Successful liver transplantation following medical management of portopulmonary hypertension: a single-center series

Outcomes of liver transplantation for porto-pulmonary hypertension in model for end-stage liver disease era

Porto-pulmonary hypertension (POPH), once considered an absolute contraindication for liver transplantation (LT), has become a more accepted indication because of the evolution of treatment with prostacyclin analogues, phosphodiesterase inhibitors and endothelin receptor antagonists. An exception model for end stage liver disease (MELD) score of 22 is assigned to candidates with documentation of effective treatment. We examined the post-transplant outcomes of patients who received LT for POPH with exception.

METHODS

Scientific Registry of Transplant Recipients data on 34,318 adult (≥ 18 years) deceased donor LT recipients transplanted between March 1, 2002 and August 31, 2010 were reviewed. The diagnosis of POPH was ascertained from MELD exception forms. Patients were followed from the time of transplant until the earlier occurrence of death or end of the follow-up period. Cox regression was used to evaluate the predictors of post-LT mortality and graft failure.

RESULTS

During the study period, 34,318 patients received deceased donor LT. Seventy eight out of 34,318 patients were transplanted for POPH with MELD exception. The 1-year adjusted risks of patient death and graft failure for patients transplanted under exception rules for POPH were significantly higher than with POPH adult recipients who did not receive exception points (death:hazard ratio [HR] = 2.25, p = 0.005 and graft failure HR = 1.96, p = 0.012).

CONCLUSIONS

This study of national data suggests that treated POPH continues to be associated with inferior early post-transplant outcomes.

Long-term follow-up of portopulmonary hypertension patients after liver transplantation

Portopulmonary hypertension (POPH) occurs in 5.3% to 8.5% of patients with advanced liver disease. The rate of survival in the absence of orthotopic liver transplantation (OLT) is reportedly 38% at 3 years and 28% at 5 years. Moderate to severe POPH [mean pulmonary artery pressure (MPAP) ≥ 35 mm Hg] is associated with a perioperative mortality rate of 50%. Single-center series have demonstrated the feasibility and short-term efficacy of OLT after POPH is controlled with vasodilators, but long-term outcomes have not been reported. Our aim was to determine graft and patient survival rates and the effects of OLT on pulmonary hypertension (PHT) in patients undergoing transplantation for POPH at our center. Four hundred eighty-eight adult patients underwent transplantation between June 2004 and January 2011, and 7 underwent transplantation for POPH after their MPAP was reduced to ≤35 mm Hg with vasodilators. These 7 patients included 3 men and 4 women with ages ranging from 39 to 54 years at the time of OLT. All patients received IV EPO or inhaled EPO during the perioperative period, and all were weaned off EPO over the course of 3 days to 8 months. Both the graft and patient survival rates were 85.7% after a median follow-up of 7.8 years. One patient had recurrent hepatitis C virus cirrhosis and recurrent POPH and died from multiorgan failure unrelated to PHT. Four of the remaining 6 patients required oral vasodilator therapy for persistent PHT. Only 2 of the 7 patients (4.4 and 8.5 years after OLT) did not have PHT. In conclusion, patients with POPH responsive to vasodilator therapy may have excellent long-term graft and patient survival after OLT. Despite the alleviation of portal hypertension by OLT, most patients have persistent or recurrent PHT that can be controlled with oral vasodilators.

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.

Pulmonary complications in chronic liver disease

The association of chronic liver disease with respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease have been characterized: hepatopulmonary syndrome (HPS), portopulmonary hypertension (POPH), and hepatic hydrothorax (HH). The development of portal hypertension is fundamental in the pathogenesis of each of these disorders. HPS is the most common condition, found in 5%-30% of cirrhosis patients, manifested by abnormal oxygenation due to the development of intrapulmonary vascular dilatations. The presence of HPS increases mortality and impairs quality of life, but is reversible with liver transplantation (LT). POPH is characterized by development of pulmonary arterial hypertension in the setting of portal hypertension, and is present in 5%-10% of cirrhosis patients evaluated for LT. Screening for POPH in cirrhosis patients eligible for LT is critical since severe POPH is a relative contraindication for LT. Patients with moderate POPH, who respond adequately to medical therapy, may benefit from LT, although sufficient controlled data are lacking. HH is a transudative pleural effusion seen in 5%-10% of cirrhosis patients, in the absence of cardiopulmonary disease. Diagnosis of HH should prompt consideration for LT, which is the ultimate treatment for HH. Conservative management includes salt restriction and diuretics, with thoracentesis and transjugular intrahepatic portosystemic shunt (TIPS) as second-line therapeutic options.

