Beta-blockers in portal hypertension: new developments and controversies

Microarray analysis demonstrates up-regulation of the endothelin-1 gene with compensatory down-regulation of the ETA receptor gene in human portal vein

High blood pressure in the portal vein, portal hypertension (PH), is the final common pathway in liver cirrhosis regardless of aetiology. Complications from PH are the major cause of morbidity and mortality in these patients. Current drug therapy to reduce portal pressure is mainly limited to β-adrenergic receptor blockade but approximately 40% of patients do not respond. Our aim was to use microarray to measure the expression of ∼20,800 genes in portal vein from patients with PH undergoing transplantation for liver cirrhosis (PH, n=12) versus healthy vessels (control, n=9) to identify potential drug targets to improve therapy. Expression of 9,964 genes above background was detected in portal vein samples. Comparing PH veins versus control (adjusted P-value < 0.05, fold change > 1.5) identified 548 up-regulated genes and 1,996 down-regulated genes. The 2,544 differentially expressed genes were subjected to pathway analysis. We identified 49 significantly enriched pathways. The endothelin pathway was ranked the tenth most significant, the only vasoconstrictive pathway to be identified. ET-1 gene (EDN1) was significantly up-regulated, consistent with elevated levels of ET-1 peptide previously measured in PH and cirrhosis. ETA receptor gene (EDNRA) was significantly down-regulated, consistent with an adaptive response to increased peptide levels in the portal vein but there was no change in the ETB gene (EDNRB). The results provide further support for evaluating the efficacy of ETA receptor antagonists as a potential therapy in addition to β-blockers in patients with PH and cirrhosis.

Effect of midodrine on HVPG in advanced chronic liver disease and acute-on-chronic liver failure-A pilot study

BACKGROUND AND AIMS

Nonselective beta-blockers (NSBB) are the mainstay for treatment of portal hypertension (PH), but require caution in decompensated cirrhosis (DC) or acute-on-chronic liver failure (ACLF) with hypotension, hyponatremia, acute kidney injury (AKI) or type 2 hepatorenal syndrome (HRS). Midodrine is oral, rapidly acting, α1-adrenergic agonist. We evaluated acute effects of midodrine on hepatic venous pressure gradient (HVPG) in DC and ACLF with contraindications to NSBB.

METHODS

Patients of DC (n = 30) with grade III ascites and serum sodium (Na) <130/systolic blood pressure (SBP) <90/type II HRS (group I) and ACLF patients (n = 30) with Na <130/SBP <90/AKI (group II) were included. HVPG was done at baseline and repeated 3 h after 10 mg midodrine. Primary outcome was HVPG response (reduction by >20% or to <12 mmHg).

RESULTS

In group I, midodrine significantly reduced HVPG (19.2 ± 4.6 to 17.8 ± 4.2, p = .02) and heart rate (HR) (86.3 ± 11.6 to 77.9 ± 13.1, p < .01) and increased mean arterial pressure (MAP) (74.1 ± 6.9 to 81.9 ± 6.6 mmHg, p < .01). In group II also, midodrine reduced HVPG (19.1 ± 4.1 to 17.0 ± 4.2) and HR (92.4 ± 13.7 to 84.6 ± 14.1) and increased MAP (85.4 ± 7.3 to 91.2 ± 7.6 mmHg), p < .01 for all. HVPG response was achieved in 3/30 (10%) in group I and 8/30 (26.7%) in group II. On logistic regression analysis, prerenal AKI (OR 11.04, 95% CI 1.83-66.18, p < .01) and increase in MAP (OR 1.22, 95% CI 1.03-1.43, p = .02) were independent predictors of response. Increase in MAP by 8.5 mmHg with midodrine had best cut-off with AUROC of .76 for response.

CONCLUSION

In decompensated cirrhosis and ACLF patients with contraindications to NSBB, midodrine is useful in decreasing HVPG. Dose of midodrine should be titrated to increase MAP atleast by 8.5 mmHg.

Ascites affects the benefit of carvedilol on patients with liver cirrhosis and esophageal and gastric varices

Esophageal and gastric varices (EGV) bleeding is a dangerous side effect of liver cirrhosis. Ascites may affect the effectiveness of carvedilol in preventing EGV rebleeding. A retrospective analysis was done on patients with EGV bleeding who visited our gastroenterology department between January 1, 2015, and October 29, 2020, and were given carvedilol therapy again. Patients were classified based on whether they had ascites. The primary outcome was EGV rebleeding. A total of 286 patients were included, with a median follow-up of 24.0 (19.0-42.0) months, comprising those without ascites (N = 155) and those with ascites (N = 131). The mean age of the patients was 55.15 ± 12.44 years, and 177 (61.9%) of them were men. There were 162 (56.6%) Child-Pugh A grades. The etiology of cirrhosis included 135 (47.2%) cases of hepatitis B. After carvedilol therapy, the patient's portal vein diameter (DPV) was widened (p < 0.05), velocity of portal vein (VPV) was slowed (p = 0.001). During the 1-year follow-up, patients with ascites had a substantially higher rebleeding rate than patients without ascites, with 24 (18.3%) versus 13 (8.4%), respectively (p = 0.013). On univariate analysis, ascites was a risk factor for rebleeding (p = 0.015). The multivariate analysis remained significant after adjusting for age, gender, etiology of cirrhosis, and previous endoscopic treatment, with OR of 2.37 (95% CI: 1.12-5.04; p = 0.025). Ascites was a risk factor for EGV rebleeding in patients undergoing carvedilol therapy. After carvedilol therapy, the patient's DPV was widened and VPV was slowed.

Implication of Hypotension in the Pathogenesis of Cognitive Impairment and Brain Injury in Chronic Liver Disease

The incidence of chronic liver disease is on the rise. One of the primary causes of hospital admissions for patients with cirrhosis is hepatic encephalopathy (HE), a debilitating neurological complication. HE is defined as a reversible syndrome, yet there is growing evidence stating that, under certain conditions, HE is associated with permanent neuronal injury and irreversibility. The pathophysiology of HE primarily implicates a strong role for hyperammonemia, but it is believed other pathogenic factors are involved. The fibrotic scarring of the liver during the progression of chronic liver disease (cirrhosis) consequently leads to increased hepatic resistance and circulatory anomalies characterized by portal hypertension, hyperdynamic circulatory state and systemic hypotension. The possible repercussions of these circulatory anomalies on brain perfusion, including impaired cerebral blood flow (CBF) autoregulation, could be implicated in the development of HE and/or permanent brain injury. Furthermore, hypotensive insults incurring during gastrointestinal bleed, infection, or liver transplantation may also trigger or exacerbate brain dysfunction and cell damage. This review will focus on the role of hypotension in the onset of HE as well as in the occurrence of neuronal cell loss in cirrhosis.

Management of liver disease and portal hypertension in common variable immunodeficiency (CVID)

Patients with common variable immunodeficiency (CVID) frequently develop liver disease and associated complications, which represent an increasingly prevalent unmet medical need. The main hepatic manifestation of CVID is nodular regenerative hyperplasia (NRH), resulting in non-cirrhotic portal hypertension (NCPH). Liver disease is often underdiagnosed, leading to poor outcomes and decreased survival. The increasing numbers of patients with CVID who are diagnosed late with progressive liver disease underscores the importance of appropriate clinical management and treatment of liver complications. At the same time, specific guidelines for the clinical management of CVID-related liver disease are still lacking. Here, we review the epidemiology of CVID-related liver disease, reveal new insights into NRH and NCPH biology and highlight recently uncovered opportunities for NCPH diagnostics in CVID. Finally, we focus on current management of liver disease, portal hypertension and its complications - the key challenge in patients with CVID. Specifically, we review recent data regarding the role of transjugular intrahepatic portosystemic shunt and liver transplantation in clinical management. The role for anticoagulants and immunosuppressants targeting the pathogenesis of NRH will also be discussed. We propose an updated algorithm for the diagnostic work-up and treatment of NCPH in CVID. Finally, we consider future needs and therapeutic opportunities for CVID-related liver disease.

