Bosentan treatment of portopulmonary hypertension related to liver cirrhosis owing to hepatitis C

International Liver Transplant Society Practice Guidelines: Diagnosis and Management of Hepatopulmonary Syndrome and Portopulmonary Hypertension

Two distinct pulmonary vascular disorders, hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) may occur as a consequence of hepatic parenchymal or vascular abnormalities. HPS and POPH have major clinical implications for liver transplantation. A European Respiratory Society Task Force on Pulmonary-Hepatic Disorders convened in 2002 to standardize the diagnosis and guide management of these disorders. These International Liver Transplant Society diagnostic and management guidelines are based on that task force consensus and should continue to evolve as clinical experience dictates. Based on a review of over 1000 published HPS and POPH articles identified via a MEDLINE search (1985-2015), clinical guidelines were based on, selected single care reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Guidelines are presented in 5 parts; I. Definitions/Diagnostic criteria; II. Hepatopulmonary syndrome; III. Portopulmonary hypertension; IV. Implications for liver transplantation; and V. Suggestions for future clinical research.

Oral pulmonary vasoactive drugs achieve hemodynamic eligibility for liver transplantation in portopulmonary hypertension

BACKGROUND AND AIMS

Portopulmonary hypertension (POPH) hampers survival of patients with cirrhosis and portal hypertension and may preclude liver transplantation (LT). Management of such patients with oral pulmonary vasoactive drugs (PVD) has not been standardized. Our aim was to assess the efficacy and safety of oral PVD for management of POPH.

METHODS

All patients treated by oral PVD (bosentan, ambrisentan, sildenafil, tadalafil) for POPH were retrospectively studied. Significant response was defined for the patients who reached the following LT eligibility criteria: mean pulmonary artery pressure (MPAP) <35mmHg or MPAP between 35 and 50mmHg with pulmonary vascular resistance (PVR) <250dynscm^-5.

RESULTS

20 patients were followed for 38 (19-57) months. Oral PVD improved MPAP (-8 [-19, +2]mmHg), PVR (-201 [-344, -68]dynscm^-5) and 6-min walk distance (+52 [-51, +112] m). Fifty-three percent of evaluable patients reached eligibility to LT criteria, of whom 5 were transplanted. Baseline MPAP>51mmHg and/or PVR>536dynscm^-5 predicted non response to treatment. Five-years survival was 53%. No worsening of cirrhosis or serious adverse effect was recorded.

CONCLUSION

Oral pulmonary vasoactive drugs are safe in cirrhotic patients with POPH. These treatments improved hemodynamic conditions allowing patients access to liver transplantation eligibility.

Portopulmonary hypertension

Portopulmonary hypertension (PoPH) refers to the condition that pulmonary arterial hypertension (PAH) occur in the stetting of portal hypertension. The development of PoPH is thought to be independent of the severity of portal hypertension or the etiology or severity of liver disease. PoPH results from excessive vasoconstriction, vascular remodeling, and proliferative and thrombotic events within the pulmonary circulation that lead to progressive right ventricular failure and ultimately to death. Untreated PoPH is associated with a poor prognosis. As PoPH is frequently asymptomatic or symptoms are generally non-specific, patients should be actively screened for the presence of PoPH. Two-dimensional transthoracic echocardiography is a useful non-invasive screening tool, but a definitive diagnosis requires invasive hemodynamic confirmation by right heart catheterization. Despite a dearth of randomized, prospective data, an ever-expanding clinical experience shows that patients with PoPH benefit from therapy with PAH-specific medications including with endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and/or prostanoids. Due to high perioperative mortality, transplantation should be avoided in those patients who have severe PoPH that is refractory to medical therapy.

