Prognostic value of acute hemodynamic response to i.v. propranolol in patients with cirrhosis and portal hypertension

Liver cirrhosis

Cirrhosis is an increasing cause of morbidity and mortality in more developed countries, being the 14th most common cause of death worldwide but fourth in central Europe. Increasingly, cirrhosis has been seen to be not a single disease entity, but one that can be subclassified into distinct clinical prognostic stages, with 1-year mortality ranging from 1% to 57% depending on the stage. We review the current understanding of cirrhosis as a dynamic process and outline current therapeutic options for prevention and treatment of complications of cirrhosis, on the basis of the subclassification in clinical stages. The new concept in management of patients with cirrhosis should be prevention and early intervention to stabilise disease progression and to avoid or delay clinical decompensation and the need for liver transplantation. The challenge in the 21st century is to prevent the need for liver transplantation in as many patients with cirrhosis as possible.

Beta-blockers in portal hypertension: new developments and controversies

There are many studies investigating the role of non-selective beta-blockers in portal hypertension. Satisfactory reduction in portal pressure is possible in a third to half of patients with propranolol and nadolol, although combining these drugs with nitrates may be more effective. Carvedilol is a more potent agent than propranolol in reducing portal pressure, particularly in non-responders, and is better tolerated. All these drugs have been studied in primary and secondary prophylaxis, sometimes in combination with band ligation and/or nitrates. There is some evidence to support combining these agents with band ligation, despite a lack of survival benefit and increased adverse events. Hemodynamic monitoring can help select non-responders who may benefit from additional therapies such as band ligation, as lack of response is associated with worse outcomes. Propranolol should be used with caution in patients with refractory ascites, although the current evidence is not of sufficient quality to justify not using these drugs in such situations. Beta-blockers have been shown to reduce bacterial translocation and spontaneous bacterial peritonitis in cirrhosis.

Hepatic venous pressure gradient: clinical use in chronic liver disease

Portal hypertension is a severe consequence of chronic liver diseases and is responsible for the main clinical complications of liver cirrhosis. Hepatic venous pressure gradient (HVPG) measurement is the best available method to evaluate the presence and severity of portal hypertension. Clinically significant portal hypertension is defined as an increase in HVPG to >10 mmHg. In this condition, the complications of portal hypertension might begin to appear. HVPG measurement is increasingly used in the clinical fields, and the HVPG is a robust surrogate marker in many clinical applications such as diagnosis, risk stratification, identification of patients with hepatocellular carcinoma who are candidates for liver resection, monitoring of the efficacy of medical treatment, and assessment of progression of portal hypertension. Patients who had a reduction in HVPG of ≥ 20% or to ≤ 12 mmHg in response to drug therapy are defined as responders. Responders have a markedly decreased risk of bleeding/rebleeding, ascites, and spontaneous bacterial peritonitis, which results in improved survival. This review provides clinical use of HVPG measurement in the field of liver disease.

Invasive and non-invasive diagnosis of cirrhosis and portal hypertension

With advances in the management and treatment of advanced liver disease, including the use of antiviral therapy, a simple, one stage description for advanced fibrotic liver disease has become inadequate. Although refining the diagnosis of cirrhosis to reflect disease heterogeneity is essential, current diagnostic tests have not kept pace with the progression of this new paradigm. Liver biopsy and hepatic venous pressure gradient measurement are the gold standards for the estimation of hepatic fibrosis and portal hypertension (PHT), respectively, and they have diagnostic and prognostic value. However, they are invasive and, as such, cannot be used repeatedly in clinical practice. The ideal noninvasive test should be safe, easy to perform, inexpensive, reproducible as well as to give numerical and accurate results in real time. It should be predictive of long term outcomes related with fibrosis and PHT to allow prognostic stratification. Recently, many types of noninvasive alternative tests have been developed and are under investigation. In particular, imaging and ultrasound based tests, such as transient elastography, have shown promising results. Although most of these noninvasive tests effectively identify severe fibrosis and PHT, the methods available for diagnosing moderate disease status are still insufficient, and further investigation is essential to predict outcomes and individualize therapy in this field.

