Beta-blockers in cirrhosis: therapeutic window or an aspirin for all?

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.

Hemodynamic Evaluation of Nonselective β-Blockers in Patients with Cirrhosis and Refractory Ascites

Background

Nonselective β-blockers (NSBB) have been associated with increased incidence of paracentesis-induced circulatory dysfunction (PICD) and reduced survival in patients with cirrhosis and refractory ascites.

Aim

To prospectively evaluate a hemodynamic response to NSBB in cirrhotics listed for liver transplantation with refractory ascites undergoing large volume paracentesis (LVP).

Methods

Patients with cirrhosis and refractory ascites, with an indication to start NSBB in primary prophylaxis for variceal bleeding, were enrolled. During two consecutive LVP, while being, respectively, off and on NSBB, cardiac output (CO), systemic vascular resistances (SVR), peripheral vascular resistances (PVR), and plasma renin activity (PRA) were noninvasively assessed.

Results

Seventeen patients were enrolled, and 10 completed the study. Before NSBB introduction, SVR (1896 to 1348 dyn·s·cm^-5; p = 0.028) and PVR (47 to 30 mmHg·min·dl·ml^-1; p = 0.04) significantly decreased after LVP, while CO showed an increasing trend (3.9 to 4.5 l/m; p = 0.06). After NSBB introduction, LVP was not associated with a significant increase in CO (3.4 to 3.8 l/m; p = 0.13) nor with a significant decrease in SVR (2002 versus 1798 dyn·s·cm^-5; p = 0.1). Incidence of PICD was not increased after NSBB introduction.

Conclusion

The negative inotropic effect of NSBB was counterbalanced by a smaller decrease of vascular resistances after LVP, probably due to splanchnic β2-blockade. This pilot study showed that NSBB introduction may be void of detrimental hemodynamic effects after LVP in cirrhotics with refractory ascites.

Non-selective beta-blockers are not associated with increased mortality in cirrhotic patients with ascites

BACKGROUND & AIMS

Controversy exists on the impact of non-selective beta-blockers (NSBBs) on survival in patients with ascites. We assessed whether NSBB treatment affects survival in a cohort of 316 consecutive patients with ascites undergoing evaluation for liver transplantation.

METHODS

Consecutive patients with cirrhosis and ascites assessed for liver transplantation between 2011 and 2014 were retrospectively evaluated. Competing risk Cox regression analysis in the whole population and in propensity score matched patients were performed to identify predictors of survival.

RESULTS

Three hundred and sixteen patients were evaluated: males 229 (73%), mean age 54 years, median follow-up: 7 months. Refractory ascites was diagnosed in 124 (39%) patients. Patients receiving NSBBs (n=128, 40.5%) had a higher frequency of previous spontaneous bacterial peritonitis (27% vs 17%, P=.025), lower frequency of refractory ascites (32% vs 44%, P=.03) but similar MELD and UKELD scores. Overall 80 (25%) patients died: 20 (16%) in the NSBB group vs. 60 (32%) in the non-NSBB group (P=.002). In multivariate competing risk Cox regression analysis, NSBB use was associated with reduced mortality (HR=0.55, 95% CI=0.33-0.94) along with prophylactic antibiotic use (HR=0.33, 95% CI=0.14-0.74), MELD score (HR=1.10, 95% CI=1.06-1.14) and sodium levels (HR=0.94, 95% CI: 0.89-0.98). No impact on survival was found when considering only patients with refractory ascites (NSBB use: HR=0.43, 95% CI=0.20-1.11).

CONCLUSIONS

Patients with ascites on NSBBs did not have impaired survival compared to those not receiving NSSBs and interestingly this observation was also confirmed in the subgroup with refractory ascites. Our results suggest that NSBBs are not detrimental, but instead seem safe even in more advanced stages of cirrhosis in patients on a transplant waiting list.

Characteristics of liver fibrosis with different etiologies using a fully quantitative fibrosis assessment tool

This study aimed to test the diagnostic performance of a fully quantitative fibrosis assessment tool for liver fibrosis in patients with chronic hepatitis B (CHB), primary biliary cirrhosis (PBC) and non-alcoholic steatohepatitis (NASH). A total of 117 patients with liver fibrosis were included in this study, including 50 patients with CHB, 49 patients with PBC and 18 patients with NASH. All patients underwent liver biopsy (LB). Fibrosis stages were assessed by two experienced pathologists. Histopathological images of LB slices were processed by second harmonic generation (SHG)/two-photon excited fluorescence (TPEF) microscopy without staining, a system called qFibrosis (quantitative fibrosis) system. Altogether 101 quantitative features of the SHG/TPEF images were acquired. The parameters of aggregated collagen in portal, septal and fibrillar areas increased significantly with stages of liver fibrosis in PBC and CHB (P<0.05), but the same was not found for parameters of distributed collagen (P>0.05). There was a significant correlation between parameters of aggregated collagen in portal, septal and fibrillar areas and stages of liver fibrosis from CHB and PBC (P<0.05), but no correlation was found between the distributed collagen parameters and the stages of liver fibrosis from those patients (P>0.05). There was no significant correlation between NASH parameters and stages of fibrosis (P>0.05). For CHB and PBC patients, the highest correlation was between septal parameters and fibrosis stages, the second highest was between portal parameters and fibrosis stages and the lowest correlation was between fibrillar parameters and fibrosis stages. The correlation between the septal parameters of the PBC and stages is significantly higher than the parameters of the other two areas (P<0.05). The qFibrosis candidate parameters based on CHB were also applicable for quantitative analysis of liver fibrosis in PBC patients. Different parameters should be selected for liver fibrosis assessment in different stages of PBC compared with CHB.

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.

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.