Registry and Survival Study in Chinese Patients With Idiopathic and Familial Pulmonary Arterial Hypertension

Diagnostic delay in pulmonary arterial hypertension: Insights from the Australian and New Zealand pulmonary hypertension registry

BACKGROUND AND OBJECTIVE

Early diagnosis of PAH is clinically challenging. Patterns of diagnostic delay in Australian and New Zealand PAH populations have not been explored in large-scale studies. We aimed to evaluate the magnitude, risk factors and survival impact of diagnostic delay in Australian and New Zealand PAH patients.

METHODS

A cohort study of PAH patients from the PHSANZ Registry diagnosed from 2004 to 2017 was performed. Diagnostic interval was the time from symptom onset to diagnostic right heart catheterization as recorded in the registry. Factors associated with diagnostic delay were analysed in a multivariate logistic regression model. Survival rates were compared across patients based on the time to diagnosis using Kaplan-Meier method and Cox regression.

RESULTS

A total of 2044 patients were included in analysis. At diagnosis, median age was 58 years (IQR: 43-69), female-to-male ratio was 2.8:1 and majority of patients were in NYHA FC III-IV (82%). Median diagnostic interval was 1.2 years (IQR: 0.6-2.7). Age, CHD-PAH, obstructive sleep apnoea and peripheral vascular disease were independently associated with diagnostic interval of ≥1 year. No improvement in diagnostic interval was seen during the study period. Longer diagnostic interval was associated with decreased 5-year survival.

CONCLUSION

PAH patients experience significant diagnostic interval, which has not improved despite increased community awareness. Age, cardiovascular and respiratory comorbidities are significantly associated with longer time to diagnosis. Mortality rates appear higher in patients who experience longer diagnostic interval.

Sex hormone exposure and reproductive factors in pulmonary arterial hypertension: a case-control study

Pulmonary arterial hypertension (PAH) is a sexually dimorphic disease that for unknown reasons affects women more than men. The role of estrogens, both endogenous and exogenous, and reproductive factors in this female susceptibility is still poorly understood. It has been strongly suggested that sex hormones may influence the development and progression of the disease. We sought to determine whether sex hormone exposures and reproductive factors associate with PAH patients compared to control subjects, using a questionnaire and interview to obtain information regarding these potential risk factors. We conducted a single-center unmatched case-control study. Six hundred and thirty-four women and men with PAH, as well as 27 subjects with BMPR2 mutations but no PAH and 132 healthy population controls were enrolled from the Vanderbilt Pulmonary Hypertension Research Cohort and researchmatch.org. Questionnaires and nurse-led interviews were conducted to obtain information regarding sex hormone exposures and reproductive factors. Additional history was obtained on enrolled patients including disease severity variables and comorbidities. Responses to the questionnaires were analyzed to describe these exposures in this population as well as assess the association between disease severity variables and sex hormone exposures. Reproductive and endogenous factors that determine lifelong estrogen exposure were similar between PAH cases and controls. Patients with associated PAH were significantly more likely to be postmenopausal compared to controls. There were similar rates of "ever-use" and duration of use of oral contraceptive pills and hormone replacement therapy in patients when compared to controls. Disease severity variables were not significantly affected by any exposure after adjusting for PAH sub-group. In contrast to our hypothesis, that a greater exposure to exogenous sources of female sex hormones associates with PAH case status, we found similar rates of endogenous and exogenous sex hormone exposure between PAH patients and unmatched controls.