Cirrhotic Multiorgan Syndrome

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

Management of portopulmonary hypertension: New perspectives

Portopulmonary hypertension (PPHTN) is a known complication of cirrhosis. Moderate-to-severe PPHTN implies an extremely poor prognosis. It occurs in 5%-10% of patients referred for liver transplantation (LT), and probably with an higher incidence in patients with large portosystemic shunts. Patients with moderate-to-severe pulmonary hypertension have been previously excluded from LT because of the extremely high surgical risk and since the post-transplant outcome reported was poor. Recently, new perspectives in the management of patients with portopulmonary hypertension are emerging. In fact, some pulmonary vasoactive drugs have become routine in the treatment of patients with idiopathic pulmonary hypertension. These drugs, particularly epoprostenol, have been recently introduced in the treatment of patients with PPHTN, and have been shown to be effective in reducing pulmonary artery pressure as well as pulmonary vascular resistances. Furthermore, recent studies seem to demonstrate that treatment with pulmonary vasoactive drugs could allow liver transplantation with acceptable surgical risks and excellent survival. Although there are not large series nor prospective studies addressing this topic, the clinical scenario of patients with PPHTN seems to be positively changing.

Pulmonary vascular complications of liver disease

Hepatopulmonary syndrome and portopulmonary hypertension are two pulmonary vascular complications of liver disease. The pathophysiology underlying each disorder is distinct, but patients with either condition may be limited by dyspnea. A careful evaluation of concomitant symptoms, the physical examination, pulmonary function testing and arterial blood gas analysis, and echocardiographic, imaging, and hemodynamic studies is crucial to establishing (and distinguishing) these diagnoses. Our understanding of the pathobiology, natural history, and treatment of these disorders has advanced considerably over the past decade; however, the presence of either still increases the risk of morbidity and mortality in patients with underlying liver disease. There is no effective medical treatment for hepatopulmonary syndrome. Although liver transplantation can resolve hepatopulmonary syndrome, there appears to be worse survival even with transplantation. Liver transplantation poses a very high risk of death in those with significant portopulmonary hypertension, where targeted medical therapies may improve functional status and allow successful transplantation in a small number of select patients.

Critical care management of patients with end-stage liver disease

OBJECTIVES

To review the management of complications related to end-stage liver disease in the intensive care unit. The goal of this review is to address topics important to the practicing physician.

DATA SOURCES

We performed an organ system-based PubMed literature review focusing on the diagnosis and treatment of critical complications of end-stage liver disease. DATA SYNTHESIS AND FINDINGS: When available, preferential consideration was given to randomized controlled trials. In the absence of trials, observational and retrospective studies and consensus opinions were included. We present our recommendations for the neurologic, cardiovascular, pulmonary, gastrointestinal, renal, and infectious complications of end-stage liver disease.

CONCLUSIONS

Complications related to end-stage liver disease have significant morbidity and mortality. Management of these complications in the intensive care unit requires awareness and expertise among physicians from a wide variety of fields.

Praziquantel reverses pulmonary hypertension and vascular remodeling in murine schistosomiasis

RATIONALE

Schistosomiasis is the most common worldwide cause of pulmonary arterial hypertension. The anti-schistosome drug praziquantel has been shown to reverse the liver fibrosis associated with Schistosoma mansoni in mice.

OBJECTIVES

We sought to determine whether praziquantel reverses established pulmonary vascular remodeling and pulmonary hypertension in a mouse model of S. mansoni.

METHODS

Mice were infected percutaneously with S. mansoni. At 17 weeks after infection mice were either killed or received two doses of praziquantel or vehicle by oral gavage. Treated mice were studied at 25 weeks after infection.

MEASUREMENTS AND MAIN RESULTS

Vehicle-treated mice demonstrated significant increases in right ventricular systolic pressures (RVSP) and right ventricular hypertrophy (RVH) at 25 weeks, accompanied by pulmonary vascular remodeling. The degree of vascular remodeling correlated with proximity to granulomas. The elevation of RVSP and RVH at 25 weeks was dependent on the presence of eggs in the lung. Praziquantel eliminated the production of eggs in feces and led to clearance of eggs from the lung and to a lesser extent from liver. Praziquantel prevented the rise in RVSP and RVH seen in vehicle-treated mice and reversed established pulmonary vascular remodeling. Praziquantel significantly reduced lung mRNA expression of IL-13, IL-8, and IL-4, but did not reduce serum cytokine levels.

