Coexistent pulmonary and portal hypertension: morphologic and clinical features

Pulmonary hypertension in primary biliary cirrhosis: a prospective study in 178 patients

OBJECTIVE. To analyze the incidence, clinical features, and prognosis of patients with primary biliary cirrhosis (PBC) complicated by pulmonary hypertension (PH).

MATERIAL AND METHODS

A total of 178 consecutive PBC patients, who were admitted to Peking Union Medical College Hospital from January 2001 to March 2007, were included in this prospective study. A structured interview, systemic rheumatological examination, laboratory tests (including autoantibodies), and Doppler echocardiography were conducted for each patient and compared between patients with and without PH.

RESULTS

Twenty-one PBC patients (11.8%) had PH. Among them, four patients (19.0%) had moderate to severe PH, and one patient died of right heart failure instead of liver failure. The incidences of Raynaud's phenomenon, interstitial lung disease, Sjögren's syndrome, and portal hypertension, the proportion of patients with a positive anti-SSA, the level of serum IgA, as well as the Mayo risk score in the PH-PBC patients were significantly higher than in the non-PH-PBC group (p = 0.02, 0.001, 0.02, 0.03, 0.006, 0.04 and 0.02, respectively).

CONCLUSIONS

PH, including moderate to severe PH, is not a rare complication of PBC. This complication is closely associated with portal hypertension and immunological dysregulation and indicates a poor prognosis.

Liver transplantation for pulmonary vascular complications of pediatric end-stage liver disease

PURPOSE

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPH) are poorly understood pulmonary complications of end-stage liver disease (ESLD). We present a case series of children with HPS and PPH.

METHODS

After institutional review board approval, query of our medical database identified children 0 to 18 years of age with ESLD diagnosed with HPS or PPH. Data were collected via chart review.

RESULTS

We identified 7 children with either HPS (n = 5) or PPH (n = 2). Patients with HPS presented with progressive dyspnea over a mean of 7 months (range, 4-12 months) at a mean of 13 years (range, 5-17 years) of age. Pulmonary shunting by albumin perfusion scan averaged 41% (range, 20%-66%) with an initial mean resting SpO(2) of 88% (range, 84%-94%) and mean SpO(2) during exertion of 79% (range, 60%-89%). Four patients required supplemental O(2) and, upon United Network for Organ Sharing (UNOS) appeal, received pediatric model for ESLD (or Child-Pugh) score exceptions, enabling them to undergo orthotopic liver transplant (OLT) within 1-2 months. The fifth patient was initially rejected by the UNOS regional review board, but 6 months of worsening hypoxemia led to OLT 2 months after successful UNOS appeal. All patients with HPS undergoing OLT experienced complete resolution of hypoxemia within 8 months. Both children with PPH were treated with intravenous epoprostenol, which lowered or stabilized mean pulmonary artery pressure and bridged them to OLT within 7 months of listing. Overall, there were no pulmonary complications; however, 1 patient with PPH expired shortly after OLT. The remaining patients are alive at a median follow-up of 27 months (range, 6-96 months).

CONCLUSION

Hepatopulmonary syndrome and PPH are uncommon complications of ESLD in children. Epoprostenol can bridge PPH patients to OLT. OLT leads to rapid resolution of HPS and PPH and currently represents the only successful treatment for these children.

Pulmonary hypertension in patients with congenital portosystemic venous shunt: a previously unrecognized association

BACKGROUND

Pulmonary arterial hypertension has been reported to be observed in association with acquired portal hypertension. However, the contribution of congenital anomalies occurring in the portal system to the development of pulmonary arterial hypertension remains to be elucidated.

METHODS

Nine patients with congenital portosystemic venous shunt were studied from January 1990 through September 2005.

RESULTS

Patent ductus venosus was detected in 5 patients, including 3 patients with an absence of the portal vein. The presence of either a gastrorenal or splenorenal shunt was evident in another 4 patients. Six patients had a history of hypergalactosemia with normal enzyme activities, as seen during neonatal screening. Six (66.7%) of the 9 patients were identified to have clinically significant pulmonary arterial hypertension (mean pulmonary artery pressure: 34-79 mm Hg; pulmonary vascular resistances: 5.12-38.07 U). The median age at the onset of pulmonary arterial hypertension was 12 years and 3 months. Histologic studies of lung specimens, which were available in 4 of the 9 patients with congenital portosystemic venous shunt, showed small arterial microthrombotic lesions in 3 patients. This characteristic finding was recognized even in the congenital portosystemic venous shunt patients without PAH.

CONCLUSIONS

This study demonstrated thromboembolic pulmonary arterial hypertension to be a crucial complication in congenital portosystemic venous shunt, and this pathologic state may be latently present in patients with pulmonary arterial hypertension of unknown etiology.

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.

