Coexistent pulmonary and portal hypertension: morphologic and clinical features

Is pulmonary arterial hypertension associated with schistosomiasis distinct from pulmonary arterial hypertension associated with portal hypertension?

Pulmonary arterial hypertension associated with schistosomiasis (SchPAH) and pulmonary arterial hypertension associated with portal hypertension (PoPAH) are lung diseases that develop in the presence of liver diseases. However, mechanistic pathways by which the underlying liver conditions and other drivers contribute to the development and progression of pulmonary arterial hypertension (PAH) are unclear for both etiologies. In turn, these unknowns limit certainty of strategies to prevent, diagnose, and reverse the resultant PAH. Here we consider specific mechanisms that contribute to SchPAH and PoPAH, identifying those that may be shared and those that appear to be unique to each etiology, in the hope that this exploration will both highlight known causal drivers and identify knowledge gaps appropriate for future research. Overall, the key pathophysiologic differences that we identify between SchPAH and PoPAH suggest that they are not variants of a single condition.

Pulmonary Assessment of the Liver Transplant Recipient

Respiratory symptoms and hypoxemia can complicate chronic liver disease and portal hypertension. Various pulmonary disorders affecting the pleura, lung parenchyma, and pulmonary vasculature are seen in end-stage liver disease, complicating liver transplantation (LT). Approximately 8% of cirrhotic patients in an intensive care unit develop severe pulmonary problems. These disorders affect waiting list mortality and posttransplant outcomes. A thorough history, physical examination, and appropriate laboratory tests help diagnose and assess the severity to risk stratify pulmonary diseases before LT. Hepatopulmonary syndrome (HPS), portopulmonary hypertension (POPH), and hepatic hydrothorax (HH) are respiratory consequences specific to cirrhosis and portal hypertension. HPS is seen in 5-30% of cirrhosis cases and is characterized by impaired oxygenation due to intrapulmonary vascular dilatations and arteriovenous shunts. Severe HPS is an indication of LT. The majority of patients with HPS resolve their hypoxemia after LT. When pulmonary arterial hypertension occurs in patients with portal hypertension, it is called POPH. All other causes of pulmonary arterial hypertension should be ruled out before labeling as POPH. Since severe POPH (mean pulmonary artery pressure [mPAP] >50 mm Hg) is a relative contraindication for LT, it is crucial to screen for POPH before LT. Those with moderate POPH (mPAP >35 mm Hg), who improve with medical therapy, will benefit from LT. A transudative pleural effusion called hepatic hydrothorax (HH) is seen in 5-10% of people with cirrhosis. Refractory cases of HH benefit from LT. In recent years, increasing clinical expertise and advances in the medical field have resulted in better outcomes in patients with moderate to severe pulmonary disorders, who undergo LT.

Symptom-based portopulmonary hypertension screening questionnaire in Japanese patients with chronic liver disease

Background and Aim

As the exact prevalence of portopulmonary hypertension (PoPH) and the etiology of chronic liver disease (CLD) remain unknown, the present study aimed to clarify these points in Japanese patients with CLD using symptom-based questionnaire screening.

Methods

Patients with CLD were asked to complete an eight-item written questionnaire on pulmonary hypertension (PH) symptoms. If at least one item response was "yes," the patient was offered ultrasonic echocardiography (UCG). Patients identified as having an intermediate or high risk of PH by UCG were referred to a cardiologist for further evaluation, whereby a definitive diagnosis of PoPH was made using right heart catheterization (RHC) findings.

Results

A total of 1111 patients with CLD completed the survey. Of the 566 symptomatic patients with at least one question answered as "yes," approximately half agreed to undergo UCG (n = 267). Compared with asymptomatic patients, symptomatic patients were significantly older, predominantly female, and more frequently exhibited cirrhosis. Based on UCG findings, 228, 12, and 8 patients had a low, intermediate, or high risk for PH, respectively. Intermediate-/high-risk patients showed significantly more advanced disease progression status than low-risk patients. The frequencies of answer to the eight questions were comparable. Ultimately, three patients were diagnosed as having PoPH (1.1% of UCG cases), one with underlying hepatitis C virus (HCV) infection and two with primary biliary cholangitis (PBC).

Conclusion

This symptom-based PoPH screening study clarified the prevalence of PoPH in CLD patients according to a PH symptom questionnaire, UCG, and RHC. Patients with HCV and PBC may have a higher risk of PoPH.

Portopulmonary Hypertension: An Updated Review

Portal hypertension may have major consequences on the pulmonary vasculature due to the complex pathophysiological interactions between the liver and lungs. Portopulmonary hypertension (PoPH), a subset of group 1 pulmonary hypertension (PH), is a serious pulmonary vascular disease secondary to portal hypertension, and is the fourth most common subtype of pulmonary arterial hypertension. It is most commonly observed in cirrhotic patients; however, patients with noncirrhotic portal hypertension can also develop it. On suspicion of PoPH, the initial evaluation is by a transthoracic echocardiogram in which, if elevated pulmonary pressures are shown, patients should undergo right heart catheterization to confirm the diagnosis. The prognosis is extremely poor in untreated patients; therefore, management includes pulmonary arterial hypertension therapies with the aim of improving pulmonary hemodynamics and moving patients to orthotopic liver transplantation (OLT). In this article, we review in detail the epidemiology, pathophysiology, process for diagnosis, and most current treatments including OLT and prognosis in patients with PoPH. In addition, we present a diagnostic algorithm that includes the current criteria to properly select patients with PoPH who are candidates for OLT.

