Splanchnic vasodilation and hyperdynamic circulatory syndrome in cirrhosis

Can Plasma Volume Determination in Cirrhosis Be Replaced by an Algorithm Using Body Weight and Hematocrit?

BACKGROUND

Patients with cirrhosis often develop hyperdynamic circulation with increased cardiac output, heart rate, and redistribution of the circulating volume with expanded plasma volume (PV). PV determination is part of the evaluation of patients with cirrhosis, but gold-standard methods are invasive, expensive, and time-consuming. Therefore, other estimations of PV would be preferable, and the aim of this study was therefore to study if PV, as assessed by a simplified algorithm based on hematocrit and weight, can replace the gold-standard method.

METHODS

We included 328 patients with cirrhosis who had their PV assessed by the indicator dilution technique as the gold-standard method (PVI-125). Actual PV was estimated as PVa = (1 - hematocrit)·(a + (b·body weight)). Ideal PV was estimated as PVi = c · body weight, where a, b, and c are constants.

RESULTS

PVI-125, PVa, and PVi were 3.99 ± 1.01, 3.09 ± 0.54, and 3.01 ± 0.65 (Mean ± SD), respectively. Although PVI-125 correlated significantly with PVa (r = 0.72, p < 0.001), a Bland-Altman plot revealed wide limits of confidence.

CONCLUSIONS

The use of simplified algorithms does not sufficiently estimate PV and cannot replace the indicator dilution technique.

Association of Cardiopulmonary Hemodynamics and Mortality in Veterans With Liver Cirrhosis: A Retrospective Cohort Study

BACKGROUND

Portopulmonary hypertension (PoPH), associated with increased mortality, can limit treatment options for liver diseases. Data on the continuum of clinical risk related to cardiopulmonary hemodynamics in PoPH are lacking.

METHODS AND RESULTS

As part of the United States national Veterans Affairs Clinical Assessment, Reporting, and Tracking database, we performed a retrospective cohort study of adults with cirrhosis undergoing right heart catheterization between October 1, 2017, and September 30, 2022. Pulmonary hypertension (mean pulmonary arterial pressure [mPAP] >20 mm Hg without PoPH) and PoPH (mPAP >20 mm Hg+pulmonary artery wedge pressure ≤15 mm Hg+pulmonary vascular resistance ≥3 WU) were defined by right heart catheterization hemodynamics. Multivariable Cox proportional hazards using natural splines for hemodynamic variables were used to evaluate the association between cardiopulmonary hemodynamics and mortality following right heart catheterization. A total of 4409 patients were included in the final analysis, predominantly men (96.3%), with a mean age of 68.5 years. Pulmonary hypertension and PoPH were observed in 71.6% and 10.2% of the cohort, respectively. Compared with a reference cardiac index of 2.5 L/min per m2, the hazard for mortality increased progressively with decreasing cardiac index, even after adjustment for mPAP and pulmonary vascular resistance. The minority of patients with PoPH (N=65, 14.5%) were prescribed pulmonary vasodilator therapy.

CONCLUSIONS

These data suggest that pulmonary hypertension and PoPH are prevalent in veterans with chronic liver disease, but low use of targeted PoPH therapy persists. Cardiac function discriminated mortality risk across a wide range of mPAP and pulmonary vascular resistance values and may diagnose and clarify prognosis in this patient population.

Role of albumin infusion in cirrhosis-associated complications

Cirrhosis is an advanced-stage liver disease that occurs due to persistent physiological insults such as excessive alcohol consumption, infections, or toxicity. It is characterised by scar tissue formation, portal hypertension, and ascites (accumulation of fluid in the abdominal cavity) in decompensated cirrhosis. This review evaluates how albumin infusion ameliorates cirrhosis-associated complications. Since albumin is an oncotic plasma protein, albumin infusion allows movement of water into the intravascular space, aids with fluid resuscitation, and thereby contributes to resolving cirrhosis-induced hypovolemia (loss of extracellular fluid) seen in ascites. Thus, albumin infusion helps prevent paracentesis-induced circulatory dysfunction, a complication that occurs when treating ascites. When cirrhosis advances, other complications such as spontaneous bacterial peritonitis and hepatorenal syndrome can manifest. Infused albumin helps mitigate these by exhibiting plasma expansion, antioxidant, and anti-inflammatory functions. In hepatic encephalopathy, albumin infusion is thought to improve cognitive function by reducing ammonia concentration in blood and thereby tackle cirrhosis-induced hepatocyte malfunction in ammonia clearance. Infused albumin can also exhibit protective effects by binding to the cirrhosis-induced proinflammatory cytokines TNFα and IL6. While albumin administration has shown to prolong overall survival of cirrhotic patients with ascites in the ANSWER trial, the ATTIRE and MACHT trials have shown either no effect or limitations such as development of pulmonary oedema and multiorgan failure.  Thus, albumin infusion is not a generic treatment option for all cirrhosis patients. Interestingly, cirrhosis-induced structural alterations in native albumin (which lead to formation of different albumin isoforms) can be used as prognostic biomarkers because specific albumin isoforms indicate certain complications of decompensated cirrhosis.

Sleep disturbances in chronic liver disease

Sleep disturbances are common in chronic liver disease and significantly impact patient outcomes and quality of life. The severity and nature of sleep disturbances vary by liver disease etiology and severity. While there is ongoing research into the association between liver disease and sleep-wake dysfunction, the underlying pathophysiology varies and, in many cases, is poorly understood. Liver disease is associated with alterations in thermoregulation, inflammation, and physical activity, and is associated with disease-specific complications, such as HE, that may directly affect sleep. In this article, we review the relevant pathophysiologic processes, disease-specific sleep-wake disturbances, and clinical management of CLD-associated sleep-wake disturbances.

Gut Microbiota and Biomarkers of Endothelial Dysfunction in Cirrhosis

Our aim was to study the association of endothelial dysfunction biomarkers with cirrhosis manifestations, bacterial translocation, and gut microbiota taxa. The fecal microbiome was assessed using 16S rRNA gene sequencing. Plasma levels of nitrite, big endothelin-1, asymmetric dimethylarginine (ADMA), presepsin, and claudin were measured as biomarkers of endothelial dysfunction, bacterial translocation, and intestinal barrier dysfunction. An echocardiography with simultaneous determination of blood pressure and heart rate was performed to evaluate hemodynamic parameters. Presepsin, claudin 3, nitrite, and ADMA levels were higher in cirrhosis patients than in controls. Elevated nitrite levels were associated with high levels of presepsin and claudin 3, the development of hemodynamic circulation, hypoalbuminemia, grade 2-3 ascites, overt hepatic encephalopathy, high mean pulmonary artery pressure, increased abundance of Proteobacteria and Erysipelatoclostridium, and decreased abundance of Oscillospiraceae, Subdoligranulum, Rikenellaceae, Acidaminococcaceae, Christensenellaceae, and Anaerovoracaceae. Elevated ADMA levels were associated with higher Child-Pugh scores, lower serum sodium levels, hypoalbuminemia, grade 2-3 ascites, milder esophageal varices, overt hepatic encephalopathy, lower mean pulmonary artery pressure, and low abundance of Erysipelotrichia and Erysipelatoclostridiaceae. High big endothelin-1 levels were associated with high levels of presepsin and sodium, low levels of fibrinogen and cholesterol, hypocoagulation, increased Bilophila and Coprobacillus abundances, and decreased Alloprevotella abundance.

Resveratrol protects against Schistosoma mansoni-induced liver fibrosis by targeting the Sirt-1/NF-κB axis

Hepatic schistosomiasis is a prevalent form of chronic liver disease that drastically affects human health. Nevertheless, an antifibrotic drug that could suppress the development of hepatic fibrosis does not exist yet. The current study aimed to evaluate the effect of resveratrol, a natural polyphenol with multiple biological activities, on Schistosoma mansoni (S. mansoni)-induced hepatic fibrosis and delineate the underlying molecular mechanism. Swiss male albino mice were randomly assigned into infected and non-infected groups. Hepatic schistosomiasis infection was induced via exposure to S. mansoni cercariae. 6 weeks later, resveratrol was administrated either as 20 mg/kg/day or 100 mg/kg/day for 4 weeks to two infected groups. Another group received vehicle and served as infected control group. At the end of the study, portal hemodynamic, biochemical, and histopathological evaluation of liver tissues were conducted. Remarkably, resveratrol significantly reduced portal pressure, portal and mesenteric flow in a dose-dependent manner. It improved several key features of hepatic injury as evidenced biochemically by a significant reduction of bilirubin and liver enzymes, and histologically by amelioration of the granulomatous and inflammatory reactions. In line, resveratrol reduced the expression of pro-inflammatory markers; TNF-α, IL-1β and MCP-1 mRNA, together with fibrotic markers; collagen-1, TGF-β1 and α-SMA. Moreover, resveratrol restored SIRT1/NF-κB balance in hepatic tissues which is the main switch-off control for all the fibrotic and inflammatory mechanisms. Taken together, it can be inferred that resveratrol possesses a possible anti-fibrotic effect that can halt the progression of hepatic schistosomiasis via targeting SIRT1/ NF-κB signaling.