Hepatic venous pressure gradient: clinical use in chronic liver disease

Portal hypertension is a severe consequence of chronic liver diseases and is responsible for the main clinical complications of liver cirrhosis. Hepatic venous pressure gradient (HVPG) measurement is the best available method to evaluate the presence and severity of portal hypertension. Clinically significant portal hypertension is defined as an increase in HVPG to >10 mmHg. In this condition, the complications of portal hypertension might begin to appear. HVPG measurement is increasingly used in the clinical fields, and the HVPG is a robust surrogate marker in many clinical applications such as diagnosis, risk stratification, identification of patients with hepatocellular carcinoma who are candidates for liver resection, monitoring of the efficacy of medical treatment, and assessment of progression of portal hypertension. Patients who had a reduction in HVPG of ≥ 20% or to ≤ 12 mmHg in response to drug therapy are defined as responders. Responders have a markedly decreased risk of bleeding/rebleeding, ascites, and spontaneous bacterial peritonitis, which results in improved survival. This review provides clinical use of HVPG measurement in the field of liver disease.

Combined therapies versus monotherapies for the first variceal bleeding in patients with high-risk varices: a meta-analysis of randomized controlled trials

BACKGROUND AND AIM

The effect of combined therapies (among non-selected beta-blockers [NSBB], endoscopic therapy, and other treatments) on the first variceal bleeding has been evaluated in several randomized controlled trials previously, and the results were controversial. We performed this meta-analysis to assess the effect of combined therapies in patients with high-risk varices without previous variceal bleeding.

METHODS

The Cochrane Library, The Cochrane Hepato-Biliary Group Controlled Trials Register, MEDLINE, and EMBASE were searched for eligible trials. Manual searches were also performed for additional studies. Upper gastrointestinal bleeding, variceal bleeding, mortality, and adverse events were evaluated as end-points by meta-analysis.

RESULTS

Twelve randomized controlled trials with 1571 patients were included. Compared with the NSBB (propranolol or nadolol) or endoscopic therapy alone, all of the combined therapies did not demonstrate significant improvements in variceal bleeding, total upper gastrointestinal bleeding, and mortality. Only the combinations of isosorbide-mononitrate or spironolactone with NSBB tended to decrease the risk of variceal bleeding when compared with the use of NSBB alone (isosorbide-mononitrate plus NSBB vs NSBB: odds ratio = 0.67, 95% confidence interval 0.40-1.13, P = 0.13; spironolactone plus NSBB vs NSBB: odds ratio = 0.41, 95% confidence interval 0.10-1.69, P = 0.22). Adverse events were more frequently observed in the combined therapy groups.

CONCLUSIONS

Based on the available evidences, no combined therapy can be recommended as the first-line treatment for the primary prevention of variceal bleeding currently. Further studies with large sample sizes and long-term follow up are warranted.

Impact of deep sedation on the accuracy of hepatic and portal venous pressure measurements in patients with cirrhosis

BACKGROUND & AIMS

Measurement of the hepatic venous pressure gradient (HVPG) offers valuable prognostic information in patients with cirrhosis. In specific circumstances, (children, agitated patients, TIPS placement) deep sedation is required. This study aims to assess the impact of deep sedation on the accuracy of hepatic/portal pressure measurements.

METHODS

Forty-four patients were included. Measurements of baseline HVPG (n = 30), HVPG response to i.v. propranolol (n = 11), portal pressure gradient (PPG) after TIPS (n = 27) and of cardio-pulmonary pressures (n = 25) were obtained in awake conditions and under deep sedation with propofol and remifentanil.

RESULTS

During deep sedation, a marked oscillation within respiratory cycle was observed in abdominal pressures. End-expiratory sedated HVPG showed a better agreement with awake HVPG (intra-class correlation coefficient - ICC 0.864) than end-inspiratory HVPG (ICC 0.796). However, in almost half of the patients both values differed by more than 10%. Accuracy was not improved by using mean HVPG along the respiratory cycle. Similarly, changes in HVPG caused by propranolol while under sedation had a poor agreement to those obtained in awake conditions. Indeed, about a half of patients were misclassified according to the 10% HVPG reduction target. After TIPS, PPG values obtained under sedation were significantly different to awake PPG, usually underestimating the awake value. The systemic hemodynamic changes induced by sedation were not associated to a greater variability of PPG/HVPG measurements.