CONCLUSIONS

The development of pulmonary hypertension associated with S. mansoni infection can be prevented by praziquantel, and established vascular remodeling can be reversed. The mechanism involves clearance of lung eggs and reduced local expression of lung cytokines.

Safety and efficacy of ambrisentan for the treatment of portopulmonary hypertension

BACKGROUND

Ambrisentan is a selective endothelin-receptor antagonist that is approved by the US Food and Drug Administration for the treatment of pulmonary arterial hypertension. We describe hemodynamic responses and clinical outcomes of patients with portopulmonary hypertension (POPH) treated with ambrisentan.

METHODS

In this observational study, we prospectively identified and followed consecutive adult patients with POPH who received monotherapy with ambrisentan ≤ 10 mg daily from January 2007 until December 2009. Liver enzymes were assessed monthly. Pulmonary hemodynamic responses were assessed using echocardiograms and right-sided heart catheterizations.

RESULTS

We identified 13 patients (seven men) with POPH and began monotherapy with ambrisentan. The median age was 57 (interquartile range [IQR], 52-60). Patients were followed for a median of 613 days (IQR, 385-1,011). The median model for end-stage liver disease score was 10 (IQR, 8.5-15); eight patients had Child-Turcotte-Pugh A classification. Median time on ambrisentan therapy was 390 days (IQR, 363-611). Two patients died, one of advanced hepatocellular carcinoma and one of septic shock following pneumonia. The mean pulmonary artery pressure decreased from a baseline median of 58 mm Hg (IQR, 37-63) to 41 mm Hg (IQR, 27-48) (P = .004). The pulmonary vascular resistance median was reduced from 445 dynes/s/cm(5) (IQR, 329-834) to 174 dynes/s/cm(5) (IQR, 121-361) (P = .008). There was no difference in the longitudinal analysis of liver function tests (aspartate aminotransferase, alanine aminotransferase, total bilirubin, and international normalized ratio) after 12 months of therapy. One patient underwent successful liver transplantation and normalized pulmonary hemodynamic responses after transplantation.

CONCLUSIONS

In this small cohort of patients with moderate to severe pulmonary hypertension in the setting of POPH, we have shown that ambrisentan monotherapy can significantly improve pulmonary hemodynamic responses without adverse effect on hepatic function.

Sildenafil monotherapy in portopulmonary hypertension can facilitate liver transplantation

Portopulmonary hypertension (POPH), or pulmonary arterial hypertension associated with cirrhosis, carries a high mortality and often precludes liver transplantation. Many POPH patients have preserved or increased cardiac output; therefore, decreasing pulmonary artery pressure rather than improving cardiac output is more important in reducing liver transplant risk, and this makes sildenafil an attractive therapeutic option. We assessed the clinical response of patients with POPH treated with sildenafil monotherapy. We retrospectively reviewed the charts of 10 patients with POPH and sildenafil monotherapy. Eight of 10 patients had hepatitis C virus infection. Patients took 31 +/- 14 mg (mean +/- standard deviation) thrice daily and were followed for 21 +/- 16 months. The World Health Organization functional class improved from 3.0 +/- 0.0 to 2.3 +/- 0.5 at 1 year (P < 0.05). Four of 8 patients increased the 6-minute walk distance at 1 year by 30 m or more. Three patients became transplant-eligible, 1 of whom underwent successful transplantation, and 3 patients have been stable without progression of liver disease or POPH. The remainder were not transplant candidates because of refractory POPH (n = 2) or other comorbidities (n = 2). We conclude that sildenafil may be an effective therapy for POPH that can stabilize or improve hemodynamics in patients with POPH and thereby facilitate liver transplantation.