Recent Advances in the Pathogenesis and Clinical Evaluation of Portal Hypertension in Chronic Liver Disease

In chronic liver disease, hepatic stellate cell activation and degeneration of liver sinusoidal endothelial cells lead to structural changes, which are secondary to fibrosis and the presence of regenerative nodules in the sinusoids, and to functional changes, which are related to vasoconstriction. The combination of such changes increases intrahepatic vascular resistance and causes portal hypertension. The subsequent increase in splanchnic and systemic hyperdynamic circulation further increases the portal blood flow, thereby exacerbating portal hypertension. In clinical practice, the hepatic venous pressure gradient is the gold-standard measure of portal hypertension; a value of ≥10 mm Hg is defined as clinically significant portal hypertension, which is severe and is associated with the risk of liver-related events. Hepatic venous pressure gradient measurement is somewhat invasive, so evidence on the utility of risk stratification by elastography and serum biomarkers is needed. The various stages of cirrhosis are associated with different outcomes. In viral hepatitis-related cirrhosis, viral suppression or elimination by nucleos(t)ide analog or direct-acting antivirals results in recompensation of liver function and portal pressure. However, careful follow-up should be continued, because some cases have residual clinically significant portal hypertension even after achieving sustained virologic response. In this study, we reviewed the current and future prospects for portal hypertension.

Portal Hypertension in Malnutrition and Sarcopenia in Decompensated Cirrhosis-Pathogenesis, Implications and Therapeutic Opportunities

Malnutrition and sarcopenia are highly prevalent in patients with decompensated cirrhosis and are associated with poorer clinical outcomes. Their pathophysiology is complex and multifactorial, with protein-calorie malnutrition, systemic inflammation, reduced glycogen stores and hormonal imbalances all well reported. The direct contribution of portal hypertension to these driving factors is however not widely documented in the literature. This review details the specific mechanisms by which portal hypertension directly contributes to the development of malnutrition and sarcopenia in cirrhosis. We summarise the existing literature describing treatment strategies that specifically aim to reduce portal pressures and their impact on nutritional and muscle outcomes, which is particularly relevant to those with end-stage disease awaiting liver transplantation.

Peri-operative extracorporeal membrane oxygenation in adult and pediatric living donor liver transplantation: a single-center experience

Background

Extracorporeal membrane oxygenation (ECMO) is a potential rescue therapy for patients with acute cardiopulmonary dysfunction refractory to conventional treatment. In this study, we described the clinical profiles and outcomes of adult and pediatric living donor liver transplantation (LDLT) patients who received ECMO support during the peri-operative period.

Methods

From June 1994 to December 2020, eleven out of the 1,812 LDLTs performed at Kaohsiung Chang Gung Memorial Hospital required ECMO support: six for respiratory failure, three for cardiogenic shock, and two for refractory septic shock. Comparison between the survivor and non-survivor groups was made.

Results

The survival rate for liver transplantation (LT) patients on ECMO support is 36.4%-40% in adults and 33.3% in pediatrics, while the survival rate per indication is as follows: acute respiratory distress syndrome (ARDS) (50%), cardiogenic shock (33.3%), and sepsis (0%). Shorter durations of LT-to-ECMO and pre-ECMO mechanical ventilation were observed in the survivor group. On the other hand, we observed persistently elevated total bilirubin levels in non-survivors, while none of the survivors had aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels >1,000 U/L. A higher proportion of non-survivors were on concurrent continuous renal replacement therapy (CRRT).

Conclusions

Our experience has proven ECMO's utility during the peri-operative period for both adult and pediatric LDLT patients, more specifically for indications other than septic shock. Further studies are needed to better understand the factors leading to poor outcomes in order to identify patients who will more likely benefit from ECMO.

Oxidative Mechanisms and Cardiovascular Abnormalities of Cirrhosis and Portal Hypertension

In patients with portal hypertension, there are many complications including cardiovascular abnormalities, hepatorenal syndrome, ascites, variceal bleeding, and hepatic encephalopathy. The underlying mechanisms are not yet completely clarified. It is well known that portal hypertension causes mesenteric congestion which produces reactive oxygen species (ROS). ROS has been associated with intestinal mucosal injury, increased intestinal permeability, enhanced gut bacterial overgrowth, and translocation; all these changes result in increased endotoxin and inflammation. Portal hypertension also results in the development of collateral circulation and reduces liver mass resulting in an overall increase in endotoxin/bacteria bypassing detoxication and immune clearance in the liver. Endotoxemia can in turn aggravate oxidative stress and inflammation, leading to a cycle of gut barrier dysfunction → endotoxemia → organ injury. The phenotype of cardiovascular abnormalities includes hyperdynamic circulation and cirrhotic cardiomyopathy. Oxidative stress is often accompanied by inflammation; thus, blocking oxidative stress can minimize the systemic inflammatory response and alleviate the severity of cardiovascular diseases. The present review aims to elucidate the role of oxidative stress in cirrhosis-associated cardiovascular abnormalities and discusses possible therapeutic effects of antioxidants on cardiovascular complications of cirrhosis including hyperdynamic circulation, cirrhotic cardiomyopathy, and hepatorenal syndrome.

[Hemodynamic Changes in Chronic Liver Disease]

Chronic liver disease causes hemodynamic changes in the body depending on the degree of progression. These hemodynamic changes begin with splanchnic vasodilation, with complications beginning to appear as the hyperdynamic changes occur. As chronic liver disease progresses, increased splanchnic vasodilation and hyperdynamic changes worsen portal hypertension and help cause or worsen chronic liver disease complications, such as ascites. Ultimately, the effective plasma volume and blood pressure decrease in the terminal stage.

Establishment and validation of a prognosis nomogram for MIMIC-III patients with liver cirrhosis complicated with hepatic encephalopathy

INTRODUCE

The purpose of this study was to establish a comprehensive prognosis nomogram for patients with liver cirrhosis complicated with hepatic encephalopathy (HE) in the intensive care unit (ICU) and to evaluate the predictive value of the nomogram.

METHOD

This study analyzed 620 patients with liver cirrhosis complicated with HE from the Medical Information Mart for Intensive Care III(MIMIC-III) database. The patients were randomly divided into two groups in a 7-to-3 ratio to form a training cohort (n = 434) and a validation cohort (n = 176). Cox regression analyses were used to identify associated risk variables. Based on the multivariate Cox regression model results, a nomogram was established using associated risk predictor variables to predict the 90-day survival rate of patients with cirrhosis complicated with HE. The new model was compared with the Sequential organ failure assessment (SOFA) scoring model in terms of the concordance index (C-index), the area under the curve (AUC) of receiver operating characteristic (ROC) analysis, the net reclassification improvement (NRI), the integrated discrimination improvement (IDI), calibration curve, and decision curve analysis (DCA).

RESULTS

This study showed that older age, higher mean heart rate, lower mean arterial pressure, lower mean temperature, higher SOFA score, higher RDW, and the use of albumin were risk factors for the prognosis of patients with liver cirrhosis complicated with HE. The use of proton pump inhibitors (PPI) was a protective factor. The performance of the nomogram was evaluated using the C-index, AUC, IDI value, NRI value, and DCA curve, showing that the nomogram was superior to that of the SOFA model alone. Calibration curve results showed that the nomogram had excellent calibration capability. The decision curve analysis confirmed the good clinical application ability of the nomogram.

CONCLUSION

This study is the first study of the 90-day survival rate prediction of cirrhotic patients with HE in ICU through the data of the MIMIC-III database. It is confirmed that the eight-factor nomogram has good efficiency in predicting the 90-day survival rate of patients.

Portal Venous Remodeling Determines the Pattern of Cirrhosis Decompensation: A Systems Analysis

INTRODUCTION

As liver disease progresses, scarring results in worsening hemodynamics ultimately culminating in portal hypertension. This process has classically been quantified through the portosystemic pressure gradient (PSG), which is clinically estimated by hepatic venous pressure gradient (HVPG); however, PSG alone does not predict a given patient's clinical trajectory regarding the Baveno stage of cirrhosis. We hypothesize that a patient's PSG sensitivity to venous remodeling could explain disparate disease trajectories.

METHODS

We created a computational model of the portal system in the context of worsening liver disease informed by physiologic measurements from the field of portal hypertension. We simulated progression of clinical complications, HVPG, and transjugular intrahepatic portosystemic shunt placement while only varying a patient's likelihood of portal venous remodeling.