The Efficacy of Carvedilol in Comparison to Propranolol in Reducing the Hepatic Venous Pressure Gradient and Decreasing the Risk of Variceal Bleeding in Adult Cirrhotic Patients: A Systematic Review

The most common cause of portal hypertension is liver cirrhosis. Portal hypertension causes many complications in cirrhotic patients; a significant complication is the formation of varices and the subsequent life-threatening variceal bleeding due to elevated portal venous pressures. Hepatic venous pressure gradient (HVPG) is the gold standard for measuring portal hypertension and guides management. Pharmacological treatments lower the HVPG, preventing the progression of varices and subsequent variceal bleeding. The pharmacological treatments frequently used in primary and secondary prophylaxis of a variceal bleed are nonselective beta (β)-adrenergic blockers. Propranolol was the first nonselective β-adrenergic blocker used for lowering HVPG and has been well studied. However, in the past decade, clinical trials have shown that carvedilol has been more effective. This study aims to establish whether carvedilol is more effective than propranolol in reducing the hepatic venous pressure gradient and decreasing the risk of variceal bleeding in adult cirrhotic patients. A systematic review has been conducted to gather relevant clinical trials comparing drugs and their effects on HVPG. Four databases: PubMed (Medical Literature Analysis and Retrieval System Online (MEDLINE)), Google Scholar, the Cochrane Library, and ScienceDirect, were analyzed, and records from January 1, 1999, to January 1, 2023, were chosen. There were a total of 1,235 potentially eligible records across the four databases. Using the eligibility criteria for this systematic review, seven studies of 533 patients were included. Across all seven clinical trials, it was found that carvedilol reduced HVPG more than propranolol and decreased the risk of variceal bleeding in adult cirrhotic patients.

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.

Clinical Applications of 4D Flow MRI in the Portal Venous System

Evaluation of the hemodynamics in the portal venous system plays an essential role in many hepatic pathologies. Changes in portal flow and vessel morphology are often indicative of disease.Routinely used imaging modalities, such as CT, ultrasound, invasive angiography, and MRI, often focus on either hemodynamics or anatomical imaging. In contrast, 4D flow MRI facilitiates a more comprehensive understanding of pathophysiological mechanisms by simultaneously and noninvasively acquiring time-resolved flow and anatomical information in a 3D imaging volume.Though promising, 4D flow MRI in the portal venous system is especially challenging due to small vessel calibers, slow flow velocities, and breathing motion. In this review article, we will discuss how to account for these challenges when planning and conducting 4D flow MRI acquisitions in the upper abdomen. We will address patient preparation, sequence acquisition, postprocessing, quality control, and analysis of 4D flow data.In the second part of this article, we will review potential clinical applications of 4D flow MRI in the portal venous system. The most promising area for clinical utilization is the diagnosis and grading of liver cirrhosis and its complications. Relevant parameters acquired by 4D flow MRI include the detection of reduced or reversed flow in the portal venous system, characterization of portosystemic collaterals, and impaired response to a meal challenge. In patients with cirrhosis, 4D flow MRI has the potential to address the major unmet need of noninvasive detection of gastroesophageal varices at high risk for bleeding. This could replace many unnecessary, purely diagnostic, and invasive esophagogastroduodenoscopy procedures, thereby improving patient compliance with follow-up. Moreover, 4D flow MRI offers unique insights and added value for surgical planning and follow-up of multiple hepatic interventions, including transjugular intrahepatic portosystemic shunts, liver transplantation, and hepatic disease in children. Lastly, we will discuss the path to clinical implementation and remaining challenges.

CYP2D6 gene polymorphic markers role in determining the optimal treatment tactics for portal hypertension in patients with liver cirrhosis

Aim. To study the polymorphic markers CYP2D6*4 (G1846A, rs3892097), CYP2D6*6 (T1707del, rs5030655), CYP2D6*10 (C100T, rs1065852), CYP2D6*41 (G2988A, rs28371725) and CYP2D6*3 (A2549del, rs4986774) role in treatment optimization of portal hypertension with propranolol in patients with liver cirrhosis (LC). Materials and methods. The study included 60 patients with LC who received propranolol therapy at a daily dose of 30 mg for 14 days. The efficacy of treatment was assessed by ultrasonography measuring the linear blood flow velocity of portal vein. Genotyping of CYP2D6*4, CYP2D6*6, CYP2D6*10, CYP2D6*41 and CYP2D6*3 was carried out by real-time polymerase chain reaction. Evaluation of the CYP2D6 activity was carried out by determining the ratio of pinoline and its metabolite concentration in morning urine using high performance liquid chromatography with mass spectrometry. Results. Positive hemodynamics in the form of any increase in the mean linear blood flow velocity of the portal vein compared to baseline was observed in 41 patients. Portal vein mean linear blood flow rate increased from 10.43.9 to 14.74.3 cm/s (p0.001). Of these, 29 patients showed an increase in this indicator by 20% from the initial one with a dynamic of 5.5 cm/s (p0.001). The regression analysis constructed by us revealed the presence of a statistically significant effect of the CYP2D6 gene polymorphic marker G1846A carriage on the propranolol therapeutic effect (p0.05). There was no statistically significant effect of polymorphic markers T1707del, C100T, G2988A, and A2549del of the CYP2D6 gene (p0.05). No convincing reliable dependence of CYP2D6 activity on the severity of LC was revealed (p0.05). Conclusion. An association was found between CYP2D6 gene polymorphic marker G1846A carriage and the hemodynamic effect of propranolol in patients with LC of the Russian population. There is a more significant positive dynamics of manifestations of portal hypertension on the background of propranolol therapy in carriers of the homozygous GG CYP2D6*4 genotype, in contrast to patients with the heterozygous GA genotype. Based on the results of the study, an algorithm has been developed for personalizing the treatment of patients with LC with nonselective b-adrenergic blockers using the method of CYP2D6 genotyping. Carriage of polymorphic markers T1707del, C100T, G2988A and A2549del gene CYP2D6 does not affect the effectiveness of propranolol therapy in patients with LC.

Adherence to Non-Selective Beta Blockers for Prevention of Variceal Bleeding in Cirrhotic Patients

BACKGROUND AND AIM

Long-term use of non-selective beta blockers (NSBBs) is essential for the prevention of esophageal variceal bleeding in liver cirrhosis but may impair the patient's adherence. The present study aimed to investigate the adherence to NSBBs to prevent variceal bleeding in cirrhotic patients.

METHODS

All patients who had an indication of NSBBs for the prophylaxis of variceal bleeding between February 2018 and June 2019 were screened. Clinical pharmacists gave pre-medication education and recorded the adherence to NSBBs during the patients' hospitalizations. Factors associated with poor adherence were evaluated by univariate logistic regression analysis. Odds ratios (OR) with 95% confidence intervals (CI) were calculated. The relationship between poor adherence during follow-up and variceal bleeding after discharge was also evaluated.

