Comparison of the effects of a cardioselective and a nonselective beta-blocker on portal hypertension in patients with cirrhosis

Pharmacologic Treatment of Portal Hypertension

Portal hypertension is the key mechanism driving the transition from compensated to decompensated cirrhosis. In this review, the authors described the pathophysiology of portal hypertension in cirrhosis and the rationale of pharmacologic treatment of portal hypertension. We discussed both etiologic and nonetiologic treatment of portal hypertension and the specific clinical scenarios how nonselective beta-blocker can be used in patients with cirrhosis. Finally, the authors summarized the evidence for emerging alternatives for portal hypertension in patients with cirrhosis.

Therapies for Cirrhotic Cardiomyopathy: Current Perspectives and Future Possibilities

Cirrhotic cardiomyopathy (CCM) is defined as cardiac dysfunction associated with cirrhosis in the absence of pre-existing heart disease. CCM manifests as the enlargement of cardiac chambers, attenuated systolic and diastolic contractile responses to stress stimuli, and repolarization changes. CCM significantly contributes to mortality and morbidity in patients who undergo liver transplantation and contributes to the pathogenesis of hepatorenal syndrome/acute kidney injury. There is currently no specific treatment. The traditional management for non-cirrhotic cardiomyopathies, such as vasodilators or diuretics, is not applicable because an important feature of cirrhosis is decreased systemic vascular resistance; therefore, vasodilators further worsen the peripheral vasodilatation and hypotension. Long-term diuretic use may cause electrolyte imbalances and potentially renal injury. The heart of the cirrhotic patient is insensitive to cardiac glycosides. Therefore, these types of medications are not useful in patients with CCM. Exploring the therapeutic strategies of CCM is of the utmost importance. The present review summarizes the possible treatment of CCM. We detail the current status of non-selective beta-blockers (NSBBs) in the management of cirrhotic patients and discuss the controversies surrounding NSBBs in clinical practice. Other possible therapeutic agents include drugs with antioxidant, anti-inflammatory, and anti-apoptotic functions; such effects may have potential clinical application. These drugs currently are mainly based on animal studies and include statins, taurine, spermidine, galectin inhibitors, albumin, and direct antioxidants. We conclude with speculations on the future research directions in CCM treatment.

Isolated Subclinical Right Ventricle Systolic Dysfunction in Patients after Liver Transplantation

Although hemodynamic alterations in end-stage liver disease (ESLD) and its association with porto-pulmonary hypertension have been well-established, the long-term effects of ESLD on RV systolic function in patients without porto-pulmonary hypertension remain disregarded. Here we aimed to assess the long-term effect of ESLD on RV function and its relationship with the use of NSBBs and clinical, laboratory and imaging parameters in end-stage liver disease. The use of NSBBs is still controversial due to concerns about reduced cardiac contractility and the possibility of increased mortality. Thirty-four liver transplant recipients were included. Demographic characteristics, laboratory and baseline echocardiography measures were obtained. Patients were recalled for transthoracic echocardiographic evaluation after transplantation. Right ventricle dysfunction was identified by having at least one value below the reference levels of RV S’, or TAPSE. Isolated subclinical RV dysfunction was observed at 20.6% of the sample population. The present study demonstrates hemodynamic circulation in cirrhosis and increased preload and afterload might have long-term effects on RV function, even the lack of porto-pulmonary hypertension. These findings underline the significance of cardiac function follow-up in cirrhotic patients after transplantation. In this study, patients treated with propranolol seemed to have better RV function and less gastrointestinal bleeding. We speculated that preoperative propranolol treatment might help preserve RV function by providing RAS suppression, improving endothelial function and hyperdynamic circulation seen in ESLD. This potential protective relationship between the use of propranolol and RV function might improve mortality or graft-failure during OLT and after liver transplantation in patients with cirrhosis.

Beta-blockers in patients with liver cirrhosis: Pragmatism or perfection?

With increasing decompensation, hyperdynamic circulatory disturbance occurs in liver cirrhosis despite activation of vasoconstrictors. Here, the concept of a therapy with non-selective beta-blockers was established decades ago. They lower elevated portal pressure, protect against variceal hemorrhage, and may also have pleiotropic immunomodulatory effects. Recently, the beneficial effect of carvedilol, which blocks alpha and beta receptors, has been highlighted. Carvedilol leads to "biased-signaling" via recruitment of beta-arrestin. This effect and its consequences have not been sufficiently investigated in patients with liver cirrhosis. Also, a number of questions remain open regarding the expression of beta-receptors and its intracellular signaling and the respective consequences in the intra- and extrahepatic tissue compartments. Despite the undisputed role of non-selective beta-blockers in the treatment of liver cirrhosis, we still can improve the knowledge as to when and how beta-blockers should be used in which patients.

β-blockers in advanced cirrhosis: More friend than enemy

Nonselective beta-adrenergic blocker (NSBB) therapy for the prevention of initial and recurrent gastrointestinal bleeding in cirrhotic patients with gastroesophageal varices has been used for the past four decades. NSBB therapy is considered the cornerstone of treatment for varices, and has become the standard of care. However, a 2010 study from the group that pioneered β-blocker therapy suggested a detrimental effect of NSBBs in decompensated cirrhosis, especially in patients with refractory ascites. Since then, numerous additional studies have incompletely resolved whether NSBBs are deleterious, although more recent evidence weighs against a harmful effect. The possibility of a "therapeutic window" has also been raised. We aimed to review the literature to analyze the pros and cons of using NSBBs in patients with cirrhosis, not only with respect to bleeding or mortality but also to other potential benefits and risks. β-blockers are highly effective in preventing first bleeding and recurrent bleeding. Furthermore, NSBBs improve congestion/ischemia of the gut mucosa, decrease intestinal permeability, and therefore indirectly alleviate systemic inflammation. β-blockers shorten the electrocardiographic prolonged QTc interval and may also decrease the incidence of hepatocellular carcinoma. On the other hand, the possibility of deleterious effects in cirrhosis has not been completely eliminated. NSBBs may be associated with an increased risk of portal vein thrombosis, although this could be correlational artifact. Overall, we conclude that β-blockers in cirrhosis are much more of a friend than enemy.

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.