CONCLUSION

Deep sedation with propofol and remifentanil adds substantial variability and uncertainty to HVPG/PPG measurements. This must be considered when using these values to estimate prognosis, or targeting HVPG/PPG reductions.

Management of varices in patients with cirrhosis

Variceal bleeding remains a life-threatening condition with a 6-week mortality rate of ∼20%. Prevention of variceal bleeding can be achieved using nonselective β-blockers (NSBBs) or endoscopic band ligation (EBL), with NSBBs as the first-line treatment. EBL should be reserved for cases of intolerance or contraindications to NSBBs. Although NSBBs cannot be used to prevent varices, if the hepatic venous pressure gradient (HVPG) is ≤10 mmHg, prognosis is excellent. Survival after acute variceal bleeding has improved over the past three decades, but patients with Child-Pugh grade C cirrhosis remain at greatest risk. Vasoactive drugs combined with endoscopic therapy and antibiotics are the best therapeutic strategy for these patients. Transjugular intrahepatic portosystemic shunts (TIPS) should be used in patients with uncontrolled bleeding or those who are likely to have difficult-to-control bleeding. Rebleeding from varices occurs in ∼60% of patients 1-2 years after the initial bleeding episode, with a mortality rate of 30%. Secondary prophylaxis should start at day 6 after initial bleeding using a combination of NSBBs and EBL. TIPS with polytetrafluoroethylene-covered stents are the preferred option in patients who fail combined treatment with NSBBs and EBL. Despite the improvement in patient survival, further studies are needed to direct the management of patients with gastro-oesophageal varices and variceal bleeding.

Assessing portal hypertension in liver diseases

Portal hypertension is a common complication of chronic liver diseases and is responsible for most clinical consequences of cirrhosis, which represent the more frequent causes of death and liver transplantation in these patients. This review is aimed at clarifying the state-of-the art assessment of portal hypertension and at discussing recent developments in this field. Particular attention is paid to new noninvasive techniques that will be soon available for potential routine use.

Venous thromboembolism in cirrhosis

The cirrhosis population represents a unique subset of patients who are at risk for both bleeding and developing venous thromboembolic events (VTEs). It has been commonly misunderstood that these patients are naturally protected from thrombosis by deficiencies in coagulation factors. As a result, the cirrhosis population is often falsely perceived to be "autoanticoagulated." However, the concept of "autoanticoagulation" conferring protection from thrombosis is a misnomer. While patients with cirrhosis may have a bleeding predisposition, not uncommonly they also experience thrombotic events. The concern for this increased bleeding risk often makes anticoagulation a difficult choice. Prophylactic and therapeutic management of VTE in patients with cirrhosis is a difficult clinical problem with the lack of clear established guidelines. The elucidation of laboratory and/or clinical predictors of VTE will be useful in this setting. This review serves to examine VTE and the use of anticoagulation in the cirrhosis population.

Indications for portal pressure measurement in chronic liver disease

Portal hypertension leads to development of serious complications such as esophageal varices, ascites, renal and cardiovascular dysfunction. The importance of the degree of portal hypertension has been substantiated within recent years. Measurement of the portal pressure is simple and safe and the hepatic venous pressure gradient (HVPG) independently predicts survival and development of complications such as ascites, HCC and bleeding from esophageal varices. Moreover, measurements of HVPG can be used to guide pharmacotherapy for primary and secondary prophylaxis for variceal bleeding. Assessment of HVPG should therefore be considered as a part of the general characterization of patients with portal hypertension in departments assessing and treating this condition.

