Effects of carvedilol and propranolol on circulatory regulation and oxygenation in cirrhosis: a randomised study

Heterogeneity of treatment response to beta-blockers in the treatment of portal hypertension: A systematic review

BACKGROUND

It has been suggested that a relevant proportion of patients do not respond to nonselective beta-blockers (NSBB)s, which raises questions regarding the need for individualized therapy. The existence of potential heterogeneity in the treatment response can be assessed using the variability ratio (VR) of the outcome measurement (in this case, HVPG) between the treated and placebo groups. We conducted a systematic review and meta-analysis of randomized controlled trials to assess the potential heterogeneity in the portal pressure response to NSBBs.

METHODS

After a systematic search, we quantified the heterogeneity of treatment response with the VR between the treatment and control groups, with VR > 1 indicating potential heterogeneity. We used a similar approach to compare carvedilol with propranolol and statins with placebo.

RESULTS

We identified 18 studies that included 965 patients. A comparison between beta-blockers and placebo showed a pooled VR of 0.99 (95% CI:0.87-1.14), which suggests a homogeneous HVPG response to NSBB at the individual patient level (ie, no evidence to support that some patients responded to beta-blockers and others did not). For the comparison between carvedilol and propranolol, pooled VR was 0.97 (95% CI 0.82-1.14), suggesting that carvedilol achieves a greater average response (rather than an increase in the proportion of responders). There was no evidence of a heterogeneous response to statins.

CONCLUSION

Our analysis did not support the existence of a heterogeneous patient-by-patient response to NSBBs in cirrhosis. These findings challenge the concept of personalized therapy based on portal pressure response and indicate that routine portal pressure measurement may not be necessary to guide NSBB therapy.

Neuroimmunomodulation of adrenoblockers during liver cirrhosis: modulation of hepatic stellate cell activity

The sympathetic nervous system and the immune system are responsible for producing neurotransmitters and cytokines that interact by binding to receptors; due to this, there is communication between these systems. Liver immune cells and nerve fibres are systematically distributed in the liver, and the partial overlap of both patterns may favour interactions between certain elements. Dendritic cells are attached to fibroblasts, and nerve fibres are connected via the dendritic cell-fibroblast complex. Receptors for most neuroactive substances, such as catecholamines, have been discovered on dendritic cells. The sympathetic nervous system regulates hepatic fibrosis through sympathetic fibres and adrenaline from the adrenal glands through the blood. When there is liver damage, the sympathetic nervous system is activated locally and systemically through proinflammatory cytokines that induce the production of epinephrine and norepinephrine. These neurotransmitters bind to cells through α-adrenergic receptors, triggering a cellular response that secretes inflammatory factors that stimulate and activate hepatic stellate cells. Hepatic stellate cells are key in the fibrotic process. They initiate the overproduction of extracellular matrix components in an active state that progresses from fibrosis to liver cirrhosis. It has also been shown that they can be directly activated by norepinephrine. Alpha and beta adrenoblockers, such as carvedilol, prazosin, and doxazosin, have recently been used to reverse CCl₄-induced liver cirrhosis in rodent and murine models.KEY MESSAGESNeurotransmitters from the sympathetic nervous system activate and increase the proliferation of hepatic stellate cells.Hepatic fibrosis and cirrhosis treatment might depend on neurotransmitter and hepatic nervous system regulation.Strategies to reduce hepatic stellate cell activation and fibrosis are based on experimentation with α-adrenoblockers.

Conversion of Propranolol to Carvedilol Improves Renal Perfusion and Outcome in Patients With Cirrhosis and Ascites

BACKGROUND

In recent years, concerns have been raised on the potential adverse effects of nonselective beta-blockers, and particularly carvedilol, on renal perfusion and survival in decompensated cirrhosis with ascites. We investigated the long-term impact of converting propranolol to carvedilol on systemic hemodynamics and renal function, and on the outcome of patients with stable cirrhosis and grade II/III nonrefractory ascites.

PATIENTS AND METHODS

Ninety-six patients treated with propranolol for esophageal varices' bleeding prophylaxis were prospectively evaluated. These patients were randomized in a 2:1 ratio to switch to carvedilol at 12.5 mg/d (CARVE group; n=64) or continue propranolol (PROPRA group; n=32). Systemic vascular resistance, vasoactive factors, glomerular filtration rate, and renal blood flow were evaluated at baseline before switching to carvedilol and after 6 and 12 months. Further decompensation and survival were evaluated at 2 years.