Management of portopulmonary hypertension: New perspectives

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

Echocardiography in liver transplant candidates

Involvement of the cardiovascular system in patients with end-stage liver disease (ESLD) is well recognized and may be seen in several scenarios in adult liver transplantation (LT) candidates. The hemodynamic effects of ESLD may result in apparent heart disease, or in some instances may mask cardiac disease. Alternatively, cardiac disease can occasionally be the underlying etiology of ESLD. LT imposes significant hemodynamic stresses, with cardiovascular complications accounting for considerable perioperative mortality and morbidity. Pre-operative assessment of the cardiac status of LT candidates is thus critically important for risk stratification and management. Cardiac imaging plays an integral role in the assessment of LT candidates. In this review, we discuss the role of cardiac imaging, including transthoracic echocardiography with Doppler and contrast enhancement, noninvasive functional assessment for routine pre-operative assessment of coronary artery disease, and transesophageal echocardiography in select cases to aid in intra-operative fluid management and monitoring in LT candidates.

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.

Portopulmonary hypertension: an update

Portopulmonary hypertension (POPH) is a serious complication of cirrhosis that is associated with mortality beyond that predicted by the Model for End-Stage Liver Disease (MELD) score. Increased pulmonary vascular resistance (PVR) may be initiated by pulmonary vasoconstriction, altered levels of circulating mediators, or shear stress, and can eventually lead to the classic vascular remodeling (plexiform lesion) that characterizes POPH. Portal hypertension is a prerequisite for the diagnosis of POPH, although the severity of pulmonary hypertension is unrelated to the severity of portal hypertension or the nature or severity of liver disease. POPH precludes liver transplantation (LT) unless the mean pulmonary artery pressure (MPAP) can be reduced to a safe level. The concept of an acceptable pressure has changed: we now consider both MPAP and PVR in the diagnosis, and we include the transpulmonary pressure gradient so that we can factor in fluid overload and left ventricular failure. Pulmonary vasodilator therapy includes oral, inhaled, and parenteral agents, and one or more of these agents may significantly lower pulmonary artery pressures to the point that LT becomes possible. The United Network for Organ Sharing recommends MELD exception points for patients with medically controlled POPH, but this varies by region. Patients who undergo LT need specialized intraoperative and postoperative management, which includes the availability of intraoperative transesophageal echocardiography for assessing right ventricular function, and rapidly acting vasodilators (eg, inhaled nitric oxide and/or epoprostenol). Published case series suggest excellent outcomes after LT for patients who respond to medical therapy.

Treatment with sildenafil and treprostinil allows successful liver transplantation of patients with moderate to severe portopulmonary hypertension

Portopulmonary hypertension (PoPH) refers to pulmonary arterial hypertension associated with portal hypertension with or without evidence of an underlying liver disease. Despite the potential for curing PoPH with liver transplantation, the presence of moderate or severe PoPH is associated with increased morbidity and mortality and is, therefore, a contraindication to transplantation. Previous studies have predominantly used intravenous epoprostenol for treatment in order to qualify patients for liver transplantation. In this retrospective case series, we describe the clinical course of 11 patients whom we successfully treated (predominantly with oral sildenafil and subcutaneous treprostinil) in order to qualify them for liver transplantation. The mean pulmonary artery pressure significantly improved from 44 to 32.9 mm Hg, and the pulmonary vascular resistance decreased from 431 to 173 dyn second cm(-5) . There were significant improvements in the cardiac output and the transpulmonary gradient with these therapies as well. All 11 patients subsequently received liver transplants with a 0% mortality rate to date; the duration of follow-up ranged from 7 to 60 months. After transplantation, 7 of the 11 patients (64%) were off all pulmonary vasodilators, and only 2 patients required transiently increased doses of prostacyclins. In conclusion, an aggressive approach to the treatment of PoPH with sildenafil and/or treprostinil and subsequent liver transplantation may be curative for PoPH in some patients.

Management of pulmonary complications in pretransplant patients

This article addresses the most common pulmonary issues that affect liver transplant candidates. Pretransplant diagnostic criteria of these pulmonary problems in liver transplant patients are reviewed. Successful pulmonary management schemes and caveats are described. Risks for liver transplant are emphasized.

