Pulmonary hypertension complicating portal hypertension: prevalence and relation to splanchnic hemodynamics

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Systemic Complications Secondary to Chronic Liver Disease

The systemic sequelae of chronic liver disease (CLD) may be due to portal hypertension and shunting, malnutrition, and/or a low grade inflammatory state. This article will focus on the consequences of chronic liver disease affecting extrahepatic organs. Portal hypertension underlies many systemic complications of CLD. Aside from varices and ascites, portal hypertension may cause both hepatopulmonary syndrome and portopulmonary hypertension leading to respiratory compromise. Cardiomyopathy may also occur secondary to end stage liver disease. Hepatorenal syndrome is also well recognised and hepatic encephalopathy is a consequence of the effect of liver dysfunction on the brain. Compromise of the immune system is well described in end-stage liver disease leading to sepsis and its consequences. Bony disease including osteoporosis and hepatic arthropathy may both be seen in children with CLD. CLD may be asymptomatic initially but then complications may present as the disease progresses. Furthermore, systemic effects of end stage liver disease may complicate liver transplant. These complications often present insidiously or at the time of acute decompensation. Thus, it is important that healthcare providers are vigilant when caring for children with CLD. This article outlines the secondary complications of CLD with an overview of the definition and diagnosis, pathophysiology, management and prognosis of each.

Pulmonary arterial hypertension associated with portal hypertension: Noninvasive comprehensive assessment using computed tomography

Pulmonary arterial hypertension associated with portal hypertension, known as portopulmonary hypertension (PoPH) is one of the important and serious pulmonary complications in patients with portal hypertension. Although there are a large number of patients with portal hypertension due to mainly liver cirrhosis, the number of cases diagnosed with PoPH are far fewer because the causes of dyspnea in patients with cirrhosis are diverse and the disease entity of PoPH is poorly recognized by clinicians. We report here the case with PoPH suggested and assessed comprehensively by dual energy computed tomography (CT) including high-resolution pulmonary CT angiography, pulmonary perfusion imaging, myocardial late iodine enhancement imaging, and myocardial extracellular volume analysis. This refined CT imaging protocol can be used in conjunction with standard chest evaluation and offers a practical and useful approach for the noninvasive "one-stop shop" evaluation of PoPH.

The Early Detection of Pulmonary Hypertension

BACKGROUND

Up to 1% of the world population and 10% of all persons over age 65 suffer from pulmonary hypertension (PH). The latency from the first symptom to the diagnosis is more than one year on average, and more than three years in 20% of patients. 40% seek help from more than four different physicians until their condition is finally diagnosed.

METHODS

This review is based on publications retrieved by a selective literature search on pulmonary hypertension.

RESULTS

The most common causes of pulmonary hypertension are left heart diseases and lung diseases. Its cardinal symptom is exertional dyspnea that worsens as the disease progresses. Additional symptoms of right heart failure are seen in advanced stages. Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are rare, difficult to diagnose, and of particular clinical relevance because specific treatments are available. For this reason, strategies for the early detection of PAH and CTEPH have been developed. The clinical suspicion of PH arises in a patient who has nonspecific symptoms, electrocardiographic changes, and an abnormal (NT-pro-)BNP concentration. Once the suspicion of PH has been confirmed by echocardiography and, if necessary, differential-diagnostic evaluation with a cardiopulmonary stress test, and after the exclusion of a primary left heart disease or lung disease, the patient should be referred to a PH center for further diagnostic assessment, classification, and treatment.

CONCLUSION

If both the (NT-pro-)BNP and the ECG are normal, PH is unlikely. Knowledge of the characteristic clinical manifestations and test results of PH is needed so that patients can be properly selected for referral to specialists and experts in PH.

[Pulmonary Complications in Patients with Liver Cirrhosis]

Portal hypertension is a clinical syndrome defined by an increased portal venous pressure. The most frequent cause of portal hypertension is liver cirrhosis, and many of the complications of cirrhosis, such as ascites and gastroesophageal variceal bleeding, are related to portal hypertension. Portal hypertension is a pathological condition caused by the accumulation of blood flow in the portal system. This blood flow retention reduces the effective circulation volume. To compensate for these changes, neurotransmitter hormone changes and metabolic abnormalities occur, which cause complications in organs other than the liver. A hepatic hydrothorax is fluid accumulation in the pleural space resulting from increased portal pressure. Hepatopulmonary syndrome and portopulmonary hypertension are the pulmonary complications in cirrhosis by deforming the vascular structure. Symptoms, such as dyspnea and hypoxia, affect the survival and the quality of life of patients. These lung complications are usually underestimated in the management of cirrhosis. This review briefly introduces the type of lung complications of cirrhosis.

Cardiac evaluation of the liver transplant candidate

PURPOSE OF REVIEW

This review aims to summarize recent changes in the cardiac evaluation of adult liver transplant candidates. Over the last several years, there have been significant advances in the use of coronary computed tomography angiography (CCTA) with and without fractional flow reserve (FFR) and increasingly widespread availability of coronary calcium scoring for risk stratification for obstructive coronary artery disease. This has led to novel strategies for risk stratification in cirrhotic patients being considered for liver transplant and an updated American Heart Association (AHA) position paper on the evaluation of liver and kidney transplant candidates. The diagnosis of cirrhotic cardiomyopathy has been refined. These new diagnostic criteria require that specific echocardiographic parameters are evaluated in all patients. The definition of pulmonary hypertension on echocardiography has been altered and no longer utilizes right atrium (RA) pressure estimates based on inferior vena cava (IVC) size and collapse. This provides more volume neutral estimates of pulmonary pressure.

RECENT FINDINGS

Although CCTA has outstanding negative predictive value, false positive results are not uncommon and often lead to further testing. Revised diagnostic criteria for cirrhotic cardiomyopathy improve risk stratification for peri-operative volume overload and outcomes. Refined pulmonary hypertension criteria provide improved guidance for right heart catheterization (RHC) and referral to subspecialists. There are emerging data regarding the safety and efficacy of TAVR for severe aortic stenosis in cirrhotic patients.