RESULTS

Our results unify hemodynamics, venous remodeling, and the clinical progression of liver disease into a mathematically consistent model of portal hypertension. We find that by varying how sensitive patients are to create venous collaterals with rising PSG we can explain variation in patterns of decompensation for patients with liver disease. Specifically, we find that patients who have higher proportions of portosystemic shunting earlier in disease have an attenuated rise in HVPG, delayed onset of ascites, and less hemodynamic shifting after transjugular intrahepatic portosystemic shunt placement.

DISCUSSION

This article builds a computational model of portal hypertension which supports that patient-level differences in venous remodeling may explain disparate clinical trajectories of disease.

Gut Dysbiosis and Hemodynamic Changes as Links of the Pathogenesis of Complications of Cirrhosis

The aim was to evaluate the relationship between gut dysbiosis and hemodynamic changes (hyperdynamic circulation) in cirrhosis, and between hemodynamic changes and complications of this disease. This study included 47 patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. Echocardiography with a simultaneous assessment of blood pressure and heart rate was performed to assess systemic hemodynamics. Patients with hyperdynamic circulation had more severe cirrhosis, lower albumin, sodium and prothrombin levels, higher C-reactive protein, aspartate aminotransferase and total bilirubin levels, and higher incidences of portopulmonary hypertension, ascites, overt hepatic encephalopathy, hypoalbuminemia, hypoprothrombinemia, systemic inflammation, and severe hyperbilirubinemia than patients with normodynamic circulation. Patients with hyperdynamic circulation compared with those with normodynamic circulation had increased abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Fusobacteria, Micrococcaceae, Intestinobacter, Clostridium sensu stricto, Proteus and Rumicoccus, and decreased abundance of Bacteroidetes, Bacteroidaceae, Holdemanella, and Butyrivibrio. The systemic vascular resistance and cardiac output values correlated with the abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Micrococcaceae, and Fusobacteria. Heart rate and cardiac output value were negatively correlated with the abundance of Bacteroidetes. The mean pulmonary artery pressure value was positively correlated with the abundance of Proteobacteria and Micrococcaceae, and negatively with the abundance of Holdemanella.

Portopulmonary Hypertension: An Updated Review

Portal hypertension may have major consequences on the pulmonary vasculature due to the complex pathophysiological interactions between the liver and lungs. Portopulmonary hypertension (PoPH), a subset of group 1 pulmonary hypertension (PH), is a serious pulmonary vascular disease secondary to portal hypertension, and is the fourth most common subtype of pulmonary arterial hypertension. It is most commonly observed in cirrhotic patients; however, patients with noncirrhotic portal hypertension can also develop it. On suspicion of PoPH, the initial evaluation is by a transthoracic echocardiogram in which, if elevated pulmonary pressures are shown, patients should undergo right heart catheterization to confirm the diagnosis. The prognosis is extremely poor in untreated patients; therefore, management includes pulmonary arterial hypertension therapies with the aim of improving pulmonary hemodynamics and moving patients to orthotopic liver transplantation (OLT). In this article, we review in detail the epidemiology, pathophysiology, process for diagnosis, and most current treatments including OLT and prognosis in patients with PoPH. In addition, we present a diagnostic algorithm that includes the current criteria to properly select patients with PoPH who are candidates for OLT.

Soluble Guanylyl Cyclase Activator BI 685509 Reduces Portal Hypertension and Portosystemic Shunting in a Rat Thioacetamide-Induced Cirrhosis Model

Portal hypertension (PT) commonly occurs in cirrhosis. Nitric oxide (NO) imbalance contributes to PT via reduced soluble guanylyl cyclase (sGC) activation and cGMP production, resulting in vasoconstriction, endothelial cell dysfunction, and fibrosis. We assessed the effects of BI 685509, an NO-independent sGC activator, on fibrosis and extrahepatic complications in a thioacetamide (TAA)-induced cirrhosis and PT model. Male Sprague-Dawley rats received TAA twice-weekly for 15 weeks (300-150 mg/kg i.p.). BI 685509 was administered daily for the last 12 weeks (0.3, 1, and 3 mg/kg p.o.; n = 8-11 per group) or the final week only (Acute, 3 mg/kg p.o.; n = 6). Rats were anesthetized to measure portal venous pressure. Pharmacokinetics and hepatic cGMP (target engagement) were measured by mass spectrometry. Hepatic Sirius Red morphometry (SRM) and alpha-smooth muscle actin (αSMA) were measured by immunohistochemistry; portosystemic shunting was measured using colored microspheres. BI 685509 dose-dependently increased hepatic cGMP at 1 and 3 mg/kg (3.92 ± 0.34 and 5.14 ± 0.44 versus 2.50 ± 0.19 nM in TAA alone; P < 0.05). TAA increased hepatic SRM, αSMA, PT, and portosystemic shunting. Compared with TAA, 3 mg/kg BI 685509 reduced SRM by 38%, αSMA area by 55%, portal venous pressure by 26%, and portosystemic shunting by 10% (P < 0.05). Acute BI 685509 reduced SRM and PT by 45% and 21%, respectively (P < 0.05). BI 685509 improved hepatic and extrahepatic cirrhosis pathophysiology in TAA-induced cirrhosis. These data support the clinical investigation of BI 685509 for PT in patients with cirrhosis. SIGNIFICANCE STATEMENT: BI 685509 is an NO-independent sGC activator that was tested in a preclinical rat model of TAA-induced nodular, liver fibrosis, portal hypertension, and portal systemic shunting. BI 685509 reduced liver fibrosis, portal hypertension, and portal-systemic shunting in a dose-dependent manner, supporting its clinical assessment to treat portal hypertension in patients with cirrhosis.

Close Relationship between Systemic Arterial and Portal Venous Pressure in an Animal Model with Healthy Liver

It is unclear to what extent systemic arterial blood pressure influences portal pressure. This relationship is clinically important as drugs, which are conventionally used for therapy of portal hypertension, may also influence systemic arterial blood pressure. This study investigated the potential correlation between mean arterial (MAP) and portal venous pressure (PVP) in rats with healthy livers. In a rat model with healthy livers, we investigated the effect of manipulation of MAP on PVP. Interventions consisted of 0.9% NaCl (group 1), 0.1 mg/kg body weight (bw) Sildenafil (low dose), an inhibitor of phosphodiesterase-5 (group 2), and 1.0 mg/kg bw Sildenafil (high dose, group 3) in 600 µL saline injected intravenously. Norepinephrine was used to increase MAP in animals with circulatory failure while PVP was monitored. Injection of the fluids induced a transient drop in MAP and PVP, probably due to a reversible cardiac decompensation. The drop in MAP and drop in PVP are significantly correlated. The time lag between change in MAP and change in PVP by 24 s in all groups suggests a cause-and-effect relationship. Ten minutes after the injection of the fluid, cardiac function was normalized. Thereafter, MAP gradually decreased. In the NaCl group, PVP decreases by 0.485% for a 1% drop of MAP, by 0.550% in the low-dose sildenafil group, and by 0.651% in the high-dose sildenafil group (p < 0.05 for difference group two vs. group one, group three vs. group one, and group three vs. group two). These data suggest that Sildenafil has an inherent effect on portal pressure that exceeds the effect of MAP. Injection of norepinephrine led to a sudden increase in MAP followed by an increase in PVP after a time lag. These data show a close relationship between portal venous pressure and systemic arterial pressure in this animal model with healthy livers. A change in MAP is consequently followed by a change in PVP after a distinct time lag. This study, furthermore, suggests that Sildenafil influences portal pressure. Further studies should be performed in a model with cirrhotic livers, as these may be important in the evaluation of vasoactive drugs (e.g., PDE-5-inhibitors) for therapy of portal hypertension.

Small Intestinal Bacterial Overgrowth Is Associated with Poor Prognosis in Cirrhosis

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is associated with numerous manifestations of cirrhosis. To determine whether the presence of SIBO affects the prognosis in cirrhosis was the aim of the study.

METHODS

This prospective cohort study included 50 patients. All participants underwent a lactulose hydrogen breath test for SIBO. The follow-up period was 4 years.

RESULTS

SIBO was detected in 26 (52.0%) patients: in 10 (52.6%) patients with compensated cirrhosis and in 16 (51.6%) ones with decompensated cirrhosis. Twelve (46.2%) patients with SIBO and four (16.7%) patients without SIBO died within 4 years (p = 0.009). Among patients with decompensated cirrhosis, 8 (50.0%) patients with SIBO and 3 (20.0%) patients without SIBO died (p = 0.027). Among patients with compensated cirrhosis, four (40.0%) patients with SIBO and one (11.1%) patient without SIBO died (p = 0.045). Among patients with SIBO, there was no difference in mortality between patients with compensated and decompensated cirrhosis (p = 0.209). It was the same for patients without SIBO (p = 0.215). SIBO affects the prognosis only in the first year of follow-up in decompensated cirrhosis, and only in subsequent years in compensated cirrhosis. Presence of SIBO (p = 0.028; HR = 4.2(1.2-14.9)) and serum albumin level (p = 0.027) were significant independent risk factors for death in cirrhosis.