Porto-pulmonary arterial hypertension: Translation of pathophysiological concepts to the bedside

Porto-pulmonary arterial hypertension (PoPAH) is a form of pulmonary arterial hypertension (PAH) that affects patients with cirrhosis, and - to a lesser extent - patients with non-cirrhotic liver diseases. Compared with other forms of PAH, PoPAH is more prevalent in male, in older subjects, and is characterized by lower mean pulmonary arterial pressure (mPAP) and lower pulmonary vascular resistance (PVR) with higher cardiac output. Despite more favorable hemodynamics and functional class, patients with PoPAH have a significantly worse survival than patients with other forms of PAH, likely because of liver-related events and therapeutic barriers to PAH-specific therapy. Furthermore, here cardiopulmonary and hepatic complications may affect treatment efficacy. These patients have been excluded from most randomized clinical trials testing PAH-specific treatments. To date, there is only one study investigating efficacy, safety, tolerability and pharmacokinetics of PAH-specific therapy in patients with PoPAH in a randomized placebo-controlled setting. In this trial the use of the endothelin-1 receptor antagonist macitentan showed clear hemodynamic benefit without safety concerns. However, the drug effects on functional capacity and mortality remain unclear. Here we review the current knowledge on the pathophysiology and management of PoPAH and report a case vignette of a patient with PoPAH due to hepatorenal polycystic disease.

Portopulmonary Hypertension: A Review of the Current Literature

Portopulmonary hypertension is defined as the development of pulmonary arterial hypertension in the setting of portal hypertension with or without liver cirrhosis. Portal hypertension-associated haemodynamic changes, including hyperdynamic state, portosystemic shunts and splanchnic vasodilation, induce significant alterations in pulmonary vascular bed and play a pivotal role in the pathogenesis of the disease. If left untreated, portopulmonary hypertension results in progressive right heart failure, with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and liver transplantation candidates, right heart catheterisation remains the gold standard for the diagnosis of the disease. Severe portopulmonary hypertension exerts a prohibitive risk to liver transplantation by conferring an elevated perioperative mortality risk. It is important for haemodynamic parameters to correspond with non-severe portopulmonary hypertension before patients can proceed with the liver transplantation. Small uncontrolled studies and a recent randomised controlled trial have reported promising results with vasodilatory therapies in clinical and haemodynamic improvement of patients, allowing a proportion of patients to undergo liver transplantation. In this review, the epidemiology, pathogenesis, diagnostic approach and management of portopulmonary hypertension are discussed. We also highlight fields of ongoing investigation pertinent to risk stratification and optimal patient selection to maximise long-term benefit from currently available treatments.

Transcatheter closure of congenital portosystemic shunts – A multicenter experience

Background:

Congenital portosystemic shunts (CPSS) are rare and present variably with hepatic encephalopathy, pulmonary arteriovenous malformations (PAVMs), and pulmonary hypertension (PH).

Objective:

The objective of the study was to see the feasibility of transcatheter closure of CPSS and their outcome.

Materials and Methods:

We analyzed the data of 24 patients of CPSS who underwent transcatheter closure from five institutions (March 2013 to April 2019). Baseline evaluation included echocardiography with bubble contrast study, ultrasound examination of the abdomen, computed tomography angiogram, and cardiac catheterization with test balloon occlusion of the CPSS. The evaluation showed cyanosis due to PAVM in 12, PH in 8, and respiratory distress in 2. Two had both cyanosis and PH. Criteria for eligibility for complete catheter closure of CPSS included demonstration of intrahepatic portal vein (PV) radicals together with a PV pressure of ≤18 mmHg on occlusion.

Results:

The median age and weight were 8 years (0.5–21) and 19.5 kg (4.2–73), respectively. Transcatheter closure was performed in 21 patients (22 procedures) using a variety of occlusive devices and stent-graft exclusion was done in one patient. Closure was not done in 3 in view of high portal venous pressures and hypoplastic PVs. During the follow-up (median: 42 months and range: 61 days–4.8 years), saturation normalized in 14 patients with PAVM. PH declined in all eight patients who underwent the procedure. Respiratory distress improved in two patients.

Conclusions:

Early and short-term follow-up results of catheter closure of CPSS appear promising. However, further, follow-up is needed to demonstrate long-term effectiveness.

Causes and Circumstances of Death in Portopulmonary Hypertension

The causes and circumstances surrounding death are poorly studied in patients with portopulmonary hypertension (PoPH). We sought to determine the specific reasons for dying and characteristics surrounding this process in patients with PoPH.

Protocol: Prospective observational study investigating the prevalence and clinical outcome of portopulmonary hypertension in Japanese patients with chronic liver disease

BACKGROUND

Portopulmonary hypertension (PoPH) is a subtype of the pulmonary arterial hypertension (PAH) associated with portal hypertension. There is a dissociation between the proportion of PoPH in PAH and that of PoPH in patients with liver cirrhosis, suggesting PoPH underdiagnosis and an incomplete understanding of this entity in the clinical setting. Specifically, real-world data in Japan is largely unknown as compared with in Europe and the United States. The present study aims to elucidate the prevalence and etiology of PoPH in Japanese patients with chronic liver disease.

METHODS AND DESIGN

In this prospective, single-center, observational investigation of PoPH patients with chronic liver disease, a targeted 2,500 Japanese adult patients regularly visiting Shinshu University Hospital in Matsumoto, Japan, for chronic liver disease will complete a standardized questionnaire on the presence of PoPH symptoms. If the respondent has signs of possible PoPH, ultrasound echocardiography (UCG) will be performed as a primary screening. In the case that UCG findings indicate pulmonary hypertension, the patient will be referred to a cardiologist for further evaluation, whereby a definitive diagnosis PoPH can be made. PoPH prevalence and etiology will be investigated at the time of diagnosis. Afterwards, patients with PoPH will be followed for five years for determination of survival rate.

DISCUSSION

This study will reveal the prevalence, etiology, and 5-year survival rate of PoPH in Japanese patients with chronic liver disease.

TRIAL REGISTRATION

This study is being performed at Shinshu University following registration as UMIN 000042287 on October 29, 2020.