SUMMARY

Increased utilization of noninvasive testing, including CCTA and/or coronary calcium scoring, can improve the negative predictive value of testing for obstructive coronary artery disease and potentially reduce reliance on coronary angiography. Application of the 2020 criteria for cirrhotic cardiomyopathy will improve systolic and diastolic function assessment and subsequent perioperative risk stratification. The use of global strain scores is emphasized, as it provides important information beyond ejection fraction and diastolic parameters. A standardized one-parameter echo cut-off for elevated pulmonary pressures simplifies both evaluation and follow-up. Innovative transcutaneous techniques for valvular stenosis and regurgitation offer new options for patients at prohibitive surgical risk.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare and progressive disease characterised by remodelling of the pulmonary arteries and progressive narrowing of the pulmonary vasculature. This leads to a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure and, if left untreated, to right ventricular failure and death. A correct diagnosis requires a complete work-up including right heart catheterisation performed in a specialised centre. Although our knowledge of the epidemiology, pathology and pathophysiology of the disease, as well as the development of innovative therapies, has progressed in recent decades, PAH remains a serious clinical condition. Current treatments for the disease target the three specific pathways of endothelial dysfunction that characterise PAH: the endothelin, nitric oxide and prostacyclin pathways. The current treatment algorithm is based on the assessment of severity using a multiparametric risk stratification approach at the time of diagnosis (baseline) and at regular follow-up visits. It recommends the initiation of combination therapy in PAH patients without cardiopulmonary comorbidities. The choice of therapy (dual or triple) depends on the initial severity of the condition. The main treatment goal is to achieve low-risk status. Further escalation of treatment is required if low-risk status is not achieved at subsequent follow-up assessments. In the most severe patients, who are already on maximal medical therapy, lung transplantation may be indicated. Recent advances in understanding the pathophysiology of the disease have led to the development of promising emerging therapies targeting dysfunctional pathways beyond endothelial dysfunction, including the TGF-β and PDGF pathways.

Human liver single nuclear RNA sequencing implicates BMPR2, GDF15, arginine, and estrogen in portopulmonary hypertension

Portopulmonary hypertension (PoPH) is a type of pulmonary vascular disease due to portal hypertension that exhibits high morbidity and mortality. The mechanisms driving disease are unknown, and transcriptional characteristics unique to the PoPH liver remain unexplored. Here, we apply single nuclear RNA sequencing to compare cirrhotic livers from patients with and without PoPH. We identify characteristics unique to PoPH in cells surrounding the central hepatic vein, including increased growth differentiation factor signaling, enrichment of the arginine biosynthesis pathway, and differential expression of the bone morphogenic protein type II receptor and estrogen receptor type I genes. These results provide insight into the transcriptomic characteristics of the PoPH liver and mechanisms by which PoPH cellular dysfunction might contribute to pulmonary vascular remodeling.

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.

How do the 2022 European Society of Cardiology/European Respiratory Society guidelines modify the diagnosis of portopulmonary hypertension in patients with cirrhosis complicated by portal hypertension? A post hoc analysis

The vertical and horizontal broken lines indicate the pre-revised criteria, whereas the vertical and horizontal solid lines indicate the 2022 European Society of Cardiology/European Respiratory Society criteria.

Estimation of the effect of atezolizumab plus bevacizumab on pulmonary arterial hypertension using computed tomography in HCC patients

The effect of the combination of atezolizumab and bevacizumab (Atez/Bev) for hepatocellular carcinoma (HCC) on pulmonary arterial hypertension (PAH) is unknown. Estimation of PAH by using computed tomography (CT) has recently been proposed. Thus, we aimed to estimate the effect of Atez/Bev on PAH using CT. Altogether, 113 patients who received Atez/Bev for HCC were enrolled. Probable PAH was defined as the diameter of the main pulmonary artery (mPA-D) ≥ 33 mm, whereas suspicious PAH was defined as mPA-D ≥ 29 mm or mPA-D/the diameter of the ascending aorta (aAo-D) ≥ 1.0. Before treatment, probable/suspicious PAH were diagnosed in 7 (6.7%)/22 (21.0%) patients, respectively. mPA-D and mPA-D/aAo-D significantly increased after induction of Atez/Bev. The increment of mPA-D was correlated with the occurrence of post-treatment respiratory/heart failure. In analysis of 55 patients who underwent CT at 3 months after the last dose of Atez/Bev, mPA-D and mPA-D/aAo-D significantly decreased. However, in the group with continuous treatment of other molecular-targeted drugs after Atez/Bev, mPA-D and mPA-D/aAo-D showed no significant change. In conclusion, PAH may not be a rare complication in patients with HCC and should be managed carefully because of the possible negative effect of Atez/Bev on PAH.

LTSI Consensus Guidelines: Preoperative Pulmonary Evaluation in Adult Liver Transplant Recipients

The relationship between chronic liver disease and respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease (CLD) have been characterized: hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. Apart from that coexisting pulmonary disease like chronic obstructive lung disease and interstitial lung disease also complicate the outcomes after liver transplantation (LT). Assessment for evaluation of underlying pulmonary disorders is essential to improve outcomes in patients with CLD, posted for LT. This consensus guideline of the Liver Transplant Society of India (LTSI) provides a comprehensive review of pulmonary issues in CLD, related and unrelated to underlying liver disease and gives recommendations for pulmonary screening in specific clinical scenarios in adults with chronic liver disease planned for LT. This document also aims to standardize the strategies for preoperative evaluation of these pulmonary issues in this subset of patients. Proposed recommendations were based on selected single case reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Additionally, this review will highlight the lacunae in our current evaluation strategy, challenges faced, and will provide direction to potentially useful futuristic preoperative evaluation strategies.

Risk factors for portopulmonary hypertension in patients with cirrhosis: a prospective, multicenter study

BACKGROUND

Tricuspid regurgitation pressure gradient (TRPG) measurement by echocardiography is recommended as the most objective examination to detect portopulmonary hypertension (PoPH). This study aimed to identify factors associated with a high TRPG in patients with cirrhosis and develop a scoring model for identifying patients who are most likely to benefit from echocardiography investigations.

