but only with left atrial volume in multivariate analysis (P=0.007). BA concentrations did not differ according to the presence of echocardiographically diagnosed cirrhotic cardiomyopathy in the two models tested.

CONCLUSION

Total serum BA levels are associated with enlarged left atrial volume and markers of the hyperdynamic circulation in patients with cirrhosis irrespective of the etiology or the severity of liver disease.

The pathophysiology of arterial vasodilatation and hyperdynamic circulation in cirrhosis

Patients with cirrhosis and portal hypertension often develop complications from a variety of organ systems leading to a multiple organ failure. The combination of liver failure and portal hypertension results in a hyperdynamic circulatory state partly owing to simultaneous splanchnic and peripheral arterial vasodilatation. Increases in circulatory vasodilators are believed to be due to portosystemic shunting and bacterial translocation leading to redistribution of the blood volume with central hypovolemia. Portal hypertension per se and increased splanchnic blood flow are mainly responsible for the development and perpetuation of the hyperdynamic circulation and the associated changes in cardiovascular function with development of cirrhotic cardiomyopathy, autonomic dysfunction and renal dysfunction as part of a cardiorenal syndrome. Several of the cardiovascular changes are reversible after liver transplantation and point to the pathophysiological significance of portal hypertension. In this paper, we aimed to review current knowledge on the pathophysiology of arterial vasodilatation and the hyperdynamic circulation in cirrhosis.

Heart and bile acids - Clinical consequences of altered bile acid metabolism

Cardiac dysfunction has an increased prevalence in diseases complicated by liver cirrhosis such as primary biliary cholangitis and primary sclerosing cholangitis. This observation has led to research into the association between abnormalities in bile acid metabolism and cardiac pathology. Approximately 50% of liver cirrhosis cases develop cirrhotic cardiomyopathy. Bile acids are directly implicated in this, causing QT interval prolongation, cardiac hypertrophy, cardiomyocyte apoptosis and abnormal haemodynamics of the heart. Elevated maternal serum bile acids in intrahepatic cholestasis of pregnancy, a disorder which causes an impaired feto-maternal bile acid gradient, have been associated with fatal fetal arrhythmias. The hydrophobicity of individual bile acids in the serum bile acid pool is of relevance, with relatively lipophilic bile acids having a more harmful effect on the heart. Ursodeoxycholic acid can reverse or protect against these detrimental cardiac effects of elevated bile acids.

Bile acids and cardiovascular function in cirrhosis

Cirrhotic cardiomyopathy and the hyperdynamic syndrome are clinically important complications of cirrhosis, but their exact pathogenesis is still partly unknown. Experimental models have proven the cardiotoxic effects of bile acids and recent studies of their varied receptor-mediated functions offer new insight into their involvement in cardiovascular dysfunction in cirrhosis. Bile acid receptors such as farnesoid X-activated receptor and TGR5 are currently under investigation as potential therapeutic targets in a variety of pathological conditions. These receptors have also recently been identified in cardiomyocytes, vascular endothelial cells and smooth muscle cells where they seem to play an important role in cellular metabolism. Chronic cholestasis leading to abnormal levels of circulating bile acids alters the normal signalling pathways and contributes to the development of profound cardiovascular disturbances. This review summarizes the evidence regarding the role of bile acids and their receptors in the generation of cardiovascular dysfunction in cirrhosis.

Increased Secondary/Primary Bile Acid Ratio in Chronic Heart Failure

OBJECTIVE

Bile acids (BAs) are now recognized as signaling molecules and emerging evidence suggests that BAs affect cardiovascular function. The gut microbiota has recently been linked to the severity of heart failure (HF), and microbial metabolism has a major impact on BA homeostasis. We aimed to investigate the pattern of BAs, and particularly microbiota-transformed (secondary) BAs, in patients with chronic HF.

METHODS AND RESULTS

This was a prospective, observational, single-center study including 142 patients with chronic HF and 20 age- and sex-matched healthy control subjects. We measured plasma levels of primary, secondary, and total BAs, and explored their associations with clinical characteristics and survival. Plasma levels of primary BAs were lower (P < .01) and the ratios of secondary to primary BAs higher (P < .001) in patients with HF compared with control subjects. Approximately 40% of patients in the upper tertile of the ratio of secondary to primary BAs died during 5.6 years of follow-up (unadjusted Cox regression: hazard ratio 1.93, 95% confidence interval 1.01-3.68, compared with the lower tertiles). However, this association was attenuated and no longer significant in multivariate analyses.

CONCLUSIONS

Levels of primary BAs were reduced and specific secondary BAs increased in patients with chronic HF. This pattern was associated with reduced overall survival in univariate analysis, but not in multivariate analyses. Future studies should assess the regulation and potential role of BA metabolism in HF.