Insulin resistance in patients with cirrhosis and portal hypertension

Insulin resistance (IR) is involved in the pathogenesis of endothelial dysfunction and is also present in patients with cirrhosis. Intrahepatic endothelial dysfunction plays a major role, increasing hepatic vascular resistance and promoting portal hypertension (PH). In addition, β-adrenergic agonists and insulin share several intracellular signaling pathways. Thus IR may influence the response to β-blockers. This study aimed at evaluating the relationship between IR and hepatic hemodynamics in patients with cirrhosis and with the portal pressure response to acute β-blockade. Forty-nine patients with cirrhosis and PH were included. Hepatic and systemic hemodynamics were measured, and IR was estimated by using the updated homeostasis model assessment (HOMA)-2 index. Patients with HOMA-2 > 2.4 were considered IR. In patients with hepatic venous pressure gradient (HVPG) ≥ 10 mmHg) [clinically significant PH (CSPH)], hemodynamic measurements were performed again 20 min after intravenous propranolol. Mean HOMA-2 index was 3 ± 1.4. Fifty-seven percent of patients had IR. A weak correlation between HOMA-2 index and HVPG was observed. Eighty-six percent of patients had CSPH. HOMA-2 index was an independent predictor of CSPH. However, in patients with CSPH, the correlation between HOMA-2 index and HVPG was lost. HVPG, but not IR, predicted the presence of esophageal varices. Response to propranolol was not different between patients with or without IR. In nondiabetic patients with cirrhosis, HOMA-2 index is directly associated with the presence of CSPH and indirectly with varices, but does not allow either grading HVPG or predicting its response to propranolol.

Carvedilol or propranolol in portal hypertension? A randomized comparison

OBJECTIVES

Carvedilol is a non-selective β-blocker with intrinsic anti-α(1)-adrenergic activity, potentially more effective than propranolol in reducing hepatic venous pressure gradient (HVPG). We compared the long-term effect of carvedilol and propranolol on HVPG and assessed whether the acute response to oral propranolol predicted the long-term HVPG response on either drug.

MATERIAL AND METHODS

HVPG was measured in 38 patients with cirrhosis and HVPG ≥ 12 mm Hg at baseline and then again 90 min after an oral dose of 80 mg propranolol. Patients were double-blinded randomized to either carvedilol (21 patients) or propranolol (17 patients) and after 90 days of treatment HVPG measurements were repeated.

RESULTS

HVPG decreased by 19.3 ± 16.1% (p < 0.01) and by 12.5 ± 16.7% (p < 0.01) in the carvedilol and propranolol groups, respectively, with no significant difference between treatment regimens (p = 0.21). Although insignificant, an acute decrease in HVPG of ≥12% was the best cut-off value to predict long-term HVPG response to propranolol when using ROC curve analysis.

CONCLUSIONS

This randomized study showed that carvedilol is at least as effective as propranolol on HVPG after long-term administration. Furthermore, a predictive value of an acute propranolol test on HVPG could not be confirmed.

Early primary prophylaxis with beta-blockers does not prevent the growth of small esophageal varices in cirrhosis: a randomized controlled trial

BACKGROUND

The efficacy of portal pressure reduction by beta-blockers and the utility of serial hepatic venous pressure gradient (HVPG) measurements for the management of small (≤5 mm) esophageal varices in patients of cirrhosis are not clear.

AIMS

The study had the following aims: to study (1) the effect of propranolol on the growth of small varices and (2) whether single or serial HVPG measurements result in a better outcome compared to no measurement in patients with small varices.

METHODS

Consecutive cirrhosis patients with small varices, without any history of variceal bleed, were randomized to receive propranolol or placebo and to undergo no HVPG, only baseline HVPG, or serial HVPG measurements.

RESULTS

A total of 150 cirrhotics (cirrhosis predominantly viral or alcohol induced) were included (77 in the beta-blocker and 73 in the placebo group). Baseline characteristics were similar. The actuarial 2-year risk of growth of varices (primary endpoint) was 11 and 16% in the propranolol and placebo group, respectively (P = 0.786). Variceal bleeding and mortality were also comparable in the two groups. Similarly, the outcome was not influenced by HVPG measurements (whether serial, only baseline, or no HVPG). A bilirubin level of ≥1.5 mg/dl was found to be an independent predictor of variceal progression.

CONCLUSIONS

In cirrhotics with small esophageal varices, nonselective beta-blockers are unable to prevent the growth of varices, variceal bleed, or mortality. HVPG monitoring of these patients did not change the outcome; however, the role of HVPG-guided therapy modification needs to be studied.