RESULTS

A total of 486 patients who underwent echocardiography were randomly allocated to the derivation and validation sets at a ratio of 2:1. Of the patients, 51 (10.5%) had TRPG ≥ 35 mmHg. The median brain natriuretic peptide (BNP) was 39.5 pg/mL. Shortness of breath (SOB) was reported by 91 (18.7%) patients. In the derivation set, multivariate analysis identified female gender, shortness of breath, and BNP ≥ 48.9 pg/mL as independent factors for TRPG ≥ 35 mmHg. The risk score for predicting TRPG ≥ 35 mmHg was calculated as follows: - 3.596 + 1.250 × gender (female: 1, male: 0) + 1.093 × SOB (presence: 1, absence: 0) + 0.953 × BNP (≥ 48.9 pg/mL: 1, < 48.9 pg/mL: 0). The risk score yielded sensitivity of 66.7%, specificity of 75.3%, positive predictive value of 25.5%, negative predict value of 94.3%, and predictive accuracy of 74.4% for predicting TRPG ≥ 35 mmHg. These results were almost similar in the validation set, indicating the reproducibility and validity of the risk score.

CONCLUSIONS

This study clarified the characteristics of patients with suspected PoPH and developed a scoring model for identifying patients at high risk of PoPH, which may be used in selecting patients that may benefit from echocardiography.

Association between Cardiovascular Disease and Liver Disease, from a Clinically Pragmatic Perspective as a Cardiologist

Cardiovascular diseases and liver diseases are closely related. Non-alcoholic fatty liver disease has the same risk factors as those for atherosclerotic cardiovascular disease and may also be a risk factor for atherosclerotic cardiovascular disease on its own. Heart failure causes liver fibrosis, and liver fibrosis results in worsened cardiac preload and congestion. Although some previous reports regard the association between cardiovascular diseases and liver disease, the management strategy for liver disease in patients with cardiovascular diseases is not still established. This review summarized the association between cardiovascular diseases and liver disease. In patients with non-alcoholic fatty liver disease, the degree of liver fibrosis progresses with worsening cardiovascular prognosis. In patients with heart failure, liver fibrosis could be a prognostic marker. Liver stiffness assessed with shear wave elastography, the fibrosis-4 index, and non-alcoholic fatty liver disease fibrosis score is associated with both liver fibrosis in patients with liver diseases and worse prognosis in patients with heart failure. With the current population ageing, the importance of management for cardiovascular diseases and liver disease has been increasing. However, whether management and interventions for liver disease improve the prognosis of cardiovascular diseases has not been fully understood. Future investigations are needed.

Portopulmonary Hypertension: Management and Liver Transplantation Evaluation

Portopulmonary hypertension (POPH) affects 5% to 6% of patients with advanced liver disease and accounts for 5% to 15% of pulmonary arterial hypertension (PAH) cases. Compared with idiopathic PAH, POPH is associated with significantly worse survival. Recent studies have improved our understanding of the role of both PAH therapy and liver transplantation (LT) in the management of POPH and their impact on overall prognosis. We performed a review of the published literature to summarize the available evidence and guidelines regarding the diagnosis and management of POPH. POPH is defined by the presence of precapillary PH in the context of portal hypertension. POPH is associated with increased perioperative risk at the time of LT, which can be stratified by mean pulmonary arterial pressure and pulmonary vascular resistance. Screening with echocardiography is recommended in all LT candidates to facilitate detection and treatment of POPH. Despite a paucity of evidence, POPH is treated similarly to idiopathic PAH with PAH therapy. These therapies are associated with improved pulmonary hemodynamics and facilitation of safe LT. LT can result in improvement or resolution of POPH in half of patients and has been associated with improved survival in highly selected patients. The prognosis in POPH is poor and is impacted by the severity of both PH and liver disease. Management with a combination of PAH therapy and LT in selected patients has been associated with improved pulmonary hemodynamics and survival.

Pulmonary vascular disease and exercise hemodynamics in chronic liver disease

BACKGROUND & AIMS

Portopulmonary hypertension (POPH) and hepatopulmonary syndrome (HPS) are severe pulmonary vascular complications of chronic liver disease and strongly associated with morbidity and mortality. The prevalence of these complications is relatively high in patients evaluated for liver transplantation, however it is virtually unknown in patients with stable chronic liver disease.

METHODS

We assessed the pulmonary hypertension (PH) and HPS prevalence in a prospective registry study of our liver out-patient clinic in a tertiary center. Between 2011 and 2016, consecutive patients with cirrhosis or non-cirrhotic portal hypertension were prospectively enrolled after written informed consent. We excluded patients with acute decompensation of liver disease and other causes of PH like severe chronic heart or lung diseases and chronic thromboembolic PH. HPS was diagnosed using contrast enhanced echocardiography and blood gas analysis. Patients were screened for PH using an algorithm implementing severity of dyspnea, echocardiography, cardiopulmonary exercise testing and exercise echocardiography employing a threshold of systolic pulmonary arterial pressure (SPAP) = 50 mmHg at peak exercise. If the algorithm indicated an increased PH risk, patients were invited for invasive investigations by means of right heart and hepatic vein catheter. We defined POPH as resting mPAP≥21 mmHg and PVR>3WU and PAWP<15 mmHg, mild PH as resting mPAP = 21-24 mmHg, and exercise PH as mPAP>30 mmHg and TPR >3 WU at peak exercise.

RESULTS

Two-hundred-five patients were enrolled (male 75%; cirrhosis 96%; median age 57 yrs). Sixty-seven patients (33%) fulfilled HPS criteria but only two (1.0%) for severe (PaO2:50-60 mmHg) or very severe HPS (PaO2<50 mmHg). In 18/77 patients (23%) undergoing exercise echocardiography, SPAP at peak exercise exceeded 50 mmHg. Finally, n = 3 (1.5%) patients were invasively diagnosed with POPH, n = 4 (2.9%) with mild PH and n = 2 with exercise PH.

CONCLUSION

In chronic liver disease, excluding acute decompensation and other causes of PH, POPH and severe HPS are rare findings while mild to moderate HPS and mild PH or exercise PH are more frequent.