RESULTS

Overall, 108 patients were screened, of whom 12 were intolerant to NSBBs. Among the 96 remaining patients who could take NSBBs, the average change of heart rate after NSBBs was -10.49 b.p.m. Twenty-two (22.9%) patients had poor adherence to NSBBs due to their refusal to take NSBBs (n = 2), complete forgetfulness to take NSBBs (n = 10), and refusal or forgetfulness to monitor heart rate (n = 10). Univariate logistic regression analysis demonstrated that only older age was significantly associated with poor adherence (OR: 1.065, 95% CI: 1.019-1.114, P = 0.005). Patients with poor adherence during follow-up were more likely to develop variceal bleeding after discharge.

CONCLUSION

A significant proportion of cirrhotic patients had poor adherence to NSBBs during their hospitalizations. Further studies should explore how to improve the patient's adherence to NSBBs.

Splenectomy with Portoazygous Disconnection for Correction of Systemic Hemodynamic Disorders in Hepatic Cirrhosis Patients with Portal Hypertension: A Prospective Single-Center Cohort Study

OBJECTIVE

To investigate the effect of splenectomy for correction of systemic hemodynamic disorders in hepatic cirrhosis patients with portal hypertension.

METHODS

Hepatic cirrhosis patients with portal hypertension were enrolled from April 2015 to July 2018. Systemic hemodynamic parameters (heart rate, mean arterial pressure (MAP), cardiac output, and total peripheral vascular resistance (TPR)) were prospectively measured at baseline and 1 week, 1, 3, and 6 months, and 1, 2, and 3 years postoperatively. Paired analysis was conducted.

RESULTS

Sixty-nine patients were eligible, and 55 (79.7%) cases had a history of upper gastrointestinal bleeding. Child-Pugh classification was grade A in 41 (59.4%) cases, grade B in 26 (37.7%) cases, and grade C in 2 (2.9%) cases. The heart rate was significantly higher at 1 week postoperatively versus the baseline (P < 0.001). Meanwhile, the heart rate was significantly lower from 3 months to 2 years postoperatively versus the baseline (P < 0.05). The MAP was significantly higher at 6 months to 2 years postoperatively versus the baseline (P < 0.05). At 1 month postoperatively and 6 months to 2 years, the cardiac output was significantly lower versus the baseline (P < 0.05). At 1 month postoperatively and 6 months to 2 years, the TPR was significantly higher versus the baseline (P < 0.05).

CONCLUSION

Splenectomy corrects systemic hemodynamic disorder in hepatic cirrhosis patients with portal hypertension, and the effect is rapid and durable.

Primary prevention of bleeding from esophageal varices in patients with liver cirrhosis: An update and review of the literature

All patients with liver cirrhosis and portal hypertension should be stratified by risk groups to individualize different therapeutic strategies to increase the effectiveness of treatment. In this regard, the development of primary prophylaxis of variceal bleeding and its management according to the severity of portal hypertension may be promising. This paper is to describe the modern principles of primary prophylaxis of esophageal variceal bleeding in patients with liver cirrhosis. The PubMed and EMbase databases, Web of Science, Google Scholar, and the Cochrane Database of Systematic Reviews were used to search for relevant publications from 1999 to 2019. The results suggested that depending on the severity of portal hypertension, patients with cirrhosis should be divided into those who need preprimary prophylaxis, which aims to prevent the formation of esophageal varices, and those who require measures that aim to prevent esophageal variceal bleeding. In subclinical portal hypertension, therapy should be etiological and pathogenetic. Cirrhosis with clinically significant portal hypertension should receive nonselective β-blockers if they have small esophageal varices and risk factors for variceal bleeding. Nonselective β-blockers are the first-line drugs for the primary prevention of bleeding from medium to large-sized esophageal varices. Endoscopic band ligation is indicated for the patients who are intolerant to nonselective β-blockers or in the case of contraindications to pharmacological therapy. In summary, the stratification of cirrhotic patients by the severity of portal hypertension and an individual approach to the choice of treatment may increase the effectiveness of therapy as well as improve survival rate of these patients.

Cirrhotic portal hypertension: From pathophysiology to novel therapeutics

Portal hypertension and bleeding from gastroesophageal varices is the major cause of morbidity and mortality in patients with cirrhosis. Portal hypertension is initiated by increased intrahepatic vascular resistance and a hyperdynamic circulatory state. The latter is characterized by a high cardiac output, increased total blood volume and splanchnic vasodilatation, resulting in increased mesenteric blood flow. Pharmacological manipulation of cirrhotic portal hypertension targets both the splanchnic and hepatic vascular beds. Drugs such as angiotensin converting enzyme inhibitors and angiotensin II type receptor 1 blockers, which target the components of the classical renin angiotensin system (RAS), are expected to reduce intrahepatic vascular tone by reducing extracellular matrix deposition and vasoactivity of contractile cells and thereby improve portal hypertension. However, these drugs have been shown to produce significant off-target effects such as systemic hypotension and renal failure. Therefore, the current pharmacological mainstay in clinical practice to prevent variceal bleeding and improving patient survival by reducing portal pressure is non-selective -blockers (NSBBs). These NSBBs work by reducing cardiac output and splanchnic vasodilatation but most patients do not achieve an optimal therapeutic response and a significant proportion of patients are unable to tolerate these drugs. Although statins, used alone or in combination with NSBBs, have been shown to improve portal pressure and overall mortality in cirrhotic patients, further randomized clinical trials are warranted involving larger patient populations with clear clinical end points. On the other hand, recent findings from studies that have investigated the potential use of the blockers of the components of the alternate RAS provided compelling evidence that could lead to the development of drugs targeting the splanchnic vascular bed to inhibit splanchnic vasodilatation in portal hypertension. This review outlines the mechanisms related to the pathogenesis of portal hypertension and attempts to provide an update on currently available therapeutic approaches in the management of portal hypertension with special emphasis on how the alternate RAS could be manipulated in our search for development of safe, specific and effective novel therapies to treat portal hypertension in cirrhosis.

Pathophysiological-based treatments of complications of cirrhosis

Detailed knowledge and understanding of the pathophysiological mechanisms and changes in hepatic and splanchnic function leading to the development of haemodynamic changes and portal hypertension in patients with cirrhosis are essential since it guides the search for targets to ameliorate liver-related abnormalities. Recent research has focused on the gut-liver axis, changes in intestinal permeability, translocation of bacterial products, and inflammation as important drivers of haemodynamic alterations and thereby targets for treatment. Additionally, treatment strategies should focus on microbiotic modulation, antiangiogenics, anti-inflammatory strategies, and modulation of bile acid metabolism. This paper aims to review contemporary pathophysiological-based treatment principles of the major complications of cirrhosis and portal hypertension and future targets for treatment.

Low dose of propranolol treatment is associated with better survival in cirrhotic patients with hepatic encephalopathy

OBJECTIVE

The use of nonselective beta blockers in cirrhotic patients experiencing complications is controversial. We aimed to investigate the association between propranolol treatment and outcomes for cirrhotic patients with hepatic encephalopathy.

METHODS

Using data from the Taiwan National Health Insurance Research Database, we identified 4754 cirrhotic patients newly diagnosed with hepatic encephalopathy between 2001 and 2010. Among them, 519 patients received propranolol treatment and the other 519 patients without exposure to propranolol were enrolled into our study, both of which were matched by sex, age, and propensity score. The Kaplan-Meier method and time-dependent-modified Cox proportional hazards models were employed for survival and multivariate-stratified analyses.