Development of ascites in compensated cirrhosis with severe portal hypertension treated with β-blockers

OBJECTIVES

In compensated cirrhosis, a threshold value of hepatic venous pressure gradient (HVPG) ≥10 mm Hg is required for the development of decompensation. However, whether the treatment of portal hypertension (PHT) can prevent the transition into development of ascites once this level has been reached is unclear. Our aim was to assess the relationship between changes in HVPG induced by β-blockers and development of ascites in compensated cirrhosis with severe PHT.

METHODS

Eighty-three patients without any previous decompensation of cirrhosis, with large esophageal varices and HVPG ≥12 mm Hg were included. After baseline hemodynamic measurements nadolol was administered and a second hemodynamic study was repeated 1-3 months later.

RESULTS

During 53±30 months of follow-up, decompensation occurred in 52 patients (62%) and in 81% of them ascites was the first manifestation. Using receiver operating characteristic curve analysis a decrease in HVPG ≥10% was the best cutoff to predict ascites. As compared with nonresponders, patients with an HVPG decrease ≥10% had a lower probability of developing ascites (19% vs. 57% at 3 years, P<0.001), refractory ascites (P=0.007), and hepatorenal syndrome (P=0.027). By Cox regression analysis hemodynamic nonresponse was the best predictor of ascites. By stepwise logistic regression, development of ascites was independently associated with nonresponse, whereas refractory ascites, hepatorenal syndrome, and spontaneous bacterial peritonitis were not.

CONCLUSIONS

In patients with compensated cirrhosis and large varices treated with β-blockers, an HVPG decrease ≥10% significantly reduces the risk of developing ascitic decompensation and other related complications such as refractory ascites or hepatorenal syndrome.

Non invasive evaluation of portal hypertension using transient elastography

The development of portal hypertension is a common consequence of chronic liver diseases leading to the formation of esophageal and gastric varices responsible for variceal bleeding, associated with a high mortality rate, as well as other severe complications such as portosystemic encephalopathy and sepsis. Measurement of hepatic venous pressure gradient (HVPG) and upper GI endoscopy are considered the gold standards for portal hypertension assessment in patients with cirrhosis. However, both types of investigation are invasive and HVPG measurement is routinely available and/or performed with adequate standards only in expert centres. There is thus a need for non invasive methods able to predict, with acceptable diagnostic accuracy, the progression of portal hypertension toward the levels of clinically significant (i.e. HVPG ≥ 10 mmHg) and severe (HVPG ≥ 12 mmHg) as well as the presence and the size of oesophageal varices. Transient elastography (TE) is a novel non invasive technology that allows measuring liver stiffness and that has gained popularity over the past few years. Although TE has been initially proposed to assess liver fibrosis, a good correlation has been reported between liver stiffness values and HVPG as well as the presence of oesophageal varices, suggesting that it could be an interesting tool for the non invasive evaluation of portal hypertension. This review is aimed at discussing the advantages and limits of TE and the perspectives for its rationale use in clinical practice for the management of patients with portal hypertension.

Adding banding ligation is effective as rescue therapy to prevent variceal rebleeding in haemodynamic non-responders to pharmacological therapy

BACKGROUND

It is unknown which is the best therapy to treat haemodynamic non-responders to pharmacological therapy after variceal bleeding.

AIM

To evaluate the efficacy of adding banding ligation to drugs to prevent variceal rebleeding in haemodynamic non-responders to drugs.

METHODS

Fifty-three cirrhotic patients with variceal bleeding underwent a hepatic venous pressure gradient (HVPG) measurement 5 days after the episode. Nadolol and nitrates were then titrated to maximum tolerated doses. A second HVPG was taken 14 days later. Responders (HVPG ≤12 mm Hg or ≥20% decrease from baseline) were maintained on drugs and non-responders had banding ligation added to drugs.