Portopulmonary hypertension: Results from a 10-year screening algorithm

Portopulmonary hypertension (POPH) is the elevation of pulmonary artery pressure due to increased resistance to pulmonary blood flow in the setting of portal hypertension. Increased mortality has occurred with attempted liver transplantation in such patients and thus, screening for POPH is advised. We examined the relationship between screening echocardiography and right heart catheterization determinations of pressure, flow, volume, and resistance. A prospective, echocardiography-catheterization algorithm was followed from 1996 to 2005. Consecutive transplantation candidates underwent Doppler echocardiography to determine right ventricular systolic pressure (RVSP). Of 1,235 patients, 101 with RVSP >50 mm Hg underwent catheterization to measure mean pulmonary artery pressure (MPAP), flow via cardiac output (CO), central volume via pulmonary artery occlusion pressure (PAOP), and resistance via calculated pulmonary vascular resistance (PVR). Bland-Altman analysis suggested marked discordance between echocardiography-derived RVSP and catheterization results. All-cause pulmonary hypertension (MPAP >25 mm Hg) was documented in 90/101 (90%) patients. Using current pressure and resistance diagnostic guidelines (MPAP >25 mm Hg, PVR > or =240 dynes/s/cm(-5)), POPH was documented in 66/101 (65%) patients. Elevated MPAP was due to increased CO and/or PAOP in 35/101 (35%) patients with normal resistance (PVR <240 dynes/s/cm(-5)). The transpulmonary gradient (MPAP-PAOP) further characterized POPH in the presence of increased volume. Model for end stage liver disease (MELD) scores correlated poorly with MPAP and PVR. In conclusion, right heart catheterization is necessary to confirm POPH and frequently identifies other reasons for pulmonary hypertension (e.g., high flow and increased central volume) in liver transplantation candidates. Severity of POPH correlates poorly with MELD scores.

Portopulmonary hypertension

Portopulmonary hypertension is a common condition in patients who have portal hypertension. This article reviews the definition and clinical presentation of this disorder and outlines our current understanding of its pathophysiology. A diagnostic approach is provided , and novel medical therapies that are being investigated to treat this condition are discussed. Finally, the safety of liver transplantation in patients who have portopulmonary hypertension is reviewed.

Portopulmonary hypertension: hemodynamics, pulmonary angiography, and configuration of the heart

BACKGROUND

The goal of the present study was to examine the cardiac configuration and pulmonary vascular changes in patients with portopulmonary hypertension (PPHTN) and compare them with those of idiopathic pulmonary arterial hypertension (IPAH).

METHODS AND RESULTS

The subjects were 10 patients with PPHTN and 18 with IPAH. In PPHTN, the increases in the right ventricular end-diastolic volume index (89+/-19 vs 128+/-50 ml/m2; p=0.04), right end-systolic volume index (50+/-19 vs 95+/-47 ml/m 2; p=0.02) and right ventricular mass index (47+/-18 g/m2 vs 79+/-31; p=0.04) were low compared with IPAH. The decrease in the right ventricular ejection fraction was also low in PPHTN (45+/-10 vs 28+/-13%; p=0.01). The degree of sparse arborization and abrupt narrowing on wedged pulmonary angiography was moderate in PPHTN compared with IPAH. In PPHTN, the proximal pulmonary arteries were dilated near the segmental arteries, which were narrow in IPAH.

CONCLUSION

Changes in the configuration of the heart were moderate in PPHTN compared with those in IPAH. The degree of sparse arborization and abrupt narrowing were also moderate in PPHTN.

The pulmonary involvement in portal hypertension: portopulmonary hypertension and hepatopulmonary syndrome

Pulmonary abnormalities are common in patients with advanced chronic liver disease. Two distinct syndromes strictly related to the presence of portal hypertension, but clearly different from a pathophysiologic point of view, have been identified. Portopulmonary hypertension, characterized by an increased pulmonary arterial pressure, is due to a progressive arteriolar vasoconstriction induced by excess local production of vasoconstrictor substances. Hepatopulmonary syndrome results from intrapulmonary microvascular dilation caused by an inadequate synthesis or metabolism of putative pulmonary vasoactive substances leading to a functional vasodilation of the pulmonary vasculature, ultimately leading to hypoxemia. Controversies on pathogenesis imply different tentative therapeutic approaches for the medical management of these conditions. The development of portopulmonary hypertension or the hepatopulmonary syndrome has important clinical and prognostic implications facing the impact of new therapeutic strategies for the management of the main complications of advanced liver diseases on cardiopulmonary function.

Hepatitis C virus and the lung: implications for therapy

Hepatitis C virus (HCV) infection is a chronic blood-borne disease that affects > 4,000,000 individuals in the United States. The majority of individuals with HVC infection acquire a chronic hepatitis that predisposes them to the complications of cirrhosis and hepatoma. Chronic HCV infection is, however, associated with multiple extrahepatic manifestations as well, including recently recognized effects on the lung. These include primary effects on lung function, as well as secondary effects in the settings of progressive liver disease and drug treatment for HCV. In this article, we discuss the emerging clinical data that support a role for HCV infection in lung disease, describe the multiple pulmonary manifestations of this viral infection, and outline the therapies available for specific pulmonary complications of chronic HCV infection.

An overview of pulmonary arterial hypertension: risks, pathogenesis, clinical manifestations, and management

This article focuses on pulmonary arterial hypertension, including both primary pulmonary hypertension (PPH) and those forms of pulmonary arterial hypertension that are related to other factors, including collagen vascular diseases, congenital shunts, portal hypertension, human immunodeficiency viral infection, and exposure to specific drugs and toxins. Risks for different types of pulmonary arterial hypertension are identified. The common pathogenesis for pulmonary arterial hypertension is discussed, and includes an overview of the role of key vasoactive substances such as nitric oxide, prostacyclin, endothelin, and thromboxane. Typical presenting clinical manifestations, recommendations for screening of patients at risk, and key diagnostic findings are discussed. The mainstay of treatment is identified as pharmacologic, and may include diuretics, digoxin, warfarin, calcium channel antagonists, and prostacyclin analogues such as epoprostenol. Surgical interventions are considered as a last resort, and may include unilateral or bilateral lung transplant or atrial septostomy. Treatment options for patients with pulmonary arterial hypertension hold more hope today than they did a decade ago and are identified so as to guide the advanced practice nurse in recognizing and then facilitating the appropriate management of patients with this rare but disabling disease.