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

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

Pulmonary arterial hypertension: the case for a bioelectronic treatment

Pulmonary arterial hypertension (PAH) is a rare disease of unknown etiology that progresses to right ventricular failure. It has a complex pathophysiology, which involves an imbalance between vasoconstrictive and vasodilative processes in the pulmonary circulation, pulmonary vasoconstriction, vascular and right ventricular remodeling, systemic inflammation, and autonomic imbalance, with a reduced parasympathetic and increased sympathetic tone. Current pharmacological treatments for PAH include several classes of drugs that target signaling pathways in vascular biology and cardiovascular physiology, but they can have severe unwanted effects and they do not typically stop the progression of the disease. Pulmonary artery denervation has been tested clinically as a method to suppress sympathetic overactivation, however it is a nonspecific and irreversible intervention. Bioelectronic medicine, in particular vagus nerve stimulation (VNS), has been used in cardiovascular disorders like arrhythmias, heart failure and arterial hypertension and could, in principle, be tested as a treatment in PAH. VNS can produce pulmonary vasodilation and renormalize right ventricular function, via activation of pulmonary and cardiac vagal fibers. It can suppress systemic inflammation, via activation of fibers that innervate the spleen. Finally, VNS can gradually restore the balance between parasympathetic and sympathetic tone by regulating autonomic reflexes. Preclinical studies support the feasibility of using VNS in PAH. However, there are challenges with such an approach, arising from the need to affect a relatively small number of relevant vagal fibers, and the potential for unwanted cardiac and noncardiac effects of VNS in this sensitive patient population.

Management of pulmonary arterial hypertension in patients aged over 65 years

Historically, pulmonary arterial hypertension (PAH) has been considered a disease of young adults, but over the last three decades, the average age at diagnosis has increased, presenting clinicians with some unique challenges. Clinical symptoms of PAH, including shortness of breath and reduced functional capacity, are not specific for the disease and may be present in older patients because of their age or as a result of comorbid conditions. Eliminating other causes for these symptoms can delay PAH diagnosis and initiation of PAH-specific treatment compared with younger patients. Currently, there are no specific guidelines relating to PAH in older patients and existing guidelines for identifying patients at potential risk of PAH may not be appropriate for patients aged over 65 years. Even though older patients tend to be diagnosed with more advanced symptoms, and evidence suggests that they are less responsive to PAH-specific therapies, treatment is often less aggressive than in younger patients. Even after adjusting for age, survival rates remain disproportionately lower in the older vs. younger PAH populations. Specific guidelines for diagnosis and treatment of older patients with PAH are needed to improve care and outcomes in this growing population. This review aims to assess the challenges associated with diagnosing and managing PAH in older patients, based on literature searches, authors' experiences, and expert opinions.

Linking lncRNAs to regulation, pathogenesis, and diagnosis of pulmonary hypertension

Pulmonary hypertension (PH) is a syndrome characterized by a persistent increase in pulmonary vascular resistance. Due to the lack of specificity in clinical manifestations, patients are usually diagnosed at the late stage of PH, which is hard to treat and often causes right heart failure and death. Furthermore, the regulation and pathogenesis of PH remain obscure. Recently, long noncoding RNAs (lncRNAs), a type of transcript longer than 200 nt that lacks protein-coding ability, have been found to substantially influence the incidence and progression of various diseases through regulating gene expression at the chromatin, transcriptional, post-transcriptional, translational, and even post-translational levels. The crucial roles of lncRNAs in PH have started to draw widespread attention. This review summarizes the regulatory, pathogenic, and diagnostic roles of lncRNAs in PH, in the hope to facilitate the search for early diagnostic markers of and effective therapeutic targets for this devastating disease.

A Nationwide multicenter registry and biobank program for deep phenotyping of idiopathic and hereditary pulmonary arterial hypertension in Korea: the PAH platform for deep phenotyping in Korean subjects (PHOENIKS) cohort

Background

Pulmonary arterial hypertension (PAH) is a progressive, chronic disease without curative treatment. Large registry data of these patient populations have been published, although, phenotypic variants within each subtype of PAH have not been elucidated. As interest towards personalized medicine grows, the need for a PAH cohort with a comprehensive understanding of patient phenotypes through multiomics approaches, called deep phenotyping, is on the rise. The PAH Platform for Deep Phenotyping in Korean Subjects (PHOENIKS) cohort is designed to collect clinical data as well as biological specimens for deep phenotyping in patients with idiopathic PAH (IPAH) and heritable PAH (HPAH) in Korea.