Incidental finding of elevated pulmonary arterial pressures during liver transplantation and postoperative pulmonary complications

BACKGROUND

In patients with end stage liver disease (ESLD) scheduled for liver transplantation (LT), an intraoperative incidental finding of elevated mean pulmonary arterial pressure (mPAP) may be observed. Its association with patient outcome has not been evaluated. We aimed to estimate the effects of an incidental finding of a mPAP > 20 mmHg during LT on the incidence of pulmonary complications.

METHODS

We examined all patients who underwent a LT at Paul-Brousse hospital between January 1,2015 and December 31,2020. Those who received: a LT due to acute liver failure, a combined transplantation, or a retransplantation were excluded, as well as patients for whom known porto-pulmonary hypertension was treated before the LT or patients who underwent a LT for other etiologies than ESLD. Using right sided pulmonary artery catheterization measurements made following anesthesia induction, the study cohort was divided into two groups using a mPAP cutoff of 20 mmHg. The primary outcome was a composite of pulmonary complications. Univariate and multivariable logistic regression analyses were performed to identify variables associated with the primary outcome. Sensitivity analyses of multivariable models were also conducted with other mPAP cutoffs (mPAP ≥ 25 mmHg and ≥ 35 mmHg) and even with mPAP as a continuous variable.

RESULTS

Of 942 patients who underwent a LT, 659 met our inclusion criteria. Among them, 446 patients (67.7%) presented with an elevated mPAP (mPAP of 26.4 ± 5.9 mmHg). When adjusted for confounding factors, an elevated mPAP was not associated with a higher risk of pulmonary complications (adjusted OR: 1.16; 95%CI 0.8-1.7), nor with 90 days-mortality or any other complications. In our sensitivity analyses, we observed a lower prevalence of elevated mPAP when increasing thresholds (235 patients (35.7%) had an elevated mPAP when defined as ≥ 25 mmHg and 41 patients (6.2%) had an elevated mPAP when defined as ≥ 35 mmHg). We did not observe consistent association between a mPAP ≥ 25 mmHg or a mPAP ≥ 35 mmHg and our outcomes.

CONCLUSION

Incidental finding of elevated mPAP was highly prevalent during LT, but it was not associated with a higher risk of postoperative complications.

Simple algorithm to narrow down the candidates to receive echocardiography in patients with chronic liver disease for suspected pulmonary hypertension

Aims

Portopulmonary hypertension (PoPH) is a subtype of pulmonary arterial hypertension related to portal hypertension. The definitive diagnosis of PoPH is made by invasive right heart catheterization. Alternatively, pulmonary arterial hypertension may be recognized noninvasively from the tricuspid regurgitant pressure gradient (TRPG), measured by echocardiography. In this study, we aimed to establish a simple algorithm to identify chronic liver disease patients with a high TRPG value in order to narrow down the candidates to receive echocardiography.

Methods and Results

TRPG was measured by echocardiography in 152 patients with chronic liver disease. Factors predictive of TRPG >30 mmHg were investigated. There were 28 (18%) cases with TRPG >30 mmHg. Independent factors associated with a high TRPG were the presence of shortness of breath, high serum brain natriuretic peptide (BNP), and low serum albumin. Child–Pugh class or the presence of ascites, varices, or encephalopathy was not associated with TRPG. There was a correlation between the serum BNP and TRPG, and the optimal cutoff value of BNP by the Youden index was 122 pg/mL, and by 100% sensitivity was 50 pg/mL. A combination of these factors identified patients with a high probability of TRPG >30 mmHg (n = 12, positive predictive value [PPV] of 83%), no probability (n = 80, PPV 0%), and intermediate probability (n = 60, PPV 25–34%). This algorithm has reduced the number of patients needing echocardiography by 53%.

Conclusions

A simple algorithm using the presence of shortness of breath, serum BNP, and albumin levels can narrow down the candidates to receive echocardiography.

The Edge of Unknown: Postoperative Critical Care in Liver Transplantation

Perioperative care of patients undergoing liver transplantation (LT) is very complex. Metabolic derangements, hypothermia, coagulopathy and thromboses, severe infections, and graft dysfunction can affect outcomes. In this manuscript, we discuss several perioperative problems that can be encountered in LT recipients. The authors present the most up-to-date information regarding predicting and treating hemodynamic instability, coagulation monitoring and management, postoperative ventilation strategies and early extubation, management of infections, and ESLD-related pulmonary complications. In addition, early post-transplant allograft dysfunction will be discussed.

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.

Pulmonary complications of portal hypertension: The overlooked decompensation

The systemic nature of cirrhosis and portal hypertension has long been recognized, and the amount of data characterizing the interplay between each system is becoming ever so complex. Lung involvement was among the first described associated entities in cirrhosis, with reports dating back to the late nineteenth century. However, it appears that throughout the years, interest in the pulmonary complications of portal hypertension has generally faded, especially in contrast to other decompensating events, as expertise in this field has primarily been concentrated in highly experienced tertiary care facilities and liver transplantation centers. Despite affecting up to 10%-15% of patients with advanced liver disease and having a proven prognostic impact, hepato-pulmonary syndrome, porto-pulmonary hypertension, and hepatic hydrothorax are frequently misdiagnosed, mistreated, or misinterpreted. This lack of precision might adversely impact patient care, referral to expert centers, and, ultimately, liver disease-related mortality and successful transplantation odds. The present minireview aims to increase awareness of the pulmonary complications of chronic liver disease by providing a brief overview of each of the three entities. The paper focuses on the essential theoretical aspects, addressing the most critical knowledge gaps on the one hand and, on the other hand, critically discussing one key issue for each complication.

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.

Portopulmonary hypertension and the risk of high right ventricular systolic pressure in liver transplant candidates

Aim

Portopulmonary hypertension (PoPH) is a rare and serious complication of liver cirrhosis and portal hypertension that can interfere with liver transplantation (LT). We evaluated the prevalence of PoPH and the clinical features of right ventricular systolic pressure (RVSP), which is equivalent to pulmonary artery systolic pressure, in LT candidates.

Methods

This was a single-center retrospective study. A total of 157 Japanese patients with decompensated liver cirrhosis or portal hypertension (76 men, median age = 52 years [range: 18–68 years]) were enrolled. The relationships between RVSP and clinical parameters, and the prevalence of PoPH in LT candidates, were evaluated.