Medical therapy for pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines

Pulmonary arterial hypertension (PAH) is often difficult to diagnose and challenging to treat. Untreated, it is characterized by a progressive increase in pulmonary vascular resistance leading to right ventricular failure and death. The past decade has seen remarkable improvements in therapy, driven largely by the conduct of randomized controlled trials. Still, the selection of most appropriate therapy is complex, and requires familiarity with the disease process, evidence from treatment trials, complicated drug delivery systems, dosing regimens, side effects, and complications. This chapter will provide evidence-based treatment recommendations for physicians involved in the care of these complex patients. Due to the complexity of the diagnostic evaluation required, and the treatment options available, it is strongly recommended that consideration be given to referral of patients with PAH to a specialized center.

Classification and epidemiology of pulmonary hypertension

Pulmonary hypertension is a complex disease that can be idiopathic, familial, or associated with a wide range of disease processes. This article outlines the classification of primary pulmonary hypertension and discusses the various types of the disease.

The biological "scrabble" of pulmonary arteriovenous malformations: considerations in the setting of cavopulmonary surgery

Pulmonary arteriovenous fistulas are vascular malformations, which, by virtue of producing abnormal vascular connections proximal to the units of gas exchange, result in intrapulmonary right-to-left shunting. These malformations or fistulas reflect at least in part disordered angiogenesis, and less commonly recruitment and dilation of pre-existing vascular channels. Pulmonary arteriovenous fistulas occur in a number of diverse clinical settings. Such fistulas are a well-established feature of the Weber-Osler-Rendu complex, or hereditary haemorrhagic telangiectasia, an autosomal dominant vascular dysplasia characterized by mucocutaneous telangiectasis, epistaxis, gastrointestinal haemorrhage, and arteriovenous malformations in the lung, brain, liver and elsewhere. They are also seen in the patient with acute or chronic liver disease, disease that is usually but not invariably severe, or those with non-cirrhotic portal hypertension. They may occur as congenital malformations, single or diffuse, large or small in isolation, and when large or extensive enough may result in hypoxaemia, clinical cyanosis, and heart failure. Cerebral vascular accidents are also a well-known complication of this disorder. An extensive literature has accumulated with regard to the pulmonary arteriovenous fistulas seen in the setting of the Weber-Osler-Rendu complex, and there is considerable information on the genetics, basic biology, clinical findings, complications and therapeutic interventions of these malformations in the setting of this syndrome. These issues, however, are not the primary considerations of this review, although some aspects of this fascinating disorder will be discussed later. Rather the focus will be on pulmonary arteriovenous malformations that develop in the setting of cavopulmonary surgery, and their relationship to the pulmonary arteriovenous fistulas occurring in the hepatopulmonary syndrome. The complex tapestry of these overlapping and intersecting clinical observations will be unfolded in the light of their chronology.

Portopulmonary hypertension and hepatopulmonary syndrome

The clinically and pathophysiologically distinct entities of portopulmonary hypertension and hepatopulmonary syndrome occur in a substantial proportion of patients who have advanced liver disease of different causes. These disorders are notoriously underdiagnosed, but they have a substantial impact on survival and require focused treatment. Abnormal intrapulmonary vascular dilatation, the hallmark of hepatopulmonary syndrome, can cause profound hypoxaemia that can be very difficult to treat. By contrast, portopulmonary hypertension results from excessive pulmonary vasoconstriction and vascular remodelling that eventually leads to right-heart failure. Insights into the pathogeneses of these syndromes have led to novel therapeutic approaches. However, in severely affected patients, effective treatment remains a difficult task. In selected patients, liver transplantation represents the only treatment option, but the decision to do isolated liver transplantation is particularly challenging in patients who have severe pulmonary disease involvement. Data from several centres have contributed to provide criteria that allow improved prediction of which patients may, or may not, benefit from liver transplantation alone.

Portopulmonary hypertension: a tale of two circulations

Pulmonary involvement is common in patients with portal hypertension and can manifest in diverse manners. Changes in pulmonary arterial resistance, manifesting either as the hepatopulmonary syndrome or portopulmonary hypertension (PPHTN), have been increasingly recognized in these patients in recent years. This review summarizes the clinicopathologic features, diagnostic criteria, as well as the latest concepts in the pathogenesis and management of PPHTN, which is defined as an elevated pulmonary artery pressure in the setting of an increased pulmonary vascular resistance and a normal wedge pressure in a patient with portal hypertension.

De novo diagnosis of portopulmonary hypertension following liver transplantation

Portopulmonary hypertension occurs in 2-8% of liver recipients. However, new onset of pulmonary hypertension following liver transplantation has been reported only once. We report de novo occurrences of portopulmonary hypertension in two liver recipients following successful liver transplantation. Although both patients had recurrent hepatitis C after the transplant, both had excellent clinical graft function. In one patient, upper endoscopy and aortogram showed evidence of persistent venous collaterals in the abdomen. Both patients presented with shortness of breath. Portopulmonary hypertension was diagnosed late, thus contributing directly to their deaths. Autopsy in one patient confirmed the absence of significant liver pathology and failed to demonstrate any source of deep venous thrombosis. This, and our earlier case report, highlights the potential for the occurrence of pulmonary hypertension following liver transplantation. Further studies are needed to determine the scope of the problem and identify patients at risk for this complication.

Arterial oxygenation associated with portopulmonary hypertension

STUDY OBJECTIVES

To characterize arterial oxygenation in patients referred to Mayo Clinic for liver transplantation with a diagnosis of portopulmonary hypertension (portoPH).

DESIGN

Prospective study.