CONCLUSIONS

SIBO is associated with poor prognosis in cirrhosis.

Current clinical understanding and effectiveness of portopulmonary hypertension treatment

Portopulmonary hypertension (PoPH) is a rare subtype of Group 1 pulmonary arterial hypertension (PAH) with a poor prognosis. According to the most up-to-date definition, PoPH is characterized by a mean pulmonary arterial pressure (PAP) of &gt;20 mmHg at rest, a pulmonary artery wedge pressure of ≤15 mmHg, and a pulmonary vascular resistance (PVR) of &gt;2 Wood units with portal hypertension. Like PAH, PoPH is underpinned by an imbalance in vasoactive substances. Therefore, current guidelines recommend PAH-specific therapies for PoPH treatment; however, descriptions of the actual treatment approaches are inconsistent. Given the small patient population, PoPH is often studied in combination with idiopathic PAH; however, recent evidence suggests important differences between PoPH and idiopathic PAH in terms of hemodynamic parameters, treatment approaches, survival, socioeconomic status, and healthcare utilization. Therefore, large, multi-center registry studies are needed to examine PoPH in isolation while obtaining statistically meaningful results. PoPH has conventionally been excluded from clinical drug trials because of concerns over hepatotoxicity. Nevertheless, newer-generation endothelin receptor antagonists have shown great promise in the treatment of PoPH, reducing PVR, PAP, and World Health Organization functional class without causing hepatotoxicity. The role of liver transplantation as a treatment option for PoPH has also been controversial; however, recent evidence shows that this procedure may be beneficial in this patient population. In the future, given the shortage of liver donors, predictors of a favorable response to liver transplantation should be determined to select the most eligible patients. Collectively, advances in these three areas could help to standardize PoPH treatment in the clinic.

EASIX Is an Accurate and Easily Available Prognostic Score in Critically Ill Patients with Advanced Liver Disease

Acute-on-chronic liver failure (ACLF) is associated with high mortality. Objective prognostic scores are important for treatment decisions. EASIX (Endothelial Activation and Stress Index) is a simple biomarker consisting of LDH, platelets, and creatinine, reflecting endothelial dysfunction after allogeneic stem cell transplantation. Considering endothelial dysfunction in the pathogenesis of ACLF, this study aimed to test the discriminative ability of EASIX in advanced liver disease. We retrospectively analysed the prognostic potential of EASIX to predict 28-day and 3-month mortality in a total of 188 liver cirrhotic patients requiring treatment at the intensive care unit. We evaluated the ability of EASIX to rule out early infections and predict the need for hemodialysis. EASIX performed moderately better than established scores in predicting 28-day mortality (AUC = 0.771) and was nearly equivalent (AUC = 0.791) to SOFA and APACHE-II in the prediction of 3-month mortality. Importantly, EASIX showed better diagnostic potential in ruling out clinically apparent infections than common proinflammatory markers (AUC = 0.861, p < 0.001) and showed suitable accuracy in predicting the need for hemodialysis (AUC = 0.833). EASIX is an accurate, objective and easily assessable biomarker for predicting mortality and complications in patients with advanced liver disease.

Heart rate variability is associated with disease severity and portal hypertension in cirrhosis

INTRODUCTION

Autonomic nervous system activity in cirrhotic portal hypertension is linked to hyperdynamic circulation. Heart rate variability (HRV) is a validated noninvasive method to assess the sympathovagal balance. To investigate the correlation between HRV parameters and degree of portal hypertension, we studied a cohort of patients with cirrhosis accounting for etiology and treatments.

PATIENTS AND METHODS

In this cross-sectional, observational cohort study, 157 outpatients of both sex with nonalcoholic cirrhosis were assessed by upper gastrointestinal endoscopy to search for esophagogastric varices. Twenty-four-hour electrocardiogram Holter monitoring with 3 HRV parameters measurement [SD of the NN intervals, root mean square successive difference of NN intervals, and SD of the averages of NN intervals (SDANN)] according to time-domain analysis were performed in all patients. Sixteen patients with large esophagogastric varices underwent measurements of the HVPG and assessment of HRV parameters at baseline and after 45 days on carvedilol.

RESULTS

The liver dysfunction, expressed by Child-Pugh class or MELD score, was directly related to root mean square successive difference of NN intervals and inversely related to SDANN. Presence of ascites was inversely related to SDANN and to SD of the NN intervals. Treatment with carvedilol had an inverse relation with SDANN. Presence and size of esophagogastric varices had an inverse relation to SDANN and SD of the NN intervals. Upon multivariate analysis the associations between SDANN and Child-Pugh class, size of varices and ascites were confirmed. In the subgroup of 16 patients undergoing HVPG measurement, pressure gradient was unrelated to heart rate and HRV parameters.

CONCLUSIONS

Time-domain HRV parameters in patients with cirrhosis, confirm the autonomic nervous system alteration, and their correlation to the degree of portal hypertension suggesting a role of the ANS in hepatic decompensation.

Transcriptome analysis of mesenteric arterioles changes and its mechanisms in cirrhotic rats with portal hypertension

Portal hypertension (PHT) is a major cause of liver cirrhosis. The formation of portosystemic collateral vessels and splanchnic vasodilation contribute to the development of hyperdynamic circulation, which in turn aggravates PHT and increases the risk of complications. To investigate the changes in mesenteric arterioles in PHT, cirrhotic rat models were established by ligating the common bile ducts. After 4 weeks, the cirrhotic rats suffered from severe PHT and splanchnic hyperdynamic circulation, characterized by increased portal pressure (PP), cardiac output (CO), cardiac index (CI), and superior mesenteric artery (SMA) flow. Mesenteric arterioles in cirrhotic rats displayed remarkable vasodilation, vascular remodeling, and hypocontractility. RNA sequencing was performed based on these findings. A total of 1,637 differentially expressed genes (DEGs) were detected, with 889 up-regulated and 748 down-regulated genes. Signaling pathways related to vascular changes were enriched, including the vascular endothelial growth factor (VEGF), phosphatidylinositol-3-kinase-AKT (PI3K-AKT), and nuclear factor kappa light chain enhancer of activated B cells (NF-κB) signaling pathway, among others. Moreover, the top ten hub genes were screened according to the degree nodes in the protein-protein interaction (PPI) network. Functional enrichment analyses indicated that the hub genes were involved in cell cycle regulation, mitosis, and cellular response to oxidative stress and nitric oxide (NO). In addition, promising candidate drugs for ameliorating PHT, such as resveratrol, were predicted based on hub genes. Taken together, our study highlighted remarkable changes in the mesenteric arterioles of cirrhotic rats with PHT. Transcriptome analyses revealed the potential molecular mechanisms of vascular changes in splanchnic hyperdynamic circulation.

Portopulmonary Hypertension: Management and Liver Transplantation Evaluation

Portopulmonary hypertension (POPH) affects 5% to 6% of patients with advanced liver disease and accounts for 5% to 15% of pulmonary arterial hypertension (PAH) cases. Compared with idiopathic PAH, POPH is associated with significantly worse survival. Recent studies have improved our understanding of the role of both PAH therapy and liver transplantation (LT) in the management of POPH and their impact on overall prognosis. We performed a review of the published literature to summarize the available evidence and guidelines regarding the diagnosis and management of POPH. POPH is defined by the presence of precapillary PH in the context of portal hypertension. POPH is associated with increased perioperative risk at the time of LT, which can be stratified by mean pulmonary arterial pressure and pulmonary vascular resistance. Screening with echocardiography is recommended in all LT candidates to facilitate detection and treatment of POPH. Despite a paucity of evidence, POPH is treated similarly to idiopathic PAH with PAH therapy. These therapies are associated with improved pulmonary hemodynamics and facilitation of safe LT. LT can result in improvement or resolution of POPH in half of patients and has been associated with improved survival in highly selected patients. The prognosis in POPH is poor and is impacted by the severity of both PH and liver disease. Management with a combination of PAH therapy and LT in selected patients has been associated with improved pulmonary hemodynamics and survival.

Extrahepatic portomesenteric obstruction resulting in splanchnic hypertension and refractory ascites

Portal hypertension is a commonly described etiology that typically stems from underlying cirrhosis. Interventional radiologists may offer several interventions in the multidisciplinary approach to managing these patients. However, it is important to ascertain the cause and type of hypertension before intervention to avoid poor outcomes. We describe a case of an 89-year-old male with pancreatic adenocarcinoma and isolated superior mesenteric venous hypertension secondary to external stent compression at the portomesenteric confluence. This resulted in refractory ascites which was significantly relieved after portal to superior mesenteric vein stent placement.