Methods

A total of 17 regional hospitals are currently working on enrolling up to 100 consecutive IPAH/HPAH patients for obtaining clinical data and biological specimens across Korea. The diagnosis of PAH is based on right heart catheterization. All clinical data is stored in a government-based online database. Each participating hospitals collect a whole blood sample from each patient, through which DNA, RNA, serum, plasma, and peripheral blood mononuclear cells will be extracted from the buffy coat layer for further multiomics analysis.

Results

Not applicable.

Conclusions

The PHOENIKS cohort is enrolling IPAH and HPAH patients across Korea to determine the prognosis and drug response in different phenotypic variant. The data generated by this cohort are expected to open new doors for personalized medicine in PAH patients of South Korea.

Trial registration

ClinicalTrials.gov NCT03933579. Registered on May 1st, 2019.

Cardioprotection Induced by Activation of GPER in Ovariectomized Rats With Pulmonary Hypertension

Pulmonary hypertension (PH) is a disease of women (female-to-male ratio 4:1), and is associated with cardiac and skeletal muscle dysfunction. Herein, the activation of a new estrogen receptor (GPER) by the agonist G1 was evaluated in oophorectomized rats with monocrotaline (MCT)-induced PH. Depletion of estrogen was induced by bilateral oophorectomy (OVX) in Wistar rats. Experimental groups included SHAM or OVX rats that received a single intraperitoneal injection of MCT (60 mg/kg) for PH induction. Animals received s.c. injection of either vehicle or G1, a GPER agonist, (400 µg/kg/day) for 14 days after the onset of disease. Rats with PH exhibited exercise intolerance and cardiopulmonary alterations, including reduced pulmonary artery flow, biventricular remodeling, and left ventricular systolic and diastolic dysfunction. The magnitude of these PH-induced changes was significantly greater in OVX versus SHAM rats. G1 treatment reversed both cardiac and skeletal muscle functional aberrations caused by PH in OVX rats. G1 reversed PH-related cardiopulmonary dysfunction and exercise intolerance in female rats, a finding that may have important implications for the ongoing clinical evaluation of new drugs for the treatment of the disease in females after the loss of endogenous estrogens.

The global view

PURPOSE OF REVIEW

To understand the global distribution of different forms of pulmonary hypertension.

RECENT FINDINGS

Different registries have explored the epidemiological characteristics of pulmonary hypertension. Interestingly, there is a clear difference in the prevalence of different forms of pulmonary hypertension in developed regions in comparison with less developed countries. This finding suggests not only that extrapolation of data should be avoided but also that the known prevalence of pulmonary hypertension might be underestimated.

SUMMARY

Pulmonary hypertension might be more prevalent than what is currently believed. Specific forms of pulmonary hypertension distributed worldwide might characterize an unrecognized burden that still have to be properly approached. This highlights the heterogeneity of pulmonary hypertension around the world. It is clear that more epidemiological data are still needed as well as studies addressing management alternatives in these specific regions.

Increasing Incidence and Prevalence of World Health Organization Groups 1 to 4 Pulmonary Hypertension: A Population-Based Cohort Study in Ontario, Canada

BACKGROUND

The World Health Organization recognizes 5 groups of pulmonary hypertension (PH), categorized by pathogenesis or comorbidity: 1-pulmonary arterial hypertension 2-left-heart disease, 3-lung disease and hypoxia 4-chronic thromboembolic disease, and 5-miscellaneous. The epidemiology of PH, apart from group 1, is largely unknown.