Portopulmonary Hypertension: From Bench to Bedside

Portopulmonary hypertension (PoPH) is defined as pulmonary arterial hypertension (PAH) associated with portal hypertension and is a subset of Group 1 pulmonary hypertension (PH). PoPH is a cause of significant morbidity and mortality in patients with portal hypertension with or without liver disease. Significant strides in elucidating the pathogenesis, effective screening algorithms, accurate diagnoses, and treatment options have been made in past 20 years. Survival of PoPH has remained poor compared to IPAH and other forms of PAH. Recently, the first randomized controlled trial was done in this patient population and showed promising results with PAH specific therapy. Despite positive effects on hemodynamics and functional outcomes, it is unclear whether PAH specific therapy has a beneficial effect on long term survival or transplant outcomes. In this review, we will discuss the epidemiology, pathophysiology, clinical and hemodynamic characteristics of PoPH. Additionally, this review will highlight the lacunae in our current management strategy, challenges faced and will provide direction to potentially useful futuristic management strategies.

Pulmonary Complications in Patients with Liver Cirrhosis

Patients with advanced chronic liver diseases, particularly with decompensated liver cirrhosis, can develop specific pulmonary complications independently of any pre-existing lung disease. Especially when dyspnea occurs in combination with liver cirrhosis, patients should be evaluated for hepato-pulmonary syndrome (HPS), porto-pulmonary hypertension (PPHT), hepatic hydrothorax and spontaneous bacterial empyema, which represent the clinically most relevant pulmonary complications of liver cirrhosis. Importantly, the pathophysiology, clinical features, diagnosis and the corresponding therapeutic options differ between these entities, highlighting the role of specific diagnostics in patients with liver cirrhosis who present with dyspnea. Liver transplantation may offer a curative therapy, including selected cases of HPS and PPHT. In this review article, we summarize the pathogenesis, clinical features, diagnostic algorithms and treatment options of the 4 specific pulmonary complications in patients with liver cirrhosis.

Ambrisentan in portopulmonary hypertension: A multicenter, open-label trial

BACKGROUND

Ambrisentan has shown effectiveness in the treatment of Group 1 pulmonary arterial hypertension (PAH). Although portopulmonary hypertension (PoPH) is a subset of Group 1 PAH, few clinical trials have been testing PAH therapies in patients with PoPH. The objective of this study is to evaluate the efficacy and safety of ambrisentan in PoPH.

METHODS

This study is a prospective, multicenter, open-label trial in which treatment-naive patients with PoPH with Child-Pugh class A/B were administered with ambrisentan for 24 weeks, followed by a long-term extension (24-28 weeks). The primary end-points were change in pulmonary vascular resistance (PVR) and 6-minutes walk distance (6MWD) at 24 weeks, whereas secondary end-points included safety, World Health Organization (WHO) functional class (FC) and echocardiographic assessments.

RESULTS

Of the 31 patients, 23 finished 24 weeks of ambrisentan therapy and 19 finished the extension. PVR decreased significantly (mean ± SD) (7.1 ± 5 vs 3.8 ± 1.8 Wood units, p < 0.001), whereas 6MWD remained unchanged (314 ± 94 vs 336 ± 108 m). Other hemodynamic parameters such as right atrial pressure (13 ± 8 vs 9 ± 4 mm Hg, p < 0.05), mean pulmonary arterial pressure (46 ± 13 vs. 38 ± 8 mm Hg, p < 0.01), cardiac index (2.6 ± 0.6 vs. 3.5 ± 0.7 liter/min/m², p < 0.001) showed improvement, whereas pulmonary capillary wedge pressure remained unchanged. Of the 22 patients with WHO FC assessments at baseline and 24 weeks, WHO FC improved significantly (p = 0.005). Most frequent drug-related adverse events were edema (38.7%) and headache (22.5%). One episode of leg edema resulted into the permanent discontinuation of ambrisentan.

CONCLUSIONS

Ambrisentan monotherapy in PoPH improves hemodynamics and FC at 24 weeks; however, it did not show any improvement in 6MWD. These preliminary outcomes should be interpreted with caution (Clinicaltrials.Gov:NCT01224210).

Pulmonary Complications of Portal Hypertension

The most common pulmonary complications of chronic liver disease are hepatic hydrothorax, hepatopulmonary syndrome, and portopulmonary hypertension. Hepatic hydrothorax is a transudative pleural effusion in a patient with cirrhosis and no evidence of underlying cardiopulmonary disease. Hepatic hydrothorax develops owing to the movement of ascitic fluid into the pleural space. Hepatopulmonary syndrome and portopulmonary hypertension are pathologically linked by the presence of portal hypertension; however, their pathophysiologic mechanisms are significantly different. Hepatopulmonary syndrome is characterized by low pulmonary vascular resistance secondary to intrapulmonary vascular dilatations and hypoxemia; portopulmonary hypertension features elevated pulmonary vascular resistance and constriction/obstruction within the pulmonary vasculature.

Hepatopulmonary Disorders: Gas Exchange and Vascular Manifestations in Chronic Liver Disease

This review concentrates on the determinants of gas exchange abnormalities in liver-induced pulmonary vascular disorders, more specifically in the hepatopulmonary syndrome. Increased alveolar-arterial O₂ difference, with or without different levels of arterial hypoxemia, and reduced diffusing capacity represent the most characteristic gas exchange disturbances in the absence of cardiac and pulmonary comorbidities. Pulmonary gas exchange abnormalities in the hepatopulmonary syndrome are unique encompassing all three pulmonary factors determining arterial PO₂ , that is, ventilation-perfusion imbalance, increased intrapulmonary shunt and oxygen diffusion limitation that, combined, interplay with two relevant nonpulmonary determinants, that is, increased total ventilation and high cardiac output. Behind the complexity of this lung-liver association there is an abnormal pulmonary vascular tone that combines inhibition of hypoxic pulmonary vasoconstriction with a reduced (or blunted) hypoxic vascular response. The pathology and pathobiology include the presence of intrapulmonary vascular dilatations with or without pulmonary vascular remodeling, i.e. angiogenesis. Liver transplantation, the only effective therapeutic approach to successfully improve and resolve the vast majority of complications induced by the hepatopulmonary syndrome, along with a large list of frustrating pharmacologic interventions, are also reviewed. Another liver-induced pulmonary vascular disorder with less gas exchange involvement, such as portopulmonary hypertension, is also considered. © 2018 American Physiological Society. Compr Physiol 8:711-729, 2018.