RESULTS

The median overall survival (OS) was significantly longer in the propranolol-treated cohort than in the untreated cohort (3.46 versus 1.88 years, P < 0.001). A dose-dependent increase in survival was observed (median OS: 4.49, 3.29, and 2.46 years in patients treated with propranolol more than 30 , 20-30 , and less than 20 mg/day, respectively [P < 0.001, P = 0.001, and P = 0.079 versus the untreated group]). In addition to reduce the risk of mortality (adjusted hazard ratio, 0.58; P < 0.001), propranolol also diminished the risk of sepsis-related death (adjusted hazard ratio, 0.31; P = 0.006) according to the multivariate analysis. However, the risk of circulatory or hepatic failure was nonsignificantly altered by propranolol treatment.

CONCLUSION

Low dose of propranolol treatment was associated with a better OS in cirrhotic patients with hepatic encephalopathy and its effects were dose dependent.

The efficacy comparison of carvedilol plus endoscopic variceal ligation and traditional, nonselective β-blockers plus endoscopic variceal ligation in cirrhosis patients for the prevention of variceal rebleeding: a meta-analysis

BACKGROUND

Currently, the first-line treatment regimen in cirrhotic patients for variceal rebleeding prophylaxis is still under debate.

AIM

This study aimed to compare the efficacy and safety of carvedilol plus endoscopic variceal ligation (EVL) and traditional, nonselective β-blockers (NSBBs) plus EVL in preventing variceal rebleeding.

PATIENTS AND METHODS

Studies were found in PubMed, the Cochrane Library, China National Knowledge Infrastructure, Wanfang Med Online, and Wiper Database. Review Manager 5.3 was used to analyze the relevant data.

RESULTS

Nine trials including 802 patients were identified (402 for carvedilol and 400 for traditional NSBBs). Carvedilol was more efficacious than traditional NSBBs in decreasing the variceal rebleeding rate [odds ratio (OR): 0.53; 95% confidence interval (CI): 0.38-0.75; P = 0.0003], lowering the degree of esophageal varices (OR: 4.40; 95% CI: 2.64-7.34; P < 0.00001), decreasing the mean arterial pressure (standard mean difference: - 0.35; 95% CI: - 0.56 to - 0.14; P = 0.0009), reducing the total adverse events occurrence (OR: 0.39; 95% CI: 0.28-0.53; P < 0.00001), and decreasing drug-related adverse events (OR: 0.37; 95% CI: 0.25-0.56; P < 0.00001). No difference was noted between carvedilol and traditional NSBBs with respect to mortality and heart rate (OR: 0.72; 95% CI: 0.43; 1.22; P = 0.22 and standard mean difference: 0.09; 95% CI: - 0.12 to 0.30; P = 0.40, respectively).

CONCLUSION

Combined with variceal ligation, carvedilol was more effective and safer than traditional NSBBs in the prevention of rebleeding in cirrhotic patients.

Carvedilol attenuates carbon tetrachloride-induced liver fibrosis and hepatic sinusoidal capillarization in mice

Aim

To investigate the effect of carvedilol on liver fibrosis and hepatic sinusoidal capillarization in mice with carbon tetrachloride (CCl₄)-induced fibrosis.

Methods

A liver fibrosis mouse model was induced by intraperitoneal CCl₄ injection for 8 weeks. The mice were divided into five experimental groups: the normal group, the oil group, the CCl₄ group, the CCl₄+carvedilol (5 mg/kg/d) group, and the CCl₄+carvedilol (10 mg/kg/d) group. The extent of liver fibrosis was evaluated by histopathological staining, and the changes in fenestrations of hepatic sinus endothelial cells were observed by scanning electron microscope (SEM). The expression of α-smooth muscle actin (α-SMA) and vascular endothelial markers was detected by immunohistochemistry and Western blot assays. The effect of carvedilol on cell apoptosis was studied via Terminal deoxynucleotidyl Transferase Mediated dUTP Nick End Labeling (TUNEL) assay, and the serum levels of matrix metalloproteinase-8 (MMP-8), vascular endothelial growth factor (VEGF), and angiopoietin-2 were detected through a Luminex assay.

Results

Liver fibrosis in CCl₄-treated mice was attenuated by reduced accumulation of collagen and the reaction of inflammation with carvedilol treatment. Carvedilol reduced the activation of hepatic stellate cells (HSCs) and increased the number of apoptotic cells. The expression of α-SMA, CD31, CD34 and VWF (von Willebrand factor) was significantly decreased after carvedilol treatment. In addition, the number of fenestrae in the hepatic sinusoid showed notable differences between the groups, and the serum levels of MMP-8, VEGF and angiopoietin-2 were increased in the mice with liver fibrosis and reduced by carvedilol treatment.

Conclusion

The study demonstrated that carvedilol could prevent further development of liver fibrosis and hepatic sinusoidal capillarization in mice with CCl₄-induced fibrosis.

Carvedilol improves liver cirrhosis in rats by inhibiting hepatic stellate cell activation, proliferation, invasion and collagen synthesis

Portal hypertension (PHT) is one of the most severe consequences of liver cirrhosis. Carvedilol is a first-line pharmacological treatment of PHT. However, the antifibrogenic effects of carvedilol on liver cirrhosis and the intrinsic mechanisms underlying these effects have not been thoroughly investigated. The present study aimed to investigate the antifibrogenic effects of carvedilol on liver cirrhosis in vivo and in vitro. Liver cirrhosis was induced in rats by carbon tetrachloride (CCl₄) administration for 9 weeks; carvedilol was administered simultaneously in the experimental group. Blood samples were collected for serum biochemistry. Liver tissues were used for fibrosis evaluation, histological examination, immunohistochemistry and western blot analysis. The human hepatic stellate cell (HSC) line LX-2 was used for in vitro studies. The effects of carvedilol on LX-2 cell proliferation and invasion were evaluated by Cell Counting Kit-8 assay and Transwell invasion assays, respectively. The effect of carvedilol on transforming growth factor β1 (TGFβ1)-induced collagen synthesis in LX-2 cells and the molecular mechanisms were examined by western blot analysis. The results demonstrated that carvedilol improved CCl₄-induced structural distortion and fibrosis in the liver. Carvedilol inhibited HSC activation, proliferation and invasion. Carvedilol inhibited HSC collagen synthesis through the TGFβ1/SMAD pathway. In conclusion, carvedilol may alleviate liver cirrhosis in rats by inhibiting HSC activation, proliferation, invasion and collagen synthesis. Carvedilol may be a potential treatment of early-stage liver cirrhosis.

Bioactivity Profile of the Diterpene Isosteviol and its Derivatives

Steviosides, rebaudiosides and their analogues constitute a major class of naturally occurring biologically active diterpene compounds. The wide spectrum of pharmacological activity of this group of compounds has developed an interest among medicinal chemists to synthesize, purify, and analyze more selective and potent isosteviol derivatives. It has potential biological applications and improves the field of medicinal chemistry by designing novel drugs with the ability to cope against resistance developing diseases. The outstanding advancement in the design and synthesis of isosteviol and its derivative has proved its effectiveness and importance in the field of medicinal chemical research. The present review is an effort to integrate recently developed novel drugs syntheses from isosteviol and potentially active pharmacological importance of the isosteviol derivatives covering the recent advances.