METHODS AND RESULTS

We describe incidence, prevalence, comorbidities, mortality and prescribing patterns for groups 1 to 4 PH from 1993 to 2012. Case definitions are based on hospitalizations and emergency department visits, using the Institute for Clinical Evaluative Sciences data, which comprises linked databases of universal coverage health service records for Ontario residents. This cohort included 50 529 patients with PH. The annual incidence of adult PH increased from 2003 to 2012 from 24.1 to 28.7 cases/100 000 population and the annual prevalence from 1993 to 2012 from 99.8 to 127.3 cases/100 000 population, respectively. The most common form of adult PH was group 2, alone (34.2%) or combined with group 3 PH (29.3%). A diagnosis of PH increased the 1-year standardized mortality ratio 7.2-fold. Mortality in adults with PH was 13.0%, 36.4%, and 62.4%, at 30 days, 1 year, and 5 years, respectively. Mortality was highest in groups 2 and 3 and lowest in group 1. PH was present in only 3.6% of people with left heart disease, 0.7% with lung disease, and 1.4% with thromboembolic disease, suggesting that PH is a relatively rare complication of these common diseases. Children (age<16 years) accounted for 3.6% of the cohort. In children group 1 PH was most common (65.2%), and 5-year mortality was lower (21.4%) than in adults. Group 1-specific PH therapies were increasingly prescribed over time and paradoxically were often used in patients who seemed to have group 2, PH based on diagnostic codes indicating left heart disease.

CONCLUSIONS

The incidence and prevalence of adult PH are increasing. Groups 2 and 3 are the most common and lethal forms of PH. This study identifies an emerging epidemic of PH that likely has substantial adverse health and economic implications.

Current status of pulmonary arterial hypertension in Korea

Pulmonary arterial hypertension (PAH) is characterized by remodeling of the distal pulmonary arteries resulting in high pulmonary vascular resistance and, eventually, right ventricular heart failure. Although current advances in PAH therapy have improved outcomes, poor survival remains a reality worldwide, including Korea. One of the most important issues in PAH is the late diagnosis, since screening or diagnostic efforts are often overlooked due to the rarity of disease. Data from Korean registries and observational cohorts show that delayed detection leads to increased morbidity. Additionally, low percentages of Korean patients are committed to intensive PAH-targeted therapy. Current Korean health insurance policies' lack of coverage for new PAH-targeted drugs and upfront combination therapy may also hamper the improvement of treatment outcomes. Understanding individual variability in response to therapeutics through deep phenotyping is a novel strategy that should be considered when treating PAH. Overall, early detection of PAH by proactive screening together with early, intensive, individualized PAH therapy using deep phenotyping is crucial for improving prognoses for PAH patients in Korea.

Incidence and survival impact of pulmonary arterial hypertension among patients with systemic lupus erythematosus: a nationwide cohort study

Background

No population-based study has investigated the cumulative incidence of pulmonary arterial hypertension (PAH) in patients with newly diagnosed systemic lupus erythematosus (SLE) or the survival impact of PAH in this population.

Method

We used a nationwide database in Taiwan and enrolled incident SLE patients between January 1, 2000, and December 31, 2013. The cumulative incidence of PAH in the SLE patients and the survival of these patients were estimated by the Kaplan-Meier method. Potential predictors of the development of PAH were determined using a Cox proportional hazards regression model.

Results

Of 15,783 SLE patients, 336 (2.13%) developed PAH. The average interval from SLE diagnosis to PAH diagnosis was 3.66 years (standard deviation [SD] 3.36, range 0.1 to 13.0 years). Seventy percent of the patients developed PAH within 5 years after SLE onset. The 3- and 5-year cumulative incidence of PAH were 1.2% and 1.8%, respectively. Systemic hypertension was an independent predictor of PAH occurrence among the SLE patients (adjusted hazard ratio 2.27, 95% confidence interval 1.59–2.97). The 1-, 3-, and 5-year survival rates of SLE patients following the diagnosis of PAH were 87.7%, 76.8%, and 70.1%, respectively.

