What's new in the treatment of portopulmonary hypertension?

Portopulmonary Hypertension

PoPH is a well-recognized complication of portal hypertension with or without cirrhosis and is classified as a subset of PAH. Identification of PoPH is crucial as it has a major impact on prognosis and liver transplant candidacy. Echocardiogram is the initial screening tool of choice and the patient should proceed to RHC for confirmation. PAH-directed therapy is the treatment of choice, allowing the patient to achieve a hemodynamic threshold to undergo a liver transplant safely.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Pulmonary Vascular Complications of Liver Disease

Pulmonary vascular disease is a frequent complication of chronic liver disease and portal hypertension, affecting up to 30% of patients. There are two distinct pulmonary vascular complications of liver disease: hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH). HPS affects 25% of patients with chronic liver disease and is characterized by intrapulmonary vasodilatation and abnormal arterial oxygenation. HPS negatively impacts quality of life and is associated with a 2-fold increased risk of death compared to controls with liver disease without HPS. Angiogenesis, endothelin-1 mediated endothelial dysfunction, monocyte influx, and alveolar type 2 cell dysfunction seem to play important roles in disease pathogenesis but there are currently no effective medical therapies. Fortunately, HPS resolves following liver transplant (LT) with improvements in hypoxemia. POPH is a subtype of pulmonary arterial hypertension (PAH) characterized by an elevated mean pulmonary arterial pressure and pulmonary vascular resistance in the setting of normal left-sided filling pressures. POPH affects 5% to 6% of patients with chronic liver disease. Although the pathogenesis has not been fully elucidated, endothelial dysfunction, inflammation, and estrogen signaling have been identified as key pathways involved in disease pathogenesis. POPH is typically treated with PAH targeted therapy and may also improve with liver transplantation in selected patients. This article highlights what is currently known regarding the diagnosis, management, pathobiology, and outcomes of HPS and POPH. Ongoing research is needed to improve understanding of the pathophysiology and outcomes of these distinct and often misunderstood pulmonary vascular complications of liver disease. © 2021 American Physiological Society. Compr Physiol 11:1-22, 2021.

Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Hemodynamic instability (HDI) during liver transplantation (LT) can be difficult to manage and increases postoperative morbidity and mortality. In addition to surgical causes of HDI, patient- and graft-related factors are also important. Nitric oxide-mediated vasodilatation is a common denominator associated with end-stage liver disease related to HDI. Despite intense investigation, optimal management strategies remain elusive. In this consensus article, experts from the International Liver Transplantation Society, the Liver Intensive Care Group of Europe, and the Society for the Advancement of Transplant Anesthesia performed a rigorous review of the most current literature regarding the epidemiology, causes, and management of HDI during LT. Special attention has been paid to unique LT-associated conditions including the causes and management of vasoplegic syndrome, cardiomyopathies, LT-related arrhythmias, right and left ventricular dysfunction, and the specifics of medical and fluid management in end-stage liver disease as well as problems specifically related to portal circulation. When possible, management recommendations are made.

Portopulmonary Hypertension: Prevalence, Clinical and Hemodynamic Features

Portopulmonary hypertension (PoPH) is a vascular complication of portal hypertension. This study aims to identify the prevalence and analyzing the clinical and hemodynamic features of patients with PoPH from a cohort of pulmonary arterial hypertension (PAH) patients. A retrospective transversal descriptive and analytical study. Patients with PoPH taken from a PAH cohort. We compare with those reported in the literature. We found prevalence of 6.1% of 244 consecutive patients with PAH, 11 females and 4 males. The mean age was 62 years and the main etiology of portal hypertension was primary biliary cirrhosis. Statistical differences were found in mean pulmonary arterial pressure, pulmonary vascular resistance, right atrial pressure; we found levels lower than reported. We found significant differences in clinical and hemodynamic characteristics such as older age and hemodynamic parameters of less severity in the group of patients analyzed compared with reported data.

Pulmonary hypertension in patients with a history of intravenous drug use

OBJECTIVE

Pulmonary hypertension may be a consequence of intrinsic elevation in pulmonary vasculature resistance or complicate numerous other conditions affecting the cardiac and respiratory systems. In this review we sought to explore the relationship between pulmonary hypertension and intravenous drug use.

METHODS

A narrative review was conducted using PubMed MeSH search with further papers identified using a standard PubMed search with relevant key terms and various synonyms.

RESULTS

HIV infection may be associated with pulmonary hypertension due to indirect consequences of viral infection, venous thromboembolism or its therapies. Anti-retroviral infection may also influence plasma concentrations of commonly used treatments for pulmonary hypertension. Intravenous drug use is acknowledged as an important portal for the acquisition of hepatitis virus C infection, with portopulmonary hypertension a potential complication associated with poor prognosis. Interferon based therapy, used in treatment of chronic hepatitis C infection, may also play a causal role in the development of pulmonary hypertension. More recently, sofosbuvir has been linked to development or exacerbation of pulmonary arterial hypertension. Certain drugs of abuse may cause pulmonary hypertension due to properties that result in direct injury to the pulmonary vasculature. The potential for embolic phenomena, complicating venous thromboembolism, recurrent embolization of particulate matter or because of right-sided endocarditis, resulting in pulmonary hypertension is an important contributing factor in the pathophysiology in this unique cohort.

CONCLUSIONS

Eliciting a history of intravenous drug use is important and may be associated with a number of less common etiologies, each with specific diagnostic and therapeutic implications.

Portopulmonary Hypertension: A Survey of Practice Patterns and Provider Attitudes

Supplemental Digital Content is available in the text.

The role of liver transplantation (LT) in the management of portopulmonary hypertension (POPH) is poorly understood. The aim of this study was to better understand provider attitudes and practice patterns regarding the management of patients with POPH and to assess the concordance between clinical practice and current guidelines.

Riociguat treatment for portopulmonary hypertension: a subgroup analysis from the PATENT-1/-2 studies

In patients with portopulmonary hypertension (n = 13) included in the 12-week randomized placebo-controlled PATENT-1 trial, riociguat was well tolerated and improved 6-min walking distance (6MWD), World Health Organization functional class (WHO FC), and other efficacy parameters; 6MWD and WHO FC improvements were sustained over two years in the open-label extension, PATENT-2.

Diagnosis, Treatment, and Management of Orthotopic Liver Transplant Candidates With Portopulmonary Hypertension

Portopulmonary hypertension (POPH) is seen in 5-8% of orthotopic liver transplantation (OLT) candidates and has significant implications for clinical outcomes. POPH is characterized by vasoconstriction and remodeling of the pulmonary vasculature. It is exacerbated by the hyperdynamic circulation that is common in advanced liver disease. Screening all OLT candidates with transthoracic echocardiography to assess pulmonary pressures and right ventricular function is crucial, as clinical symptoms alone are not reliable. Any significant right ventricular dysfunction or dilatation along with an elevation in estimated pulmonary pressures usually triggers further investigation with right heart catheterization. The mainstays of therapy of POPH are vasodilators that are used in pulmonary arterial hypertension. They include monotherapy or combination therapy with prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors/guanylate cyclase stimulator. Limited evidence from smaller studies and case series suggests that a timely diagnosis of POPH and the early initiation of treatment improve patient outcomes, whether or not OLT is ultimately undertaken. Given the historically high perioperative mortality rate of more than 35%, POPH remains a contraindication to OLT unless it is treated and responsive to vasodilator therapy. We review the current literature and International Liver Transplant Society practice guidelines (2016) for the latest in understanding POPH, its pathogenesis, diagnosis, modern pharmacological treatment, indications, and contraindications for OLT, as well as perioperative management.

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.

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.