Selection of β-Blocker in Patients With Cirrhosis and Acute Myocardial Infarction: A 13-Year Nationwide Population-Based Study in Asia

Background It is not clear whether β₁-selective or nonselective β-blockers should be used in patients with cirrhosis and acute myocardial infarction. Methods and Results Medical records were retrieved from Taiwan NHIRD (National Health Insurance Research Database) during 2001-2013. Patients were excluded for age <20, previous acute myocardial infarction, contraindication to β-blockers, chronic obstructive pulmonary disease, asthma, or atrioventricular conduction disease. Patients who died during index admission, had a follow-up <6 months, had a medication ratio of either β₁-selective or nonselective β-blocker <80%, or who switched between β-blockers were also excluded. Patients on β₁-selective blockers and nonselective β-blockers were propensity score matched and compared for outcome. Primary outcomes were 1- and 2-year cardiovascular events, liver adverse outcomes, and all-cause mortality. A total of 203 595 patients with acute myocardial infarction were enrolled, of whom 6355 had cirrhosis. After screening for exclusion criteria, 1769 patients (655 patients on β-blockers and 1114 patients not on β-blockers) were eligible for analysis. Among patients on β-blockers, propensity score matching was performed, and 218 patients on β₁-selective blockers and 218 patients on nonselective β-blockers were studied. During a 2-year follow-up, patients on β₁-selective blockers had significantly fewer major cardiac and cerebrovascular events (hazard ratio=0.62; 95% confidence interval=0.42-0.91; P=0.014), a trend toward lower all-cause mortality (hazard ratio=0.66; 95% confidence interval=0.38-1.14; P=0.135), and nonworsening liver outcome (hazard ratio=0.66; 95% confidence interval=0.38-1.14; P=0.354). Conclusions In patients with cirrhosis and acute myocardial infarction, selecting a β-blocker is a clinical dilemma. Our study showed that the use of β₁-selective blockers is associated with lower risks of major cardiac and cerebrovascular events.

Systematic review with a meta-analysis: clinical effects of statins on the reduction of portal hypertension and variceal haemorrhage in cirrhotic patients

BACKGROUND

Statins may improve outcomes in patients with cirrhosis. We performed a systematic review and meta-analysis to evaluate the effect of statins on patients with cirrhosis and related complications, especially portal hypertension and variceal haemorrhage.

METHODS

Studies were searched in the PubMed, Embase and Cochrane library databases up to February 2019. The outcomes of interest were associations between statin use and improvement in portal hypertension (reduction >20% of baseline or <12 mm Hg) and the risk of variceal haemorrhage. The relative risk (RR) with a 95% CI was pooled and calculated using a random effects model. Subgroup analyses were performed based on the characteristics of the studies.

RESULTS

Eight studies (seven randomised controlled trials (RCTs) and one observational study) with 3195 patients were included. The pooled RR for reduction in portal hypertension was 1.91 (95% CI, 1.04 to 3.52; I²=63%) in six RCTs. On subgroup analysis of studies that used statin for 1 month, the RR was 2.01 (95% CI, 1.31 to 3.10; I²=0%); the pooled RR for studies that used statins for 3 months was 3.76 (95% CI, 0.36 to 39.77; I²=75%); the pooled RR for studies that used non-selective beta-blockers in the control group was 1.42 (95% CI, 0.82 to 2.45; I²=64%); the pooled RR for studies that used a drug that was not reported in the control group was 4.21 (95% CI, 1.52 to 11.70; I²=0%); the pooled RR for studies that used simvastatin was 2.20 (95% CI, 0.92 to 5.29; I²=69%); RR for study using atorvastatin was 1.82 (95% CI, 1.00 to 3.30). For the risk of a variceal haemorrhage, the RR based on an observational study was 0.47 (95% CI, 0.23 to 0.94); in two RCTs, the pooled RR was 0.88 (95% CI, 0.52 to 1.50; I²=0%). Overall, the summed RR was 0.64 (95% CI, 0.42 to 0.99; I²=6%).

CONCLUSION

Statins may improve hypertension and decrease the risk of variceal haemorrhage according to our assessment. However, further and larger RCTs are needed to confirm this conclusion.

Repurposing of approved cardiovascular drugs

Research and development of new drugs requires both long time and high costs, whereas safety and tolerability profiles make the success rate of approval very low. Drug repurposing, applying known drugs and compounds to new indications, has been noted recently as a cost-effective and time-unconsuming way in developing new drugs, because they have already been proven safe in humans. In this review, we discuss drug repurposing of approved cardiovascular drugs, such as aspirin, beta-blockers, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, cardiac glycosides and statins. Regarding anti-tumor activities of these agents, a number of experimental studies have demonstrated promising pleiotropic properties, whereas all clinical trials have not shown expected results. In pathological conditions other than cancer, repurposing of cardiovascular drugs is also expanding. Numerous experimental studies have reported possibilities of drug repurposing in this field and some of them have been tried for new indications ('bench to bedside'), while unexpected results of clinical studies have given hints for drug repurposing and some unknown mechanisms of action have been demonstrated by experimental studies ('bedside to bench'). The future perspective of experimental and clinical studies using cardiovascular drugs are also discussed.

Effect of propranolol on survival in patients with decompensated cirrhosis: a nationwide study based Danish patient registers

BACKGROUND & AIMS

We assessed the impact of propranolol on death, risk of hepatorenal syndrome and peritonitis in patients with cirrhosis.

METHODS

This study was a retrospective observational study and data were retrieved from Danish databases. We used our own criteria to stratify the patients into groups of patients with mildly decompensated cirrhosis or severely decompensated cirrhosis. A subgroup of patients with a history of peritonitis was also analyzed. Follow-up time was limited to 2 years from cohort entry. The reported hazard ratios (HR) with 95% confidence interval (CI) were based on a propensity score matched cohort.

RESULTS

Among 3719 patients, we found 3075 patients with mildly and 644 with severely decompensated cirrhosis. Propranolol was used by 20% of the patients. Among the patients with mildly decompensated cirrhosis, propranolol use vs. non-propranolol was related with a HR of 0.7 (95% CI 0.6-0.9) and among the patients with severely decompensated cirrhosis, the HR was 0.6 (95% CI 0.4-0.9). Reduced mortality was found for doses of propranolol lower than 160 mg/day only. Among 361 patients with peritonitis, we found reduced mortality in the propranolol group with a HR of 0.5 (95% CI 0.3-0.8). The use of propranolol was associated with a HR of 0.4 (95% CI 0.2-0.9) for developing peritonitis during follow-up among patients with severely decompensated cirrhosis.

CONCLUSIONS

In patients with decompensated cirrhosis, we found an association between propranolol use and reduced mortality risk for doses lower than 160 mg/day.

Lack of clinical or haemodynamic rebound after abrupt interruption of beta-blockers in patients with cirrhosis

BACKGROUND

Beta-blockers may have to be interrupted in patients with cirrhosis. The concept of a rebound after interruption of beta-blockers is based on an animal study and on isolated case reports of variceal bleeding.

AIM

To determine if a rebound occurs in patients with cirrhosis following abrupt interruption of beta-blockers.

METHODS

We prospectively included all consecutive patients with cirrhosis undergoing right heart and hepatic vein catheterisation. Four groups were defined: 'no beta-blockers' including patients not receiving beta-blockers; '≤1 day', '2-3 days' and '≥4 days' classified according to the time patients had interrupted beta-blockers before catheterisation. Results were expressed as median (interquartile range).

RESULTS

A total of 150 patients were included. Among the 25 patients in the groups '2-3 days' and '≥4 days', median duration of beta-blockers interruption was 4 (3-6) days. No gastrointestinal bleeding occurred during that period, nor during the following month. Hepatic venous pressure gradient was not different among patients in usually treated with beta-blockers. After adjustment, beta-blockers interruption was not associated with hepatic venous pressure gradient. Cardiac index was higher in the '≥4 days' group [4.6 L/min/m(2) (3.5-5.1)] than in the '≤1 day' group [3.4 (2.6-4.0); P = 0.001] or in the '2-3 days' group [3.1 (2.7-3.7); P = 0.007], but not different from the 'no beta-blockers' group.