Conclusions

PAH is a rare complication of SLE and the majority of PAH cases occur within the first 5 years following SLE diagnosis. Systemic hypertension may be a risk factor for PAH development in the SLE population. The overall 5-year survival rate after PAH diagnosis was 70.1%.

Influence of riociguat treatment on pulmonary arterial hypertension : A meta-analysis of randomized controlled trials

BACKGROUND

Riociguat treatment might be beneficial for pulmonary arterial hypertension. However, the results of studies to date are controversial. We conducted a systematic review and meta-analysis to explore the influence of riociguat treatment on pulmonary arterial hypertension.

METHODS

The PubMed, Embase, Web of science, EBSCO, and Cochrane Library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of riociguat treatment on pulmonary arterial hypertension were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. This meta-analysis was performed using the random effects model.

RESULTS

Seven RCTs were included in the meta-analysis. Compared with a control intervention in pulmonary arterial hypertension, riociguat treatment was able to substantially improve results of the six-minute walking distance (6-MWD; standardized mean difference [SMD] = 0.53; 95% CI = 0.36-0.69; p < 0.00001), EQ-5D score (SMD = 0.35; 95% CI = 0.15-0.54; p = 0.0005), and cardiac index (SMD = 0.94; 95% CI = 0.59-1.29; p < 0.00001). The Living With Pulmonary Hypertension (LPH) score (SMD = -0.33; 95% CI = -0.50--0.17; p < 0.0001) and pulmonary vascular resistance (PVR; SMD = -0.88; 95% CI = -1.05--0.70; p < 0.00001) were significantly reduced after riociguat treatment. There was no increase in adverse events with riociguat treatment compared with the control intervention (RR = 1.04; 95% CI = 0.98-1.09; p = 0.19).

CONCLUSION

Riociguat treatment for pulmonary arterial hypertension led to a significant increase in the 6‑MWD, EQ-5D score, and cardiac index, as well as a decrease in LPH score and PVR.

Macrophage migration inhibitory factor (MIF) in the development and progression of pulmonary arterial hypertension

Macrophage migration inhibitory factor (MIF) has been described as a pro-inflammatory cytokine and regulator of neuro-endocrine function. It plays an important upstream role in the inflammatory cascade by promoting the release of other inflammatory cytokines such as TNF-alpha and IL-6, ultimately triggering a chronic inflammatory immune response. As lungs can synthesize and release MIF, many studies have investigated the potential role of MIF as a biomarker in assessment of patients with pulmonary arterial hypertension (PAH) and using anti-MIFs as a new therapeutic modality for PAH.

Pulmonary hypertension experience in an expert university hospital

Objective:

Pulmonary artery hypertension (PAH) is characterized by remodeling of the small pulmonary arteries, leading to a progressive increase in pulmonary vascular resistance and right ventricular failure. In this study, we aimed to share our 10 years of experience dealing with pulmonary hypertension (PH) and provide information in real-life settings in terms of demographics, clinical course, PH subgroup distribution, and treatment patterns in patients with PAH in a tertiary center.

Methods:

In this retrospective, single-center, observational study, we screened the patients who applied to PH outpatient clinic of İstanbul University Institute of Cardiology due to the suspicion of PAH between 2008 and 2017. While group 1, 4, and 5 PH patients were included, group 2 and 3 PH patients were excluded from the study.

Results:

Our study group comprised 162 patients (115 females, 71%). The female: male ratio was 2.4. The mean age was 52±16 years. Most (86.4%) of the patients were in group 1 PH (PAH). The rest (13.6%, n=22) of the patients were in group 4 PH (chronic thromboembolic PH). In group 1 PH, 45.7% of patients (n=64) were classified as having idiopathic PAH (IPAH) after excluding the alternative diagnosis using PH diagnostic algorithm. The remaining 54.3% of group 1 PH patients (n=76) had various diseases that caused PAH, which is called associated PAH (APAH); APAH group included PAH associated with congenital heart diseases (n=70), connective tissue disorders (scleroderma, n=4) and portal hypertension (n=2).