RESULTS

During a 12-month follow-up, carvedilol induced an ongoing improvement of systemic vascular resistance (1372±34 vs. 1254±33 dynes/c/cm5; P=0.02) along with significant decreases in plasma renin activity (4.05±0.66 vs. 6.57±0.98 ng/mL/h; P=0.01) and serum noradrenaline (76.7±8.2 vs. 101.9±10.5 pg/mL; P=0.03) and significant improvement of glomerular filtration rate (87.3±2.7 vs. 78.7±2.3 mL/min; P=0.03) and renal blood flow (703±17 vs. 631±12 mL/min; P=0.03); no significant effects were noted in the PROPRA group. The 2-year occurrence of further decompensation was significantly lower in the CARVE group than in the PROPRA group (10.5% vs. 35.9%; P=0.003); survival at 2 years was significantly higher in the CARVE group (86% vs. 64.1%; P=0.01, respectively).

CONCLUSION

Carvedilol at the dose of 12.5 mg/d should be the nonselective beta-blocker treatment of choice in patients with cirrhosis and nonrefractory ascites, as it improves renal perfusion and outcome.

Pharmacological management of portal hypertension and its complications in children: lessons from adults and opportunities for the future

INTRODUCTION

Portal hypertension (PHT) and its complications in children are thought to be distinct from adult PHT in several areas, including the underlying bio-physiology of a child in which PHT develops, but also because of the pediatric-specific etiologies that drive disease progression. And yet pharmacologic approaches to PHT in children are mainly based on adult data, modified for pediatric practice. This reality has been driven by a lack of data specific to children.

AREAS COVERED

The authors discuss current therapeutic approaches to PHT in children, including management of acute gastrointestinal variceal bleed, pharmacotherapy in prophylaxis, and established and emerging therapies to combat systemic co-morbidities that result from PHT. The few areas where pediatric-specific data exist are highlighted and the many gaps in knowledge that remain unresolved are underscored.

EXPERT OPINION

Despite decades of experience, optimal management of pediatric PHT remains undefined. In large part, this can be directly linked to a lack of basic understanding related to the unique pathophysiology and natural history that defines PHT in children. As a result, meaningful research into the utility and effectiveness of pharmacotherapy in children with PHT remains in its infancy. Large, multi-center, prospective studies will be needed to begin to establish an infrastructure on which a pediatric-specific research agenda can be built.

QT interval abnormalities and heart rate variability in patients with cirrhosis

BACKGROUND AND STUDY AIMS

We aimed to assess the relationship of the QT interval and heart rate variability with the severity and aetiology of cirrhosis and determine the effect of propranolol on them.

PATIENTS AND METHODS

This prospective study included 44 patients with cirrhosis categorised into three groups based on the Child-Pugh score: groups 1, 2 and 3 (with 12, 15 and 15 patients, respectively). Demographic characteristics, propranolol administration, severity of cirrhosis evaluated by the Child-Pugh score, aetiology of cirrhosis, and serum sodium, potassium and calcium levels were evaluated. All patients underwent 24 h-Holter monitoring. Corrected QT interval (QTc), average heart rate, standard deviation of normal-to-normal intervals (SDNN) and corrected SDNN (cSDNN) were evaluated.

RESULTS

The average QTc was significantly longer in group 3 than in groups 1 and 2 (453.4 ± 17.4 vs 422.8 ± 18.6 and 428.9 ± 17.24 ms, p < 0.001). The median SDNN was 70 ms and was significantly lower in group 3 vs groups 1 and 2 (77; interquartile range [IQR], 67-89.5 vs 57; IQR, 38-68 and 75 ms; IQR, 61-81 ms, p = 0.003). cSDNN was significantly lower in group 3 vs groups 1 and 2 (200.0 ± 42.6 vs 254.5 ± 75.3 and 277.8 ± 110.6 ms, p = 0.022). Propranolol administration resulted in a significant increase in the average SDNN value but had no effect on cSDNN or QTc. QTc was associated with the Child-Pugh class (p < 0.001), viral aetiology (p = 0.009) and sex (p = 0.010); SDNN was associated with the mean heart rate (p = 0.015) and Child-Pugh class (p = 0.024).

CONCLUSION

QTc interval prolongation and decreased SDNN are common in cirrhosis. Their prevalence is closely associated with disease severity. Propranolol has no effects on cSDNN or QTc.

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.

Portal hypertension: The desperate search for the placenta

We propose that the circulatory impairments produced, in both portal hypertension and liver cirrhosis, to a certain degree resemble those characterizing prenatal life in the fetus. In fact, the left-right circulatory syndrome is common in cirrhotic patients and in the fetus. Thus, in patients with portal hypertension and chronic liver failure, the re-expression of a blood circulation comparable to fetal circulation is associated with the development of similar amniotic functions, i.e., ascites production and placenta functions, and portal vascular enteropathy. Therefore, these re-expressed embryonic functions are extra-embryonic and responsible for prenatal trophism and development.