Spleen stiffness: a predictive factor of dismal prognosis in liver cirrhosis

Portal hypertension (PH) is a major complication of liver cirrhosis, as it predisposes to the development of serious clinical manifestations such as ascites, hepatic encephalopathy and variceal bleeding, aggravating the prognosis of patients. Hepatic vein pressure gradient (HVPG) is considered the reference method for the estimation of the presence and severity of PH, but this procedure is available only in specialized centers. Alternatively, many non-invasive methods have been proposed in order to substitute HVPG. Among them, liver stiffness measurement (LSM) has been widely used, as it has been shown to correlate well with HVPG, though this relationship seems to weaken in values of HVPG higher than 12 mmHg, the threshold of serious complications development. Several studies supported the use of spleen stiffness measurement (SSM) instead of LSM, anticipating to a more adequate assessment of this advanced stage of PH. The aim of this paper is to critically appraise and summarize the literature about the role of SSM as a predictive tool of liver decompensation and prognosis, highlighting the strengths and the potential limitations of the studies published so far. EXPERT'S OPINION: The utility of SSM in ruling out high risk for bleeding varices in cirrhotic patients has been demonstrated, driving the Baveno VII consensus to encompass SSM in its last recommendations, though its use in patients with non-viral cirrhosis remains to be validated. We believe that in the near future, SSM alone or combined with other tests, will being used not only for sparing upper endoscopies, but also for predicting decompensation and prognosis in advanced compensated cirrhotic patients, regardless of liver disease's etiology. Herein, we present the data that support this consideration, pointing out these issues that should further be investigated in order to elucidate and intensify the value of SSM in the management of patients with liver cirrhosis.

A Rare Hemorrhagic, Orange-Colored Ascites, Challenging Traditional Ascitic Fluid Analysis

Analysis of ascitic fluid can offer useful information in developing and supporting a differential diagnosis. As one of the most prevalent complications in patients with cirrhosis, ascitic fluid aids in differentiating a benign condition from malignancy. Both the gross appearance of the ascitic fluid, along with fluid analysis, play a major role in diagnosis. Here, we discuss a patient with liver cirrhosis, esophageal varices, hepatitis C, and alcohol abuse, who had a paracentesis performed, which revealed a turbid, viscous, orange-colored ascitic fluid that has not been documented in literature. Ascitic fluid is routinely analyzed based on gross appearance, cell count, and serum ascites albumin gradient (SAAG) score. An appearance of turbidity or cloudiness has commonly suggested an inflammatory process. In our case, fluid analysis revealed a red blood cell count of 24 250/mcL, further suggesting inflammation. However, it also revealed an insignificant number of inflammatory cells, with a total nucleated cell count of 14/mcL. This rich-orange color has posed a challenge in classification and diagnosis of the underlying cause of ascites, with one classification system suggesting inflammation, while another suggesting portal hypertension. Furthermore, we have traditionally relied on the SAAG score to aid in determining portal hypertension as an underlying cause of ascites. With a 96.7% accuracy rate, the SAAG score incorrectly diagnosed portal hypertension in this patient. In this article, we aim to explore how this rare, orange-colored ascitic fluid has challenged the traditional classification system of ascites.

The hepato-cardiac disorders in Tibetan residents with hepatic echinococcosis: A case-control echocardiography study

BACKGROUND

Clinical guidelines indicate that chronic highland exposure could induce pulmonary hypertension; chronic hepatic disease may affect cardiac structure and functions. However, the simultaneous impact of hepatic echinococcosis (HE) and chronic highland exposure on cardiac structure and function in Tibetan residents are under-investigated.

METHODS

One hundred and twenty patients with HE, 23 healthy high-altitude migrants with a mean residence time of 7.15 ± 1.12 years, and 46 healthy Tibetan permanent residents were enrolled in this study. All participants received comprehensive transthoracic echocardiography.

RESULTS

High-altitude migrants have a relatively lower pulmonary artery flow velocity (PV) and a slightly higher pulmonary artery mean pressure (PAMP) than the Tibetan permanent residents. Patients with HE presented relatively smaller dimensions of the main pulmonary artery and branches and a bigger right atrium and right ventricular cavity size than the two control groups. PV, PAMP and numbers of detectable tricuspid regurgitation jet velocity (TRJV), right ventricular fractional area change (RV_FAC), tricuspid annular plane systolic excursion (TAPSE), the ratio of tricuspid inflow velocities at early diastole to tricuspid annular early diastolic excursion velocity (RV_E/e') and right ventricular myocardial performance index (RV_MPI) were increased in patients with HE compared to the two control groups. Similarly, decreased LVEF and Impaired left ventricular diastolic function were identified in patients with HE compared to the two control groups.

CONCLUSIONS

Patients with HE presented with impaired biventricular contractile performance and diastolic dysfunction.

Bioinformatics Analysis of Common Genetic and Molecular Traits and Association of Portal Hypertension with Pulmonary Hypertension

Portal hypertension (PH) is an important cause of pulmonary arterial hypertension(PAH), but its mechanism is still unclear. We used genetic data analysis to explore the shared genes and molecular mechanisms of PH and PAH. We downloaded the PH and PAH data from the GEO database, and used the weighted gene coexpression network analysis method (WGCNA) to analyze the coexpression modules of idiopathic noncirrhotic portal hypertension (INCPH) and cirrhotic portal hypertension (CPH) and pulmonary hypertension, respectively. Enrichment analysis was performed on the common genes, and differential gene expressions (DEGs) were used for verification. The target genes of INCPH and PAH were obtained by string and cytoscape software, and the miRNAs of target genes were predicted by miRwalk, miRDB, and TargetScan and their biological functions were analyzed; finally, we used PanglaoDB to predict the expression of target genes in cells. In WGCNA, gene modules significantly related to PAH, CPH, and INCPH were identified, and enrichment function analysis showed that the common pathway of PAH and CPH were “P53 signaling pathway,” “synthesis of neutral lipids”; PAH and INCPH are “terminal,” “Maintenance Regulation of Granules,” and “Toxin Transport.” DEGs confirmed the results of WGCNA; the common miRNA functions of PAH and cirrhosis were enriched for “P53 signaling pathway,” “TGF-β signaling pathway,” “TNF signaling pathway,” and “fatty acid metabolism,” and the miRNAs-mRNAs network suggested that hsa-miR-22a-3p regulates MDM2 and hsa-miR-34a-5p regulates PRDX4; the target genes of PAH and INCPH are EIF5B, HSPA4, GNL3, RARS, UTP20, HNRNPA2B1, HSP90B1, METAP2, NARS, SACM1L, and their target miRNA function enrichment showed EIF5B, HNRNPA2B1, HSP90B1, METAP2, NARS, SACM1L, and HSPA4 are associated with telomeres and inflammation, panglaoDB showed that target genes are located in endothelial cells, smooth muscle cells, etc. In conclusion, the mechanism of pulmonary hypertension induced by portal hypertension may be related to telomere dysfunction and P53 overactivation, and lipid metabolism and intestinal inflammation are also involved in this process.

Evaluation of the definition of hyperdynamic circulation in patients with cirrhosis and ascites

The aim of this study was to evaluate potential criteria for defining hyperdynamic circulation in patients with cirrhosis according to the severity of ascites and its association with the activation of vasoactive systems and markers of systemic inflammation. Cross-sectional study of patients with cirrhosis and right heart catheter measurement from two different academic centers. We evaluated systemic vascular resistance (SVR)/cardiac output (CO) according to ascites severity. The first substudy evaluated the possible definition, the second validated the findings, and the third evaluated the possible mechanisms. Comparisons were performed by means of t test, Mann-Whitney U test, and analysis of variance. Finally, linear regression curves were adjusted to evaluate the relationship between CO and SVR according to the severity of ascites and compensated or decompensated stage of cirrhosis. The study included 721 patients (substudy 1, n = 437; substudy 2, n = 197; substudy 3, n = 87). Hyperdynamic circulation (HC), defined by absolute cutoffs, had no association with the presence or severity of ascites in the first two cohorts. No association was observed between HC with renin, aldosterone, or markers of bacterial translocation. Comparison of linear regression curves showed a shift of the CO-SVR relationship to the left in patients with refractory ascites (p < 0.001) compared to patients without ascites as well as to patients with decompensated cirrhosis (p = 0.002). Conclusion: HC according to the traditional concept of high CO and low SVR is not always present in ascites. Evaluation of the CO-SVR relationship according to the severity of ascites shows a shift to the left, suggesting that the presence of HC would be defined by this shift, independent of absolute values.

Effect of probiotics on hemodynamic changes and complications associated with cirrhosis: A pilot randomized controlled trial

BACKGROUND

Bacterial translocation exacerbates the hyperdynamic circulation observed in cirrhosis and contributes to a more severe disease course. Probiotics may reduce bacterial translocation and may therefore be useful to redress the circulatory imbalance.

AIM

To investigate the effect of probiotics on hemodynamic parameters, systemic inflammation, and complications of cirrhosis in this randomized placebo-controlled trial.