Conclusion:

Our data provides important information in real-life settings in terms of demographics, clinical course, PH subgroup distribution, and treatment patterns in patients with PAH in a reference tertiary center in Turkey.

Sex differences in pulmonary arterial hypertension: role of infection and autoimmunity in the pathogenesis of disease

Registry data worldwide indicate an overall female predominance for pulmonary arterial hypertension (PAH) of 2–4 over men. Genetic predisposition accounts for only 1–5% of PAH cases, while autoimmune diseases and infections are closely linked to PAH. Idiopathic PAH may include patients with undiagnosed autoimmune diseases based on the relatively high presence of autoantibodies in this group. The two largest PAH registries to date report a sex ratio for autoimmune connective tissue disease-associated PAH of 9:1 female to male, highlighting the need for future studies to analyze subgroup data according to sex. Autoimmune diseases that have been associated with PAH include female-dominant systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, Sjögren’s syndrome, and thyroiditis as well as male-dominant autoimmune diseases like myocarditis which has been linked to HIV-associated PAH. The sex-specific association of PAH to certain infections and autoimmune diseases suggests that sex hormones and inflammation may play an important role in driving the pathogenesis of disease. However, there is a paucity of data on sex differences in inflammation in PAH, and more research is needed to better understand the pathogenesis underlying PAH in men and women. This review uses data on sex differences in PAH and PAH-associated autoimmune diseases from registries to provide insight into the pathogenesis of disease.

Pulmonary arterial hypertension: pathogenesis and clinical management

Pulmonary hypertension is defined as a resting mean pulmonary artery pressure of 25 mm Hg or above. This review deals with pulmonary arterial hypertension (PAH), a type of pulmonary hypertension that primarily affects the pulmonary vasculature. In PAH, the pulmonary vasculature is dynamically obstructed by vasoconstriction, structurally obstructed by adverse vascular remodeling, and pathologically non-compliant as a result of vascular fibrosis and stiffening. Many cell types are abnormal in PAH, including vascular cells (endothelial cells, smooth muscle cells, and fibroblasts) and inflammatory cells. Progress has been made in identifying the causes of PAH and approving new drug therapies. A cancer-like increase in cell proliferation and resistance to apoptosis reflects acquired abnormalities of mitochondrial metabolism and dynamics. Mutations in the type II bone morphogenetic protein receptor (BMPR2) gene dramatically increase the risk of developing heritable PAH. Epigenetic dysregulation of DNA methylation, histone acetylation, and microRNAs also contributes to disease pathogenesis. Aberrant bone morphogenetic protein signaling and epigenetic dysregulation in PAH promote cell proliferation in part through induction of a Warburg mitochondrial-metabolic state of uncoupled glycolysis. Complex changes in cytokines (interleukins and tumor necrosis factor), cellular immunity (T lymphocytes, natural killer cells, macrophages), and autoantibodies suggest that PAH is, in part, an autoimmune, inflammatory disease. Obstructive pulmonary vascular remodeling in PAH increases right ventricular afterload causing right ventricular hypertrophy. In some patients, maladaptive changes in the right ventricle, including ischemia and fibrosis, reduce right ventricular function and cause right ventricular failure. Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure. PAH targeted therapies (prostaglandins, phosphodiesterase-5 inhibitors, endothelin receptor antagonists, and soluble guanylate cyclase stimulators), used alone or in combination, improve functional capacity and hemodynamics and reduce hospital admissions. However, these vasodilators do not target key features of PAH pathogenesis and have not been shown to reduce mortality, which remains about 50% at five years. This review summarizes the epidemiology, pathogenesis, diagnosis, and treatment of PAH.

Pulmonary Arterial Hypertension and the Sex Hormone Paradox

PURPOSE OF REVIEW

Prevalence and outcome differences between women and men with pulmonary arterial hypertension (PAH) raise questions about the role of sex hormones in disease pathobiology. This review will summarize the current understanding of sex and sex hormone pathways and their influence on heart-lung function in health and in disease.