Acute right ventricular failure after orthotopic liver transplantation

The interdependence between the heart and liver in maintaining hemodynamic stability during the perioperative period of either orthotopic heart (OHT) or liver (OLT) transplantation is important. The pre-transplant hemodynamic changes that occur in patients with end-stage liver disease (ESLD) can include decreased systemic vascular resistance, poor ventricular response to stress and increased cardiac output (CO). Concomitant pulmonary disorders are often present in ESLD. Portopulmonary hypertension (PoPHTN) is an important marker for increased mortality in liver transplant patients. The pathophysiologic mechanisms specific to PoPHTN have been compared with other known forms of pulmonary hypertension, including primary pulmonary hypertension, and has been found to fall within a spectrum of disorders related to factors both due to intrinsic liver failure [with resultant portal hypertension and hepatopulmonary syndrome (HPS)] as well as pulmonary vascular remodeling. We present a 47-year-old Caucasian female with ESLD secondary to non-alcoholic steatohepatitis and HPS. Our current case demonstrates the difficulty in managing patients with acute pulmonary hypertension after OLT. Review of the contemporary literature demonstrated a total of eight case reports of post-transplant severe pulmonary hypertension thought to be due to a combination of either HPS or PoPHTN. This case highlights the complexities of patient management in the acute setting after OLT. Furthermore, it demonstrates the intricate role of careful preoperative evaluation and screening in patients undergoing workup for solid organ transplantation.

Differential diagnosis of hepatopulmonary syndrome (HPS): Portopulmonary hypertension (PPH) and hereditary hemorrhagic telangiectasia (HHT)

Hepatopulmonary syndrome (HPS) is a severe complication of advanced liver disease associated with an extremely poor prognosis. HPS is diagnosed in 4-47% of patients with cirrhosis and in 15-20% of candidates for liver transplantation. In addition, severe hypoxia is associated with a high risk of complications of liver transplantation (a 30% chance during the first 90 days) and increases the gap between transplantation and improving arterial oxygenation. The pathogenesis of HPS is not fully understood, and no effective pharmacological treatment has been developed yet. Currently, the treatment of choice for HPS is orthotopic liver transplantation. Non-specific clinical criteria and the lack of standardized diagnostic criteria for determining HPS can lead to diagnostic errors. Portopulmonary hypertension and hereditary hemorrhagic telangiectasia, also known as Osler-Weber-Rendu syndrome, are pulmonary complications of liver disease which should be differentially diagnosed from HPS.

Portopulmonary hypertension in children: a rare but potentially lethal and under-recognized disease

Portopulmonary hypertension (PoPH) is defined by the combination of portal hypertension and precapillary pulmonary arterial hypertension (PAH). Very little is known about this process in pediatric patients but prognosis is generally poor. We review our institutional experience and report on five patients with pediatric PoPH. The median age of PoPH diagnosis was six years and PAH was 14 years. PAH diagnosis was made by echocardiogram in all patients, four of whom also had cardiac catheterization. The median mean pulmonary artery pressure (mPAP) was 48.5 mmHg (interquartile range [IQR] = 46–60) with a median pulmonary vascular resistance index (PVRi) of 9 WU*M² (IQR = 8–22). All were acute pulmonary vasodilator testing non-responsive. All patients received targeted therapies. Three of five patients (60%) died despite an evidence-based approach to care. Of those who died, timing from the PoPH diagnosis to death ranged from three days to three years. Based upon our limited experience, PoPH is a disorder with significant mortality in childhood and challenges in treatment. Future research, focused on screening and early targeted treatment strategies, may alter the current dismal prognosis for these children.

Respiratory Complication in Liver Disease

Cirrhosis, the twelfth leading cause of death, accounts for 1.1% of all deaths in the United States. Although there are multiple pulmonary complications associated with liver disease, the most important complications that cause significant morbidity and mortality are hepatopulmonary syndrome, hepatic hydrothorax, and portopulmonary hypertension. Patients with cirrhosis who complain of dyspnea should be evaluated for these complications. This article reviews these complications.

Pulmonary hypertension's variegated landscape: a snapshot

The many types of pulmonary hypertension (PH) are so protean in their biological origin, histological expression, and natural history that it is difficult to create a summary picture of the disease, or to easily compare and contrast characteristics of one type of PH with another. For newcomers to the field, however, such a picture would facilitate a broad understanding of PH. In this paper, we suggest that four characteristics are fundamental to describing the nature of various types of PH, and that taken together they define a number of patterns of PH expression. These characteristics are histopathology, developmental origin, associated clinical conditions, and potential for resolution. The “snapshot” is a way to concisely display the ways that these signal characteristics intersect in select specific types of PH, and is an effort to summarize these patterns in a way that facilitates a “big picture” comprehension of this disease.