Carvedilol Ameliorates Intrahepatic Angiogenesis, Sinusoidal Remodeling and Portal Pressure in Cirrhotic Rats

BACKGROUND Carvedilol is the first-line drug for the primary prophylaxis of variceal bleeding due to portal hypertension (PHT) in liver cirrhosis. This study aimed to investigate the effects of carvedilol on intrahepatic angiogenesis and sinusoidal remodeling in cirrhotic rats and explore the underlying mechanisms of carvedilol in PHT. MATERIAL AND METHODS For in vivo experiments, carbon tetrachloride was used to induce liver cirrhosis in rats, and carvedilol was simultaneously administered by gavage. The portal pressure was measured in rats, and liver tissues were examined by immunohistochemistry. Sinusoidal remodeling was observed by transmission electron microscopy. For in vitro experiments, the effects of carvedilol on fibronectin (FN) synthesis in human umbilical vein endothelial cells (HUVECs) were explored by quantitative real-time polymerase chain reaction and western blot analysis. RESULTS Portal vein pressure measurements showed that carvedilol reduced portal pressure in cirrhotic rats. Immunohistochemistry assays indicated that carvedilol ameliorated intrahepatic angiogenesis. Transmission electron microscopy examination demonstrated that carvedilol improved sinusoidal remodeling. In the in vitro experiments, carvedilol suppressed transforming growth factor β1 (TGFβ1)-induced FN synthesis in HUVECs by inhibition of the TGFβ1/Smads pathway. CONCLUSIONS Carvedilol ameliorated intrahepatic angiogenesis, sinusoidal remodeling and portal pressure in cirrhotic rats. Carvedilol improved sinusoidal remodeling by suppressing FN synthesis in endothelial cells. Carvedilol has potential utility for treating early-stage liver cirrhosis.

Insuffisance rénale aiguë et syndrome hépatorénal chez le patient cirrhotique : actualités diagnostiques et thérapeutiques

La survenue d’une insuffisance rénale aiguë ou AKI (acute kidney injury) chez un patient cirrhotique est un événement de mauvais pronostic. Parmi les AKI, une entité spécifique au patient cirrhotique décompensé est le syndrome hépatorénal (SHR) dont la définition ainsi que la stratégie thérapeutique ont été réactualisées récemment. La prise en charge de l’AKI hors SHR n’est pas spécifique au patient cirrhotique. La prise en charge du SHR repose sur l’association d’un traitement vasoconstricteur intraveineux et d’un remplissage vasculaire par sérum d’albumine concentrée. Cette association thérapeutique permet d’améliorer le pronostic des patients répondeurs. En contexte d’AKI chez le patient cirrhotique, l’épuration extrarénale (EER) peut être envisagée en cas de non-réponse au traitement médical. La décision de débuter une prise en charge invasive avec EER dépend principalement de la présence d’un projet de transplantation hépatique (TH). En l’absence d’un tel projet, cette décision devrait être prise après évaluation du pronostic à court terme du patient dépendant du nombre de défaillance d’organes et d’autres variables telles que l’âge ou les comorbidités. L’objectif de cette mise au point est de discuter des récentes modifications de la définition de l’AKI et en particulier du SHR chez les patients cirrhotiques, de détailler la prise en charge spécifique du SHR et d’évoquer les processus décisionnels menant ou non à l’instauration d’une EER chez les patients non répondeurs au traitement médical en milieu réanimatoire.

Angiotensin II receptor blockers for the treatment of portal hypertension in patients with liver cirrhosis: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Randomized controlled trials (RCTs) showed inconsistent results regarding the efficacy of angiotensin II receptor blockers (ARBs) on portal pressure as indicated by hepatic venous pressure gradient (HVPG).

METHODS

A meta-analysis of RCTs was performed to evaluate the influence of ARBs treatment on HVPG. PubMed, Embase, and Cochrane's Library were searched for relevant RCTs. A fixed or a randomized effect model was used to pool the results according the heterogeneity. Subgroup analyses were performed to explore the source of heterogeneity.

RESULTS

Eleven RCTs with 394 patients were included. ARBs treatment did not significantly change HVPG as compared with controls (weighted mean difference [WMD] = -0.63, 95% confidence interval [CI] -1.73 to 0.47 mmHg, p = 0.26; I2 = 60%). These results were consistent in studies comparing ARBs with propranolol (WMD = -0.40, 95% CI -2.22 to 1.41 mmHg, p = 0.67; I2 = 68%), and those comparing ARBs with non-active controls including placebo or no treatment (WMD = -1.05, 95% CI -2.33 to 0.24 mmHg, p = 0.13; I2 = 44%). These results were also not affected by the individual ARBs used. Moreover, treatment of ARBs significantly reduced mean arterial blood pressure (WMD = -6.12, 95% CI -9.69 to -2.55 mmHg, p = 0.008; I2 = 53%), and the risk of symptomatic hypotension was increased (RR = 4.13, 95% CI 0.94 to 18.18, p = 0.06; I2 = 0%).

CONCLUSIONS

ARBs did not reduce portal pressure in patients with cirrhosis; moreover, the risk of symptomatic hypotension may increase.

The effects of propranolol on heart rate variability and quantitative, mechanistic, pain profiling: a randomized placebo-controlled crossover study

Background and aims

The autonomic nervous system (ANS) is capable of modulating pain. Aberrations in heart rate variability (HRV), reflective of ANS activity, are associated with experimental pain sensitivity, chronic pain, and more recently, pain modulatory mechanisms but the underlying mechanisms are still unclear. HRV is lowered during experimental pain as well as in chronic pain conditions and HRV can be increased by propranolol, which is a non-selective β-blocker. Sensitization of central pain pathways have been observed in several chronic pain conditions and human mechanistic pain biomarkers for these central pain pathways include temporal summation of pain (TSP) and conditioned pain modulation (CPM). The current study aimed to investigate the effect of the β-blocker propranolol, and subsequently assessing the response to standardized, quantitative, mechanistic pain biomarkers.

Methods

In this placebo-controlled, double-blinded, randomized crossover study, 25 healthy male volunteers (mean age 25.6 years) were randomized to receive 40 mg propranolol and 40 mg placebo. Heart rate, blood pressure, and HRV were assessed before and during experimental pain tests. Cuff pressure pain stimulation was used for assessment of pain detection (cPDTs) and pain tolerance (cPTTs) thresholds, TSP, and CPM. Offset analgesia (OA) was assessed using heat stimulation.

Results

Propranolol significantly reduced heart rate (p<0.001), blood pressure (p<0.02) and increased HRV (p<0.01) compared with placebo. No significant differences were found comparing cPDT (p>0.70), cPTT (p>0.93), TSP (p>0.70), OA-effect (p>0.87) or CPM (p>0.65) between propranolol and placebo.

Conclusions

The current study demonstrated that propranolol increased HRV, but did not affect pressure pain sensitivity or any pain facilitatory or modulatory outcomes.

Implications

Analgesic effects of propranolol have been reported in clinical pain populations and the results from the current study could indicate that increased HRV from propranolol is not associated with peripheral and central pain pathways in healthy male subjects.