CONCLUSIONS

Abrupt interruption of beta-blockers is associated neither with an apparent increase in the risk of variceal bleeding nor with a haemodynamic rebound. Thus, interruption of beta-blockers in patients with cirrhosis may not require particular dosing or surveillance.

β-Blocker therapy ameliorates hypersplenism due to portal hypertension in children

BACKGROUND/PURPOSE

Thrombocytopenia due to hypersplenism precludes percutaneous liver biopsy in many cases of chronic liver disease (CLD). The aim of this study was to assess the efficacy of propranolol in correcting platelet counts (>100,000/mm(3)) to ensure percutaneous liver biopsy in children with CLD.

METHODS

From January 2005 to December 2012, 51 consecutive children (mean age 11.5 ± 3.0 years, 34 boys) with CLD who needed liver biopsy but could not be done due to hypersplenism-related thrombocytopenia (platelets <100,000/mm(3) and/or total leukocyte counts <4,000/mm(3) with splenomegaly) were recruited and given a 4-week trial of long-acting propranolol (1.5-2 mg/kg/day). Hemodynamic parameters and splenic artery hemodynamics by Doppler ultrasound were recorded before and after the propranolol trial. Response to therapy was defined as improvement of platelet counts to ≥10(5)/mm(3).

RESULTS

Thirty-two (62.7%) children responded to propranolol therapy and their mean platelet counts increased from 57.5 ± 13.0 × 10(3) to 140.7 ± 43.3 × 10(3)/mm(3), p = 0.0001. Liver biopsy could be done in 29. While comparing responders with non-responders, baseline spleen size (7.4 ± 3.3 vs. 12.7 ± 4.5 cm, p = 0.0001) and platelet counts (57.5 ± 13.0 × 10(3) vs. 39.5 ± 14.5 × 10(3), p = 0.0001) were found to be significant. ROC curve suggested a cut-off value of ≤8.5 cm of spleen and ≥53,000 platelets as predictors of response. With propranolol, mean arterial pressure and spleen size reduced (p < 0.05) and splenic artery resistance increased significantly (p = 0.005) in responders.

CONCLUSIONS

Propranolol corrects thrombocytopenia and makes liver biopsy possible in almost two-thirds of cases by reducing splenic sequestration through splenic artery vasoconstriction. The baseline spleen size and platelet counts determine the effectiveness of therapy. A trial of β-blocker is worth carrying out in cases where liver biopsy is contraindicated due to hypersplenism-related thrombocytopenia.

The changing role of beta-blocker therapy in patients with cirrhosis

Cirrhosis is a leading cause of death in the United States and worldwide. Beta-blockers have been established in numerous studies as part of the cornerstone of the medical management of cirrhosis, particularly in the primary and secondary prevention of variceal hemorrhage. However, new evidence has cautioned the use of beta-blockers in patients with end-stage cirrhosis and refractory ascites. In this article, we review the beneficial effects of beta-blocker therapy, the potential harms of aggressive beta-blocker therapy, and provide suggestions regarding the appropriate use of this class of medications in patients with cirrhosis.

Effect of propranolol on the relationship between QT interval and vagal modulation of heart rate variability in cirrhotic patients awaiting liver transplantation

BACKGROUND

Prolonged corrected QT (QT(c)) interval and vagal dysfunction are common occurrences in liver cirrhosis and are determinants of mortality in patients with chronic liver disease. We evaluated whether propranolol can affect the relationship between QT(c) interval and cardiac vagal control of heart rate variability (HRV) in cirrhotic patients awaiting liver transplantation.

METHODS

We compared 50 cirrhotic patients (M/F = 43/7, 52.6 ± 8.4 years, Child-Pugh class A/B/C: 9/24/17) receiving propranolol with a sex-, age-, and liver disease severity-matched control group of 50 patients (M/F = 43/7, 52.0 ± 8.3 year, Child-Pugh class A/B/C: 9/24/17) not receiving propranolol. Among the parameters evaluated were QT(c) interval and cardiac vagal indices of HRV, including the root mean square of successive differences in R-R intervals (RMSSD); spectral power in the high-frequency range (HF); standard deviation (SD)1 in Poincare plot; and sample entropy. Correlations between QT(c) interval and vagal indices of HRV were analyzed.

RESULTS

The mean duration of preoperative propranolol treatment in the propranolol group was 19.4 ± 24.7 months. QT(c) interval was significantly lower, whereas RMSSD, HF, SD1, and sample entropy were significantly higher in the propranolol group than in the control group. Correlation coefficients between QT(c) interval and RMSSD, HF, SD1, and sample entropy were higher in the propranolol group than in the control group.

CONCLUSIONS

The prolonged QT(c) interval observed in cirrhotic patients may be reduced by propranolol administration, an effect attributable to improved vagal cardiac modulation. These findings suggest that propranolol may have a beneficial effect on perioperative mortality in cirrhotic patients awaiting liver transplantation.

Evaluation of regional hepatic perfusion (RHP) by contrast-enhanced ultrasound in patients with cirrhosis

BACKGROUND & AIMS

Ultrasonographic contrast agents allow the assessment of myocardial and renal perfusion through the analysis of refill kinetics after microbubbles rupture. This study evaluated the feasibility of contrast-enhanced ultrasonographic (CEUS) estimations of regional hepatic perfusion in patients with cirrhosis, and its correlation with clinical and hemodynamic parameters.

METHODS

Fifty-five patients with cirrhosis undergoing hepatic vein catheterization were included. Hepatic perfusion was studied by CEUS (using Contrast Coherent Imaging) during a continuous i.v. infusion of microbubbles (SonoVue®); after their rupture (high insonation power), tissue refill was digitally recorded and time-intensity curves were electronically calculated on a region of interest of the right hepatic lobe. Regional hepatic perfusion (RHP) was calculated as microbubbles velocity×microbubble concentration. During hepatic vein catheterization, we measured hepatic blood flow by indocyanine green (ICG) infusion, hepatic venous pressure gradient (HVPG), and cardiac output (Swan-Ganz catheter).

RESULTS

RHP was higher in patients than in healthy controls (5.1±3.7 vs. 3.4±0.7, p=0.003), and correlated with MELD (R=0.403, p=0.002), Child-Pugh score (R=0.348, p=0.009), and HVPG (R=0.279, p=0.041). RHP inversely correlated with ICG extraction (R=-0.346, p=0.039), ICG intrinsic clearance (R=-0.327, p=0.050), and ICG clearance (R=0.517, p=0.001), and directly correlated with hyperdynamic syndrome markers (cardiac index R=0.422, p=0.003; mean arterial pressure R=-0.405, p=0.004; systemic vascular resistance R=-0.496, p=0.001).