Carvedilol versus traditional, non-selective beta-blockers for adults with cirrhosis and gastroesophageal varices

BACKGROUND

Non-selective beta-blockers are recommended for the prevention of bleeding in people with cirrhosis, portal hypertension and gastroesophageal varices. Carvedilol is a non-selective beta-blocker with additional intrinsic alpha₁-blocking effects, which may be superior to traditional, non-selective beta-blockers in reducing portal pressure and, therefore, in reducing the risk of upper gastrointestinal bleeding.

OBJECTIVES

To assess the beneficial and harmful effects of carvedilol compared with traditional, non-selective beta-blockers for adults with cirrhosis and gastroesophageal varices.

SEARCH METHODS

We combined searches in the Cochrane Hepato-Biliary's Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, and Science Citation Index with manual searches. The last search update was 08 May 2018.

SELECTION CRITERIA

We included randomised clinical trials comparing carvedilol versus traditional, non-selective beta-blockers, irrespective of publication status, blinding, or language. We included trials evaluating both primary and secondary prevention of upper gastrointestinal bleeding in adults with cirrhosis and verified gastroesophageal varices.

DATA COLLECTION AND ANALYSIS

Three review authors (AZ, RJ and LH), independently extracted data. The primary outcome measures were mortality, upper gastrointestinal bleeding and serious adverse events. We undertook meta-analyses and presented results using risk ratios (RR) or mean differences (MD), both with 95% confidence intervals (CIs), and I² values as a marker of heterogeneity. We assessed bias control using the Cochrane Hepato-Biliary domains and the quality of the evidence with GRADE.

MAIN RESULTS

Eleven trials fulfilled our inclusion criteria. One trial did not report clinical outcomes. We included the remaining 10 randomised clinical trials, involving 810 participants with cirrhosis and oesophageal varices, in our analyses. The intervention comparisons were carvedilol versus propranolol (nine trials), or nadolol (one trial). Six trials were of short duration (mean 6 (range 1 to 12) weeks), while four were of longer duration (13.5 (6 to 30) months). Three trials evaluated primary prevention; three evaluated secondary prevention; while four evaluated both primary and secondary prevention. We classified all trials as at 'high risk of bias'. We gathered mortality data from seven trials involving 507 participants; no events occurred in four of these. Sixteen of 254 participants receiving carvedilol and 19 of 253 participants receiving propranolol or nadolol died (RR 0.86, 95% CI 0.48 to 1.53; I² = 0%, low-quality evidence). There appeared to be no differences between carvedilol versus traditional, non-selective beta-blockers and the risks of upper gastrointestinal bleeding (RR 0.77, 95% CI 0.43 to 1.37; 810 participants; 10 trials; I² = 45%, very low-quality evidence) and serious adverse events (RR 0.97, 95% CI 0.67 to 1.42; 810 participants; 10 trials; I² = 14%, low-quality evidence). Significantly more deaths, episodes of upper gastrointestinal bleeding and serious adverse events occurred in the long-term trials but there was not enough information to determine whether there were differences between carvedilol and traditional, non-selective beta-blockers, by trial duration. There was also insufficient information to detect differences in the effects of these interventions in trials evaluating primary or secondary prevention. There appeared to be no differences in the risk of non-serious adverse events between carvedilol versus its comparators (RR 0.55, 95% CI 0.23 to 1.29; 596 participants; 6 trials; I² = 88%; very low-quality evidence). Use of carvedilol was associated with a greater reduction in hepatic venous pressure gradient than traditional, non-selective beta-blockers both in absolute (MD -1.75 mmHg, 95% CI -2.60 to -0.89; 368 participants; 6 trials; I² = 0%; low-quality evidence) and percentage terms (MD -8.02%, 95% CI -11.49% to -4.55%; 368 participants; 6 trials; I² = 0%; low-quality evidence). However, we did not observe a concomitant reduction in the number of participants who failed to achieve a sufficient haemodynamic response (RR 0.76, 95% CI 0.57 to 1.02; 368 participants; 6 trials; I² = 42%; very low-quality evidence) or in clinical outcomes.

AUTHORS' CONCLUSIONS

We found no clear beneficial or harmful effects of carvedilol versus traditional, non-selective beta-blockers on mortality, upper gastrointestinal bleeding, serious or non-serious adverse events despite the fact that carvedilol was more effective at reducing the hepatic venous pressure gradient. However, the evidence was of low or very low quality, and hence the findings are uncertain. Additional evidence is required from adequately powered, long-term, double-blind, randomised clinical trials, which evaluate both clinical and haemodynamic outcomes.

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.