Portopulmonary hypertension: from diagnosis to treatment

Portopulmonary hypertension is a form of pulmonary arterial hypertension that has gained interest in recent years with the development of liver transplantation techniques and new pulmonary vasodilator therapies. Portopulmonary hypertension is defined as pulmonary artery hypertension associated with portal hypertension with or without advanced hepatic disease. Echocardiography plays a major role in screening for portopulmonary hypertension but right heart catheterization remains the gold standard for diagnosis. The treatment of patients with portopulmonary hypertension consists of general measures that apply to all patients that carry the diagnosis of pulmonary hypertension and specific vasodilator therapies. These new therapies showed encouraging results in patients who would otherwise have a contraindication for liver transplantation. The review presents a summary of the current knowledge on the epidemiology, diagnosis, treatment and prognosis of patients with portopulmonary hypertension.

The heart in liver transplantation

The heart and liver are organs that are closely related in both health and disease. Patients who undergo liver transplantation may suffer from heart disease that is: (a) related to the original cause of the liver disease such as hemochromatosis, (b) related to the liver disease itself, or (c) related to other associated conditions. Furthermore, liver transplantation is one of the most cardiovascular stressful events that a patient with cirrhosis may undergo. After liver transplantation, the progression of pre-existing or the development of new-onset cardiac disease may occur. This article reviews the relationship between the heart and liver transplantation in the pre-transplant, intra-operative, and post-transplant periods.

Portopulmonary hypertension: short review

Portopulmonary hypertension (PoPH) is an underrecognized complication of portal hypertension, related to cirrhosis and noncirrhotic portal hypertension. PoPH has been found in 5-6% of patients with decompensated liver disease and may adversely affect outcome after liver transplantation. The prevalence of PoPH is unrelated to the severity of liver disease but associated with female sex and underlying autoimmune liver disease. Diagnosis of PoPH is based on screening with Doppler echocardiography and confirmation by right-heart catheterization. Treatment options with proven efficacy in idiopathic pulmonary hypertension include endothelin receptor antagonists, prostanoids, and sildenafil. In PoPH, such targeted treatment was found to be safe in small uncontrolled studies but randomized trials demonstrating its benefit are lacking.

Postoperative Care of the Liver-Transplant Patient

Liver transplantation (LT) is performed to improve life expectancy and quality of life in patients with advanced chronic liver disease (CLD), and to save life in the context of acute liver failure (ALF). These two groups of patients differ significantly in terms of mean age, prior comorbidity, and degree of extra-hepatic organ dysfunction, requiring substantially different approaches to supportive care. Common aspects of care are those directed at the transplanted organ itself, with regard to monitoring and recognition of early dysfunction, initiation of immunosuppression, and management of surgical complications. Close liaison with the multidisciplinary team, which will include the intensivist, transplant surgeon, transplant hepatologist, anesthesiologist, and radiologist, is required.

Rapid normalization of portopulmonary hypertension after living donor liver transplantation

Portopulmonary hypertension (PPHTN) is a relatively rare complication of end-stage liver disease, and a serious problem in the context of liver transplantation. Herein we have reported a case of decompensated liver cirrhosis with PPHTN, which rapidly resolved after adult-to-adult living donor liver transplantation (LDLT). A 54-year-old man was referred to our hospital with end-stage liver cirrhosis owing to chronic hepatitis C. Preoperative mean pulmonary artery pressure (mPAP), as assessed by right heart catheterization, was 38 mm Hg. Continuous infusion of epoprostenol decreased the mPAP to 24 mm Hg over 44 days. He underwent LDLT using a right hepatic lobe graft donated by his son. The postoperative course was uneventful, epoprostenol was weaned by postoperative day (POD) 21, and the mPAP normalized to 21 mm Hg on POD 28. The patient was discharged on POD 31 without any vasodilators. Our case revealed that liver transplantation can rapidly resolve PPTHN.