RECENT FINDINGS

Female sex has been shown to be a risk factor for the development of PAH, but women have improved survival compared to men with PAH. These paradoxical observations are likely driven in part by complex sex hormone signaling and processing pathways and their interaction with the pulmonary vasculature and the right ventricle. These relationships may vary depending on an individual's underlying sex, age, and/or genetic substrate. The study of the connections between sex, sex hormones, the pulmonary circulation, and the right ventricle may improve our understanding of disease epidemiology and outcomes and lead to new treatment strategies for PAH.

Definition, epidemiology and registries of pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a subcategory of pulmonary hypertension (PH) that comprises a group of disorders with similar pulmonary vascular pathology. Though PH is common, the estimated incidence of IPAH is 1-3 cases per million, making it a rare disease. The hemodynamic definition of PAH is a mean pulmonary artery pressure at rest >OR = 25 mm Hg in the presence of a pulmonary capillary wedge pressure <OR = 15 mmHg with pulmonary vascular resistance (PVR) greater than 3 WU. Specific maneuvers during right heart catheterization can be utilized to disclose vasoreactivity and heart failure with preserved ejection fraction, which have implications for management. The inherent complexity in studying a rare disease that exhibits clinical overlap with a common syndrome necessitated the creation of registries. These registries have been indispensable in the characterization and mapping of the natural history of the disease. Equations and risk calculators derived from registries have given clinicians a basis for risk stratification and prognostication. The sequential accumulation of data since the registries began in the 1980s allows for comparisons to be made. Patients who are differentiated by treatment eras and environments can be contrasted. Variability among inclusion criteria similarly allows for comparisons of these subpopulations. This article provides an overview of available registries, highlights insights provided by each and discusses key issues around the interpretation and extrapolation of data from PAH registries. Registries have allowed us to appreciate the improvement in survival afforded by modern therapy and enhanced detection of this disease. Moving forward, a more global approach to registries is needed, as is enhanced collaboration and centralization.

Pathobiology of pulmonary arterial hypertension: understanding the roads less travelled

The pathobiology of pulmonary arterial hypertension (PAH) is complex and incompletely understood. Although three pathogenic pathways have been relatively well characterised, it is widely accepted that dysfunction in a multitude of other cellular processes is likely to play a critical role in driving the development of PAH. Currently available therapies, which all target one of the three well-characterised pathways, provide significant benefits for patients; however, PAH remains a progressive and ultimately fatal disease. The development of drugs to target alternative pathogenic pathways is, therefore, an attractive proposition and one that may complement existing treatment regimens to improve outcomes for patients. Considerable research has been undertaken to identify the role of the less well-understood pathways and in this review we will highlight some of the key discoveries and the potential for utility as therapeutic targets.

Development of prognostic tools in pulmonary arterial hypertension: Lessons from modern day registries

Pulmonary arterial hypertension (PAH) is characterised by increased pressure in the pulmonary arteries leading to right-sided ventricular failure, and death. Identification of factors that affect patient survival is important to improve patient management and outcomes. The first registry to evaluate survival and develop a prognostic model was the National Institutes of Health (NIH) registry in 1981. Importantly this prognostic model is based on data collected prior to availability of PAH-targeted therapies and does not reflect survival rates for treated patients. Since the 1980s, however, four modern registries of PAH now exist which compensate for the NIH equations shortcomings and include the French National registry, Pulmonary Hypertension Connection registry, the Mayo registry, and the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL). The similarities and difference in these registries are highlighted in this review and although similar in many respects, the four registries vary in patient population, including the numbers of newly and previously diagnosed patients, as well as the era of observation, period of survival, and timing of assessment of potential predictive factors. Despite this, the predictive factors identified in each registry and described in detail within the body of this manuscript share surprising homology in that disease aetiology, patient gender and factors reflective of right heart failure are integral in depicting survival. Future modifications of modern prognostic equations should be an ongoing goal of the PAH community in order to provide increased accuracy with identification of novel risk factors and prediction of disease course.