RESULTS

Mean follow-up was 28 months. In 5 patients the second HVPG could not be performed because of early rebleeding. The remaining 48 patients were classified as responders (n=24) and non-responders (n=24), who had banding added. No baseline differences were observed between groups. Variceal rebleeding occurred in 12% of the 48 patients whose haemodynamic response was assessed. Responders on drug therapy presented a 16% rebleeding rate, whilst non-responders rescued with banding showed an 8% rebleeding rate. Rebleeding-related mortality was not different between groups.

CONCLUSION

In a HVPG-guided strategy, adding banding ligation to drugs is an effective rescue strategy to prevent rebleeding in haemodynamic non-responders to drug therapy.

Hepatic venous pressure gradient measurement in clinical hepatology

Portal hypertension is key to the natural history of cirrhosis and the standard way to assess it is the hepatic venous pressure gradient. Hepatic venous pressure gradient is a strong predictor of variceal bleeding/survival and is the only suitable tool to assess the response of portal hypertension to medical treatment. The clinical applications, indications and timing for hepatic venous pressure gradient measurement, together with measurement principles and costs, are reviewed.

Should we routinely measure portal pressure in patients with cirrhosis, using hepatic venous pressure gradient (HVPG) as guidance for prophylaxis and treatment of bleeding and re-bleeding? Yes!

Portal hypertension is key to the natural history of cirrhosis. The standard way to assess portal hypertension is the hepatic venous pressure gradient (HVPG). HVPG has been convincingly shown to be a strong predictor of variceal bleeding and survival. In addition, it has been shown to predict other portal hypertension-related clinical events, to include fluid retention and hepatic encephalopathy. Finally, HVPG is the only suitable tool to assess the response of portal hypertension to medical treatment. Thus, although not necessarily easy to measure, HVPG provides the clinician with information which is prognostically crucial and otherwise unobtainable.

Low-molecular-weight heparin in patients with advanced cirrhosis

BACKGROUND & AIMS

The use of low-molecular-weight heparins (LMWH) in patients with advanced liver diseases is frequently avoided because of the enhanced risk of bleeding complications. However, many patients with impaired liver function are at a high risk of thrombosis or have an indication for therapeutic anticoagulation. Therefore, the aim of this study was to evaluate the pharmacokinetics of LMWH in patients with cirrhosis.

METHODS

Eighty-four consecutive patients with cirrhosis and a clinical indication for prophylactic or therapeutic anticoagulation were included. The LMWH doses were chosen according to current guidelines. Antifactor Xa activity (anti-Xa) was assessed on two consecutive days, 4 h after drug administration. The severity of liver disease was quantified using Child-Turcotte-Pugh score, the MELD score and clinical features and was correlated with the anti-Xa value and the occurrence of complications.

RESULTS

Antifactor Xa activity was negatively correlated with the severity of the liver disease, and a positive correlation was observed between antithrombin-III (AT) levels and anti-Xa value. AT itself was negatively correlated with the severity of liver disease. Seven patients had an episode of variceal bleeding. No patient died during the observation interval and no thromboembolic events occurred.

CONCLUSION

Prophylactic use of LMWH in patients with cirrhosis appears to be safe. A decreased anti-Xa value in cirrhotic patients and a negative correlation with liver function challenge the unconditional use of anti-Xa assays in LMWH monitoring in cirrhotic patients and reveals a potential limitation of anti-Xa analysis in these patients. Low levels of AT, because of reduced hepatic synthesis, are the most likely cause of this phenomenon.

Comparison of balloon vs. straight catheter for the measurement of portal hypertension

BACKGROUND

The hepatic venous pressure gradient (HVPG) is used as an estimation of portal pressure (PP) in the management of patients with cirrhosis. Two methods are available using either a straight or a balloon catheter, but have never been compared head-to-head.

AIM

To compare the two methods of determining HVPG, straight and balloon catheter, regarding reproducibility and reliability.

METHODS

In 47 patients with liver cirrhosis, HVPG was assessed using both catheters in sequence. In another 29 patients, the wedged hepatic venous pressure (WHVP) determined either with straight or balloon catheter was correlated with a direct measurement of PP. Variation coefficient and intraclass correlation coefficient were calculated.