SETTING

Liver transplantation program and pulmonary hypertension clinic in a tertiary referral center.

PARTICIPANTS

Twenty consecutive patients with abnormal pulmonary hemodynamics documented by right-heart catheterization (mean pulmonary artery pressure [MPAP] > or = 25 mm Hg, pulmonary vascular resistance [PVR] > or = 120 dyne.s.cm(-5), and pulmonary capillary wedge pressure [PCWP] < or = 15 mm Hg). Liver transplant candidates with normal pulmonary hemodynamics via screening Doppler echocardiography (n = 40) served as control subjects. A subgroup of patients underwent postural and inspired 100% oxygen blood gas analysis, contrast echocardiography, and technetium-labeled macroaggregated albumin ((99m)TcMAA) lung/brain scanning to identify and quantitate the degree of intracardiac or intrapulmonary shunting.

MEASUREMENTS AND RESULTS

portoPH was moderate to severe (MPAP > 35 mm Hg) in 18 of 20 patients (90%). Arterial-alveolar oxygen pressure gradient (P[A-a]O(2)) was abnormal (> or = 20 mm Hg) in 16 of 20 patients (80%). PaO(2) was abnormal (< or = 70 mm Hg) in 3 of 20 patients (15%). Pa0(2) was significantly less and P(A-a)O(2) was significantly greater compared to control subjects (p < 0.001). All patients had normal (99m)TcMAA brain uptake (< 6%) and negative transthoracic contrast echocardiographic findings. No significant correlations were found between oxygenation and hemodynamic variables (MPAP, PVR, PVR index, and transpulmonary gradient).

CONCLUSIONS

Arterial oxygenation associated with portoPH was frequently abnormal and significantly worse when compared to patients with normal pulmonary hemodynamics by Doppler echocardiography. Hypoxemia, as measured by PaO(2) and P(A-a)O(2), was usually mild even in the setting of moderate-to-severe portoPH.

Unexplained pulmonary hypertension in chronic myeloproliferative disorders

AIM

To investigate the potential association between the chronic myeloid disorders (CMDs), including the chronic myeloproliferative disorders, and pulmonary hypertension (PH).

METHODS

Retrospective chart review of patients who had received diagnoses of both CMD and PH. Patients with a known cause of PH were excluded. The diagnosis of a CMD was based on established criteria. The diagnosis of PH was based on echocardiographic data or right heart catheterization data.

RESULTS

Twenty-six patients satisfied the criteria for both a CMD and PH. Twelve patients had myeloid metaplasia with myelofibrosis (MMM), 5 patients had essential thrombocythemia (ET), 6 patients had polycythemia vera, 2 patients had a myelodysplastic syndrome, and 1 patient had chronic myeloid leukemia. Twenty-two patients (92%) received treatment for their CMDs, which included therapy with hydroxyurea (18 patients), anagrelide (7 patients), and busulfan (3 patients). PH was diagnosed a median of 8 years after recognition of the CMD (range, 0 to 26 years). The median right ventricular systolic pressure (RVsys) was 71 mm Hg (range, 32 to 105 mm Hg). RVsys correlated with the platelet count in patients with MMM (r = 0.30) and ET (r = 0.6) and with the hemoglobin levels in patients with PV (r = 0.77). Treatment of CMD did not seem to affect the severity of the pulmonary artery pressures as measured by serial echocardiography. With a median survival time of 18 months after the diagnosis of PH, the cause of death in the majority of the patients was cardiopulmonary.

CONCLUSIONS

The current study suggests a higher than expected incidence of PH in patients with MMM, PV, and ET. Prognosis in such a setting is poor and may not be influenced by aggressive treatment of the underlying hematologic disorder.

Regional and systemic hemodynamic disturbances in cirrhosis

In cirrhosis of the liver there is an imbalance between factors mediating vasodilatation such as nitric oxide and factors mediating vasoconstriction such as endothelins. These imbalances result in portal hypertension, hepatorenal syndrome, portopulmonary hypertension, hepatopulmonary syndrome, as well as alterations in cerebral blood flow.

Pulmonary hemodynamics and perioperative cardiopulmonary-related mortality in patients with portopulmonary hypertension undergoing liver transplantation

In the setting of moderate to severe pulmonary artery hypertension, orthotopic liver transplantation (OLT) may be complicated by pulmonary hemodynamic instability and cardiopulmonary mortality. We retrospectively studied the relationship between cardiopulmonary-related mortality and initial (untreated) pre-OLT pulmonary hemodynamics in 43 patients with portopulmonary hypertension who underwent attempted OLT. Thirty-six patients were reported in 18 peer-reviewed studies, and 7 patients underwent OLT at our institution since 1996. Transplantation procedure outcome, mean pulmonary artery pressure (MPAP), pulmonary vascular resistance (PVR), cardiac output, pulmonary capillary wedge pressure, and transpulmonary gradient (TPG) are summarized. Overall mortality was reported in 15 of 43 patients (35%). Fourteen of the 15 deaths (93%) were primarily related to cardiopulmonary dysfunction. Two deaths were intraoperative, 8 deaths occurred during the transplantation hospitalization, and 4 patients died of cardiopulmonary deterioration posthospitalization. In 4 patients, the transplantation procedure could not be successfully completed. Cardiopulmonary mortality was associated with greater pre-OLT MPAP (49 +/- 14 v 36 +/- 7 mm Hg; P <.005), PVR (441 +/- 173 v 261 +/- 156 dynes.s.cm(-5); P <.005), and TPG (37 +/- 13 v 22 +/- 10 mm Hg; P <.005). MPAP of 50 mm Hg or greater was associated with 100% cardiopulmonary mortality. In patients with an MPAP of 35 to less than 50 mm Hg and PVR of 250 dynes.s.cm(-5) or greater, the mortality rate was 50%. No mortality was reported in patients with a pre-OLT MPAP less than 35 mm Hg or TPG less than 15 mm Hg. Cardiopulmonary-related mortality in OLT patients with portopulmonary hypertension was frequent and associated with significantly increased pre-OLT MPAP, PVR, and TPG compared with survivors. Treated or untreated, we recommend intraoperative cancellation or advise against proceeding to OLT for an MPAP of 50 mm Hg or greater. Patients with an MPAP of 35 to less than 50 mm Hg and PVR of 250 dynes.s.cm(-5) or greater appear to be at high risk for cardiopulmonary-related mortality after OLT. A prospective study is needed to define optimal pretransplantation treatments and pulmonary hemodynamic criteria that minimize OLT mortality associated with portopulmonary hypertension.