Results

The cardiological parameters were as follows: brain natriuretic peptide (BNP), 39.1 (4.0–780.5) pg/mL; RVSP, 31.2 (16.0–122.4) mmHg; ejection fraction, 58% (28–72%); and mean peak tricuspid regurgitation velocity, 2.3 (1.5–5.3) m/s. The RVSP was significantly higher in females (p = 0.02) and primary biliary cholangitis (PBC) patients (p = 0.01), and was weakly correlated with the BNP level (r = 0.40, p = 0.01). For RVSPs of < 36 and ≥ 36 mmHg, the 5-year survival rates were 36.1% versus 34.1%, and 85.4% versus 85.3%, in non-LT and LT cases, respectively (p = 0.47 and 0.69, respectively). Among six patients with an RVSP ≥ 50 mmHg, three (1.9%) were diagnosed with PoPH and treated with vasodilators.

Conclusions

PoPH was observed in 3 cases (1.9%) in 157 LT candidates. In patients with suspected mild pulmonary hypertension (RVSP, 36 - 50 mmHg), LT was successfully performed.

Predictors of survival in portopulmonary hypertension: a 20-year experience

BACKGROUND AND OBJECTIVES

Portopulmonary hypertension (PoPH) is a rare complication of portal hypertension associated with poor survival. Scarce data is available on predictors of survival in PoPH with conflicting results. We sought to characterize the outcomes and variables associated with survival in a large cohort of patients with PoPH in an American population of patients.

STUDY DESIGN AND METHODS

We identified PoPH patients from the Cleveland Clinic Pulmonary Hypertension Registry between 1998 and 2019. We collected prespecified data, particularly focusing on hepatic and cardiopulmonary assessments and tested their effect on long-term survival.

RESULTS

Eighty patients with PoPH with a mean ± SD age of 54 ± 10 years, (54% females) were included in the analysis. The median Model for End-Stage Liver Disease with sodium (MELD-Na) score was 13.0 (10.0-18.0) at PoPH diagnosis. World Health Association functional class III-IV was noted in 57%. Mean pulmonary arterial pressure was 47 ± 10 mmHg and pulmonary vascular resistance 6.0 ± 2.8 Woods units. A total of 63 (78.5%) patients were started on pulmonary arterial hypertension (PAH)-specific treatment during the first 6 months of diagnosis. Survival rates at 1-, 3- and 5-year were 77, 52 and 34%, respectively. Cardiopulmonary hemodynamics as well as PAH-specific treatment did not affect survival. In the multivariable model, MELD-Na, resting heart rate and the presence of hepatic encephalopathy were independent predictors of survival.

CONCLUSION

PoPH patients have poor 5-year survival which is strongly associated to the severity of underlying liver disease and not to the hemodynamic severity of PoPH; therefore efforts should be focused in facilitating liver transplantation for these patients.

Screening for portopulmonary hypertension using computed tomography-based measurements of the main pulmonary artery and ascending aorta diameters in patients with portal hypertension

AIM

This study aimed to demonstrate the feasibility of identifying candidates of portopulmonary hypertension (PoPH) from general portal hypertension patients based on chest computed tomography (CT) results.

METHODS

One hundred and thirty patients with portal hypertension who had undergone interventional radiology therapies at our hospital between August 2011 and July 2021 were included, and preoperative clinical data were collected. Suspicious PoPH was defined as main pulmonary artery diameter (mPA-D) ≥ 29 mm or the ratio of mPA-D to ascending aorta diameter (mPA-D/aAo-D) ≥ 1.0, and probable PoPH as mPA-D ≥ 33 mm based on the chest CT. Prevalence of suspicious and probable PoPH was evaluated, and the differences in clinical characteristics of each population were compared.

RESULTS

Overall, 29 (22.3%) and 5 (3.8%) patients were categorized as suspicious and probable PoPH, respectively. Univariate analyses revealed that female sex, higher shortest diameter of inferior vena cava, presence of portosystemic shunts ≥ 5 mm, and lower blood urea nitrogen levels were significantly associated with suspicious PoPH (p < 0.05). Multivariate analyses identified all four factors as significantly independent determinants of suspicious PoPH (p < 0.05). In addition, among the population of suspicious PoPH, there were significant differences in seven parameters, including total bilirubin levels and spleen volume between patients with and without probable PoPH (p < 0.05). However, no significant independent indicators of probable PoPH were found.

CONCLUSIONS

CT-based measurements of mPA-D and mPA-D/aAo-D have the potential to screen patients with suspicious PoPH in clinical practice focused on portal hypertension.

Pulmonary Vascular Resistance Predicts Mortality and Graft Failure in Transplantation Patients With Portopulmonary Hypertension

Portopulmonary hypertension (POPH) is a pulmonary vascular disease associated with significant morbidity and mortality in those with liver disease, conferring a higher mortality in patients awaiting liver transplantation (LT). Although not a transplant indication, patients with POPH can experience significant clinical improvement following LT, and those maintaining a mean pulmonary artery pressure (MPAP) <35mm Hg and a pulmonary vascular resistance (PVR) <5 Woods units (WU) are granted additional listing points to expedite LT. The effect of POPH on posttransplant outcomes such as mortality and graft failure, however, is not well defined. We performed a retrospective cohort study of the US Organ Procurement and Transplantation Network database of all adult patients who underwent LT between January 1, 2006, and December 1, 2020. Using adjusted accelerated failure time models, we examined the relationship between a diagnosis of POPH and outcomes following LT and the relationship between pre-LT hemodynamics and post-LT survival (alive with a functioning graft) in patients with POPH. Compared with those undergoing transplants without exception points, patients with POPH had comparable post-LT survival rates but were significantly more likely to have graft failure. Both pre-LT MPAP and PVR predicted post-LT survival in POPH, with a pre-LT PVR of ≥1.6 WU, more than doubling the hazard for mortality (death or a nonfunctioning graft; coefficient, 2.01; standard error, 0.85; hazard ratio, 2.21; P = 0.02). POPH may confer a significantly higher risk of post-LT graft failure compared with patients with cirrhosis without POPH, and a pre-LT PVR of ≥1.6 WU may predict post-LT survival. Further investigation into the relationship between pre-LT hemodynamics, right ventricular function, and post-LT outcomes of mortality and graft failure in POPH is needed.