CONCLUSIONS

RHP increases in patients with cirrhosis and correlates with the degree of liver failure and hyperdynamic syndrome. RHP increases along with liver functional reserve decrease, suggesting that RHP increase occurs mainly through anatomical/functional shunts. RHP by CEUS is a feasible novel, objective, quantitative, non-invasive tool, potentially useful for the estimation of hepatic perfusion in patients with cirrhosis.

[Progress in portal hypertension]

In patients with portal hypertension due to cirrhosis, the mechanisms responsible for circulatory modifications are well-known. An elevation in intrahepatic vascular resistance related to a hepatic endothelin hyperproduction and an arterial nitric oxide (NO) hyperproduction. The presence and the degree of portal hypertension might be determined by the measurement of the hepatic venous pressure gradient but non-invasive technique as FibroTest or FibroScan might be useful to estimate the presence of severe portal hypertension. Numerous substances decrease portal pressure either by reducing hepatic vascular resistance or by reducing portal tributary blood flow. The combination of both types of substances is probably the best pharmacological treatment of portal hypertension but further hemodynamic and clinical studies are needed.

Comparative effects of carvedilol and lercanidipine on ultrafiltration and solute transport in CAPD patients

BACKGROUND

Peritonitis, the type of buffer used in the dialysate, continue ambulatory peritoneal dialysis (CAPD) of greater than two years duration, increased exposure to dialysate glucose, diabetes mellitus, and the use of beta blockers may contribute to impaired ultrafiltration.

OBJECTIVES

The aim of the present study is to compare the effects of a calcium-channel blocker and a beta-blocker on the peritoneal transport and clearance.

METHODS

We studied 48 patients with ESRD on chronic peritoneal dialysis, included 27 females and 19 males with mean age 42.6 +/- 16.4 years. Two patients were excluded from the study due to peritonitis. Patients were treated either with carvedilol or lercanidipine. In all patients; peritoneal equilibration test (PET), ultrafiltration (UF), Kt/V ratio, creatinine clearance (CrCl), systolic blood pressure, diastolic blood pressure, serum BUN, creatinine, glucose, sodium, potassium, albumin, cholesterol, and triglyceride values were obtained before and after 8 weeks from the start of the drug treatment.

RESULTS

Lercanidipine and carvedilol showed a good antihypertensive effect in CAPD patients. Both drugs had a good tolerability profile and showed no effect on plasma lipids. There were no differences in terms of PET, ultrafiltration, Kt/V ratio, CrCl, systolic blood pressure, diastolic blood pressure, serum BUN, creatinine, glucose, sodium, and potassium values between both patient groups. After antihypertensive treatment, neither group showed a difference in the above-mentioned parameters (p > 0.05) except potassium, which was significantly higher in the carvedilol group (p < 0.05).

CONCLUSIONS

In CAPD patients. short-term usage of carvedilol has no effect on ultrafiltration and solute transport like lercanidipine. Both drugs showed a good antihypertensive effect.

Octreotide enhances portal pressure reduction induced by propranolol in cirrhosis: a randomized, controlled trial

BACKGROUND

In vitro, octreotide potentiates vasoconstriction in isolated, preconstricted, mesenteric arterial vessels. In cirrhotic patients, portal pressure (HVPG) reduction induced by propranolol is partly due to splanchnic vasoconstriction.

AIM

To evaluate HVPG effects of octreotide administration in cirrhotic patients receiving long-term propranolol.

PATIENTS AND METHODS

A randomized, controlled trial. First study: a total of 28 patients were studied at baseline and 30 and 60 minutes after octreotide (200 mug) (N = 14) or placebo (N = 14) and then treated with propranolol for approximately 30 days (106 +/- 5 mg/day). Second study: after baseline evaluation patients received octreotide or placebo as they were assigned to in the first study and measurements repeated 30 and 60 minutes later.

RESULTS

In the first study baseline HVPG was 18.7 +/- 0.9 mmHg and decreased to 17.1 +/- 1.1 mmHg and 17.1 +/- 1.0 mmHg (both P < 0.05 vs baseline) at 30 and 60 minutes after octreotide, respectively. Eight patients decreased their HVPG after octreotide. In the second study baseline HVPG was 15.6 +/- 1.3 mmHg (P < 0.01 vs baseline HVPG in first study) and decreased to 14.1 +/- 1.2 mmHg and 14.1 +/- 1.3 mmHg (25.7 +/- 5% lower than baseline HVPG in the first study, P < 0.01) (both P < 0.05 vs baseline) at 30 and 60 minutes after octreotide, respectively. Nine patients (2 responders/7 nonresponders to propranolol) decreased their HVPG after octreotide. Octreotide effects may be mediated by potentiation and additive mechanisms.

CONCLUSIONS

Octreotide enhances HVPG reduction induced by propranolol in cirrhotic patients.

Current management of the complications of portal hypertension: variceal bleeding and ascites

Portal hypertension is one of the main consequences of cirrhosis. It results from a combination of increased intrahepatic vascular resistance and increased blood flow through the portal venous system. The condition leads to the formation of portosystemic collateral veins. Esophagogastric varices have the greatest clinical impact, with a risk of bleeding as high as 30% within 2 years of medium or large varices developing. Ascites, another important complication of advanced cirrhosis and severe portal hypertension, is sometimes refractory to treatment and is complicated by spontaneous bacterial peritonitis and hepatorenal syndrome. We describe the pathophysiology of portal hypertension and the current management of its complications, with emphasis on the prophylaxis and treatment of variceal bleeding and ascites.

Beta blocker prophylaxis for patients with variceal hemorrhage

GOALS

To characterize beta blocker therapy for the primary and secondary prevention of variceal hemorrhage.

BACKGROUND

Variceal hemorrhage is one of the more frequent and severe complications of portal hypertension due to liver disease. Beta blocker therapy has been demonstrated to decrease risk of first bleed in patients with evidence of varices and recurrent bleeding and mortality in patients with history of prior variceal hemorrhage.

STUDY

A total of 106 patients with liver disease hospitalized with suspected variceal hemorrhage were retrospectively reviewed.

RESULTS

Half of patients had known varices, 44 (41.5%) of whom had experienced prior variceal hemorrhage. Only 21 (20%) were receiving beta blocker therapy at admission and 41 (48%) at discharge. The majority were not receiving therapy for primary prophylaxis (94%). Specific characteristics associated with beta blocker use could not be identified, although more patients with history of greater than two variceal hemorrhages were receiving beta blocker at admission (73% vs. 41%, P = 0.04)

CONCLUSIONS

This study suggests that liver disease patients with varices are often not receiving beta blocker therapy to reduce risk of first or subsequent variceal hemorrhage. Opportunity exists to optimize use of this proven prophylactic treatment and bridge an apparent gap in standard of care.