Current Approach to the Diagnosis and Management of Portopulmonary Hypertension

Portopulmonary hypertension (POPH) is a form of pulmonary arterial hypertension occurring in the setting of portal hypertension with or without hepatic cirrhosis. The presence of both portal and pulmonary vascular disease contributes to complicated hemodynamics and therapeutic challenges, though the severities do not appear to correlate directly. Diagnosis of POPH, and distinction from the commonly observed hyperdynamic state of end-stage liver disease, is typically accomplished with an initial screening transthoracic echocardiogram, followed by right heart catheterization for confirmation of hemodynamic parameters. Though few studies have directly evaluated use in POPH, pulmonary artery-directed therapy is the cornerstone of management, along with consideration of liver transplantation. Perioperative and long-term outcomes are variable, but uniformly worse in the setting of uncontrolled pulmonary pressures. Risk stratification and optimal patient selection for these interventions are areas of ongoing investigation.

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.

Portopulmonary hypertension in liver transplant candidates

Pulmonary vascular disorders including portopulmonary hypertension (PoPHT) are among the common complications of liver disease and are prognostically significant. Survival is very low without medical treatment and liver transplantation. With advances in medical therapy for elevated pulmonary artery pressure (PAP) and liver transplant surgery, survival of patients with PoPHT and advanced liver disease is significantly improved. Because of the prognostic significance of PoPHT and the limited donor pool, a comprehensive preoperative cardio-pulmonary assessment is of great importance in cirrhotic patients prior to transplant surgery. Therefore, a detailed transthoracic Doppler echocardiographic examination must be an essential component of this evaluation. Patients with mild PoPHT can safely undergo liver transplant surgery. In cases of moderate to severe PoPHT, right heart catheterization (RHC) should be performed. In patients with moderate to severe PoPHT on RHC (mean PAP 35-45 mmHg), vasodilator therapy should be attempted. Liver transplantation should be encouraged in cases that demonstrate a positive response. Bridging therapy with specific pulmonary arterial hypertension treatment agents should be considered until the transplant surgery and should be continued during the peri- and post-operative periods as needed.

Intrapulmonary vascular dilatations are common in portopulmonary hypertension and may be associated with decreased survival

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are pulmonary vascular complications of portal hypertension with divergent clinicopathologic features and management. The presence of intrapulmonary vascular dilatations (IPVDs), detected by agitated saline contrast-enhanced transthoracic echocardiography (cTTE), is an essential feature of HPS but is not typically characteristic of POPH. Although IPVDs have been reported rarely in POPH, the prevalence and significance of this finding have not been systematically studied. We conducted a retrospective chart review of 80 consecutive patients diagnosed with POPH from January 1, 2002 to June 30, 2014 with documentation of cTTE findings, pulmonary hemodynamics, oxygenation, and survival. A total of 34 of the 80 patients (42%) underwent cTTE during initial diagnosis of POPH. IPVDs were detected in 20/34 patients (59%); intracardiac shunting was detected in 9/34 patients (26%; 4 also had IPVDs); and 9 patients (26%) had negative cTTE with no evidence of IPVD or intracardiac shunting. Patients with IPVD had decreased survival as compared to those without IPVD (P = 0.003), a trend that persisted after exclusion of liver transplant recipients (P =  0.07). The IPVD group had a trend toward higher Model for End-Stage Liver Disease score with and without incorporating sodium (MELD or MELD-Na; P = 0.05 for both). The right ventricular index of myocardial performance (RIMP) was lower in the IPVD group (median, 0.4 versus 0.6; P = 0.006). Patients with moderate or large IPVDs (n = 6) had worse oxygenation parameters (partial pressure of arterial oxygen, diffusing capacity of the lung for carbon monoxide, and alveolar-arterial oxygen gradient) as compared to the rest of the cohort. Unexpectedly, IPVDs were frequently documented in POPH and associated with decreased survival. To further understand this observation, we recommend screening for IVPD in all patients with POPH.

Portopulmonary hypertension: an update

Portopulmonary hypertension represents a serious lung vascular disorder, defined as the presence of pulmonary arterial hypertension that is associated with portal hypertension, with or without the presence of significant liver disease. Transthoracic echocardiography represents the single best initial tool for the diagnostic evaluation in portopulmonary hypertension, and right heart catheterization remains the gold standard for definitive diagnosis. Despite the lack of randomized controlled trials in portopulmonary hypertension, some therapies have demonstrated improvements in cardiopulmonary haemodynamics and right ventricular function as described in case reports and case series. Specialists should be able to recognize indications and contraindications for liver transplantation in the setting of portopulmonary hypertension, and this review focuses on the appropriate diagnostic approach and current advances in medical therapies. Recognition of patients eligible for liver transplantation is needed to improve quality of life and survival.

Effectiveness of phosphodiesterase-5 inhibitor therapy for portopulmonary hypertension

BACKGROUND

Portopulmonary hypertension is associated with significant morbidity and mortality. Phosphodiesterase-5 inhibitor therapy is efficacious in other causes of WHO group I pulmonary arterial hypertension.

OBJECTIVE

To evaluate the efficacy and safety of phosphodiesterase-5 inhibitor therapy in patients with portopulmonary hypertension.

METHODS

A single-centre retrospective cohort study that included patients with a diagnosis of portopulmonary hypertension was performed. The primary outcome was change in pulmonary vascular resistance after six months of phosphodiesterase-5 inhibitor therapy. A secondary evaluation investigated the effect on other hemodynamic measurements, 6 min walk distance, functional class, safety outcomes and survival.

RESULTS

Of 1385 patients screened, 25 patients with portopulmonary hypertension were identified, of whom 20 received a phosphodiesterase-5 inhibitor. After six months, there was a significant decrease in pulmonary vascular resistance (-236 dyn • s • cm(-5) [95% CI -343 dyn • s • cm(-5) to -130 dyn • s • cm(-5)]; P<0.001), mean pulmonary artery pressure (-8.9 mmHg [95% CI -13.7 mmHg to -4.2 mmHg]; P=0.001) and an increase in Fick cardiac output (0.9 L/min [95% CI 0.1 L/min to 1.6 L/min]; P=0.02). There was no change in 6 min walk distance. The proportion of subjects with a WHO functional class III or IV was significantly reduced at six months compared with baseline (18% versus 61%; P=0.002). Safety outcomes did not reveal any adverse events.

