Michael B. Fallon

Hepatopulmonary syndrome and portopulmonary hypertension: a report of the multicenter liver transplant database.

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PortoPH) are pulmonary vascular consequences of advanced liver disease associated with significant mortality after orthotopic liver transplantation (OLT). Data from 10 liver transplant centers were collected from 1996 to 2001 that characterized the outcome of patients with either HPS (n = 40) or PortoPH (n = 66) referred for OLT. Key variables (PaO2 for HPS, mean pulmonary artery pressure [MPAP], pulmonary vascular resistance [PVR], and cardiac output [CO] for PortoPH) were analyzed with respect to 3 definitive outcomes (those denied OLT, transplant hospitalization survivors, and transplant hospitalization nonsurvivors). OLT was denied in 8 of 40 patients (20%) with HPS and 30 of 66 patients (45%) with PortoPH. Patients with HPS who were denied OLT had significantly worse PaO2 compared with patients who underwent transplantation (47 vs. 52 mm Hg, P < .005). Transplant hospitalization survival was associated with higher pre‐OLT PaO2 (55 vs. 37 mm Hg; P < .005). MPAP was significantly higher (53 vs. 45 mm Hg; P < .015) and PVR was significantly worse (614 vs. 335 dynes · s · cm−5; P < .05) in patients with PortoPH who were denied OLT compared with patients who underwent transplantation. Transplant hospitalization mortality was 16% (5/32) in patients with HPS and 36% (13/36) in patients with PortoPH. All of the deaths in patients with PortoPH occurred within 18 days of OLT; 5 of the 13 deaths in patients with PortoPH occurred intraoperatively. We concluded that patients with HPS (based on a combination of low PaO2 and nonpulmonary factors) and patients with PortoPH (based on pulmonary hemodynamics) were frequently denied OLT because of pre‐OLT test results and comorbidities. For patients who subsequently underwent OLT, transplant hospitalization mortality remained significant for both those with HPS (16%) and PortoPH (36%). (Liver Transpl 2004;182:10.)

Diagnostic utility of contrast echocardiography and lung perfusion scan in patients with hepatopulmonary syndrome

BACKGROUND & AIMS Two modalities, contrast echocardiography and lung perfusion scan, are used to identify intrapulmonary vascular dilatation and diagnose hepatopulmonary syndrome (HPS), but a comparison of these two procedures has not been performed. The aim of this study was to compare the use of these diagnostic modalities in detecting intrapulmonary vascular dilatation and diagnosing HPS. METHODS Forty consecutive outpatients with biopsy-proven cirrhosis had contrast echocardiography, a lung perfusion scan, and arterial blood gases analyzed. RESULTS Fifteen of 40 cirrhotics (38%) had positive contrast echocardiogram results. Seven patients with positive echocardiogram results had gas exchange abnormalities and could be considered to have HPS (7 of 40 [17.5%]). Three of these patients were hypoxemic and had no concurrent cardiopulmonary disease, and each had positive contrast echocardiogram and lung perfusion scan results and were readily diagnosed as having HPS. The other 4 patients (3 hypoxemic and 1 normoxemic with an elevated alveolar-arterial gradient) had coexisting intrinsic lung disease and/or chest radiograph abnormalities complicating the diagnosis of HPS, and each had positive echocardiogram and negative lung scan results. The remaining 8 patients with positive echocardiogram results had normal lung scan and normal gas exchange results. No patient had positive lung scan and negative contrast echocardiogram results. CONCLUSIONS Contrast echocardiography is the most useful screening test for intrapulmonary vasodilatation and may be positive more frequently than lung perfusion scans in patients with HPS.

Evaluation for liver transplantation in adults: 2013 practice guideline by the American Association for the Study of Liver Diseases and the American Society of Transplantation

Guidelines on Evaluation for Liver Transplantation (LT) were published in 2005 by the American Association for the Study of Liver Diseases (AASLD). In the interim there have been major advances in the management of chronic liver disease, most notably in antiviral therapy for chronic viral hepatitis. Nonalcoholic fatty liver disease (NAFLD) has assumed increasing prominence as a cause of cirrhosis and hepatocellular carcinoma (HCC) requiring liver transplant. Furthermore, individual disease indications for LT such as HCC have been refined and specific guidelines have appeared for chronic viral hepatitis. Reflecting the need for a multidisciplinary approach to the evaluation of this complex group of patients who have the comorbidities typical of middle age, recommendations have been developed to assist in their cardiac management. With an increasing number of long-term survivors of LT there has been a greater focus on quality of life and attention to comorbid conditions impacting recipient longevity. The purpose of the current Guidelines is to provide an evidence-based set of recommendations for the evaluation of adult patients who are potentially candidates for LT. These recommendations provide a data-supported approach. They are based on the following: (1) formal review and analysis of the recently published world literature on the topic; (2) guideline policies covered by the AASLDPolicy on Development and Use of Practice Guidelines; and (3) the experience of the authors in the specified topic. Intended for use by physicians, these recommendations suggest preferred approaches to the diagnostic, therapeutic and preventive aspects of care. They are intended to be flexible, in contrast to standards of care, which are inflexible policies to be followed in every case. Specific recommendations are based on relevant published information. To more fully characterize the available evidence supporting the recommendations, the AASLD Practice Guidelines Committee has adopted the classification used by the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) workgroup with minor modifications (Table 1). The classifications and recommendations are based on three categories: the source of evidence in levels I through III; the quality of evidence designated by high (A), moderate (B), or low quality (C); and the strength of recommendations classified as strong or weak.*