Accuracy of Doppler echocardiography in the assessment of pulmonary hypertension in liver transplant candidates

Pulmonary hypertension has been associated with poor outcome after liver transplantation. We assessed the diagnostic accuracy of Doppler echocardiography in detecting significant pulmonary hypertension. Seventy-four potential liver transplant candidates underwent Doppler echocardiography in which the systolic right ventricular pressure (RVsys) was used to estimate the systolic pulmonary artery pressure (PAsys). Group 1 included 39 consecutive patients with RVsys >/=50 mm Hg who underwent elective right heart catheterization. Group 2 consisted of 35 patients with RVsys <50 mm Hg in whom pulmonary artery pressures were measured at the beginning of the transplantation procedure. The accuracy of the estimates by Doppler echocardiography was assessed against measurements made by direct catheterization. Patients in groups 1 and 2 were comparable in their demographic and liver disease characteristics. There was a strong correlation between RVsys by Doppler echocardiography and PAsys by right heart catheterization (r =.78, P <.01). Of the 39 patients in group 1, 29 (72%) had at least moderate pulmonary hypertension (mean pulmonary artery pressure [MPAP] >/=35 mm Hg), including 12 (30%) with severe pulmonary hypertension (MPAP >/=50 mm Hg). Only 1 of the group 2 patients had MPAP >/=35 mm Hg. Thus, in the diagnosis of moderate to severe pulmonary hypertension, the sensitivity of echocardiography was 97% and specificity was 77%. Doppler echocardiography is an accurate screening test to detect moderate to severe pulmonary hypertension. We advise that liver transplant candidates with RVsys >/=50 mm Hg undergo right heart catheterization to fully characterize pulmonary hemodynamics.

Pulmonary hypertension as a result of asymptomatic portosystemic shunt

This report describes a patient with severe pulmonary hypertension accompanied by a congenital intrahepatic portosystemic shunt. Primary pulmonary hypertension was suspected initially because none of the classic symptoms of a portosystemic shunt were present. Physicians should note that disorders of the portal system may cause pulmonary hypertension even in the absence of symptoms suggesting liver disease.

Pulmonary hypertension associated with postoperative biliary atresia: report of two cases

The authors report on 2 patients with biliary atresia in whom pulmonary hypertension (PH) developed in the long-term follow-up after hepatoportoenterostomy. Both had portal hypertension and had undergone distal splenorenal shunt. Dyspnea developed around 14 to 15 years of age. Cardiac catheterization showed pulmonary artery pressure (PAP) of 99/37 (58) and 67/32 (48) mm Hg, respectively, which did not respond to vasodilators. One patient suffered from respiratory tract infection followed by right heart failure and subsequent death at 20 years of age. Postmortum histological findings exhibited severe thickening of the pulmonary artery wall. PH may grow insidiously even after successful hepatoportoenterostomy. Careful monitoring of PAP and hemodynamic response of PAP to vasodilators is essential for evaluating the reversibility of PH and making treatment decisions.

Obesity drugs and the heart

Appetite suppressant-related pulmonary hypertension and valvular heart disease are established disorders. Currently, the mechanism of these disorders is not certain. An estimated 6 million Americans and 70 million persons worldwide have been exposed to fenfluramine and dexfenfluramine. The clinical significance and long-term prognosis of cardiovascular effects and, thus, the potential public health effect of these disorders are not known. Longitudinal studies are required to further evaluate these disease processes. In addition, although isolated cases of regression of pulmonary hypertension and valve disease have been reported after the cessation of appetite suppressant therapy, the natural history remains uncertain.

High prevalence of pulmonary diffusion abnormalities without interstitial changes in long-term survivors of liver transplantation

Abnormalities in lung function are frequent findings in patients with terminal stage chronic liver disease. While spirometric parameters improve early after liver transplantation, a reduction in diffusion capacity has been reported up to 15 months after transplantation. It is unknown to what extent this disturbance in gas exchange occurs among long term survivors after liver transplantation. We assessed lung function in terms of spirometry, and gas exchange as well as pulmonary morphology by high resolution computed tomography (HRCT) in 40 patients 38 months (median, range 20-147 months) after liver transplantation. The prevalence of restrictive or obstructive changes was not different from predicted values. For the whole group of long-term survivors the carbon monoxide transfer coefficient (KCO) was reduced to 71.3 + 12.0% predicted (P < 0.05). HRCT revealed interstitial changes in only 2/40 (5.0%), emphysematous bullae in 2/40 (5.0%) and pleural thickening in 9/40 (22.5%). Diffusion abnormalities are prevalent in the majority of patients after liver transplantation, whereas spirometric abnormalities are absent also in the long term. The high prevalence of impaired gas exchange and the absence of interstitial lesions imply that changes in pulmonary blood vessels are the most likely cause.