Portopulmonary hypertension associated with congenital absence of the portal vein treated with bosentan

Portopulmonary hypertension (PPHTN) is pulmonary arterial hypertension (PAH) associated with portal hypertension. It is a common condition among liver transplantation candidates; however, its association with congenital absence of the portal vein (CAPV) has not yet been established. CAPV is a very rare developmental anomaly, which is usually accompanied by abnormal mesenteric drainage that bypasses the liver. Here, we report a rare case of severe PPHTN secondary to CAPV.

Initial experience using continuous intravenous treprostinil to manage pulmonary arterial hypertension in patients with end-stage liver disease

Treprostinil is a prostacyclin analog and has been used on idiopathic pulmonary arterial hypertension (PAH). There is only limited clinical experience using treprostinil to manage PAH in patients with end-stage liver disease (ESLD). We report three ESLD patients with PAH, who were treated with continuous intravenous treprostinil. A 59-year-old woman with ESLD secondary to alcoholic hepatitis had portopulmonary hypertension with mean pulmonary arterial pressure (mPAP) of 44 mmHg and transpulmonary gradient (TPG) of 23 mmHg. Treprostinil at 45 ng/kg/min for 6 months decreased mPAP to 23 (TPG to 8). A 53-year-old man had ESLD secondary to alcoholic hepatitis with PAH caused by multiple pulmonary embolisms (mPAP of 32 and TPG of 23). Treprostinil at 36 ng/kg/min for 3 months decreased mPAP to 23 and TPG to 14. Both patients underwent uneventful liver transplantation. A 48-year-old man had ESLD secondary to hepatitis C and portopulmonary hypertension with mPAP of 60 and TPG of 44. Two years after intravenous treprostinil at 106 ng/kg/min, his mPAP decreased to 44 and TPG to 30. These results demonstrate that for a selected group of ESLD patients with PAH, a continuous intravenous infusion of treprostinil appears to be safe and effective.

Successful treatment of portopulmonary hypertension with bosentan: case report

Pulmonary arterial hypertension (PAH) is found in 2-20% of cirrhosis patients who have portal hypertension (portopulmonary hypertension, PPHT). Endothelin (ET), a potent vasoconstrictor, is likely to play a role in the pathogenesis of portal hypertension. We describe the long-term successful use of the dual ET(A)/ET(B) receptor antagonist bosentan in a 43-year-old male with alcohol-related cirrhosis (Child-Pugh A), right ventricular enlargement and dysfunction, respectively, and moderate PAH. Elevated pulmonary arterial pressure was substantially reduced and exercise capacity increased. Improvement was maintained over 2 years, and bosentan treatment continues in this patient. Our report is in line with a series of current reports in PPHT that support the use of bosentan in this subset of PAH patients.

Endothelin and endothelin receptor antagonism in portopulmonary hypertension

Portopulmonary hypertension (PPHT) is a rare but devastating complication in patients with portal hypertension, characterized by pulmonary arterial obliterative disease with a concomitant rise in pulmonary vascular resistance. A broad body of evidence has accumulated, indicating that endothelin (ET) peptides and their cognate receptors are causally involved in the pathophysiology of pulmonary arterial hypertension (PAH) owing to different aetiologies, including PPHT. In addition, the ET system may be involved in hepatic fibrotic remodelling and portal hypertension. Several experimental models have provided evidence that ET receptor antagonism may have therapeutic potential in PPHT. Initial experience has accumulated during the last 2 years, suggesting that targeting the ET system may have beneficial effects in the clinical setting. In these studies, the orally active, dual ET receptor antagonist bosentan improved pulmonary haemodynamics and functional capacity. These effects were sustained and occurred in the absence of adverse events. If these observations can be corroborated by controlled clinical trials, bosentan would offer several advantages over available therapies, which have major drawbacks owing to their invasive and demanding mode of application.