METHODS

This single-blind randomized placebo-controlled study included 40 patients with Child-Pugh class B and C cirrhosis; 24 patients received probiotics (Saccharomyces boulardii) for 3 mo, and 16 patients received a placebo over the same period. Liver function and the systemic hemodynamic status were evaluated pre- and post-intervention. Echocardiography and simultaneous blood pressure and heart rate monitoring were performed to evaluate systemic hemodynamic indicators. Cardiac output and systemic vascular resistance were calculated.

RESULTS

Following a 3-mo course of probiotics in comparison to the control group, we observed amelioration of hyperdynamic circulation [a decrease in cardiac output (P = 0.026) and an increase in systemic vascular resistance (P = 0.026)] and systemic inflammation [a decrease in serum C-reactive protein levels (P = 0.044)], with improved liver function [an increase in serum albumin (P = 0.001) and a decrease in the value of Child-Pugh score (P = 0.001)] as well as a reduction in the severity of ascites (P = 0.022), hepatic encephalopathy (P = 0.048), and cholestasis [a decrease in serum alkaline phosphatase (P = 0.016) and serum gamma-glutamyl transpeptidase (P = 0.039) activity] and an increase in platelet counts (P < 0.001) and serum sodium level (P = 0.048).

CONCLUSION

Probiotic administration was associated with amelioration of hyperdynamic circulation and the associated complications of cirrhosis.

Anticoagulant therapy for splanchnic vein thrombosis: an individual patient data meta-analysis

Robust evidence on the optimal management of splanchnic vein thrombosis (SVT) is lacking. We conducted an individual patient meta-analysis to evaluate the effectiveness and safety of anticoagulation for splanchnic vein thrombosis (SVT). MEDLINE, EMBASE, and clincaltrials.gov., were searched up to June 2021 for prospective cohorts or randomized clinical trials including patients with SVT. Data from individual datasets were merged, and any discrepancy with published data was resolved by contacting study authors. Three studies for a total of 1635 patients were included. Eighty-five percent of patients received anticoagulation for a median duration of 316 days (range 1 to 730 days). Overall, incidence rates for recurrent VTE, major bleeding, and mortality were 5.3/100 patients-years (p-y) (95% CI, 5.1 to 5.5), 4.4/100 p-y (95% CI, 4.2 to 4.6), and 13.0/100 p-y (95% CI, 12.4 to 13.6), respectively. The incidence rates of all outcomes were lower during anticoagulation and higher after treatment discontinuation or when anticoagulation was not administered. In multivariable analysis, anticoagulant treatment appeared to be associated with a lower risk of recurrent VTE (Hazard Ratio [HR] 0.42; 95% CI, 0.27 to 0.64), major bleeding (HR 0.47; 95% CI, 0.30 to 0.74), and mortality (HR 0.23; 95% CI, 0.17 to 0.31). Results were consistent in patients with cirrhosis, solid cancer, myeloproliferative neoplasms, unprovoked SVT, and SVT associated with transient or persistent non-malignant risk factors. In patients with SVT the risk of recurrent VTE and major bleeding is substantial. Anticoagulant treatment is associated with reduced risk of both outcomes.

The Value of Liver and Spleen Stiffness for Evaluation of Portal Hypertension in Compensated Cirrhosis

Patients with compensated advanced chronic liver disease who develop clinically significant portal hypertension (CSPH) are at high risk for hepatic decompensation and mortality if left untreated. Liver biopsy and hepatic venous pressure gradient (HVPG) measurements are the current gold standard procedures for determining fibrosis severity and diagnosing CSPH, respectively; however, both are invasive, limiting their use in clinical practice and larger trials of novel agents. As such, there is an unmet clinical need for reliable, validated, noninvasive measures to detect CSPH and to further assess portal hypertension (PH) severity. Alterations in the biomechanical properties of the liver or spleen in patients with cirrhosis can be quantified by tissue elastography, which examines the elastic behavior of tissue after a force has been applied. A variety of methods are available, including magnetic resonance elastography, shear-wave elastography, and the most thoroughly investigated measure, vibration-controlled transient elastography. Liver stiffness (LS) and spleen stiffness (SS) measurements offer valuable alternatives to detect and monitor CSPH. Both LS and SS correlate well with HVPG, with thresholds of LS >20-25 kPa and SS >40-45 kPa indicating a high likelihood of CSPH. Because SS is a direct and dynamic surrogate of portal pressure, it has the potential to monitor PH severity and assess PH improvement as a surrogate marker for clinical outcomes. Importantly, SS seems to be superior to LS for monitoring treatment response in clinical trials focusing on reducing PH.

Measurement of multiple spleen lengths is not necessary for non-invasive prediction of high-risk esophagogastric varices

AIM

To validate an appropriate spleen size measurement technique for the prediction of high-risk esophagogastric varices.

METHODS

This retrospective cross-sectional study included 369 patients who underwent ultrasonography and computed tomography (CT) of the spleen and esophagogastroduodenoscopy between January 2018 and December 2020. Maximum spleen length, width, and craniocaudal length were measured in a longitudinal view. The two-dimensional (2D) spleen index (maximum length × maximum width in the longitudinal view) was calculated. A three-dimensional (3D) spleen index was then defined as follows: 2D spleen index × maximum length in the transverse view. The similarity in spleen volume measured by CT and ultrasonography (spleen index) was assessed by the correlation coefficient. The diagnostic accuracies of the spleen index, platelet/spleen length, and platelet/spleen index were calculated to determine the overall diagnostic accuracy.

RESULTS

Compared to the other spleen indices, our 3D spleen index was significantly better correlated with spleen volume on CT (r = 0.91, 95% confidence interval 0.89-0.92, p < 0.001). Receiver-operating characteristic curve analyses revealed no significant difference between the 3D and 2D indices (p = 0.228) but did show a significant difference between the 3D and one-dimensional indices (p = 0.020). Although the area under the curve for the platelet count combined with the spleen index or length was higher than that for our 3D index, there was no significant difference between platelet count and spleen index or length (p = 0.078).

CONCLUSIONS

Platelet/spleen length has a reasonable ability to predict high-risk esophagogastric varices, even though measurement of two or three factors can be correlated with spleen volume.

Gut-liver axis in cirrhosis: Are hemodynamic changes a missing link?

Recent evidence suggests that the condition of the gut and its microbiota greatly influence the course of liver disease, especially cirrhosis. This introduces the concept of the gut–liver axis, which can be imagined as a chain connected by several links. Gut dysbiosis, small intestinal bacterial overgrowth, and intestinal barrier alteration lead to bacterial translocation, resulting in systemic inflammation. Systemic inflammation further causes vasodilation, arterial hypotension, and hyperdynamic circulation, leading to the aggravation of portal hypertension, which contributes to the development of complications of cirrhosis, resulting in a poorer prognosis. The majority of the data underlying this model were obtained initially from animal experiments, and most of these correlations were further reproduced in studies including patients with cirrhosis. However, despite the published data on the relationship of the disorders of the gut microbiota with the complications of cirrhosis and the proposed pathogenetic role of hemodynamic disorders in their development, the direct relations between gut dysbiosis and hemodynamic changes in this disease are poorly studied. They remain a missing link in the gut–liver axis and a challenge for future research.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Pulmonary Vascular Complications of Liver Disease

Pulmonary vascular disease is a frequent complication of chronic liver disease and portal hypertension, affecting up to 30% of patients. There are two distinct pulmonary vascular complications of liver disease: hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH). HPS affects 25% of patients with chronic liver disease and is characterized by intrapulmonary vasodilatation and abnormal arterial oxygenation. HPS negatively impacts quality of life and is associated with a 2-fold increased risk of death compared to controls with liver disease without HPS. Angiogenesis, endothelin-1 mediated endothelial dysfunction, monocyte influx, and alveolar type 2 cell dysfunction seem to play important roles in disease pathogenesis but there are currently no effective medical therapies. Fortunately, HPS resolves following liver transplant (LT) with improvements in hypoxemia. POPH is a subtype of pulmonary arterial hypertension (PAH) characterized by an elevated mean pulmonary arterial pressure and pulmonary vascular resistance in the setting of normal left-sided filling pressures. POPH affects 5% to 6% of patients with chronic liver disease. Although the pathogenesis has not been fully elucidated, endothelial dysfunction, inflammation, and estrogen signaling have been identified as key pathways involved in disease pathogenesis. POPH is typically treated with PAH targeted therapy and may also improve with liver transplantation in selected patients. This article highlights what is currently known regarding the diagnosis, management, pathobiology, and outcomes of HPS and POPH. Ongoing research is needed to improve understanding of the pathophysiology and outcomes of these distinct and often misunderstood pulmonary vascular complications of liver disease. © 2021 American Physiological Society. Compr Physiol 11:1-22, 2021.