CONCLUSIONS

Phosphodiesterase-5 inhibitor therapy improved hemodynamics and functional class at six months in a cohort of patients with portopulmonary hypertension.

Thrombocytopenia is an independent predictor of mortality in pulmonary hypertension

BACKGROUND

Established prognostic factors for pulmonary hypertension (PH) include brain natriuretic peptide, troponins and hemodynamic measures such as central venous pressure and cardiac output. The prognostic role of thrombocytopenia, however, has yet to be determined in patients with PH. The aim of this study was to evaluate effect of thrombocytopenia on mortality in patients with PH.

METHODS

521 patients with severe PH, defined by a pulmonary artery systolic pressure >60 mm Hg on transthoracic echocardiography and a platelet count measured within one month after diagnosis were enrolled from three hospitals of Montefiore Medical Center. The cohort was divided into two groups: mild thrombocytopenia to a normal platelet count (platelet count 100,000-450,000 per uL); and moderate to severe thrombocytopenia (platelet count <100,000 per uL). Inpatient and social security death records were used to determine 1-year all-cause mortality.

RESULTS

Mean age was 70.3 ± 15.6 with 40% of patients being male. Overall mortality at 1 year was 30.7%, with increased mortality in PH patients with mild thrombocytopenia compared to those with moderate to severe thrombocytopenia (46.5% vs. 27.0%, p < 0.001). In multivariate analysis, moderate to severe thrombocytopenia remained an independent predictor of mortality (HR 1.798, 95% CI 1.240-2.607, p = 0.002).

CONCLUSIONS

Moderate to severe thrombocytopenia is an independent predictor of higher mortality in patients with severe PH. These findings may support the use of thrombocytopenia as a useful prognostic indicator in patients with severe PH.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Portopulmonary hypertension

Portopulmonary hypertension (POPH) is defined as pulmonary arterial hypertension (PAH) complicated by portal hypertension, with or without advanced hepatic disease. Significant percentage of patients with cirrhotic liver disease has high cardiac output and subsequently elevated pulmonary arterial pressures (PAP). However, patients with POPH develop a progressive increase in pulmonary vascular resistance (PVR), which is generally lower than that observed in other forms of PAH.

The prognosis of untreated patients with POPH is very poor and the outcome of liver transplant (LT) in those patients is determined by the degree of severity of the associated pulmonary hemodynamics.

In this narrative review, we describe the clinical presentation of POPH, the pathobiology, and the clinical implication of pulmonary hemodynamics. We also provide evidence-based recommendations for the diagnosic and management approaches of POPH.

Living-donor liver transplantation for congenital biliary atresia with porto-pulmonary hypertension and moderate or severe pulmonary arterial hypertension: Kyoto University experience

Porto-pulmonary hypertension with moderate or severe pulmonary arterial hypertension (PAH) is viewed as a contraindication to liver transplantation (LT) because of associated poor outcomes; however, patients with biliary atresia (BA) are generally good candidates for LT. Ten patients with moderate/severe PAH underwent living-donor liver transplantation (LDLT) at our institution; eight of these patients had BA and were the focus of this study. Preoperative therapies, including prostaglandin (PG)I2 , were introduced. When mean pulmonary arterial pressure (mPAP) after treatment was <40 mmHg or initial mPAP without therapy was <35 mmHg, we performed an acute volume challenge test to evaluate right ventricular function. LDLT was performed when mPAP after anesthetic induction was confirmed at ≤35 mmHg. Six patients had favorable responses to preoperative treatment and catheter testing, but two patients showed poor responses. The two patients with poor responses had poor clinical courses with unstable mPAP after LDLT. The other six patients had successful courses with well-controlled mPAP, and PGI2 was withdrawn or weaned following LDLT. Survival did not significantly differ between the eight BA recipients with moderate/severe PAH and 77 age-matched BA recipients without PAH from the same time period. LDLT has major benefits for BA patients with well-controlled PAH.

Portopulmonary hypertension

Portopulmonary hypertension (POPH) is the presence of pulmonary arterial hypertension in patients with portal hypertension. Among liver transplant (LT) candidates, reported incidence rates of POPH range from 4.5% to 8.5%. In patients with LT, intraoperative death and immediate post-LT mortality are feared clinical events when transplantation is attempted in the setting of untreated, moderate to severe POPH; therefore, POPH precludes LT unless the mean pulmonary artery pressure can be reduced to a safe level and right ventricular function optimized. Specific pulmonary artery vasodilator medications seem effective in reducing pulmonary artery pressures and improving right ventricular function and survival.

Clinical aspects of portopulmonary hypertension

Portopulmonary hypertension (PoPH) is an often neglected form of pulmonary hypertension where pulmonary hypertension occurs in the presence of portal hypertension. PoPH is important to diagnose and treat as it may improve the patient's quality of life and improve the outcome after liver transplantation. In this review, we discuss the clinical aspects of PoPH including its pathophysiology, diagnosis, treatment, and prognosis.

Living-donor liver transplantation for moderate or severe porto-pulmonary hypertension accompanied by pulmonary arterial hypertension: a single-centre experience over 2 decades in Japan

BACKGROUND

Candidates for orthotopic liver transplantation (OLT) often have porto-pulmonary hypertension (PPHTN) with pulmonary arterial hypertension (PAH). Poor outcomes of PPHTN contraindicate OLT. There are no guidelines for living-donor liver transplantation (LDLT) in PPHTN patients.