Rifaximin and Propranolol Combination Therapy Is More Effective than Propranolol Monotherapy for the Reduction of Portal Pressure: An Open Randomized Controlled Pilot Study

Background/Aims

Non-selective beta blockers (NSBBs) are currently the only accepted regimen for preventing portal hypertension (PHT)-related complications. However, the effect of NSBBs is insufficient in many cases. Bacterial translocation (BT) is one of the aggravating factors of PHT in cirrhosis; therefore, selective intestinal decontamination by rifaximin is a possible therapeutic option for improving PHT. We investigated whether the addition of rifaximin to propranolol therapy can improve hepatic venous pressure gradient (HVPG) response.

Methods

Sixty-four cirrhosis patients were randomly assigned to propranolol monotherapy (n=48) versus rifaximin and propranolol combination therapy (n=16). Baseline and post-treatment HVPG values, BT-related markers (lipopolysaccharide [LPS], LPS-binding protein [LBP], interleukin-6 [IL-6], and tumor necrosis factor α [TNF-α]), serological data, and adverse event data were collected. HVPG response rate was the primary endpoint.

Results

Combination therapy was associated with better HVPG response rates than monotherapy (56.2% vs 87.5%, p=0.034). In combination therapy, posttreatment BT-related markers were significantly decreased (LPS, p=0.005; LBP, p=0.005; IL-6, p=0.005; TNF-α, p=0.047).

Conclusions

Rifaximin combination therapy showed an additive effect in improving PHT compared to propranolol monotherapy. These pilot data suggest that the addition of rifaximin to NSBBs could be a good therapeutic option for overcoming the limited effectiveness of NSBBs.

Role of the renin-angiotensin system in hepatic fibrosis and portal hypertension

The renin-angiotensin system (RAS) is an important regulator of cirrhosis and portal hypertension. As hepatic fibrosis progresses, levels of the RAS components angiotensin (Ang) II, Ang-(1-7), angiotensin-converting enzyme (ACE), and Ang II type 1 receptor (AT1R) are increased. The primary effector Ang II regulates vasoconstriction, sodium homoeostasis, fibrosis, cell proliferation, and inflammation in various diseases, including liver cirrhosis, through the ACE/Ang II/AT1R axis in the classical RAS. The ACE2/Ang-(1-7)/Mas receptor and ACE2/Ang-(1-9)/AT2R axes make up the alternative RAS and promote vasodilation, antigrowth, proapoptotic, and anti-inflammatory effects; thus, countering the effects of the classical RAS axis to reduce hepatic fibrogenesis and portal hypertension. Patients with portal hypertension have been treated with RAS antagonists such as ACE inhibitors, Ang receptor blockers, and aldosterone antagonists, with very promising hemodynamic results. In this review, we examine the RAS, its roles in hepatic fibrosis and portal hypertension, and current therapeutic approaches based on the use of RAS antagonists in patients with portal hypertension.

Betablockers do not increase efficacy of band ligation in primary prophylaxis but they improve survival in secondary prophylaxis of variceal bleeding

BACKGROUND

Endoscopic band ligation (EBL) is used for primary (PP) and secondary prophylaxis (SP) of variceal bleeding. Current guidelines recommend combined use of non-selective beta-blockers (NSBBs) and EBL for SP, while in PP either NSBB or EBL should be used.

AIM

To assess (re-)bleeding rates and mortality in cirrhotic patients receiving EBL for PP or SP for variceal bleeding.

METHODS

(Re-)bleeding rates and mortality were retrospectively assessed with and without concomitant NSBB therapy after first EBL in PP and SP.

RESULTS

Seven hundred and sixty-six patients with oesophageal varices underwent EBL from 01/2005 to 06/2015. Among the 284 patients undergoing EBL for PP, n = 101 (35.6%) received EBL only, while n = 180 (63.4%) received EBL + NSBBs. In 482 patients on SP, n = 163 (33.8%) received EBL only, while n = 299 (62%) received EBL + NSBBs. In PP, concomitant NSBB therapy neither decreased bleeding rates (log-rank: P = 0.353) nor mortality (log-rank: P = 0.497) as compared to EBL alone. In SP, similar re-bleeding rates were documented in EBL + NSBB vs EBL alone (log-rank: P = 0.247). However, EBL + NSBB resulted in a significantly lower mortality rate (log-rank: P<0.001). A decreased risk of death with EBL + NSBB in SP (hazard ratio, HR: 0.50; P<0.001) but not of rebleeding, transplantation or further decompensation was confirmed by competing risk analysis. Overall NSBB intake reduced 6-months mortality (HR: 0.53, P = 0.008) in SP, which was most pronounced in patients without severe/refractory ascites (HR: 0.37; P = 0.001) but not observed in patients with severe/refractory ascites (HR: 0.80; P = 0.567).

CONCLUSIONS

EBL alone seems sufficient for PP of variceal bleeding. In SP, the addition of NSBB to EBL was associated with an improved survival within the first 6 months after EBL.

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.

The 35-year odyssey of beta blockers in cirrhosis: any gender difference in sight?

Cirrhosis is the end-stage of chronic liver disease and leads to the development of portal hypertension and its complications such as esophagogastric varices. Non-selective beta blockers (NSBB) are the keystone for the treatment of portal hypertension since the 1980s and, over the decades, several studies have confirmed their beneficial effect on the prevention of variceal (re)bleeding. Pharmacological studies showed effects of gender, sex hormones, oral contraceptives, and pregnancy on cytochrome P450 (CYPs) enzymes that metabolise NSBB, suggesting that gender differences might exist in the effect of NSBB. In this review, we focused on the 35-year knowledge about the use of beta blockers in cirrhosis and potential gender differences. We specifically examined the role of NSBB in pre-primary, primary and secondary prophylaxis of variceal bleeding, compared two commonly used NSBB (i.e., Propranolol and Carvedilol), and present the current controversies about the window of treatment in advanced cirrhosis with a specific focus on gender differences in NSBB effects. NSBB are not currently recommended in pre-primary prophylaxis of varices mainly because of lack of proven efficacy. On the other hand, NSBB are strongly recommended in patient with cirrhosis as primary (as alternative to endoscopic band ligation, EBL) and secondary prophylaxis (in addition to EBL) of variceal bleeding. To date, no studies have focused specifically on the effect of gender on NSBB treatment. Data extrapolated from clinical studies show that gender was neither a risk factor for the development of varices nor associated with a different response to treatment in primary or secondary prophylaxis. According to the available guidelines, no different, gender-based treatment for portal hypertension is recommended.

Hemodynamic Response to Carvedilol is Maintained for Long Periods and Leads to Better Clinical Outcome in Cirrhosis: A Prospective Study

BACKGROUND

Non-selective beta-blockers (NSBBs), e.g. propranolol, are recommended for prophylaxis of variceal bleeding in cirrhosis. Carvedilol, a newer NSBB with additional anti-α1-adrenergic activity, is superior to propranolol in reducing portal pressure. Repeated HVPG measurements are required to identify responders to NSBB. We aimed to determine whether a single-time HVPG measurement, using acute-hemodynamic-response-testing, is sufficient to predict long-term response to carvedilol, and whether these responders have better clinical outcome.

METHODS

Consecutive patients with cirrhosis, aged 18-70 years, in whom NSBB was indicated for primary/secondary prophylaxis of variceal bleeding, and who underwent HVPG were included. Acute-hemodynamic-response was defined as a decrease in HVPG ≥10% from baseline or absolute HVPG value declining to <12 mm Hg, 1 h after 25 mg oral carvedilol. The aims of the study were to determine: the proportion of patients who achieved acute-hemodynamic-response to carvedilol; whether HVPG-response is maintained for 6 months; and clinical outcome of acute-responders to carvedilol therapy for 6 months.