Inhaled NO accelerates restoration of liver function in adults following orthotopic liver transplantation

Ischemia/reperfusion (IR) injury in transplanted livers contributes to organ dysfunction and failure and is characterized in part by loss of NO bioavailability. Inhalation of NO is nontoxic and at high concentrations (80 ppm) inhibits IR injury in extrapulmonary tissues. In this prospective, blinded, placebo-controlled study, we evaluated the hypothesis that administration of inhaled NO (iNO; 80 ppm) to patients undergoing orthotopic liver transplantation inhibits hepatic IR injury, resulting in improved liver function. Patients were randomized to receive either placebo or iNO (n = 10 per group) during the operative period only. When results were adjusted for cold ischemia time and sex, iNO significantly decreased hospital length of stay, and evaluation of serum transaminases (alanine transaminase, aspartate aminotransferase) and coagulation times (prothrombin time, partial thromboplastin time) indicated that iNO improved the rate at which liver function was restored after transplantation. iNO did not significantly affect changes in inflammatory markers in liver tissue 1 hour after reperfusion but significantly lowered hepatocyte apoptosis. Evaluation of circulating NO metabolites indicated that the most likely candidate transducer of extrapulmonary effects of iNO was nitrite. In summary, this study supports the clinical use of iNO as an extrapulmonary therapeutic to improve organ function following transplantation.

Use of macroaggregated albumin lung perfusion scan to diagnose hepatopulmonary syndrome: A new approach

BACKGROUND & AIMS We have reported that contrast echocardiography is a sensitive screening test for the hepatopulmonary syndrome (HPS). However, contrast echocardiography lacks specificity because many cirrhotic patients have positive study results with normal arterial blood gases and therefore do not fulfill criteria for HPS. The aim of this study was to assess the role of macroaggregated albumin lung perfusion scans (MAA scans) in the diagnosis of HPS. METHODS MAA scans were performed in 25 patients with HPS, 25 cirrhotic patients without HPS, and 15 hypoxemic subjects with intrinsic lung disease alone. An MAA shunt fraction was calculated from brain and lung counts. RESULTS MAA scan results were positive in 21 of 25 patients with HPS and negative in all controls. All 21 patients with positive MAA scans had PO2 values of <60 mm Hg. There was a strong inverse correlation between the degree of the MAA shunt fraction and arterial hypoxemia (r = -0.726). CONCLUSIONS A positive MAA scan result in cirrhosis is specific for the presence of moderate to severe HPS. We speculate that MAA scans may be particularly useful in evaluating the contribution of HPS to the hypoxemia in cirrhotic patients with intrinsic lung disease.

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 · second · cm−5, and pulmonary capillary wedge pressure ≤ 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. (HEPATOLOGY 2008.)

Impact of Hepatopulmonary Syndrome on Quality of Life and Survival in Liver Transplant Candidates

BACKGROUND & AIMS Hepatopulmonary syndrome (HPS) affects 10%-30% of patients with cirrhosis and portal hypertension, but the impact on functional status, quality of life, and survival is poorly defined. We assessed the impact of HPS in patients evaluated for liver transplantation. METHODS We performed a prospective multicenter cohort study of patients being evaluated for liver transplantation in 7 academic centers in the United States. Patients with HPS (defined as an increased alveolar-arterial oxygen gradient with intrapulmonary vasodilation) were compared with those without HPS in terms of demographics and clinical variables. New York Heart Association functional class, quality of life, and survival were assessed. RESULTS Seventy-two patients with HPS and 146 patients without HPS were compared. There were no differences in age, sex, or etiology or severity of liver disease between the groups; however, patients with HPS were less likely to have a history of smoking (P = .03). Patients with HPS had worse New York Heart Association functional class (P = .005) and had significantly worse quality of life in certain domains compared with patients without HPS. In addition, patients with HPS also had a significantly increased risk of death compared with patients without HPS despite adjustment for age, sex, race/ethnicity, Model for End-Stage Liver Disease score, and liver transplantation (adjusted hazard ratio = 2.41; 95% confidence interval, 1.31-4.41; P = .005). CONCLUSIONS HPS was associated with a significant increase in risk of death as well as worse functional status and quality of life in patients evaluated for liver transplantation.