RESULTS

Variation coefficients for balloon catheter were 0.07 (HVPG), 0.02 (WHVP) and 0.06 [free hepatic venous pressure (FHVP)]. Variation coefficients for straight catheter were 0.17 (HVPG), 0.06 (WHVP) and 0.07 (FHVP), demonstrating a significantly wider variation of the HVPG and WHVP measurements (P < 0.001). Comparison of WHVP with PP revealed a correlation coefficient of 0.72 (P = 0.004) using balloon catheter and 0.58 (P = 0.011) using straight catheter.

CONCLUSIONS

Measurements with the balloon catheter currently represent the most reliable and reproducible method to assess HVPG. The results are of particular clinical relevance if repeated measurements are required for therapeutic adjustments.

Primary prevention of variceal hemorrhage

Variceal hemorrhage is one of the leading causes of death in patients with cirrhosis, with the 6-week mortality after each episode ranging from 15% to 20%. The two main strategies for primary prevention of variceal bleeding in patients with cirrhosis and varices are the administration of nonselective β-blockers or the obliteration of varices with use of endoscopic band ligation. In this review, we present and critically review the latest data on primary prevention of variceal hemorrhage. We advocate that nonselective β-blockers should be the first line therapy, and band ligation should be offered only in cases of intolerance or side effects. We also explore potential future therapies based on preliminary experimental and clinical data.

Measurement of hepatic vein pressure gradient in children with chronic liver diseases

BACKGROUND & AIMS

The aim of this study is to present our preliminary experience with Hepatic Vein Pressure Gradient (HVPG) measurements in pediatric patients with chronic liver disease.

METHODS

Institutional review board approval was obtained. HVPG was measured in 20 pediatric patients, mean age 82+/-54 months, with chronic liver disease, without extrahepatic portal vein obstruction. In nine patients the end-stage liver disease was secondary to biliary atresia; in the remaining 11, to various causes. Eleven patients had esophageal varices at endoscopy, 14 had perigastric and periesophageal collaterals at imaging scan, three had ascites, 12 had low platelet count, and all had splenomegaly.

RESULTS

Hepatic vein catheterization was technically possible in all patients without complications. HVPG values were elevated in all but three patients, ranging between 2 and 33 mmHg (mean 11.3+/-7.2 mmHg), thus indicating a sinusoidal component in portal hypertension. A salient finding was the presence of hepatic venovenous shunts in 7 out of 9 patients with biliary atresia; however, the HVPG could still be measured distal to the shunts, but in three patients (with an HVPG of 8 mmHg) it was determined in an area with a small venovenous communication still visible, therefore underestimating the actual portal pressure gradient. No venovenous shunts were detected in the non-biliary atresia patients.

CONCLUSIONS

HVPG is a feasible procedure in pediatric patients. Patients with biliary atresia very frequently have communicating vessels between hepatic veins. This hitherto unacknowledged finding can lead to the underestimation of portal pressure by HVPG measurement.

Clinical pharmacology of portal hypertension

Portal hypertension is an increase in pressure in the portal vein and its tributaries. It is defined as a portal pressure gradient (the difference in pressure between the portal vein and the hepatic veins) greater than 5 mm Hg. Although this gradient defines portal hypertension, a gradient of 10 mm Hg or greater defines clinically significant portal hypertension, because this pressure gradient predicts the development of varices, decompensation of cirrhosis, and hepatocellular carcinoma. The most direct consequence of portal hypertension is the development of gastroesophageal varices that may rupture and lead to the development of variceal hemorrhage. This article reviews the pathophysiologic bases of the different pharmacologic treatments for portal hypertension in patients with cirrhosis and places them in the context of the natural history of varices and variceal hemorrhage.