RESULTS

The study included 69 patients (median age 51, males 93%). Alcohol was the most common etiology; 59% patients belonged to Child-Pugh class B. NSBB was indicated for primary prophylaxis in 36% and secondary prophylaxis in 64% patients. According to the response criteria, 67% patients were found to be acute-hemodynamic-responders. At 6 months, 92% patients were found to be still maintaining their hemodynamic response to carvedilol. Using intention-to-treat analysis, 76% patients maintained their response. These acute responders, on chronic treatment with carvedilol during the 6-month period, had lesser episodes of variceal bleeding, better ascites control, and improved MELD and CTP scores, than non-carvedilol treated non-responders. However, survival remained similar in both the groups.

CONCLUSIONS

A single-time HVPG measurement with acute-hemodynamic-response-testing is simple and reliable method for identifying patients who are more likely to respond to carvedilol therapy. The HVPG-response is maintained over a long period in majority of these patients and carvedilol therapy leads to better clinical outcome in these patients.

Indocyanine green retention test (ICG-r15) as a noninvasive predictor of portal hypertension in patients with different severity of cirrhosis

BACKGROUND AND AIMS

Portal hypertension is a severe consequence of chronic liver disease, responsible for the main clinical complications of cirrhosis. Measurement of the hepatic venous pressure gradient (HVPG) provides important clinical information, but the procedure is invasive and demands expert skills of the staff.In the present study, we aimed to investigate the relationship between the constant infusion indocyanine green (ICG) clearance, the calculated ICG retention test after 15 min (ICG-r15), and HVPG in patients with different severity of cirrhosis for validation of ICG-r15 as a noninvasive predictor of portal hypertension.

METHODS

A total of 325 patients were studied. During a hemodynamic investigation, the ICG clearance was determined using the constant infusion technique and ICG-r15 was calculated.

RESULTS

Assessment of the diagnostic performance of ICG clearance and ICG-r15 as predictors of HVPG above 10 mmHg was performed by receiver operating characteristic curve analyses.The ICG clearance and ICG-r15 performed well in all three Child classes, with the most significant results among Child class A patients [area under the receiver operating characteristic (AUROC)=0.832] and less significant results in Child class B (AUROC=0.7448) and Child class C patients (AUROC=0.7392). Only six out of 102 patients in Child class C had HVPG of less than 12 mmHg.

CONCLUSION

ICG-r15 can be used as an indirect assessment of significant portal hypertension in compensated cirrhotic patients. ICG-r15 may be suitable as a screening tool for the identification of patients for endoscopy and measurement of HVPG.Further validation of ICG-r15 together with other predictors of portal hypertension and its clinical use is encouraged.

Emerging therapies for portal hypertension in cirrhosis

INTRODUCTION

Counteracting splanchnic vasodilatation and increased portal-collateral blood flow has been the mainstay for the treatment of portal hypertension (PH) over the past three decades. However, there is still large room for improvement in the treatment of PH.

AREAS COVERED

The basic mechanism leading to portal hypertension is the increased hepatic vascular resistance to portal blood flow caused by liver structural abnormalities inherent to cirrhosis and increased hepatic vascular tone. Molecules modulating microvascular dysfunction which have undergone preclinical and clinical trials are summarized, potential drug development issues are addressed, and situations relevant to design of clinical trials are considered.

EXPERT OPINION

Experimental and clinical evidence indicates that molecules modulating liver microvascular dysfunction may allow for 30-40% reduction in portal pressure. Several agents could be utilized in the earlier stages of cirrhosis (antifibrotics, antiangiogenics, etiological therapies) may allow reduction of fibrosis and halt progression of PH. This 'nip at the bud' policy, by combining therapies with existing agents used in advanced phase of cirrhosis and novel agents which could be used in early phase of cirrhotic spectrum, which are likely to hit the market soon would be the future strategy for PH therapy.

[Aspects of pathogenetc pharmacotherapy for portal hypertension in liver cirrhosis]

The review of literature considers the principles of medical treatment for portal hypertension in liver cirrhosis, which are based on the current views of its development mechanisms. It describes both current pharmacotherapy methods for portal hypertension and drugs, the efficacy of which is being investigated.

Combined administration of propranolol + AG490 offers better effects on portal hypertensive rats with cirrhosis

BACKGROUND AND AIMS

AG490, the specific inhibitor of JAK2/STAT3 signaling, has been shown to decrease portal pressure, splanchnic hyperdynamic circulation and liver fibrosis in cirrhotic rats. Nonselective betablockers such as propranolol are the only drugs recommended in the treatment of portal hypertension. The aim of this study was to explore the combinative effect of treatment with propranolol and AG490 on portal hypertension.

METHODS

Rats induced by common bile duct ligation were treated with vehicle, AG490, propranolol, or AG490 + propranolol for 2 weeks. Hemodynamics parameters were assessed. Expressions of phospho-STAT3 protein and its down-regulated cytokines in splanchnic organs were detected by ELISA or western blot. Lipopolysaccharide binding protein (LBP) and IL-6 were assessed by ELISA or western blot. Characterization of liver and mesentery was performed by histological analyses.

RESULTS

Highly expressed phospho-STAT3 protein in cirrhotic rats could successfully be inhibited by AG490 or AG490 + propranolol treatments but not by propranolol alone. Both AG490 and propranolol significantly reduced portal pressure and hyperdynamic splanchnic circulation, and combination of AG490 and propranolol achieved an additive effect than with either drug alone. AG490, alone or in combination with propranolol, inhibited liver fibrosis, splenomegaly and splanchnic angiogenesis. Increased markers of bacterial translocation (LBP and IL6) were greatly reduced by propranolol but not by AG490.

CONCLUSIONS

The combination of propranolol and AG490 caused a greater improvement of portal hypertension and might therefore offer a potentially promising therapy in the portal hypertension treatment.

Non-selective beta-blockers in cirrhosis: Current concepts and controversies

Non-selective beta-blockers (NSBBs) have been at the forefront in the management of portal hypertension in liver cirrhosis for the last three decades, a trusty component in the armamentarium of the Hepatologist. The role of beta-blockers has been cemented for years in cardiac disease including angina, hypertension and in heart failure, however NSBBs with their non-selective effects on β1 and β2 receptors have led to them fondly being termed “the hepatologist’s aspirin”. NSBBs’ role in reduction of portal pressure in the setting of primary and secondary prophylaxis for variceal haemorrhage has been well established. NSBBs include propranolol, nadolol and carvedilol - with the latter having been shown to be effective in patients who often fail to demonstrate a haemodynamic response to propranolol. Recent observational studies however have served for the Hepatology community to question the beneficial role of NSBBs in portal hypertension, especially in advanced cases with refractory ascites. The deleterious effect in patients with refractory ascites in a few studies led to a U-turn in clinical practice, with some in the Hepatology community withdrawing their usage in patients with advanced cirrhosis. This also led to the “window hypothesis” suggesting there may be only be a finite time frame when NSBBs have a beneficial effect in portal hypertension. The window hypothesis proposed the window for the benefits of NSBBs is closed in early portal hypertension, opening as portal hypertension progresses with it closing in advanced liver disease. The window was proposed to close in conditions such as refractory ascites or spontaneous bacterial peritonitis when patients may not necessarily mount a compensatory haemodynamic response when on NSBBs. Some centres however have continued the practice of NSBBs in advanced cirrhosis with published data challenging the scepticisms of other groups who stop NSBBs. Thus the debate, like the window hypothesis has opened, with more questions to be answered about NSBB’s mechanism of action not only in reducing portal hypertension but also their effects on systemic haemodynamics and on the pro-inflammatory pathways often activated in cirrhosis especially in advanced disease. This article serves to review the role of NSBBs in the management of portal hypertension/cirrhosis and concentrate on current concepts and controversies in this field.