Association between the albumin-bilirubin (ALBI) score and severity of portopulmonary hypertension (PoPH): A data-mining analysis

INTRODUCTION

Portopulmonary hypertension (PoPH) is a severe complication of chronic liver disease. We aimed to investigate the etiology of chronic liver disease and the factors associated with the severity of PoPH.

SUBJECTS AND METHODS

Echocardiography was undergone in 833 patients with chronic liver disease during 2005-2019 and 13 patients (1.6%) were diagnosed with PoPH in this observational study. At the diagnosis of PoPH, liver function was evaluated by albumin-bilirubin (ALBI) score. Severe PoPH was defined as (1) mean pulmonary arterial pressure (mPAP) ≥50 mmHg or (2) mPAP: 35-49 mmHg and pulmonary vascular resistance ≥400 dyne/s/cm⁵ . Factors associated with severe PoPH were evaluated by decision-tree analysis.

RESULTS

In patients with PoPH, the leading etiology of chronic liver disease was hepatitis C virus (HCV) (46.2% [sustained virological response (SVR): 23.1% and non-SVR: 15.4%]). Severe PoPH was observed in 53.8% of patients and the 5-year survival rate was 48.1%. There was a significant correlation of mPAP with ALBI score (r = 0.6456, p = 0.0171). In the decision-tree and random forest analyses, the most impacted classifier for severe PoPH was the ALBI score. In patients with ALBI score ≥-1.45, all patients showed severe PoPH, while the prevalence of severe PoPH was 25.0% in patients with ALBI score <-1.45.

CONCLUSIONS

We found that HCV including SVR was the major etiology of chronic liver disease in patients with PoPH. Moreover, we revealed that the ALBI score was the most impacted factor associated with severe PoPH. Thus, ALBI score may be useful for the estimation of pulmonary vascular resistance.

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.

Effects of sildenafil on right ventricle remodelling in Portopulmonary hypertension

Portopulmonary hypertension (PoPH) is a clinical condition associated with end-stage liver disease, described by the coexistence of pulmonary arterial hypertension (PAH) and portal hypertension. In PoPH patients, there is a right ventricle (RV) remodeling to compensate for the increased resistance in the lung circulation. There are no studies on the effects of the PAH-targeted pharmacological treatment on the RV dimension and function. The present study summarizes our experience in patients with PoPH treated with sildenafil in a period of 6 years (from 2013 to 2019). We enrolled 64 consecutive patients identified as PoPH, all treated with sildenafil (57.6% in monotherapy; in the other cases in association with macitentan; in 19.0% with initial combination therapy). A hemodynamic invasive cardiopulmonary study was performed at baseline and after 6 months of sildenafil treatment. In our population we showed a significative improvement in RV performance, with a significant increase in RV stroke volume (+33%), RV ejection fraction (+31%) and RV stroke work index (+17.5%). We registered the reduction of the RV cavity dimension over time in all patients treated with sildenafil (RV end diastolic diameter decreased by 15% after 6 months of follow-up). Regarding diastolic function, we highlighted a very significant reduction in RV end-diastolic pressure (-50% concerning baseline). Sildenafil was effective both when used as monotherapy and in combination with macitentan. In conclusion, Sildenafil had a positive impact on RV systolic and diastolic function in patients with PoPH and was able to conditionate the reverse remodeling of the RV.

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.

The clinical characteristics, treatment, and survival of portopulmonary hypertension in Japan

Background

Portopulmonary hypertension (PoPH) refers to the simultaneous presentation of pulmonary arterial and portal hypertension. However, few reports have included the characteristics and treatments for patients with PoPH of Asian population; thus, we investigated the clinical characteristics, treatment, and survival of these patients in a Japanese cohort.

Methods

Pulmonary arterial hypertension (PAH) has been included in the National Research Project on Intractable Disease in Japan; therefore, we extracted data of patients with PoPH from the forms of newly registered cases of the project from 2012 to 2013 (for 2 years), and updated cases of the project in 2013 (Study 1, n = 36 newly registered forms, n = 46 updated forms). Additionally, for Study 2, we performed a retrospective, observational cohort study at Chiba University Hospital (n = 11). We compared the characteristics between patients with PoPH and those with idiopathic/heritable PAH (I/H-PAH).

Results

Both studies showed higher cardiac outputs (COs) and cardiac indexes (CIs), lower pulmonary vascular resistance (PVR), and less treated with combination therapy in patients with PoPH than those with I/H-PAH. In Study 2, the overall and disease-specific survival between PoPH and I/H-PAH were similar. Conversely, many patients (45%) had to change their PAH-specific medicine because of adverse effects.

Conclusion

As seen in western countries, Japanese patients with PoPH showed higher COs and CIs, better exercise tolerance, and lower PVRs than patients with I/H-PAH. Further studies are needed to improve PoPH treatments.

Keeping Patients with End-Stage Liver Disease Alive While Awaiting Transplant: Management of Complications of Portal Hypertension

Complications of portal hypertension such as gastroesophageal variceal hemorrhage, ascites, and spontaneous bacterial peritonitis, as well as pulmonary complications, are often responsible for diminished quality of life, excess morbidity and mortality, increased health care resource use and expenditure, and dropout from the liver transplant (LT) waiting list. Therefore, the care of LT candidates on the waiting list must be centered on anticipation and prompt intervention for these complications.

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.

Noninvasive imaging assessment of portal hypertension

Portal hypertension (PH) is a spectrum of complications of chronic liver disease (CLD) and cirrhosis, with manifestations including ascites, gastroesophageal varices, splenomegaly, hypersplenism, hepatic hydrothorax, hepatorenal syndrome, hepatopulmonary syndrome and portopulmonary hypertension. PH can vary in severity and is diagnosed via invasive hepatic venous pressure gradient measurement (HVPG), which is considered the reference standard. Accurate diagnosis of PH and assessment of severity are highly relevant as patients with clinically significant portal hypertension (CSPH) are at higher risk for developing acute variceal bleeding and mortality. In this review, we discuss current and upcoming noninvasive imaging methods for diagnosis and assessment of severity of PH.