Improvement in pulmonary hemodynamics during intravenous epoprostenol (prostacyclin): A study of 15 patients with moderate to severe portopulmonary hypertension

Pulmonary hypertension associated with increased pulmonary vascular resistance (PVR) and occurring in the setting of portal hypertension is referred to as "portopulmonary hypertension." Intravenous epoprostenol (prostacyclin) is a potent pulmonary and systemic vasodilator with antithrombotic properties. It can decrease PVR and pulmonary artery pressure in patients with primary (idiopathic) pulmonary hypertension. Using right-heart catheterization, we evaluated the acute pulmonary hemodynamic effects of intravenous epoprostenol in patients with moderate to severe pulmonary hypertension (mean pulmonary artery pressure [MPAP] >/=35 mm Hg) associated with clinical manifestations of portal hypertension. Effects of long-term infusion of epoprostenol were also evaluated. We studied 15 consecutive patients with portopulmonary hypertension; 14 underwent acute administration of epoprostenol, and no significant side effects were noted. Ten patients received continuous epoprostenol (range, 8 days-30 months). Acute changes in PVR (-34% +/- 18%), MPAP (-16% +/- 10%), and cardiac output (CO) (+21 +/- 18%), were statistically significant (P <.01). Long-term use of epoprostenol further lowered PVR (-47% +/- 12% from baseline and -31% +/- 22% from the acute change; P <.05) in the 6 patients restudied by right-heart catheterization. Death occurred in 6 of 10 (60%) of those receiving long-term epoprostenol. In moderate to severe portopulmonary hypertension, intravenous epoprostenol resulted in a significant improvement (both acute and long-term) in PVR, MPAP, and CO. Potential adverse effects on portal hypertension and implications for orthotopic liver transplantation (OLT), however, require further study.

Pulmonary hypertension in patients with myelofibrosis secondary to myeloproliferative diseases

We examined the clinical characteristics of six patients with myelofibrosis secondary to myeloproliferative diseases whose clinical courses were complicated by pulmonary hypertension to determine possible causal links between the two disorders. Six patients (four male, two female), with diagnoses of myeloproliferative disease, myelofibrosis (one with polycythemia vera, three with agnogenic myeloid metaplasia, one with unclassified myeloproliferative syndrome, one with essential thrombocytosis), and pulmonary hypertension are presented. Measurement of the pulmonary artery pressure was performed by Doppler echocardiography in all patients and by right sided heart catheterization in four patients. The range of resting pulmonary artery systolic pressure was 35 to 47 mmHg above the mean right atrium by echocardiography. One patient had autopsy evidence of pulmonary myeloid metaplasia and interstitial fibrosis; another had acute leukemic infiltration of the lung parenchyma. All patients had thrombocytosis; symptomatology in one patient with marked thrombocytosis improved with plateletpheresis. Two patients suffered systemic thrombosis. All patients had severe hepatomegaly. Two patients had evidence of left ventricular dysfunction. The interval between the development of dyspnea and death was less than seven months in five of the patients. A causal link between pulmonary hypertension and myelofibrosis secondary to myeloproliferative diseases is suggested for each patient. Hematopoietic infiltration of the pulmonary parenchyma, portal hypertension, thrombocytosis, hypercoagulability, and left ventricular failure may account in part for the development of pulmonary hypertension in these patients. Patients with myelofibrosis and dyspnea should have Doppler echocardiography to evaluate pulmonary artery pressures.

Pulmonary vascular morphological changes in cirrhotic patients undergoing liver transplantation

Cirrhosis and portal hypertension may be associated with pulmonary hypertension and pulmonary dysfunction. However, morphological pulmonary vascular lesions in patients with cirrhosis have not been well characterized morphometrically. We morphometrically evaluated pulmonary vessels in liver transplant recipients with pretransplantation cirrhosis and correlated our findings with pretransplantation cardiopulmonary function, postoperative course, and postmortem cardiopulmonary findings. Autopsy lung slides from 23 transplant recipients with pretransplantation cirrhosis were examined. External vessel diameter, intimal thickness, and arterial medial thickness were measured with a micrometer after pentachrome staining. The percent of total diameter comprised by intima or media was calculated for each vessel. Medical records were reviewed for smoking history, pretransplantation cardiopulmonary function testing, and postoperative course. Autopsy cases without liver or significant cardiopulmonary diseases, matched for age, sex, and smoking history, served as controls. Transplant recipients had significantly more pulmonary venous intimal thickening than matched controls (P <.0001). Sixty-five percent (15 of 23) of these patients had some degree of pretransplantation pulmonary dysfunction, defined by abnormalities in pulmonary function tests, oxygen saturation, and/or increased pulmonary artery pressures. However, the severity of venous intimal thickening did not correlate with the severity of pretransplantation pulmonary dysfunction. Arterial intimal and medial thickness were not statistically significantly different from controls. Pulmonary venous intimal thickening and resultant luminal impingement are morphological findings not previously described in this population. The arterial lesion, when present, is similar to that seen in pulmonary hypertension from other causes. These pulmonary vascular lesions may be implicated in pulmonary dysfunction in patients with cirrhosis and may be associated with increased posttransplantation cardiopulmonary morbidity and mortality.

Early liver transplantation is crucial in children with liver disease and pulmonary artery hypertension

BACKGROUND/AIMS

Early liver transplantation is crucial in children with liver disease and pulmonary artery hypertension. Some severe pulmonary vascular anomalies associated with portal hypertension disappear after isolated liver transplantation. Evolution of pulmonary artery hypertension due to plexogenic arteriopathy is controversial, as this association is still considered a contraindication to isolated liver transplantation. Outcome of pulmonary hypertension after isolated liver transplantation is reported in three patients with portal hypertension.