Survival in infection-related acute-on-chronic liver failure is defined by extrahepatic organ failures

Infections worsen survival in cirrhosis; however, simple predictors of survival in infection‐related acute‐on‐chronic liver failure (I‐ACLF) derived from multicenter studies are required in order to improve prognostication and resource allocation. Using the North American Consortium for Study of End‐stage Liver Disease (NACSELD) database, data from 18 centers were collected for survival analysis of prospectively enrolled cirrhosis patients hospitalized with an infection. We defined organ failures as 1) shock, 2) grade III/IV hepatic encephalopathy (HE), 3) need for dialysis and mechanical ventilation. Determinants of survival with these organ failures were analyzed. In all, 507 patients were included (55 years, 52% hepatitis C virus [HCV], 15.8% nosocomial infection, 96% Child score ≥7) and 30‐day evaluations were available in 453 patients. Urinary tract infection (UTI) (28.5%), and spontaneous bacterial peritonitis (SBP) (22.5%) were the most prevalent infections. During hospitalization, 55.7% developed HE, 17.6% shock, 15.1% required renal replacement, and 15.8% needed ventilation; 23% died within 30 days and 21.6% developed second infections. Admitted patients developed none (38.4%), one (37.3%), two (10.4%), three (10%), or four (4%) organ failures. The 30‐day survival worsened with a higher number of extrahepatic organ failures, none (92%), one (72.6%), two (51.3%), three (36%), and all four (23%). I‐ACLF was defined as ≥2 organ failures given the significant change in survival probability associated at this cutoff. Baseline independent predictors for development of ACLF were nosocomial infections, Model for Endstage Liver Disease (MELD) score, low mean arterial pressure (MAP), and non‐SBP infections. Independent predictors of poor 30‐day survival were I‐ACLF, second infections, and admission values of high MELD, low MAP, high white blood count, and low albumin. Conclusion: Using multicenter study data in hospitalized decompensated infected cirrhosis patients, I‐ACLF defined by the presence of two or more organ failures using simple definitions is predictive of poor survival. (Hepatology 2014;60:250–256)

New Consensus Definition of Acute Kidney Injury Accurately Predicts 30-Day Mortality in Patients With Cirrhosis and Infection

BACKGROUND & AIMS Participants at a consensus conference proposed defining cirrhosis-associated acute kidney injury (AKI) based on a >50% increase in serum creatinine level from the stable baseline value in <6 months or an increase of ≥ 0.3 mg/dL in <48 hours. We performed a prospective study to evaluate the ability of these criteria to predict mortality within 30 days of hospitalization among patients with cirrhosis and infection. METHODS We followed up 337 patients with cirrhosis who were admitted to the hospital with an infection or developed an infection during hospitalization (56% men; 56 ± 10 years of age; Model for End-Stage Liver Disease [MELD] score, 20 ± 8) at 12 centers in North America. We compared data on 30-day mortality, length of stay in the hospital, and organ failure between patients with and without AKI. RESULTS In total, based on the consensus criteria, 166 patients (49%) developed AKI during hospitalization. Patients who developed AKI were admitted with higher Child-Pugh scores than those who did not develop AKI (11.0 ± 2.1 vs 9.6 ± 2.1; P < .0001) as well as higher MELD scores (23 ± 8 vs 17 ± 7; P < .0001) and lower mean arterial pressure (81 ± 16 vs 85 ± 15 mm Hg; P < .01). Higher percentages of patients with AKI died within 30 days of hospitalization (34% vs 7%), were transferred to the intensive care unit (46% vs 20%), required ventilation (27% vs 6%), or went into shock (31% vs 8%); patients with AKI also had longer stays in the hospital (17.8 ± 19.8 vs 13.3 ± 31.8 days) (all P < .001). Of the AKI episodes, 56% were transient, 28% were persistent, and 16% resulted in dialysis. Mortality was higher among those without renal recovery (80%) compared with partial (40%) or complete recovery (15%) or those who did not develop AKI (7%; P < .0001). CONCLUSIONS Among patients with cirrhosis, 30-day mortality is 10-fold higher among those with irreversible AKI than those without AKI. The consensus definition of AKI accurately predicts 30-day mortality, length of hospital stay, and organ failure.

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.