METHODS

We present our experiences of LDLT in six patients with moderate or severe PPHTN, along with our institutional guidelines. Three had liver cirrhosis and three were non-cirrhotic. Catheterization studies were undertaken before, during and after LDLT, and the mean pulmonary arterial pressure (mPAP), cardiac output (CO), pulmonary vascular resistance and total peripheral resistance (TPR) were monitored.

RESULTS

The results showed significant differences in CO and TPR between cirrhotic and non-cirrhotic patients before, during and after LDLT. Cirrhotic patients showed systemic hyperdynamic state. Two cirrhotic patients showed poor responses to pre-transplant treatment, and continued to have increased PAH and poor clinical courses after LDLT. LDLT has an advantage of flexible timing of LT. Currently in our institution, PPHTN patients with mPAP <40 mmHg are registered for LDLT after treatment and catheterization. However, LDLT is performed when mPAP is ≤35 mmHg, leading to improved outcomes.

CONCLUSION

PPHTN patients with well-controlled PAH, or secondary PAH resulting from porto-systemic shunts, may be appropriate candidates for LDLT after careful considerations.

Preoperative Assessment and Management of Liver Transplant Candidates With Portopulmonary Hypertension

Pulmonary artery hypertension (PAH) that occurs as a consequence of portal hypertension is termed portopulmonary hypertension (POPH) and is associated with significant morbidity and mortality. Among liver transplant (LT) candidates, reported incidence rates of POPH range from 4.5% to 8.5%. The severity of POPH is unrelated to the severity of portal hypertension or the liver disease. In LT patients, intraoperative death and immediate post-LT mortality are feared clinical events when transplantation is attempted in the setting of untreated, moderate to severe POPH. Specific pulmonary artery vasodilator medications (PAH-specific therapy) appear effective in reducing pulmonary artery pressures, improving right ventricular (RV) function and survival. Thus, screening for and accurately diagnosing POPH prior to LT has become a standard of care. The post-LT course of patients with moderate POPH is unpredictable, but most patients can be weaned from PAH-specific therapy over time. In this article, we present an overview of the preoperative assessment of POPH with an emphasis on risk assessment for transplant and the most recent medical treatment options.

Review article: liver transplantation for the pulmonary disorders of portal hypertension

BACKGROUND

Liver transplantation is potentially a life-saving therapeutic intervention for patients with portopulmonary hypertension and hepatopulmonary syndrome. However, due to limited data, listing criteria for patients with these conditions have not been clearly established. Indeed, this has led some to speculate that transplantation may not be appropriate in cases of moderate-to-severe portopulmonary hypertension and severe hepatopulmonary syndrome.

AIM

To critically discuss the utility of LT for the treatment of hepatopulmonary syndrome and portopulmonary hypertension.

METHODS

A literature search was conducted in 2012 on PubMed, Ovid Embase, Ovid Medline and Scopus using the following search terms: hepatopulmonary syndrome, portopulmonary hypertension, pulmonary arterial hypertension, liver transplantation. Relevant manuscripts were included in the review.

RESULTS

Liver transplantation has established itself as an effective treatment for selected patients with hepatopulmonary syndrome and portopulmonary hypertension. A multidisciplinary team approach incorporating focused strategies (both pre- and post-operatively) aimed at improving oxygenation in patients with hepatopulmonary syndrome has led to a dramatic improvement in patient outcomes. Additionally, careful patient selection and the use of targeted pulmonary vascular therapies are successfully being used to treat portopulmonary hypertension and 'bridge' patients to successful liver transplantation.

CONCLUSIONS

Liver transplantation is an effective therapy for patients with hepatopulmonary syndrome and portopulmonary hypertension. However, rigorous screening and early identification of these conditions allied with aggressive pre-operative optimisation of physiology and diligent post-operative care are imperative to ensuring a good outcome.

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.

2009 ESC/ERS pulmonary hypertension guidelines and connective tissue disease

Pulmonary hypertension was defined as mean pulmonary artery pressure ≥ 25 mmHg at the 4th World Symposium on Pulmonary Hypertension. In 2009, the European Society of Cardiology and European Respiratory Society jointly created guidelines for practical pulmonary hypertension classifications and treatments based on the discussions at the 4th World Symposium. This classification is characterized by division into five groups: Pulmonary arterial hypertension (PAH); Pulmonary hypertension due to left heart disease; Pulmonary hypertension due to lung disease and/or hypoxia; Chronic thromboembolic pulmonary hypertension; and Pulmonary hypertension with unclear and/or multifactorial mechanisms. PAH is a common and fatal complication of connective tissue disease (CTD), but pulmonary hypertension in CTD consists of PAH, pulmonary hypertension caused by myocardial involvement, pulmonary veno-occlusive disorder, pulmonary hypertension due to interstitial lung disease. PAH has been studied widely in SSc and the estimated prevalence of 7-12%. Treatment of CTD associated PAH (CTD-PAH) consists of general therapeutic options and specific treatment. Specific treatment of CTD-PAH patients is targeted to produce vasodilatation. Calcium channel blockers (CCBs) are indicated in cases where a sufficient decrease in pulmonary arterial pressure is seen in vasoreactivity testing. If vasoreactivity is absent in CTD-PAH patients, the treatment consists of the endothelin receptor antagonists, the prostacyclin analogues and phosphodiesterase-type 5 inhibitors. Few data are available to support the use of immunosuppression in CTD-PAH. However, some case reports suggested that a minority of CTD-PAH patients could benefit from immunosuppressive therapy. The treatment of CTD-PAH patients may differ from the treatment of idiopathic PAH.

Prevalence of spontaneous portosystemic shunts in patients with portopulmonary hypertension and effect on treatment

BACKGROUND & AIMS

We documented the frequency of large spontaneous portosystemic shunts in patients with moderate or severe portopulmonary hypertension (POPH) and determined the association between large shunts and response to treatment.