Role of acute elevation of portal venous pressure by exogenous glucagon on gastric mucosal injury in rats with portal hypertension

Time-course studies revealed the increased susceptibility of the gastric mucosa to noxious injury in portal hypertension correlates with the level of elevated portal venous pressure and hyperglucagonemia. Whether acute elevation of portal venous pressure by exogenous glucagon aggravates such injury is not known. We tested the hypothesis that glucagon in a dose sufficient to acutely elevate portal venous pressure aggravates noxious injury of the gastric mucosa in rats with portal hypertension. Infusion of a portal hypotensive dose of somatostatin should reverse these changes. In anesthetized rats with portal vein ligation, glucagon, somatostatin or the combination was administered intravenously in a randomized, coded fashion. Acidified ethanol-induced gastric mucosal injury was determined. Portal venous pressure and gastric mucosal perfusion and oxygenation (reflectance spectrophotometry) were monitored to confirm the effects of the respective intravenous treatments. Exogenous glucagon exacerbated acidified ethanol-induced gastric mucosal injury. The exacerbation was attenuated by somatostatin. These changes paralleled the portal hypertensive and hypotensive effects of glucagon and somatostatin, respectively. Our data suggest that a unique mechanism is triggered with the onset of portal hypertension. In an antagonistic manner, glucagon and somatostatin modulate this novel mechanism that controls portal venous pressure and susceptibility of the gastric mucosa to noxious injury.

Hemodynamic response to pharmacological treatment of portal hypertension and long-term prognosis of cirrhosis

In cirrhotic patients under pharmacologic treatment for portal hypertension, a reduction in hepatic venous pressure gradient (HVPG) of >or=20% of baseline or to <or=12 mm Hg markedly reduces the risk of variceal rebleeding. This study was aimed at evaluating whether these hemodynamic targets also prevent other complications of portal hypertension and improve long-term survival. One hundred five cirrhotic patients included in prospective trials for the prevention of variceal rebleeding were studied. Seventy-three of the patients had 2 separate HVPG measurements, at baseline and under pharmacologic therapy with propranolol +/- isosorbide mononitrate. Patients were followed for up to 8 years. Survival and risk of developing portal hypertension-related complications were compared between responders and nonresponders. Twenty-eight patients showed a reduction of HVPG >or=20% of baseline or to <or=12 mm Hg (responders), and 45 patients were nonresponders. Nonresponders had a significantly greater risk of developing variceal rebleeding (P =.013), ascites (P =.025), spontaneous bacterial peritonitis (P =.003), hepatorenal syndrome (P =.026), and hepatic encephalopathy (P =.024) than responders. Eight-year cumulative probability of survival was significantly lower in nonresponders than in responders (52% vs. 95%, respectively, P =.003). At multivariate analysis, being a nonresponder was independently associated with the risk of developing rebleeding, ascites, spontaneous bacterial peritonitis, and lower survival. In conclusion, in cirrhotic patients receiving pharmacologic treatment for prevention of variceal rebleeding, a decrease in HVPG >or=20% or to <or=12 mm Hg is associated with a marked reduction in the long-term risk of developing complications of portal hypertension and with improved survival.

Role of spleen enlargement in cirrhosis with portal hypertension

The possible relationships between splenomegaly and portal hypertension have been analysed in patients with cirrhosis. In this condition, splenomegaly is not only caused by portal congestion, but it is mainly due to tissue hyperplasia and fibrosis. The increase in spleen size is followed by an increase in splenic blood flow, which participates in portal hypertension actively congesting the portal system.

Primary prophylaxis of variceal hemorrhage

Figure 3 shows an algorithm for the primary prevention of variceal hemorrhage. Pharmacologic therapy is the current standard of treatment for the primary prophylaxis of esophageal variceal bleeding. Patients with medium or large varices should be treated with a nonselective beta-blocker with the dose titrated to achieve a 25% decrement in resting heart rate or a heart rate of 55 to 60 bpm. The development of symptoms will, of course, limit the dose used. As discussed previously, these therapeutic endpoints are not well correlated with decreases in portal pressure. Measurement of the HVPG before therapy and after 3 months of therapy provides a rational approach to drug dosing. If the HVPG decreases by 20% or to less than 12 mm Hg, the medication dose will be effective in preventing hemorrhage. If, however, the HVPG is not appropriately lowered, a long-acting nitrate may be added. Patients with small varices should be observed, with endoscopic examinations every 2 years to assess progression of variceal size. Endoscopic therapy is not indicated for the primary prevention of variceal bleeding.

Review article: a drug therapy for the prevention of variceal haemorrhage

The development of varices is a major complication of cirrhosis, and variceal haemorrhage has a high mortality. There have been major advances in the primary and secondary prevention of variceal haemorrhage over the last 20 years involving endoscopic, radiological and pharmacological approaches. This review concentrates principally on drug therapy, particularly on the numerous haemodynamic studies. Many of these drugs have not been studied in clinical trials, but provide data about the underlying pathogenesis of portal hypertension. Also covered in this review are the randomized controlled trials and meta-analyses that involve a large number of patients. These trials involve relatively few drugs such as non-selective beta-blockers and nitrates. Correlations between haemodynamic and clinical parameters are discussed. Despite the recent increase in the use of alternative endoscopic therapies, an effective and well tolerated drug remains a clinically important research goal.

Complications of cirrhosis. I. Portal hypertension

Increased resistance to portal blood flow is the primary factor in the pathophysiology of portal hypertension, and is mainly determined by the morphological changes occurring in chronic liver diseases. This is aggravated by a dynamic component, due to the active-reversible- contraction of different elements of the porto-hepatic bed. A decreased synthesis of NO in the intrahepatic circulation is the main determinant of this dynamic component. This provides a rationale for the use of vasodilators to reduce intrahepatic resistance and portal pressure. Another factor contributing to aggravate the portal hypertension is a significant increase in portal blood flow, caused by arteriolar splanchnic vasodilation and hyperkinetic circulation. Splanchnic arteriolar vasodilation is a multifactorial phenomenon, which may involve local (endothelial) mechanisms as well as neurogenic and humoral pathways. Most pharmacological treatments have been aimed at correcting the increased portal blood inflow by the use of splanchnic vasoconstrictors, such as beta-blockers, vasopressin derivatives and somatostatin. Several studies have demonstrated that changes in the hepatic venous pressure gradient (HVPG) during maintenance therapy are useful to identify those patients who are going to have a variceal bleeding or rebleeding. The wide individual variation in the HVPG response to pharmacological treatment makes it desirable to schedule follow-up measurements of HVPG during pharmacological therapy. A priority for research in the forthcoming years is to develop accurate non-invasive methods to assess prognosis, which can be used to substitute or as surrogate indicators of the HVPG response. In the clinical management of portal hypertension, beta-blockers are at present the only accepted treatment for the prevention of variceal bleeding. Whether the association of isosorbide-5-mononitrate will improve the high efficacy of beta-blockers is questionable. The efficacy of more aggressive techniques, such as endoscopic band ligation, should be further tested against beta-blockers in patients with a high risk of bleeding. In the treatment of acute variceal bleeding, administration of somatostatin or terlipressin is an established therapy. It may be used alone or, preferably, as an initial treatment before sclerotherapy or endoscopic band ligation. No more than two sessions of endoscopic treatment should be used to control the bleeding. If the bleeding is not easily controlled, other alternatives such as transjugular intrahepatic portosystemic shunts (TIPS) or derivative surgery should be considered, the former being the best in patients with poor liver function. Recent studies suggest that early measurement of HVPG during variceal bleeding may be used as a guide for therapeutic decisions in the treatment of patients with acute variceal bleeding. Those patients with a high HVPG have a high risk of poor evolution, and may be candidates for more intensive and aggressive therapy, such as surgery or TIPS. Those with lower HVPG have a very high probability of an uneventful evolution, and may thus be managed more conservatively using medical and endoscopic treatments. Pharmacological agents (propranolol or nadolol), endoscopic treatment (preferably banding ligation) or surgery can be used to prevent rebleeding. A pending task for the new millennium is to assess whether the early treatment of asymptomatic, compensated cirrhotic patients with portal pressure reducing agents can prevent the development of esophageal varices and of other complications of portal hypertension.