Prevalence and characteristics of portopulmonary hypertension in cirrhotic patients who underwent both hepatic vein and pulmonary artery catheterization

Portopulmonary hypertension (PoPH) is a well-known complication of liver cirrhosis. The aim of this study was to clarify the pulmonary hemodynamics and the prevalence and characteristics of PoPH in patients with portal hypertension.

METHODS

The subjects were 335 patients with portal hypertension diagnosed by hepatic vein pressure gradient (HVPG). Among them, 186 patients received measurements of pulmonary artery pressure (PAP), pulmonary artery wedge pressure (PAWP) and pulmonary vascular resistance (PVR). PoPH was diagnosed by PAP >20 mmHg, PVR ≥3 Wood units (WU) and PAWP ≤15 mmHg.

RESULTS

The Child-Pugh classification was class A in 53, B in 92 and C in 41 patients. Median (range) values of HVPG, PAP, PVR and PAWP were 18.4 (5.5-39.0) mmHg, 12.9 (6.6-40.8) mmHg, 0.8 (0.1-4.5) WU and 7.5 (2.2-15.4) mmHg, respectively. Of six patients with PAP >20 mmHg, four had autoimmune hepatitis or primary biliary cholangitis, with the prevalence being significantly higher than that in patients with PAP ≤20 mmHg. Meanwhile, no significant difference was noted in the hepatic functional reserve or HVPG between patients with PAP >20 mmHg and ≤20 mmHg. Only two patients met the diagnostic criteria of PoPH and both patients were Child-Pugh B. The Child-Pugh score and HVPG were not associated with PoPH.

CONCLUSIONS

Our study demonstrated that only two patients were complicated by PoPH. High PAP values were noted in patients with primary biliary cholangitis or autoimmune hepatitis. However, the presence of PoPH and high PAP were not associated with the degree of hepatic functional reserve or HVPG.

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.

Pulmonary Complications in Candidates for Liver Transplantation

The liver plays a pivotal role in maintaining the homeostasis of various organ systems. Also, end-stage liver disease and its complications are major causes of morbidity and mortality among adults. Individuals who develop a chronic liver disease are at increased risk of progression to multi-organ dysfunction, including the pulmonary system. The clinical complications of pulmonary problems related to the presence of liver disease range from mild (such as hypoxemia) to life-threatening diseases (such as portopulmonary hypertension and hepatopulmonary syndrome). Herein, the major pulmonary complications related to liver cirrhosis and considerations for performing liver transplantation are reviewed.

Clinical Outcomes after Liver Transplantation in Patients with Portopulmonary Hypertension

BACKGROUND

Portopulmonary hypertension (POPH) is the presence of pulmonary arterial (PA) hypertension in patients with portal hypertension and is associated with significant morbidity and mortality. In a cohort of POPH patients, we describe the clinical outcomes of POPH patients who underwent liver transplantation (LT).

METHODS

Retrospectively collected data from a prospectively assembled cohort of all consecutive POPH adults evaluated in three transplant centers from 1996 to 2019.

RESULTS

From a cohort of 228 POPH patients, 50 patients underwent LT. Significant hemodynamic improvement after PA-targeted therapy was observed, with 58% receiving only monotherapy pre-transplant. After LT, 21 (42%) patients were able to discontinue and remained off PA-targeted therapy. The 1, 3, and 5 year unadjusted survival rates after LT were 72%, 63% and 60%, respectively. An elevated pulmonary vascular resistance (PVR) before LT was associated with worse survival rate (HR 1.91, 95% CI 1.07-3.74, p=0.04). No survival difference was observed in those granted MELD exception or transplants performed before or after the year 2010.

CONCLUSION

Significant number of POPH patients discontinued PA-targeted therapy after LT. Higher PVR before LT was associated with worse survival, as was monotherapy use. Despite effective PA-targeted therapies, POPH survival outcomes after LT in our cohort were modest and may reflect the need for more aggressive therapy.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Current Status and Implications for Liver Transplantation

PURPOSE OF REVIEW

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) are both pulmonary vascular complications of advanced liver disease; however, these syndromes have distinct pathophysiology, clinical implications, and management.

RECENT FINDINGS

While both conditions are associated with portal hypertension, HPS results from diffuse pulmonary capillary vasodilation and PoPH results from vasoconstriction and vascular remodeling of pulmonary arteries. In HPS, no medical therapies clearly improve outcomes; however, patients have excellent post-LT outcomes with near uniform reversal of hypoxemia. In PoPH, several medical therapies used in idiopathic pulmonary hypertension have been shown improve pulmonary hemodynamics, symptoms, and potentially LT outcomes; however, further study is needed to determine best treatment regimens, long-term outcomes on medical therapy, and role of LT.

SUMMARY

While HPS results in severe hypoxemia that is usually reversible by LT, PoPH patients develop progressive pulmonary hypertension that may improve with medical therapy.

Role of echocardiography in screening for portopulmonary hypertension in liver transplant candidates: a meta-analysis

Objectives

To demonstrate the screening value of echocardiography for portopulmonary hypertension (POPH) in liver transplant candidates.

Design

Systematic review and meta-analysis.

Background

POPH is a complication of end-stage liver disease that adversely affects the outcome of orthotopic liver transplant. There are no specific symptoms in the early stage of POPH. POPH reduce the survival rate of patients with end-stage liver disease specially if they are not diagnosed. Therefore, early detection may improve prognosis. The objective of this study is to explore the screening value of echocardiography on liver transplant candidates for screening of POPH compared to right heart catheterization (RHC).

Method

PubMed, EMBASE and the Cochrane Library were searched by two independent reviewers for potentially eligible studies published up to 30 June 2019 to retrieve data based on per-patient analysis. STATA, Meta-DiSc, and RevMan were applied to perform this meta-analysis.

Results

Our search yielded 1576 studies, of which 11 satisfied the inclusion criteria. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the summary receiver operating characteristic (SROC) curve (AUC) of echocardiography for POPH were 0.85 (95% CI [0.65–0.94]), 0.83 (95% CI [0.73–0.90]), 4.99 (95% CI [3.03–8.21]), 0.19 (95% CI [0.07–0.46]), and 0.91 (95% CI [0.88–0.93]), respectively. Deeks’ funnel plot did not indicate the existence of publication bias (P = 0.66).