Exercise physiology in cirrhosis and the potential benefits of exercise interventions: A review

Reduction in muscle mass is a highly prevalent phenomenon in cirrhosis and is now well-documented to be associated with significant morbidity and mortality. Research into muscle loss in cirrhosis remains limited by an ongoing poor understanding of its relationship with muscle function, physical activity, and aerobic capacity. Alterations in exercise physiology have been documented in studies of individuals with cirrhosis that provide important information on physical function that is not captured by simple quantification of muscle mass. Despite expert consensus recommending regular exercise in end-stage liver disease to maintain muscle mass and function, there is little evidence guiding clinicians as to which form of exercise or delivery mechanism is most effective. It also remains unproven whether any specific intervention can alter clinically relevant outcomes. This review article summarizes the available literature regarding the changes in exercise physiology observed in cirrhosis, the associated impact on physical capacity, and the results of existing trials that examine the potential benefits of exercise delivery in patients with cirrhosis, particularly pertaining to their impact on exercise physiology.

Sleep and liver disease: a bidirectional relationship

Sleep is a complex, highly regulated process essential for human health and wellbeing. Increasingly, sleep-wake disturbance has been implicated in the pathogenesis of chronic liver disease, particularly the development and progression of non-alcoholic fatty liver disease and alcohol-related liver disease. Patients with cirrhosis also have a high burden of sleep abnormalities with substantial implications for their quality of life and physical health. This Review summarises the epidemiology and pathophysiology of sleep-wake disturbance in liver disease and discusses the multiple converging pathways leading to abnormal sleeping patterns in patients with cirrhosis. This includes contributions from altered melatonin metabolism, neuromuscular complications, and aberrant thermoregulation. In turn, a vicious cycle is established whereby disrupted sleep can further contribute to liver disease progression. We also begin to unravel the complex, interlinking relationship between sleep-wake disturbance and hepatic encephalopathy, discussing both overlapping and distinct mechanisms and clinical features. Finally, we summarise the current and future therapeutic approaches aiming to improve sleep quality in patients with cirrhosis.

Cyclic GMP in Liver Cirrhosis-Role in Pathophysiology of Portal Hypertension and Therapeutic Implications

The NO-cGMP signal transduction pathway plays a crucial role in tone regulation in hepatic sinusoids and peripheral blood vessels. In a cirrhotic liver, the key enzymes endothelial NO synthase (eNOS), soluble guanylate cyclase (sGC), and phosphodiesterase-5 (PDE-5) are overexpressed, leading to decreased cyclic guanosine-monophosphate (cGMP). This results in constriction of hepatic sinusoids, contributing about 30% of portal pressure. In contrast, in peripheral arteries, dilation prevails with excess cGMP due to low PDE-5. Both effects eventually lead to circulatory dysfunction in progressed liver cirrhosis. The conventional view of portal hypertension (PH) pathophysiology has been described using the "NO-paradox", referring to reduced NO availability inside the liver and elevated NO production in the peripheral systemic circulation. However, recent data suggest that an altered availability of cGMP could better elucidate the contrasting findings of intrahepatic vasoconstriction and peripheral systemic vasodilation than mere focus on NO availability. Preclinical and clinical data have demonstrated that targeting the NO-cGMP pathway in liver cirrhosis using PDE-5 inhibitors or sGC stimulators/activators decreases intrahepatic resistance through dilation of sinusoids, lowering portal pressure, and increasing portal venous blood flow. These results suggest further clinical applications in liver cirrhosis. Targeting the NO-cGMP system plays a role in possible reversal of liver fibrosis or cirrhosis. PDE-5 inhibitors may have therapeutic potential for hepatic encephalopathy. Serum/plasma levels of cGMP can be used as a non-invasive marker of clinically significant portal hypertension. This manuscript reviews new data about the role of the NO-cGMP signal transduction system in pathophysiology of cirrhotic portal hypertension and provides perspective for further studies.

Amelioration of systemic inflammation in advanced chronic liver disease upon beta-blocker therapy translates into improved clinical outcomes

OBJECTIVE

Systemic inflammation promotes the development of clinical events in patients with advanced chronic liver disease (ACLD). We assessed whether (1) non-selective beta blocker (NSBB) treatment initiation impacts biomarkers of systemic inflammation and (2) whether these changes in systemic inflammation predict complications and mortality.

DESIGN

Biomarkers of systemic inflammation, that is, white blood cell count (WBC), C reactive protein (CRP), interleukin-6 (IL-6) and procalcitonin (PCT) were determined at sequential hepatic venous pressure gradient (HVPG) measurements without NSBB and under stable NSBB intake. The influence of NSBB-related changes in systemic inflammation on the risk of decompensation and liver-related death was analysed using competing risk regression.

RESULTS

Our study comprised 307 stable patients with ACLD (Child-A: 77 (25.1%), Child-B: 161 (52.4%), Child-C: 69 (22.5%), median HVPG: 20 (IQR 17-24) mm Hg) including 231 (75.2%) with decompensated disease.WBC significantly decreased upon NSBB therapy initiation (median: -2 (IQR -19;+13)%, p=0.011) in the overall cohort. NSBB-related reductions of WBC (Child-C: -16 (-30;+3)% vs Child-B: -2 (-16;+16)% vs Child-A: +3 (-7;+13)%, p<0.001) and of CRP (Child-C: -26 (-56,+8)% vs Child-B: -16 (-46;+13)% vs Child-A: ±0 (-33;+33)%, p<0.001) were more pronounced in advanced stages of cirrhosis. The NSBB-associated changes in WBC correlated with changes in CRP (Spearman's ρ=0.228, p<0.001), PCT (ρ=0.470, p=0.002) and IL-6 (ρ=0.501, p=0.001), but not with changes in HVPG (ρ=0.097, p=0.088).An NSBB-related decrease in systemic inflammation (ie, WBC reduction ≥15%) was achieved by n=91 (29.6%) patients and was found to be an independent protective factor of further decompensation (subdistribution HR, sHR: 0.694 (0.49-0.98), p=0.038) in decompensated patients and of liver-related mortality in the overall patient cohort (sHR: 0.561 (0.356-0.883), p=0.013).

CONCLUSION

NSBB therapy seems to exert systemic anti-inflammatory activity as evidenced by reductions of WBC and CRP levels. Interestingly, this effect was most pronounced in Child-C and independent of HVPG response. An NSBB-related WBC reduction by ≥15% was associated with a decreased risk of further decompensation and death.

Critically Ill COVID-19 Patient with Chronic Liver Disease - Insights into a Comprehensive Liver Intensive Care

The novel coronavirus-related coronavirus disease 2019 (COVID-19) pandemic has been relentless in disrupting and overwhelming healthcare the world over. Clinical outcomes of COVID-19 in patients with chronic comorbidities, especially in those with metabolic syndrome, are well documented. Chronic liver disease and cirrhosis patients are a special sub-group, among whom the management of COVID-19 is challenging. Understanding the pathophysiology of COVID-19 in patients with cirrhosis and portal hypertension improves our identification of at-risk patients for disease progression that will further help compartmentalize generalized and specialized treatment options in this special patient group. In this exhaustive review, we critically review the impact of COVID-19 on the liver and in chronic liver disease and cirrhosis patients. We further discuss common features associated with the pathophysiology of COVID-19 and cirrhosis, based on the renin-angiotensin system and deliberate current literature on guidelines for the treatment of COVID-19 and extrapolate the same to the cirrhosis population to provide a concise and stepwise, evidence-based management for cirrhosis patients with severe and critical COVID-19. There are no specific management guidelines for cirrhosis patients with COVID-19 and current recommendations for treatment are as per guidelines for general population. Nevertheless, specific issues like avoiding corticosteroids in decompensated patients with variceal bleeding, suspected sepsis, high grade hepatic encephalopathy and acute kidney injury, use of early mechanical ventilation strategies in those with severe ascites and hepatopulmonary syndrome, avoidance of remdesivir in advanced liver disease, and application of liver-specific severity scores for prognostication and identification of futility need to be highlighted.

First-Pass Arrival Interval of Ultrasound Contrast Medium in the Hepatic Artery and Portal Vein as a Marker for Assessment of Liver Transplant Recipients

BACKGROUND

This study measures the first-pass arrival times in the hepatic artery and portal vein of the transplanted liver using contrast-enhanced ultrasound (CEUS) and assess its correlation with graft performance in the early posttransplant period.

METHODS

This study evaluated 35 liver transplant recipients who underwent CEUS examination within 1 month of transplant surgery. CEUS under contrast-specific harmonic imaging mode were recorded for 60 seconds immediately after intravenous administration of microbubble ultrasound contrast medium (Sonazoid, GE Healthcare, Oslo, Norway). The recorded video clips were reviewed by 2 readers to determine the first-pass arrival times in the hepatic artery and portal vein, and the difference between the 2 was defined as the arterial-portal arrival interval (APAI). Laboratory data on the same date of CEUS examination were collected as indicators to correlate with APAI.