Cardiovascular changes in cirrhosis: pathogenesis and clinical implications

Liver cirrhosis is associated with a wide range of cardiovascular abnormalities including hyperdynamic circulation, cirrhotic cardiomyopathy, and pulmonary vascular abnormalities. The pathogenic mechanisms of these cardiovascular changes are multifactorial and include neurohumoral and vascular dysregulations. Accumulating evidence suggests that cirrhosis-related cardiovascular abnormalities play a major role in the pathogenesis of multiple life-threatening complications including hepatorenal syndrome, ascites, spontaneous bacterial peritonitis, gastroesophageal varices, and hepatopulmonary syndrome. Treatment targeting the circulatory dysfunction in these patients may improve the short-term prognosis while awaiting liver transplantation. Careful fluid management in the immediate post-transplant period is extremely important to avoid cardiac-related complications. Liver transplantation results in correction of portal hypertension and reversal of all the pathophysiological mechanisms that lead to the cardiovascular abnormalities, resulting in restoration of a normal circulation. The following is a review of the pathogenesis and clinical implications of the cardiovascular changes in cirrhosis.

Right atrial pressure is not adequate to calculate portal pressure gradient in cirrhosis: a clinical-hemodynamic correlation study

Hepatic venous pressure gradient (HVPG), the difference between wedge and free hepatic venous pressure, is the preferred method for estimating portal pressure. However, it has been suggested that hepatic atrial pressure gradient (HAPG)--the gradient between wedge hepatic venous pressure and right atrial pressure (RAP)--might better reflect variceal hemodynamics. The aim of this study was to (1) investigate whether HAPG with nonselective beta-blockers correlates with prognosis in cirrhotic patients with portal hypertension at baseline and during treatment; (2) compare the prognostic value of HAPG with that of HVPG; and (3) investigate the agreement between portoatrial gradient (PAG) and portocaval gradient (PCG) in patients with transjugular intrahepatic portosystemic shunt (TIPS). We included 154 cirrhotic patients with varices with a complete hemodynamic study at baseline and on chronic treatment for primary (n = 71) or secondary (n = 83) prophylaxis for bleeding and 99 patients with TIPS. All patients were followed for up to 2 years; portal hypertensive-related bleeding and bleeding-free survival were analyzed. HVPG was equal or lower than HAPG in all patients (-3.2 mm Hg; P < 0.001). Agreement between HAPG and HVPG was modest, especially in patients with increased intra-abdominal pressure. One hundred two patients were HVPG nonresponders and 52 patients were HVPG responders to nonselective beta-blockers, whereas 101 patients were HAPG nonresponders and 53 patients were HAPG responders (k = 0.610). HVPG response revealed an excellent predictive value for bleeding risk and bleeding-free survival; HAPG did not. In our TIPS patients, 20% had a PCG < or =12 mm Hg and a PAG >12 mm Hg, which may have induced unnecessary overdilation of the TIPS.

CONCLUSION

The excellent prognostic information provided by HVPG response to drug therapy is lost if HAPG response is considered. RAP should not be used for the calculation of portal pressure gradient in patients with cirrhosis.

Role of endoscopy in primary prophylaxis for esophageal variceal bleeding

Cirrhosis is the leading cause of portal hypertension in the Western world. From a clinical standpoint, the most significant consequence of portal hypertension is the development of esophageal varices. Despite the many advances in the management of variceal bleeding, it remains a life-threatening complication of portal hypertension. Primary prophylaxis to prevent the first bleeding episode in patients with cirrhosis and esophageal varices is therefore critically important in the management of patients with cirrhosis.

The clinical use of HVPG measurements in chronic liver disease

Portal hypertension is a severe, almost unavoidable complication of chronic liver diseases and is responsible for the main clinical consequences of cirrhosis. Measurement of the hepatic venous pressure gradient (HVPG) is currently the best available method to evaluate the presence and severity of portal hypertension. Clinically significant portal hypertension is defined as an increase in HVPG to >or=10 mmHg; above this threshold, the complications of portal hypertension might begin to appear. Measurement of HVPG is increasingly used in clinical hepatology, and numerous studies have demonstrated that the parameter is a robust surrogate marker for hard clinical end points. The main clinical applications for HVPG include diagnosis, risk stratification, identification of patients with hepatocellular carcinoma who are candidates for liver resection, monitoring of the efficacy of medical treatment, and assessment of progression of portal hypertension. Patients who experience a reduction in HVPG of >or=20% or to <12 mmHg in response to drug therapy are defined as 'responders'. Responders have a markedly decreased risk of bleeding (or rebleeding), ascites, and spontaneous bacterial peritonitis, which results in improved survival.