Conclusions

Echocardiography, a noninvasive modality, provides superior screening for POPH, but the diagnosis of POPH still requires RHC. PROSPERO registration number CRD42019144589.

Lipids and ketones dominate metabolism at the expense of glucose control in pulmonary arterial hypertension: a hyperglycaemic clamp and metabolomics study

Individuals with idiopathic pulmonary arterial hypertension (PAH) display reduced oral glucose tolerance. This may involve defects in pancreatic function or insulin sensitivity but this hypothesis has not been tested; moreover, fasting nutrient metabolism remains poorly described in PAH. Thus, we aimed to characterise fasting nutrient metabolism and investigated the metabolic response to hyperglycaemia in PAH.12 participants (six PAH, six controls) were administered a hyperglycaemic clamp, while 52 (21 PAH, 31 controls) underwent plasma metabolomic analysis. Glucose, insulin, C-peptide, free fatty acids and acylcarnitines were assessed from the clamp. Plasma metabolomics was conducted on fasting plasma samples.The clamp verified a reduced insulin response to hyperglycaemia in PAH (-53% versus control), but with similar pancreatic insulin secretion. Skeletal muscle insulin sensitivity was unexpectedly greater in PAH. Hepatic insulin extraction was elevated in PAH (+11% versus control). Plasma metabolomics identified 862 metabolites: 213 elevated, 145 reduced in PAH (p<0.05). In both clamp and metabolomic cohorts, lipid oxidation and ketones were elevated in PAH. Insulin sensitivity, fatty acids, acylcarnitines and ketones correlated with PAH severity, while hepatic extraction and fatty acid:ketone ratio correlated with longer six-min walk distance.Poor glucose control in PAH could not be explained by pancreatic β-cell function or skeletal muscle insulin sensitivity. Instead, elevated hepatic insulin extraction emerged as an underlying factor. In agreement, nutrient metabolism in PAH favours lipid and ketone metabolism at the expense of glucose control. Future research should investigate the therapeutic potential of reinforcing lipid and ketone metabolism on clinical outcomes in PAH.

Pulmonary manifestations of chronic liver disease: a comprehensive review

Hepatopulmonary syndrome (HPS) and porto-pulmonary hypertension (PoPH) represent relatively common pulmonary vascular complications of advanced liver disease. Despite distinct differences in their pathogenetic background, both clinical states are characterized by impaired arterial oxygenation and limited functional status, and are associated with increased pre-transplantation mortality. Accumulation of ascitic fluid in the pleural cavity, known as hepatic hydrothorax (HH), is another frequent manifestation of decompensated cirrhosis, which may cause severe respiratory dysfunction, depending on the volume of the effusion, the rapidity of its development and its resistance to therapeutic measures. Orthotopic liver transplantation constitutes the only effective treatment able to resolve the pulmonary complications of liver disease. A prioritization policy for liver transplantation has evolved over the past years regarding advanced stages of HPS, yielding favorable outcomes regarding post-transplantation survival and HPS resolution. In contrast, severe PoPH is associated with poor post-transplantation survival. Hence, liver transplantation is recommended only for patients with PoPH and an acceptable reduction in pulmonary pressure values, after receiving PoPH-targeted vasodilating therapy. This review focuses on basic pathogenetic and diagnostic principles and discusses the current therapeutic approaches regarding HPS, PoPH, and HH.

Liver transplantation and cardiac illness: Current evidences and future directions

Contraindications to liver transplantation are gradually narrowing. Cardiac illness and chronic liver disease may manifest independently or may be superimposed on each other due to shared pathophysiology. Cardiac surgery involving the cardiopulmonary bypass in patients with Child-Pugh Class C liver disease is associated with a high risk of perioperative morbidity and mortality. Liver transplantation involves hemodynamic perturbations, volume shifts, coagulation abnormalities, electrolyte disturbances, and hypothermia, which may prove fatal in patients with cardiac illness depending upon the severity. Additionally, cardiovascular complications are the major cause of adverse postoperative outcomes after liver transplantation even in the absence of cardiac pathologies. Clinical decision-making has remained an unsettled issue in these clinical scenarios. The absence of randomized clinical studies has further crippled our endeavours for a consensus on the management of patients with end-stage liver disease with cardiac illness. This review seeks to address this complex clinical setting by gathering information from published literature. The management algorithm in this review may facilitate clinical decision making and augur future research.

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).

Sex, Gender, and Sex Hormones in Pulmonary Hypertension and Right Ventricular Failure

Pulmonary hypertension (PH) encompasses a syndrome of diseases that are characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling and that frequently lead to right ventricular (RV) failure and death. Several types of PH exhibit sexually dimorphic features in disease penetrance, presentation, and progression. Most sexually dimorphic features in PH have been described in pulmonary arterial hypertension (PAH), a devastating and progressive pulmonary vasculopathy with a 3-year survival rate <60%. While patient registries show that women are more susceptible to development of PAH, female PAH patients display better RV function and increased survival compared to their male counterparts, a phenomenon referred to as the "estrogen paradox" or "estrogen puzzle" of PAH. Recent advances in the field have demonstrated that multiple sex hormones, receptors, and metabolites play a role in the estrogen puzzle and that the effects of hormone signaling may be time and compartment specific. While the underlying physiological mechanisms are complex, unraveling the estrogen puzzle may reveal novel therapeutic strategies to treat and reverse the effects of PAH/PH. In this article, we (i) review PH classification and pathophysiology; (ii) discuss sex/gender differences observed in patients and animal models; (iii) review sex hormone synthesis and metabolism; (iv) review in detail the scientific literature of sex hormone signaling in PAH/PH, particularly estrogen-, testosterone-, progesterone-, and dehydroepiandrosterone (DHEA)-mediated effects in the pulmonary vasculature and RV; (v) discuss hormone-independent variables contributing to sexually dimorphic disease presentation; and (vi) identify knowledge gaps and pathways forward. © 2020 American Physiological Society. Compr Physiol 10:125-170, 2020.