Cirrhotic Multiorgan Syndrome

Patients with cirrhosis and portal hypertension are at an increased risk of the development of circulatory dysfunction that may potentially result in multiple organ failure. Apart from the liver, this may involve the heart, lungs, kidneys, the immune system, the adrenal glands, and other organ systems. As the disease progresses, the circulation becomes hyperdynamic, and signs of cardiac, pulmonary, and renal dysfunction are observed, in addition to reduced survival. Infections and an altered cardiac function known as cirrhotic cardiomyopathy may be precipitators for the development of other complications such as hepatorenal syndrome. In patients with chronic organ dysfunction, various precipitating events may induce an acute-on-chronic renal failure and acute-on-chronic liver failure that negatively affect the prognosis. Future research on the pathophysiologic mechanisms of the complications and the precipitating factors is essential to understand the basics of the treatment of these challenging conditions. The aim of the present review is to focus on the development and precipitating factors of various organ failures in patients with decompensated cirrhosis.

Contemporary concepts of the medical therapy of portal hypertension under liver cirrhosis

Severe complications of liver cirrhosis are mostly related to portal hypertension. At the base of the pathogenesis of portal hypertension is the increase in hepatic vascular resistance to portal blood flow with subsequent development of hyperdynamic circulation, which, despite of the formation of collateral circulation, promotes progression of portal hypertension. An important role in its pathogenesis is played by the rearrangement of vascular bed and angiogenesis. As a result, strategic directions of the therapy of portal hypertension under liver cirrhosis include selectively decreasing hepatic vascular resistance with preserving or increasing portal blood flow, and correcting hyperdynamic circulation and pathological angiogenesis, while striving to reduce the hepatic venous pressure gradient to less than 12 mmHg or 20% of the baseline. Over the last years, substantial progress in understanding the pathophysiological mechanisms of hemodynamic disorders under liver cirrhosis has resulted in the development of new drugs for their correction. Although the majority of them have so far been investigated only in animal experiments, as well as at the molecular and cellular level, it might be expected that the introduction of the new methods in clinical practice will increase the efficacy of the conservative approach to the prophylaxis and treatment of portal hypertension complications. The purpose of the review is to describe the known methods of portal hypertension pharmacotherapy and discuss the drugs that may affect the basic pathogenetic mechanisms of its development.

Is it time to replace propranolol with carvedilol for portal hypertension?

Beta-adrenergic receptor antagonists (β-blockers) have been well established for use in portal hypertension for more than three decades. Different Non-selective β-blockers like propranolol, nadolol, timolol, atenolol, metoprolol and carvedilol have been in clinical practice in patients with cirrhosis. Carvedilol has proven 2-4 times more potent than propranolol as a beta-receptor blocker in trials conducted testing its efficacy for heart failure. Whether the same effect extends to its potency in the reduction of portal venous pressures is a topic of on-going debate. The aim of this review is to compare the hemodynamic and clinical effects of carvedilol with propranolol, and attempt assess whether carvedilol can be used instead of propranolol in patients with cirrhosis. Carvedilol is a promising agent among the beta blockers of recent time that has shown significant effects in portal hypertension hemodynamics. It has also demonstrated an effective profile in its clinical application specifically for the prevention of variceal bleeding. Carvedilol has more potent desired physiological effects when compared to Propranolol. However, it is uncertain at the present juncture whether the improvement in hemodynamics also translates into a decreased rate of disease progression and complications when compared to propranolol. Currently Carvedilol shows promise as a therapy for portal hypertension but more clinical trials need to be carried out before we can consider it as a superior option and a replacement for propranolol.

Inhibition of Janus kinase-2 signalling pathway ameliorates portal hypertensive syndrome in partial portal hypertensive and liver cirrhosis rats

BACKGROUND AND AIMS

JAK2/STAT3 signalling promotes fibrosis, angiogenesis and inflammation in many diseases; however, the role of this pathway in portal hypertension remains obscure. This study aimed to explore the function of JAK2/STAT3 signalling in portal hypertension and estimate the potential therapeutic effect of treatment with the specific inhibitor AG490.

METHODS

Rats induced by partial portal vein ligation and common bile duct ligation were treated with AG490 for two weeks. Haemodynamic parameters were assessed. The levels of phospho-STAT3 protein and related cytokines were detected by western blotting of splanchnic organs. Liver, spleen and intestine characterization was performed using histological analyses. Peripheral blood cell counts were also detected.

RESULTS

High levels of phospho-STAT3 protein were detected in portal hypertensive rats. AG490 effectively inhibited JAK2/STAT3 signalling and its downstream cytokines and provided protective effects by decreasing splanchnic neovascularization and inflammation and by attenuating portal pressure and hyperdynamic splanchnic circulation. In cirrhosis rats, AG490 inhibited intrahepatic fibrosis, angiogenesis and inflammation. AG490 improved the peripheral blood cell counts and the splenomegaly observed in these rats.

CONCLUSIONS

JAK2/STAT3 signalling is essential in portal hypertension, and targeting JAK2/STAT3 may be a promising therapy to treat this condition.

Beta-blockers in cirrhosis and refractory ascites: a retrospective cohort study and review of the literature

OBJECTIVE

It is currently discussed if beta-blockers exert harmful effects and increase mortality in patients with cirrhosis and refractory ascites. In this study, we provide an overview of the available literature in this field in combination with a retrospective analysis of 61 patients with cirrhosis and refractory ascites in a tertiary unit.

MATERIAL AND METHODS

We performed a systematic search of literature in May 2014. In addition, 61 patients with cirrhosis and ascites were identified and followed from development of refractory ascites until death or end of follow-up.

RESULTS

Fourteen trials (9 trials on propranolol, 1 case-control study and 4 retrospective analyses) were identified. One trial suggested an increased mortality in patients treated with beta-blockers and refractory ascites. The results of the remaining trials were inconclusive. No increase in mortality among beta-blocker-treated patients was found in the present retrospective analysis.

CONCLUSIONS

Treatment with beta-blockers may increase mortality in patients with cirrhosis and refractory ascites. However, the current evidence is sparse and high-quality studies are warranted to clarify the matter.

Primary prevention of bleeding from esophageal varices in patients with liver cirrhosis

Variceal bleeding is a life threatening situation with mortality rates of at least 20%. Prophylactic treatment with non-selective beta blockers (NSBBs) is recommended for patients with small varices that have not bled but with increased risk for bleeding. The recommended treatment strategies on primary prevention of variceal bleeding in patients with medium and large-sized varices are NSBBs or endoscopic band ligation. Nitrates, shunt surgery and sclerotherapy are not recommended in this setting. In this review, the most recent data on prevention of esophageal variceal bleeding are presented. Available data derived from randomized-controlled trials suggest both treatment strategies, and according to Baveno V consensus in portal hypertension “the choice of treatment should be based on local resources and expertise, patient preference and characteristics, side-effects and contra-indications”.