Propranolol stereoisomer plasma concentrations and portal haemodynamic response in patients with liver cirrhosis

BACKGROUND

The haemodynamic effect of propranolol on portal pressure in patients with portal hypertension is highly variable and does not correlate with propranolol racemate plasma concentrations.

AIM

To investigate the stereoselective metabolism of the propranolol enantiomers and its impact on portal haemodynamics in patients with liver cirrhosis since only S-propranolol is haemodynamically active.

METHODS

Twenty patients with liver cirrhosis and portal hypertension received 40 mg propranolol orally. Portal blood velocity (PBV) and propranolol stereoisomer plasma concentrations were determined.

RESULTS

During the 4 h examination period we observed a significant reduction in PBV (18.3 +/- 2.2%, P < 0.0001) vs. baseline. The area under the curve (AUC) during the study period was significantly different for the two isomers (S-propranolol 1217.0 +/- 118.5 nmol.h/L; R-propranolol 728.8 +/- 103.8 nmol.h/L, P < 0.0001). Seven patients (35%) were portal haemodynamic non-responders to propranolol. Propranolol stereoisomer AUC values were no different between responders (S-propranolol 1133. 3 +/- 132.0 nmol.h/L; R-propranolol 718.0 +/- 129.7 nmol.h/L) and non-responders (S-propranolol 1371.8 +/- 250.5 nmol.h/L; R-propranolol 746.9 +/- 200.3 nmol.h/L); neither was there a correlation between propranolol enantiomer plasma concentrations and the portal haemodynamic effect.

CONCLUSIONS

Our data demonstrate a stereoselective metabolism of propranolol enantiomers in liver cirrhosis. However, following oral propranolol administration, stereoisomer plasma concentrations do not predict the portal haemodynamic effect.

Noninvasive hemodynamic measurements of superior mesenteric artery in the prediction of portal pressure response to propranolol

BACKGROUND/AIMS

The portal pressure response to propranolol administration is heterogeneous in patients with cirrhosis. The aim of this study was to examine the diagnostic accuracy of noninvasive hemodynamic parameters of superior mesenteric artery (SMA) and femoral artery (FA) in the prediction of portal pressure response to propranolol.

METHODS

Twenty-six patients with cirrhosis were studied. Portal pressure was assessed by measurements of hepatic venous pressure gradient. Mean arterial pressure and heart rate were also recorded. Cardiac index, and flow velocity of SMA and FA, and pulsatility index of SMA and FA were then measured by means of Doppler ultrasonography. After intravenous propranolol administration (0.10 mg/kg), the above measurements were repeated.

RESULTS

Propranolol significantly reduced cardiac index, heart rate, SMA flow velocity, and FA flow velocity and increased SMA pulsatility index and FA pulsatility index. Although propranolol significantly decreased hepatic venous pressure gradient, a reduction of > or =20% was seen in only 10 patients (good responders); the remaining 16 patients exhibited <20% reduction (poor responders). No significant differences in clinical and baseline hemodynamic data were found in the two groups. There were no also significant differences in changes in heart rate and cardiac index. However, reductions in SMA and FA flow velocity were significantly greater in good responders than in poor responders. Although there was no the increase in FA pulsatility index, the increase in SMA pulsatility index was significantly greater in good responders than in poor responders. When appropriate cut-off points were determined for these variables, overall predictive values of SMA flow velocity (-20%) and SMA pulsatility index (+15%) were 91% and 83%, whereas the overall predictive value of FA flow velocity (-25%) was only 69%.

CONCLUSIONS

These results suggest that SMA flow velocity and SMA pulsatility index, but not FA flow velocity and FA pulsatility index, are useful noninvasive parameters in the prediction of portal pressure response to propranolol administration.

Hemodynamic and metabolic effects of terlipressin in patients with cirrhosis receiving a nonselective beta-blocker

Terlipressin (Glypressin), a vasopressin analog, may be administered to patients with cirrhosis receiving a beta-adrenergic antagonist. Since terlipressin alone and beta-blockers alone both decrease portal pressure, a combination of these substances may have additional portal hypotensive effects. However, the negative side effects of terlipressin may be accentuated by long-term beta-blockade. Thus, the present study examined hemodynamic and metabolic responses to terlipressin in 12 patients receiving nonselective beta-blockers (propranolol or nadolol). Hemodynamics and oxygen (O2) -derived variables were measured prior to and 30 min after the administration (intravenous bolus) of terlipressin (1 to 2 mg, according to body weight). The hepatic venous pressure gradient and azygos blood flow significantly decreased (from 15.3 +/- 1.1 to 12.5 +/- 1.1 mm Hg, and from 0.6 +/- 0.1 to 0.5 +/- 0.1 liters/min, respectively). Arterial and pulmonary wedged pressures significantly increased. Heart rate, cardiac index, and O2 consumption were not significantly affected by terlipressin. In conclusion, in patients with cirrhosis being treated with a nonselective beta-blocker, terlipressin administration decreased portal pressure. Moreover, terlipressin induced only mild systemic hemodynamic effects in these patients. These results suggest that terlipressin can be administered in patients receiving a beta-adrenergic blocker.

A study of the antiulcer mechanisms of propranolol in rats

Although propranolol has been shown to protect against ethanol and stress ulceration, the antiulcer mechanisms are still unclear. The present study examined the antiulcer mechanisms of propranolol in three different types of ulceration induced respectively by ethanol (60%), indomethacin (30 mg/kg) and stress (cold-restraint). Propranolol pretreatment in the highest dose (10 mg/kg) given either intraperitoneally (i.p.) or orally (p.o.) prevented gastric mucosal damage in these three ulcer models. The three doses of the drug (2.5, 5 or 10 mg/kg) dose-dependently decreased systemic blood pressure which was accompanied by a reduction of gastric mucosal blood flow. These findings suggest that the protection was unrelated to an improvement of local circulation in the stomach. However, propranolol preserved the mucus levels in the three types of ulcer models. The beta-adrenoceptor blocker also increased the basal gastric mucosal potential difference. These findings indicate that propranolol strengthens the mucosal barrier by the preservation of mucosal mucus and enhancement of the mucosal integrity in the stomach.