RESULTS

The intra- and inter-rater reliability for APAI measurement were excellent, with intraclass correlation coefficients > .95. The mean APAI was 4.5 ± 1.8 seconds (range, 2.0-10.5 seconds). The APAI was positively correlated with the serum total bilirubin level (r = 0.357, P = .035) and negatively correlated with the platelet count (r = -0.354, P = .037). At the 5 second cutoff point, a total serum bilirubin of >8 mg/dL was reported in 5 of 11 patients (45.4%) with APAI of >5 seconds and in only 3 of 24 patients (12.5%) with APAI of <5 seconds (P < .05).

CONCLUSIONS

The APAI is a quantitative marker that links the hemodynamics and the clinical status of the liver graft.

Natural history of functional tricuspid regurgitation: impact of cardiac output

AIMS

Tricuspid regurgitation (TR) was long forgotten until recent studies alerting on its prognostic impact. Cardiac output (CO) is the main objective of heart mechanics. We sought to compare clinical and echocardiographic data of patients with TR from inclusion to 1-year follow-up according to initial CO.

METHODS AND RESULTS

Patients with isolated secondary TR and left ventricular ejection fraction (LVEF) ≥40% were prospectively included. All patients had a clinical and echocardiographic evaluation at baseline and after 1 year. Echocardiographic measurements were centralized. The patients were partitioned according to their CO at baseline. The primary outcome was all-cause death. Ninety-five patients completed their follow-up. The majority of patients had normal CO (n = 64, 67.4%), whereas 16 (16.8%) patients had low-CO and 12 (12.6%) had high-CO. right ventricular function was worse in the low-CO group but with improvement at 1 year (30% increase in tricuspid annular plane systolic excursion). LVEF and global longitudinal strain were significantly worse in the low-CO group. Overall, 18 (19%) patients died during follow-up, of which 10 (55%) patients had abnormal CO. There was a U-shaped association between CO and mortality. Normal CO patients had significantly better survival (87.5% vs. 62.5% and 66.67%) in the low- and high-CO groups, respectively, even after adjustment (heart rate 2.23 for the low-CO group and 9.08 for high-CO group; P = 0.0174).

CONCLUSION

Significant isolated secondary TR was associated with 19% of mortality. It is also associated with higher long-term mortality if CO is abnormal, suggesting a possible role for evaluating better and selecting patients for intervention.

Portal Venous Flow Is Increased by Jejunal but Not Colonic Hydrogen Sulfide in a Nitric Oxide-Dependent Fashion in Rats

Hydrogen sulfide (H2S) is a recently discerned endogenous signaling molecule that modulates the vascular system. Endogenous hydrogen sulfide has been shown to dilate both the mesenteric and portal vasculature. Gut microbiome, via sulfur reducing bacteria, is another source of H2S production within the gut lumen; this source of H2S is primarily produced and detoxified in the colon under physiologic conditions. Nitric oxide (NO), a major endogenous vasodilator in the portal circulation, participates in H2S-induced vasodilation in some vascular beds. We hypothesize that jejunal but not colonic H2S increases portal vein flow in a NO-dependent fashion. To evaluate the effects of luminal H2S, venous blood flow, portal venous pressure, and systemic venous pressure were measured in rats after administration of either vehicle or an H2S donor (NaHS) into the jejunum or the colon. We found that portal venous pressure and systemic pressure did not change and were similar between the three study groups. However, portal venous blood flow significantly increased following jejunal administration of NaHS but not in response to colonic NaHS or vehicle administration. To test the contribution of NO production to this response, another group of animals was treated with either an NO synthase inhibitor (N-Ω-nitro-L-arginine, L-NNA) or saline prior to jejunal NaHS infusion. After L-NNA pretreatment, NaHS caused a significant fall rather than increase in portal venous flow compared to saline pretreatment. These data demonstrate that H2S within the small intestine significantly increases portal venous blood flow in a NO-dependent fashion.

Anticoagulant therapy for splanchnic vein thrombosis: a systematic review and meta-analysis

Treatment of splanchnic vein thrombosis (SVT) is challenging, and evidence to guide therapeutic decisions remains scarce. The objective of this systematic review and meta-analysis was to determine the efficacy and safety of anticoagulant therapy for SVT. MEDLINE, EMBASE, and clinicaltrials.gov were searched from inception through December 2019, without language restrictions, to include observational studies and randomized controlled trials reporting radiological or clinical outcomes in patients with SVT. Pooled proportions and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated in a random-effects model. Of 4312 records identified by the search, 97 studies including 7969 patients were analyzed. In patients receiving anticoagulation, the rates of SVT recanalization, SVT progression, recurrent venous thromboembolism (VTE), major bleeding, and overall mortality were 58% (95% CI, 51-64), 5% (95% CI, 3-7), 11% (95% CI, 8-15), 9% (95% CI, 7-12), and 11% (95% CI, 9-14), respectively. The corresponding values in patients without anticoagulation were 22% (95% CI, 15-31), 15% (95% CI, 8-27), 14% (95% CI, 9-21), 16% (95% CI, 13-20), and 25% (95% CI, 20-31). Compared with no treatment, anticoagulant therapy obtained higher recanalization (RR, 2.39; 95% CI, 1.66-3.44) and lower thrombosis progression (RR, 0.24; 95% CI, 0.13-0.42), major bleeding (RR, 0.73; 95% CI, 0.58-0.92), and overall mortality (RR, 0.45; 95% CI, 0.33-0.60). These results demonstrate that anticoagulant therapy improves SVT recanalization and reduces the risk of thrombosis progression without increasing major bleeding. The incidence of recurrent VTE remained substantial in patients receiving anticoagulation, as well. Effects were consistent across the different subgroups of patients. This trial was registered on the PROPERO database at (https://www.crd.york.ac.uk/prospero//display_record.php?ID=CRD42019127870) as #CRD42019127870.

Cardiac output states in patients with severe functional tricuspid regurgitation: impact on treatment success and prognosis

AIMS

To investigate whether there is evidence for distinct cardiac output (CO) based phenotypes in patients with chronic right heart failure associated with severe tricuspid regurgitation (TR) and to characterize their impact on TR treatment and outcome.

METHODS AND RESULTS

A total of 132 patients underwent isolated transcatheter tricuspid valve repair (TTVR) for functional TR at two centres. Patients were clustered according to k-means clustering into low [cardiac index (CI) < 1.7 L/min/m² ], intermediate (CI 1.7-2.6 L/min/m² ) and high CO (CI > 2.6 L/min/m² ) clusters. All-cause mortality and clinical characteristics during follow-up were compared among different CO clusters. Mortality rates were highest for patients in a low (24%) and high CO state (42%, log-rank P < 0.001). High CO state patients were characterized by larger inferior vena cava diameters (P = 0.003), reduced liver function, higher incidence of ascites (P = 0.006) and markedly reduced systemic vascular resistance (P < 0.001) as compared to TTVR patients in other CO states. Despite comparable procedural success rates, the extent of changes in right atrial pressures (P = 0.01) and right ventricular dimensions (P < 0.001) per decrease in regurgitant volume following TTVR was less pronounced in high CO state patients as compared to other CO states. Successful TTVR was associated with the smallest prognostic benefit among low and high CO state patients.

CONCLUSIONS

Patients with chronic right heart failure and severe TR display distinct CO states. The high CO state is characterized by advanced congestive hepatopathy, a substantial decrease in peripheral vascular tone, a lack of response of central venous pressures to TR reduction, and worse prognosis. These data are relevant to the pathophysiological understanding and management of this important clinical syndrome.

Skin temperature variability is an independent predictor of survival in patients with cirrhosis

Background

Cirrhosis is a disease with multisystem involvement. It has been documented that patients with cirrhosis exhibit abnormal patterns of fluctuation in their body temperature. However, the clinical significance of this phenomenon is not well understood. The aim of this study was to determine if temperature variability analysis can predict survival in patients with cirrhosis.

Methods

Thirty eight inpatients with cirrhosis were enrolled in the study. Wireless temperature sensors were used to record patients’ proximal skin temperature for 24 hr. The pattern of proximal temperature fluctuation was assessed using the extended Poincaré plot to measure short‐term and long‐term proximal temperature variability (PTV). Patients were followed up for 12 months, and information was collected on the occurrence of death/liver transplantation.

Results

During the follow‐up period, 15 patients (39%) died or underwent transplantation for hepatic decompensation. Basal proximal skin temperature absolute values were comparable in survivors and nonsurvivors. However, nonsurvivors showed a significant reduction in both short‐term and long‐term HRV indices. Cox regression analysis showed that both short‐term and long‐term PTV indices could predict survival in these patients. However, only measures of short‐term PTV were shown to be independent of the severity of hepatic failure in predicting survival. Finally, the prognostic value of short‐term PTV was also independent of heart rate variability, that is, a measure of autonomic dysfunction.

Conclusion

Changes in the pattern of patients’ temperature fluctuations, rather than their absolute values, hold key prognostic information, suggesting that impaired thermoregulation may play an important role in the pathophysiology of cirrhosis.