Plasma levels of S100A4 in portopulmonary hypertension

We previously showed that a single nucleotide polymorphism in S100A4 was associated with portopulmonary hypertension (PPHTN) in patients with advanced liver disease. We aimed to determine the association between plasma levels of S100A4 and PPHTN. We performed a case-control study of patients with advanced liver disease. Cases with PPHTN had mean pulmonary artery pressure >25 mmHg, pulmonary vascular resistance >240 dynes s cm(-5) and pulmonary capillary wedge pressure </=15 mmHg. Controls with liver disease had right ventricular systolic pressure <40 mmHg and normal right atrial and ventricular morphology by echocardiography. Plasma samples were assayed for S100A4. The study sample included 14 cases with PPHTN and 32 controls with liver disease. There was no difference in mean age between cases and controls (p = 0.52). Seventy-nine percent of cases were female compared with 44% of controls (p = 0.03). There was no difference in S100A4 levels between cases and controls (p = 0.58). Both groups had significantly higher S100A4 levels than healthy volunteers (p <0.05). There was no significant difference in plasma levels of S100A4 between PPHTN patients and controls with liver disease, although liver disease itself was associated with increased S100A4 levels.

Pulmonary manifestations of liver diseases

Respiratory problems are common in patients with chronic liver diseases. The most common causes are disorders that are not related to liver diseases such as asthma and COPD. In addition certain liver diseases that are associated with specific pulmonary abnormalities, and conditions associated with end stage liver disease like tense ascites and intercostal muscular wasting are considered. Finally two unique disorders characterizing by vascular abnormalities independent of cardiorespiratory disorder-the hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are observed. These disorders have different pathogenesis, different clinical pictures, treatment and prognosis. This article reviews the epidemiology, pathophysiology, clinical features, evaluation and current therapy of these two disorders.

Genetic risk factors for portopulmonary hypertension in patients with advanced liver disease

RATIONALE

Portopulmonary hypertension (PPHTN) occurs in 6% of liver transplant candidates. The pathogenesis of this complication of portal hypertension is poorly understood.

OBJECTIVES

To identify genetic risk factors for PPHTN in patients with advanced liver disease.

METHODS

We performed a multicenter case-control study of patients with portal hypertension. Cases had a mean pulmonary artery pressure >25 mm Hg, pulmonary vascular resistance >240 dynes.s(-1).cm(-5), and pulmonary capillary wedge pressure < or =15 mm Hg. Controls had a right ventricular systolic pressure < 40 mm Hg (if estimated) and normal right-sided cardiac morphology by transthoracic echocardiography. We genotyped 1,079 common single nucleotide polymorphisms (SNPs) in 93 candidate genes in each patient.

MEASUREMENTS AND MAIN RESULTS

The study sample included 31 cases and 104 controls. Twenty-nine SNPs in 15 candidate genes were associated with the risk of PPHTN (P < 0.05). Multiple SNPs in the genes coding for estrogen receptor 1, aromatase, phosphodiesterase 5, angiopoietin 1, and calcium binding protein A4 were associated with the risk of PPHTN. The biological relevance of one of the aromatase SNPs was supported by an association with plasma estradiol levels.

CONCLUSIONS

Genetic variation in estrogen signaling and cell growth regulators is associated with the risk of PPHTN. These biologic pathways may elucidate the mechanism for the development of PPHTN in certain patients with severe liver disease.

Portopulmonary hypertension

It has been widely accepted that development of porto-pulmonary hypertension (POPH) is independent of the cause of portal hypertension. The degree of hepatic damage and liver function do not correlate with predisposition to POPH or its severity. However, portal hypertension has been confirmed as a prerequisite for developing pulmonary hypertension. Transthoracic echocardiography is the best screening test for the presence of POPH, but a diagnosis of POPH can be established only by right heart catheterization. Randomized controlled trials comparing the efficacy and safety of different pharmacologic strategies are lacking in patients with POPH. The general management includes diuretics and oxygen supplementation. Notably, moderate to severe POPH predisposes candidates for orthotopic liver transplantation to a higher risk of perioperative mortality. Vasomodulating pharmacologic agents are used in patients with moderate to severe POPH to decrease pulmonary arterial hypertension, thereby permitting liver transplantation to be performed safely. Epo-prostenol is the best-studied medication, and bosentan appears promising.