Noninvasive measurement of femoral blood flow and portal pressure response to propranolol in patients with cirrhosis

This study investigated the correlation between changes in hepatic and systemic hemodynamics and femoral blood flow (FBF), measured by dual-beam pulsed wave Doppler, in 58 portal hypertensive patients receiving propranolol (0.15 mg/Kg intravenously; n = 44) or placebo (n = 14) under double-blind conditions. Placebo administration had no effects. Propranolol caused significant reductions (P < .0001) in hepatic venous pressure gradient (HVPG; from 19.1 +/- 4.1 to 16.2 +/- 4.2 mm Hg), azygos blood flow (from 563 +/- 204 to 387 +/- 176 mL/min), cardiac index (CI; from 4.4 +/- 1.0 to 3.3 +/- 0.8 L/m2/min), and FBF (from 237 +/- 79 to 176 +/- 58 mL/m2/min). In 17 patients HVPG decreased below 12 mm Hg and/or more than 20% of the baseline value (good response; mean change, -26 +/- 8%); in the remaining 27 patients (poor response) the mean change in HVPG was less: -9 +/- 6%. Patients with a good response had bled less often from varices, had significantly higher FBF (272 +/- 73 vs. 215 +/- 76 mL/m2/min) and lower baseline HVPG (16.8 +/- 3.9 vs. 20.6 +/- 3.6 mm Hg) than those with poor response in HVPG. The good response was also associated with greater decreases in FBF (-33 +/- 12 vs. -19 +/- 13% in poor responders), CI (-30 +/- 9 vs. -19 +/- 12%), and heart rate (-19 +/- 5 vs. -16 +/- 6%). A decrease in FBF of > 20% predicted a good response in 16 of 28 patients (positive predictive value, 57%).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic responses to selective blockade of beta 2- and beta 1-adrenoceptors in conscious rats with cirrhosis

This study examined the hemodynamic effects of selective beta 2-adrenergic blockade (ICI 118,551, 100 micrograms/kg intravenous (i.v.)), selective beta 1-blockade (atenolol, 2 mg i.v.) and nonselective beta-blockade (propranolol, 2 mg i.v.) in conscious rats with cirrhosis. Pressure and blood flow measurements (radioactive microsphere method) were performed before and following drug administration. ICI 118,551 significantly decreased portal tributary blood flow (21%), portal pressure (4%) and cardiac index (12%). Portal tributary blood flow decreases were significantly more marked than changes in cardiac index. Atenolol significantly decreased portal tributary blood flow (27%), portal pressure (15%), cardiac index (17%) and arterial pressure (7%). Propranolol significantly decreased portal tributary blood flow (37%), portal pressure (17%), cardiac index (30%), and arterial pressure (9%). Portal tributary blood flow decreases due to ICI 118,551, but not those due to atenolol, were significantly less marked than the decreases caused by propranolol. ICI 118,551- and atenolol-induced cardiac index decreases were significantly less marked than propranolol-induced decreases. In conclusion, in rats with cirrhosis, selective beta 2-blockade reduces portal pressure and portal tributary blood flow mainly by a direct effect on splanchnic vessels. This portal hypotensive action, however, was slight. Propranolol decreases portal tributary blood flow by the combination, but not the summation, of its beta 1- and beta 2-blocking effects.

Hemodynamic effects of acute administration of furosemide in patients with cirrhosis receiving beta-adrenergic antagonists

In patients with cirrhosis, both beta-blockers and diuretics decrease the degree of portal hypertension. Since their mechanisms of action differ, the combination of these two substances should induce a more pronounced effect on portal pressure than one of these substances alone. Thus, the hemodynamic effects of furosemide were evaluated in ten patients with cirrhosis receiving beta-blockers. One hour after furosemide (0.75 mg/kg intravenously) administration, cardiac output decreased significantly from 6.2 +/- 0.6 to 5.2 +/- 0.3 l/min and blood volume from 8.0 +/- 1.6 to 5.3 +/- 0.5 l. Mean arterial pressure was not affected. Wedged and free hepatic venous pressures did not change significantly; nor did the hepatic venous pressure gradient (19.6 +/- 1.7 to 18.6 +/- 1.5 mmHg). Azygos blood flow was not affected (0.46 +/- 0.05 to 0.50 +/- 0.07 l/min). In conclusion, this study did not demonstrate that the addition of furosemide to propranolol further decreased portal pressure in patients with cirrhosis. The long-term effects of this combination are unknown and should be tested.

Effects of beta-adrenoceptor antagonists on portal vein hypertension and ethanol-induced gastric mucosal damage in rats

The effects of various beta-adrenoceptor antagonists, with different pharmacological properties, on systemic and portal vein blood pressure and on ethanol-induced gastric mucosal damage were examined in surgically-induced portal hypertensive rats. Propranolol (5, 10 or 20 mg kg-1), nadolol (5 or 10 mg kg-1), metoprolol (10 or 20 mg kg-1), labetalol (20 or 40 mg kg-1) and pindolol (3 or 6 mg kg-1) reduced systemic blood pressure to a similar degree in both portal vein-ligated and sham-operated rats. All beta-adrenoceptor antagonists, except for pindolol, significantly reduced portal venous pressure and ethanol-induced macroscopic gastric mucosal damage in portal hypertensive animals. Sham-operated rats had lower portal venous pressure and less gastric damage compared with portal hypertensive rats, but both were unaffected by beta-adrenoceptor antagonist pretreatment. We conclude that: propranolol, nadolol, metoprolol and labetalol are effective in reducing the portal venous pressure and ethanol-induced gastric mucosal damage in portal hypertensive rats, but not in portal normotensive animals; there was no direct relationship between the reduction of portal vein and systemic blood pressure; and local anaesthetic action is probably important in reducing the portal vein pressure and ethanol-induced gastric mucosal lesions, while the intrinsic sympathomimetic effect can counteract the actions of the beta-adrenoceptor antagonists on portal venous pressure and gastric mucosa.

Pharmacological treatment of portal hypertension: hemodynamic effects and prevention of bleeding

In the past 10 years, it has been clearly shown that vasoactive substances reduce portal pressure in patients or animals with portal hypertension. Some of these substances act by inducing splanchnic vasoconstriction, while others reduce hepatic and porto-systemic collateral vascular resistance and, thus, induce a portal hypotensive effect. Still others induce arterial hypotension, which causes a vasoconstrictive effect in the splanchnic territory. Since these drugs act on different vascular receptors, their combination should have a more marked effect on portal hypertension. Up to now, only nonselective beta-blockers have been used in the prevention of first gastrointestinal bleeding in patients with portal hypertension and esophageal varices and in the prevention of recurrent gastrointestinal bleeding. These trials have shown that propranolol or nadolol significantly reduce either a first episode of bleeding or recurrent bleeding. This pharmacological treatment also improves the survival rate in these patients. All of these studies have helped us to understand, in part, why gastrointestinal hemorrhage occurs in certain patients. Additional studies of beta-blockers or other substances are, nevertheless, necessary to select patients who will respond to this type of treatment. Finally, it is possible that the pharmacological treatment of portal hypertension may also be used before esophageal varices occur.