METHODS

After echocardiographic diagnosis, the patients had a complete hemodynamic exploration, and two had a lung biopsy. After liver transplantation, the survivors had echocardiographic follow up and a second hemodynamic exploration.

RESULTS

In two children, pulmonary pressures and resistances returned to near-normal values 1 and 6 years after successful isolated liver transplantation. The third patient, with the most severe arteriopathy, had to wait 1 year for a donor, and the attempted transplantation was complicated by ventricular tachycardia; death occurred 2 days after surgery.

CONCLUSIONS

Liver transplantation can reverse pulmonary artery hypertension due to high pulmonary resistances complicating liver disease with portal hypertension, provided it is carried out at an early stage. Early detection of pulmonary hypertension by systematic echocardiography may thus be crucial in these children with portal hypertension.

Human immunodeficiency virus infection and pulmonary hypertension: two new cases and a review of 86 reported cases

In this article, we describe pulmonary hypertension in two men (31 and 43 years of age) with human immunodeficiency virus (HIV) infection who were examined at Mayo Clinic Rochester. Among 88 reported cases (including the two current ones) of HIV- or acquired immunodeficiency syndrome (AIDS)-associated pulmonary hypertension, 61% were male; the age range was 2 to 56 years (mean, 32). Dyspnea was the usual initial symptom. Of the 74 patients in whom pulmonary artery pressure was recorded or calculated by echocardiography, systolic pressures ranged from 49 to 118 mm Hg (mean, 68). Of the 33 cases in which lung tissue was evaluated microscopically, 28 (85%) were of the plexogenic variant of pulmonary arterial hypertension. Of the other five cases examined histologically, three consisted of thrombotic pulmonary arteriopathy (one was due to recurrent thromboembolism, and the other two were due to in situ thrombosis), and two were of pulmonary venoocclusive disease. No correlation existed between either CD4 counts or a history of pulmonary infections and the development of pulmonary hypertension. In 15 of the 88 patients (17%), confounding factors for hypertensive pulmonary vascular disease were present, including coexisting liver disease in 13 and coagulation abnormalities in 2. In 83% of the patients, the development of pulmonary hypertension seems to have been related primarily to the chronic HIV infection. Pulmonary hypertension was more rapidly progressive in patients with HIV or AIDS than in those with primary pulmonary hypertension; the reported time intervals between onset of symptoms and diagnosis were 6 months and 30 months, respectively. The 1-year survival rate for patients with HIV and pulmonary hypertension was 51%, based on the follow-up data compiled from the 63 patients in whom it was described; this compares with a 1-year survival rate of 68% for patients with primary pulmonary hypertension. Death was considered a direct consequence of pulmonary hypertension in 29 (76%) of the 38 fatal cases.

Asymptomatic primary pulmonary hypertension associated with liver cirrhosis

We report a case of asymptomatic primary pulmonary hypertension associated with liver cirrhosis (type B) and portal hypertension found by chance during a preoperative Swan-Gantz catheterization study. Our experience suggests that the actual prevalence of primary pulmonary hypertension associated with liver cirrhosis may be greater than that previously reported. During the follow-up of liver cirrhosis with portal hypertension, we should consider primary pulmonary hypertension, even if the patient is free of symptoms, and a chest X-ray check may be necessary.

Pulmonary hypertension: considerations in the liver transplant candidate

Pulmonary hypertension is a potentially lethal complication of end-stage liver disease with a prevalence of 2%. In the setting of liver transplantation, the prevalence may be as high as 12%. Given the potential importance of this syndrome to the transplantation community, the purpose of this review is to summarize the current state of understanding of portopulmonary hypertension and to suggest potential management strategies for (1) liver transplant candidates with suspected pulmonary hypertension and (2) intraoperative pulmonary hypertension following liver allograft reperfusion.

Frequency and clinical implications of increased pulmonary artery pressures in liver transplant patients

OBJECTIVE

To characterize the pulmonary hemodynamics and identify predictors of pulmonary hypertension in a group of patients before liver transplantation and to determine whether pulmonary hypertension in these patients is related to survival.

MATERIAL AND METHODS

In 362 patients before their first liver transplantation (between 1985 and 1993), the clinical history, laboratory data, and results of pulmonary function tests were recorded. Pulmonary artery (PA) catheterization was performed after induction of anesthesia at the time of transplantation. Monthly follow-up was maintained.

RESULTS

A hyperdynamic circulation was often present -- an increased mean cardiac output (7.6 L/min), increased mean PA pressure (20.9 mm Hg), correlation of mean PA pressure with cardiac output (r = 0.25; P<0.001), and decreased mean pulmonary vascular resistance (60 dynes times s/cm5). Mean PA pressures were more than 25 mm Hg in 72 patients (20%). Pulmonary hypertension (defined as mean PA pressure of more than 25 mm Hg and pulmonary vascular resistance in excess of 120 dynes times s/cm5) occurred in 15 patients (4%). Pulmonary function tests revealed obstruction in 7%, restriction in 18%, and low diffusing capacity in 46%. By univariate analysis, lower forced expiratory volume in 1 second, forced vital capacity, and total lung capacity were the only preoperative factors associated with pulmonary hypertension (P<0.05). Survival was significantly lower in patients with acute fulminant hepatitis (P<0.001), the group with the highest mean PA pressure, than in those with other diagnoses. Increased PA pressures or mild to moderate pulmonary hypertension was not found to be associated with a worse survival by univariate or multivariate analysis.