METHODS

We performed a retrospective case-control study of data from patients with mild (mean pulmonary artery pressure [MPAP], 25-35 mm Hg; n = 18), moderate (MPAP, 35-50 mm Hg; n = 45), and severe POPH (MPAP, >50 mm Hg; n = 16). Data were compared with those from controls (normal echocardiography with estimated right ventricular systolic pressure, <35 mm Hg; n = 122). Spontaneous portosystemic shunts greater than 10 mm in diameter, identified by computed tomography or magnetic resonance, were classified as large. Response to treatment at 6 months was defined by right ventricular systolic pressure or MPAP as significant (<35 mm Hg), partial (35-50 mm Hg), or no response (>50 mm Hg).

RESULTS

The frequency of spontaneous shunts did not differ significantly between groups of subjects with severe (n = 14 of 16), moderate (n = 38 of 45), or mild POPH (n = 11 of 18) or normal echocardiograms (controls, n = 86 of 122) (P = .77). Large shunts were associated with severe (14 of 16) and moderate POPH (32 of 45), compared with mild POPH (6 of 18) or controls (30 of 122) (P < .01). In 13 patients with severe POPH, large shunts were associated with lack of response to treatment in 90% (8 of 9) or partial response in 50% (2 of 4). Among 27 patients with moderate POPH, large shunts were associated with no response to treatment in 13 of 19 (68%) and a partial response in 2 of 6 (33%).

CONCLUSIONS

Large spontaneous portosystemic shunts are associated significantly with moderate and severe POPH, and with lack of response to treatment.

Portopulmonary hypertension

Portopulmoanry hypertension (POPH) is a form of pulmonary arterial hypertension (PAH) associated with portal hypertension with or without underlying chronic liver disease. POPH is increasingly recognized and recent evidence suggests that it is one of the leading causes of PAH. The pathophysiology of POPH is poorly understood although the pathological changes in pulmonary vasculature in advanced POPH are similar to those seen in idiopathic pulmonary hypertension. The prognosis in patients with liver disease who also suffer from significant POPH is considered to be poor. Higher degree of pulmonary artery pressure (PAP) may preclude a patient from liver transplant as mortality in these patients is high. The treatment with vasodilator therapy has shown to improve both hemodynamics and clinical outcome in POPH in retrospective studies and in some case series. The aim of medical management is to bring PAP <35 mmHg that may make a patient with POPH and advanced liver disease eligible for liver transplant, which otherwise would have been denied because of high PAP.

Usefulness of acute pulmonary vasoreactivity test of sildenafil in treatment of portopulmonary hypertension. A case report

A 50-year-old man diagnosed with liver cirrhosis type C was referred to our hospital because of right heart failure with pulmonary hypertension. Echocardiography revealed enlargement of the right atrium and ventricle with severe tricuspid regurgitation. The peak flow velocity of tricuspid regurgitation by continuous wave Doppler echocardiography was 452 cm/s. Right heart catheterization demonstrated severe pulmonary hypertension [pulmonary arterial pressure (PAP) systolic/diastolic/mean = 73/20/41 mmHg and pulmonary vascular resistance (PVR) = 509 dyn s cm^-5] with portal hypertension. We diagnosed the patient as having portopulmonary hypertension (PoPH). Although we treated the patient with a prostacyclin analog, tricuspid regurgitation velocity was increased to 480 cm/s four years after the start of the therapy. To select drugs for the treatment of PoPH, we performed an acute vasoreactivity test of sildenafil during right heart catheterization. Since single administration of sildenafil (20 mg) decreased PAP (93/30/55-77/27/44 mmHg) and PVR (908-833 dyn s cm^-5), we added sildenafil (20 mg, t.i.d.) to the prostacyclin analog. Tricuspid regurgitation velocity decreased to 403 cm/s one year after the addition of sildenafil. An acute vasoreactivity test of sildenafil during right heart catheterization was useful for the decision of the drug to be used in the treatment of PoPH.

A consensus approach to the classification of pediatric pulmonary hypertensive vascular disease: Report from the PVRI Pediatric Taskforce, Panama 2011

Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.

Cardiovascular changes in cirrhosis: pathogenesis and clinical implications

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

Prevalence of hepatic parasites in Korean wild rats (Rattus norvegicus) and their association with pulmonary arteriolar medial hypertrophy

C hepatica, an important zoonotic parasite, and C fasciolaris are common parasites in rodents. In rodent livers, C hepatica causes sequential morphologic changes that are designated as early, intermediate, or late phase, and C fasciolaris forms cysts surrounded by fibroplasia and granulomatous inflammation. The present study describes the prevalence of these parasites and associated liver and lung lesions in wild rats (Rattus norvegicus) living around pig farms in South Korea. Selected parenchymal organs, including liver and lung, of 89 wild rats were examined. Of 89 rats, 28 (31.5%) were infected with either C hepatica or C fasciolaris or with both parasites. Severe medial hypertrophy of small arterioles was observed in the lungs of 11 of the 28 parasite-infected rats (P < .01). The pulmonary arteriolar hypertrophy in the rats infected with C hepatica was strongly associated with early and/or intermediate phases (88.8%) of morphologic change in the livers (P < .01). As such, this report is the first to suggest a significant association between parasite-induced hepatitis and pulmonary arteriolar hypertrophy in rodents. Further studies are warranted for the use of C hepatica-infected rats as an animal model to explore the underlying mechanisms of portopulmonary hypertension in humans.

Pulmonary complications of cirrhosis

Advanced liver disease and portal hypertension produce various intrathoracic complications that involve the pleural space, the lung parenchyma, and the pulmonary circulation. Dyspnea and arterial hypoxemia are the most common symptoms and signs in patients with such complications. This article focuses on the diagnosis and management of hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. All are pulmonary processes associated with end-stage liver disease that lead to significant morbidity and affect the quality of life of patients who are suffering from liver cirrhosis.