Nipradilol, a new beta-blocker with vasodilatory properties, in experimental portal hypertension: a comparative haemodynamic study with propranolol

The haemodynamic effects of nipradilol, a new non-selective beta-adrenoreceptor blocker with vasodilating actions like nitroglycerin, were examined in rats with portal hypertension due to portal vein stenosis. Portal hypertensive rats were divided into five groups receiving infusion of placebo, 3 mg of propranolol, 300, 600 and 1200 micrograms of nipradilol. At its highest dose, nipradilol achieved a reduction of 34.4 +/- 4.4% in heart rate which was similar to that in the propranolol group (36.5 +/- 2.4%). Also for other systemic haemodynamic parameters, the nipradilol 1200 micrograms group exhibited changes not significantly different from those in the propranolol group; mean arterial pressure (-13 vs -14%), cardiac index (-37 vs -31%) and systemic vascular resistance (+29 vs +32%). In contrast to the similar changes in the systemic circulation, a 1200 micrograms dose of nipradilol lowered portal pressure significantly more than propranolol (-4.3 +/- 0.6 vs -2.9 +/- 0.2 mmHg, P < 0.05). Nipradilol then reduced portal blood flow by 22% (P < 0.05) without a significant change in portocollateral resistance. On the other hand, propranolol not only caused a reduction in portal blood flow of 30% (P < 0.01), but also an increase in portocollateral resistance of 21% (P < 0.05). The results suggest that nipradilol may ensure a more effective control of portal hypertension than propranolol, presumably via its venodilatory action on portocollateral vessels.

Hemodynamic and pharmacokinetic study of tertatolol in patients with alcoholic cirrhosis and portal hypertension

Tertatolol, a recently developed beta 1-beta 2-blocker has two advantages: it does not induce withdrawal syndrome after abrupt cessation, and it preserves renal function. It has been suggested that the kinetics of tertatolol in patients with hepatic dysfunction are altered. Therefore, the hemodynamic effects and pharmacokinetics following the acute administration of tertatolol were studied in cirrhotic patients with portal hypertension. Systemic, splanchnic and renal hemodynamics were evaluated before and 30 min after the simultaneous administration of 2.5 mg tertatolol p.o. and 1.25 mg deuterated tertatolol i.v. in 10 cirrhotic patients with esophageal varices. The pharmacokinetics of tertatolol were evaluated over a 4-day period. Tertatolol significantly decreased heart rate (-22 +/- 10%), cardiac output (-26 +/- 8%), and hepatic blood flow (-27 +/- 23%). The hepatic venous pressure gradient decreased from 15.7 +/- 5.0 to 12.9 +/- 4.0 mmHg (-17 +/- 13%, P < 0.01). Three out of 10 patients were non-responders to tertatolol. Renal blood flow (-9 +/- 28%) and intrinsic hepatic clearance of indocyanin green (-9 +/- 25%) were not significantly modified. The duration of effective beta-blockade was far less than 12 h. Tertatolol was rapidly absorbed with a Cmax of 70 +/- 51 micrograms/l at a peak time of 0.75 +/- 0.26 h. In comparison with healthy volunteers referred to in literature sources, plasma clearance was reduced to 49 +/- 28 ml/min, bioavailability was increased to 72 +/- 20%, and the volume of distribution was increased to 50 +/- 34 l, probably due, in part, to a weaker protein binding -85%--effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic effects of nipradilol, a new beta-adrenergic antagonist combined with a nitroxy base, in rats with intra- or extra-hepatic portal hypertension

It has been demonstrated that beta-adrenergic antagonists and nitrovasodilators reduce portal pressure in patients with portal hypertension. Thus, the hemodynamic effects of nipradilol, a new beta-adrenergic antagonist combined with a nitroxy base, was studied in conscious and unrestrained rats in two models of portal hypertension. The hemodynamic effects were compared to those obtained after propranolol administration. Both nipradilol (20 mg/kg) and propranolol (20 mg/kg) significantly decreased portal pressure in both groups of portal hypertensive rats. In cirrhotic rats, nipradilol decreased portal pressure (-24 +/- 2%) more than propranolol (-9 +/- 2%). Both nipradilol and propranolol significantly decreased portal tributary blood flow and cardiac index in both groups. Changes in portal tributary blood flow and cardiac index were not significantly different between nipradilol and propranolol. Propranolol, but not nipradilol significantly increased hepatocollateral resistance in cirrhotic rats but not in portal vein stenosed rats. Thus, the marked reduction of portal pressure after nipradilol administration depends in part on a limited increase in hepatocollateral resistance. Nipradilol significantly decreased mean arterial pressure, while propranolol did not change this value in either groups. In conclusion, nipradilol markedly decreased portal pressure in rats with portal hypertension. This beneficial effect suggests that nipradilol should be tested in the patients with portal hypertension.

Effects of terlipressin on hemodynamics and oxygen content in conscious portal vein stenosed and cirrhotic rats receiving propranolol

Terlipressin is used in patients with variceal bleeding but its effects in patients receiving beta-adrenergic antagonists are unknown. In this study, the hemodynamic effects of terlipressin were evaluated in conscious portal hypertensive rats which had previously received a single dose of propranolol. Moreover, oxygen content and acid-base status were studied. In portal vein stenosed and cirrhotic rats, the addition of terlipressin (0.05 mg/kg) to propranolol (0.4 mg/kg) produced a decrease in portal pressure of 34% and 17%, respectively, and in portal tributary blood flow of 46% and 42%, respectively. In cirrhotic rats, however, the decrease in portal pressure was not significantly different when propranolol was combined with terlipressin than when propranolol was administered alone. Cardiac index also further decreased after terlipressin administration. In both groups of rats, these values were similar to those observed after terlipressin alone. In portal vein stenosed rats but not in cirrhotic rats, arterial pH was significantly lower following the combination of propranolol plus terlipressin than following saline, propranolol or terlipressin alone. In conclusion, terlipressin further reduces both portal pressure and cardiac index in rats with portal hypertension receiving beta-blockers. In portal vein stenosed rats but not in cirrhotic rats, the addition of terlipressin to propranolol induces acidemia. This study suggests that terlipressin might further reduce portal pressure in patients with portal hypertension treated with beta-blockers.

Balloon tamponade and vasoactive drugs in the control of acute variceal haemorrhage

Successful pharmacological arrest of haemorrhage might avoid the risk of aspiration associated with tamponade and early studies have suggested that the vasoactive agent somatostatin may be as effective and perhaps safer than tamponade in controlling variceal haemorrhage. In our view, vasopressin has not established a role in management but we retain an open mind regarding the potential use of terlipressin in combination with nitroglycerin. It is unlikely that any of these agents can improve significantly our ability to control variceal haemorrhage when compared to balloon tamponade but they may reduce the incidence of pulmonary complications and thereby reduce subsequent mortality. Tamponade has proved successful in controlling acute haemorrhage from oesophageal varices in our hands. Late complications continue to give cause for concern but until effective safe alternatives to tamponade are developed, we continue to advocate its use for emergency control of acute variceal haemorrhage. Our own studies have shown that the high mortality seen in this patient population may reflect the severity of the underlying liver disease rather than failure of a management policy employing oesophageal tamponade for the initial control of acute variceal haemorrhage.