CONCLUSION

Increased PA pressure is common in liver transplant patients (20%). "True" pulmonary hypertension occurred in only 4% of our patients and was not associated with an adverse outcome.

Hepatopulmonary syndrome. A pulmonary vascular complication of liver disease

Hepatopulmonary syndrome is part of the spectrum of pulmonary vascular disorders seen in advanced liver disease. The pathophysiology of these entities likely is dependent on the degree of pulmonary vasoconstriction or vasodilation that occurs. Our understanding of hepatopulmonary syndrome has helped further our knowledge of the interaction of the liver and the lung. Advances in the management of this disorder, especially liver transplantation, finally have allowed us to offer some hope to patients with this disease.

Pulmonary complications of liver transplantation

The preoperative pulmonary evaluation of organ transplant candidates involves the diagnosis of unexplained pulmonary infiltrates or symptoms, interpretation of pulmonary function abnormalities, and an assessment of surgical risk. Pretransplant pulmonary considerations in patients with end-stage hepatic diseases relate primarily to hypoxemia from poorly understood intrapulmonary vascular dilatations, mechanical dysfunction, and states of increased extravascular lung water. Except in severe cases, however, these generally do not prohibit liver transplantation, and even are likely to improve after transplant surgery. Early postoperative complications may be categorized as those expected from extensive intra-abdominal surgery that requires significant volume resuscitation, which typically are managed in the usual manner for those clinical situations. As immunosuppression begins to have an effect, the LTx recipient becomes susceptible to the same opportunistic infectious organisms (with their frequent pulmonary involvement) that cause significant morbidity and mortality in recipients of other solid organ transplants. Because many of the immunosuppressive agents also are the same, noninfectious side effects such as pulmonary edema and malignancy also are similar. As with all immunocompromised patients, prophylaxis, when possible, persistent infection surveillance, and an aggressive diagnostic and therapeutic approach help decrease the impact of pulmonary dysfunction in LTx recipients.

Pulmonary hypertension: considerations in the liver transplant candidate

Pulmonary hypertension is a potentially lethal complication of end-stage liver disease with a prevalence of 2%. In the setting of liver transplantation, the prevalence may be as high as 12%. Given the potential importance of this syndrome to the transplantation community, the purpose of this review is to summarize the current state of understanding of portopulmonary hypertension and to suggest potential management strategies for (1) liver transplant candidates with suspected pulmonary hypertension and (2) intraoperative pulmonary hypertension following liver allograft reperfusion.

Pulmonary hypertension in chronic liver disease

Pulmonary hypertension develops in approximately 2% of patients with portal hypertension. Diagnosis is often difficult and requires a high degree of clinical suspicion. Treatment of patients with portal and pulmonary hypertension is limited, and mean survival following diagnosis is approximately 15 months. The effect of liver transplantation on the natural history of disease is discussed.

Magnetic resonance imaging-derived parameter of portal flow predicts volume-mediated pulmonary hypertension in liver transplantation candidates

BACKGROUND

Pulmonary hypertension is a source of perioperative mortality after orthotopic liver transplantation (OLT). The purpose of this study is to (1) characterize the pulmonary hemodynamic response in OLT candidates, and (2) determine whether portal flow index (PFI), a magnetic resonance imaging (MRI)-derived parameter, is a useful predictor of the pulmonary hemodynamic response.

METHODS

Twenty-five consecutive OLT candidates underwent right heart catheterization with pressure measurements at baseline and after infusion of 1 L of crystalloid. MRI, chest roentgenography, electrocardiography, and echocardiography were also performed as routine screening techniques. Sixteen patients in intensive care unit with normal liver function served as controls.

RESULTS

After volume infusion, pulmonary hypertension (mean pulmonary artery pressure greater than 25 mm Hg) developed in 9 of 25 OLT candidates with elevations in both pulmonary capillary wedge and mean pulmonary pressures. In contrast, 0 of 16 controls experienced pulmonary hypertension (p < 0.01). Although routine modalities did not predict this hemodynamic response, PFI had a 94% specificity and 78% sensitivity.

CONCLUSIONS

OLT candidates exhibit volume-induced pulmonary hypertension with responses suggestive of left ventricular dysfunction. The significance of this observation is unknown, but the MRI-derived parameter, PFI, may serve as a screening technique to limit catheterization to a select group of OLT candidates.

Primary plexogenic pulmonary hypertension shows imperfect formation of the internal elastic lamina of the pulmonary arteries

Lung tissue from subjects dying from primary plexogenic pulmonary hypertension (PPH) has shown defects of elastin formation of the lung arteries. Lung vessels from 5 cases of PPH were compared with those of 9 age-matched normal subjects, and 24 individuals having secondary pulmonary hypertension (2 degrees PH). PPH cases and those with 2 degrees PH due to congenital heart disease with left-to-right shunts (2 degrees PH, LRS), showed active proliferation of medial smooth muscle cells (SMC) through defects of the internal elastic lamina (IEL) into the arterial lumen to form typical plexiform lesions. Larger arteries showed accelerated intimal thickening similar to normal aging. Plexiform lesions were not seen in normal subjects or in those developing high pulmonary pressures later in life. The observations showed that the development of discontinuities of the IEL of the pulmonary arteries and intimal thickening is accelerated in normal subjects by high pulmonary artery pressure, especially when this is established at a very young age. They suggest that such discontinuities occur in PPH due to inherent abnormality of the elastin of the arterial walls, with advanced early proliferation of medial SMC and obstruction of the pulmonary arterial circulation.