Recent advances in cirrhotic cardiomyopathy

Cirrhotic cardiomyopathy, a cardiac dysfunction presented in patients with cirrhosis, represents a recently recognized clinical entity. It is characterized by altered diastolic relaxation, impaired contractility, and electrophysiological abnormalities, in particular prolongation of the QT interval. Several mechanisms seem to be involved in the pathogenesis of cirrhotic cardiomyopathy, including impaired function of beta-receptors, altered transmembrane currents, and overproduction of cardiodepressant factors, like nitric oxide, tumor necrosis factor α, and endogenous cannabinoids. Diastolic dysfunction is the first manifestation of cirrhotic cardiomyopathy and reflects the increased stiffness of the cardiac mass, which leads to delayed left ventricular filling. On the other hand, systolic incompetence is presented later, is usually unmasked during pharmacological or physical stress, and predisposes to the development of hepatorenal syndrome. The prolongation of QT is found in about 50 % of cirrhotic patients, but rarely leads to fatal arrhythmias. Cirrhotics with blunted cardiac function seem to have poorer survival rates compared to those without, and the risk is particularly increased during the insertion of transjugular intrahepatic portosystemic shunt or liver transplantation. Till now, there is no specific treatment for the management of cirrhotic cardiomyopathy. New agents, targeting to its pathogenetical mechanisms, may play some role as future therapeutic options.

The effect of carvedilol and propranolol on portal hypertension in patients with cirrhosis: a meta-analysis

PURPOSE

Several randomized controlled clinical trials have been conducted to investigate the role of carvedilol and propranolol on the effect of portal pressure in patients with cirrhosis, leading to controversial results. Current meta-analysis was performed to compare the efficacy of the two drugs on portal pressure.

PATIENTS AND METHODS

Two-hundred and ninety eligible patients were recruited. Published studies were selected based on PubMed, the Cochrane Library, Chinese Journal Full-text Database, and Wanfang Database. The outcome measurements included the mean difference (MD) in the percentage of hepatic vein pressure gradient reduction (%HVPG reduction), the risk ratio (RR) of nonresponders in hemodynamic assessment, and the percentage of mean arterial pressure reduction (%MAP reduction). Subgroup analysis was performed.

RESULTS

Seven trials were identified (including five acute and three long-term drug administration randomized controlled trials). A summary of pooled MD between the %HVPG reduction is as follows: overall -8.62 (confidence interval [CI] -11.76, -5.48, P<0.00001), acute -10.05 (CI -14.24, -5.86, P<0.00001), and long term -6.80 (CI -11.53, -2.07, P=0.005), while summary of pooled RR of hemodynamic nonresponders with carvedilol was as follows: overall 0.64 (CI 0.51, 0.81, P=0.0002), acute 0.63 (CI 0.47, 0.85, P=0.002), and long term 0.67 (CI 0.47, 0.97, P=0.03). Both of the outcome measurements favored carvedilol. Significant heterogeneity (P<0.1, I (2)=92%) existed between the two treatment groups in %MAP reduction. No considerable difference could be observed in the %MAP reduction through the poor overlapping CI boundaries.

CONCLUSION

Carvedilol has a greater portal hypertensive effect than propranolol. Further comparative trials of the two drugs are required to identify the effect of MAP reduction.

Kidney injury in cirrhosis: pathophysiological and therapeutic aspects of hepatorenal syndromes

Acute kidney injury (AKI) is frequent in patients with cirrhosis. AKI and hyponatraemia are major determinants of the poor prognosis in advanced cirrhosis. The hepatorenal syndrome (HRS) denotes a functional and potential reversible impairment of renal function. Type 1 HRS, a special type of AKI, is a rapidly progressive AKI, whereas the renal function in type 2 HRS decreases more slowly. HRS is precipitated by factors such as sepsis that aggravate the effective hypovolaemia in decompensated cirrhosis, by lowering arterial pressure and cardiac output and enhanced sympathetic nervous activity. Therefore, attempts to prevent and treat HRS should seek to improve liver function and to ameliorate arterial hypotension, central hypovolaemia and cardiac output, and to reduce renal vasoconstriction. Ample treatment of HRS is important to prevent further progression and death, but as medical treatment only modestly improves long-term survival, these patients should always be considered for liver transplantation. Hyponatraemia, defined as serum sodium <130 mmol/L, is common in patients with decompensated cirrhosis. From a pathophysiological point of view, hyponatraemia is related to an impairment of renal solute-free water excretion most likely caused by an increased vasopressin secretion. Patients with cirrhosis mainly develop hypervolaemic hyponatraemia. Current evidence does not support routine use of vaptans in the management of hyponatraemia in cirrhosis.