Survival in portopulmonary hypertension: Mayo Clinic experience categorized by treatment subgroups

To determine the natural history of portopulmonary hypertension (POPH), a retrospective screening-right heart catheterization-survival analysis of patients was performed. We categorized patients by three treatment subgroups: (1) no therapy for pulmonary hypertension (PH) or liver transplantation (LT), (2) therapy for PH alone and (3) therapy for PH followed by LT. Seventy-four patients were identified between 1994 and 2007. Nineteen patients received no therapy for PH and no LT representing the natural history of POPH. Five-year survival was 14%, and 54% had died within 1 year of diagnosis. Five-year survival in 43 patients receiving therapy for PH but no LT was 45%, and 12% had died within 1 year of diagnosis. Twelve patients underwent LT and 5-year survival for the nine receiving therapy for PH was 67% versus 25% in the three who were not pretreated with prostacyclin therapy. The survival of untreated patients with POPH was poor. Subgroups of patients selected to medical treatment with or without LT had better long-term survival. Mortality did not correlate with baseline hemodynamic variables, type of liver disease or severity of hepatic dysfunction. Medical therapy for POPH should be considered in all patients with POPH, but the treatment effects and impact on those considered for LT still requires well-designed, prospective study before practice guidelines can be suggested.

The liver transplant recipient with cardiac disease

Liver transplantation is a stressful condition for the cardiovascular system of patients with advanced hepatic disease. The underlying hemodynamic and cardiac status of patients with cirrhosis is crucial to determine which patients should became recipients. Generally preoperative cardiovascular testing is performed on potential candidates who are more than 45 years old, or have diabetes mellitus, or peripheral vascular disease, or more than two standard cardiac risk factors. Recent data suggest that the prevalence of coronary artery disease among patients with cirrhosis is much greater than previously believed; it likely mirrors or exceeds the prevalence rate in the healthy population. The morbidity and mortality of patients with coronary artery disease who undergo orthotopic liver transplantation (OLT) without treatment are unacceptably high. In conclusion, accurate preoperative cardiac evaluation according to the new American Heart Association & American College of Cardiology should lead to detect and treat coronary artery disease before liver transplantation. In case of alcohol-related cardiomyopathy, portopulmonary hypertension, and hypertrophic cardiomyopathy, there should be a case-by-case discussion by the hepatologist and cardiologist to consider the patient for liver transplantation. No robust data are available on the impact of decompensated dilated heart failure in this setting. If a recipient with cardiac disease is scheduled for OLT, we strongly suggest advanced intra- and postoperative hemodynamic monitoring plus transesophageal echocardiography.

Clinical risk factors for portopulmonary hypertension

Portopulmonary hypertension affects up to 6% of patients with advanced liver disease, but the predictors and biologic mechanism for the development of this complication are unknown. We sought to determine the clinical risk factors for portopulmonary hypertension in patients with advanced liver disease. We performed a multicenter case-control study nested within a prospective cohort of patients with portal hypertension recruited from tertiary care centers. Cases had a mean pulmonary artery pressure > 25 mm Hg, pulmonary vascular resistance > 240 dynes x second x cm(-5), and pulmonary capillary wedge pressure < or = 15 mm Hg. Controls had a right ventricular systolic pressure < 40 mm Hg (if estimable) and normal right-sided cardiac morphology by transthoracic echocardiography. The study sample included 34 cases and 141 controls. Female sex was associated with a higher risk of portopulmonary hypertension than male sex (adjusted odds ratio = 2.90, 95% confidence interval 1.20-7.01, P = 0.018). Autoimmune hepatitis was associated with an increased risk (adjusted odds ratio = 4.02, 95% confidence interval 1.14-14.23, P = 0.031), and hepatitis C infection was associated with a decreased risk (adjusted odds ratio = 0.24, 95% confidence interval 0.09-0.65, P = 0.005) of portopulmonary hypertension. The severity of liver disease was not related to the risk of portopulmonary hypertension.

CONCLUSION

Female sex and autoimmune hepatitis were associated with an increased risk of portopulmonary hypertension, whereas hepatitis C infection was associated with a decreased risk in patients with advanced liver disease. Hormonal and immunologic factors may therefore be integral to the development of portopulmonary hypertension.

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

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

Management strategies for patients with pulmonary hypertension in the intensive care unit

OBJECTIVE

Pulmonary hypertension may be encountered in the intensive care unit in patients with critical illnesses such as acute respiratory distress syndrome, left ventricular dysfunction, and pulmonary embolism, as well as after cardiothoracic surgery. Pulmonary hypertension also may be encountered in patients with preexisting pulmonary vascular, lung, liver, or cardiac diseases. The intensive care unit management of patients can prove extremely challenging, particularly when they become hemodynamically unstable. The objective of this review is to discuss the pathogenesis and physiology of pulmonary hypertension and the utility of various diagnostic tools, and to provide recommendations regarding the use of vasopressors and pulmonary vasodilators in intensive care.

DATA SOURCES AND EXTRACTION

We undertook a comprehensive review of the literature regarding the management of pulmonary hypertension in the setting of critical illness. We performed a MEDLINE search of articles published from January 1970 to March 2007. Medical subject headings and keywords searched and cross-referenced with each other were: pulmonary hypertension, vasopressor agents, therapeutics, critical illness, intensive care, right ventricular failure, mitral stenosis, prostacyclin, nitric oxide, sildenafil, dopamine, dobutamine, phenylephrine, isoproterenol, and vasopressin. Both human and animal studies related to pulmonary hypertension were reviewed.

CONCLUSIONS

Pulmonary hypertension presents a particular challenge in critically ill patients, because typical therapies such as volume resuscitation and mechanical ventilation may worsen hemodynamics in patients with pulmonary hypertension and right ventricular failure. Patients with decompensated pulmonary hypertension, including those with pulmonary hypertension associated with cardiothoracic surgery, require therapy for right ventricular failure. Very few human studies have addressed the use of vasopressors and pulmonary vasodilators in these patients, but the use of dobutamine, milrinone, inhaled nitric oxide, and intravenous prostacyclin have the greatest support in the literature. Treatment of pulmonary hypertension resulting from critical illness or chronic lung diseases should address the primary cause of hemodynamic deterioration, and pulmonary vasodilators usually are not necessary.

Prostanoid therapy for pulmonary arterial hypertension

Epoprostenol and the structurally related compounds treprostinil, iloprost, and beraprost are collectively referred to as prostanoids. The discovery of epoprostenol in 1976 and unequivocal demonstration of its efficacy in 1996 dramatically altered the approach to therapy for pulmonary arterial hypertension (PAH). Development of prostanoids available through multiple routes of administration and the discovery and development of other agents acting through alternative pathways continue to expand the array of therapeutic options. The use of prostanoids in combination with other PAH drugs and for treating pulmonary hypertensive disorders outside of the PAH classification are areas of ongoing research.

Portopulmonary hypertension

As a result of the success of orthotopic liver transplantation, there has been increasing interest in the diagnosis and therapeutic options for the pulmonary vascular complications of hepatic disease. These pulmonary vascular complications range from the hepatopulmonary syndrome, which is characterized by intrapulmonary vascular dilatations, to portopulmonary hypertension (POPH), which is characterized by an elevated pulmonary vascular resistance as a consequence of obstruction to pulmonary arterial blood flow. This review concentrates on POPH.

Hepatopulmonary syndrome and portopulmonary hypertension

The incidence of pulmonary vascular disorders is significantly increased in patients with liver disease. Intrapulmonary shunting with hypoxemia in patients with liver disease is diagnosed as hepatopulmonary syndrome (HPS), whereas precapillary pulmonary vessel obliteration is identified as portopulmonary hypertension (PPHTN). Because the symptoms of liver disease can mimic those of pulmonary vascular disease, all patients with hepatic failure should be screened for these two diseases. Pulse oximetry effectively screens for hypoxemia associated with HPS, whereas an elevated right ventricular systolic pressure estimated by echocardiography identifies patients at risk of having PPHTN. Liver transplantation is the only effective medical therapy for HPS. However, those who have a resting arterial oxygenation less than 50 mm Hg or a shunt measured by scintigraphic perfusion greater than 20% have an unacceptably high mortality rate following surgery. Compared with HPS, there are more therapeutic options that can bridge patients with PPHTN to transplantation. Drugs used to manage idiopathic pulmonary hypertension have shown promise in the treatment of PPHTN. Prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors have improved transplant survival. Despite treatment, however, perioperative mortality for patients with PPHTN remains high. Even with successful transplantation, HPS and PPHTN can persist or develop de novo. Long-term follow-up and surveillance of liver transplant recipients is thus indicated to identify HPS and PPHTN following surgery.

Pretransplant management of the cirrhotic patient

Cirrhosis is the twelfth commonest cause of death in the United States, with more than 27,000 deaths and more than 421,000 hospitalizations annually. Currently, there are more than 17,000 patients awaiting liver transplantation in the United States across the 11 United Network for Organ Sharing regions. Approximately 10% of such patients will die awaiting transplantation.