Healthcare resource utilization and costs for patients with pulmonary arterial hypertension: real-world documentation of functional class

BACKGROUND AND AIMS

Pulmonary arterial hypertension (PAH) is a rare medical disease in which patients experience increased pulmonary vascular resistance (PVR) and pulmonary arterial pressure that can result in remodeling of the pulmonary vasculature and heart, and eventually lead to right heart failure and death. As PAH progresses, patients become unable to perform even routine daily tasks without severe shortness of breath (dyspnea), fatigue, dizziness, and fainting (syncope). Treatment strategies largely depend on assessment of an individual patient's WHO Functional Class. The aim of the present study was to determine whether PAH functional decline, as described by the WHO Functional class (FC), is associated with increased healthcare costs for patients.

METHODS

Patients with a prescription for a FDA-approved treatment for PAH and a medical claim indicating chronic pulmonary heart disease or right heart catheterization were identified from an administrative claims database. Provider-reported data from prior authorization forms required for advanced PAH therapies and medical charts were examined for reported FC. Healthcare resource utilization and costs were the primary outcomes of interest. Costs were accounted in 2014 US dollars ($) from a healthcare payer perspective.

RESULTS

Patients with a reported FC-IV were observed to have the worst outcomes; averaging significantly more inpatient admissions, longer average lengths of stay, and more emergency department visits than the other FC sub-groups, resulting in higher medical costs.

CONCLUSIONS

Using administrative data to document disease severity, this study replicates and expands on findings obtained from the registry study; disease severity was associated with higher healthcare resource utilization and costs. Stakeholders' implications for patient management are discussed.

Health Disparities in Patients with Pulmonary Arterial Hypertension: A Blueprint for Action. An Official American Thoracic Society Statement

BACKGROUND

Health disparities have a major impact in the quality of life and clinical care received by minorities in the United States. Pulmonary arterial hypertension (PAH) is a rare cardiopulmonary disorder that affects children and adults and that, if untreated, results in premature death. The impact of health disparities in the diagnosis, treatment, and clinical outcome of patients with PAH has not been systematically investigated.

OBJECTIVES

The specific goals of this research statement were to conduct a critical review of the literature concerning health disparities in PAH, identify major research gaps and prioritize direction for future research.

METHODS

Literature searches from multiple reference databases were performed using medical subject headings and text words for pulmonary hypertension and health disparities. Members of the committee discussed the evidence and provided recommendations for future research.

RESULTS

Few studies were found discussing the impact of health disparities in PAH. Using recent research statements focused on health disparities, the group identified six major study topics that would help address the contribution of health disparities to PAH. Representative studies in each topic were discussed and specific recommendations were made by the group concerning the most urgent questions to address in future research studies.

CONCLUSIONS

At present, there are few studies that address health disparities in PAH. Given the potential adverse impact of health disparities, we recommend that research efforts be undertaken to address the topics discussed in the document. Awareness of health disparities will likely improve advocacy efforts, public health policy and the quality of care of vulnerable populations with PAH.

Preliminary results from a nationwide adult cardiology perspective for pulmonary hypertension: RegiStry on clInical outcoMe and sUrvival in pulmonaRy hypertension Groups (SIMURG)

OBJECTIVE

The present study was designed to evaluate the characteristics of pulmonary hypertension (PH) and adult cardiology practice patterns for PH in our country.

METHODS

We evaluated preliminary survey data of 1501 patients with PH (females, 69%; age, 44.8±5.45) from 20 adult cardiology centers (AdCCs).

RESULTS

The average experience of AdCCs in diagnosing and treating patients with PH was 8.5±3.7 years. Pulmonary arterial hypertension (PAH) was the most frequent group (69%) followed by group 4 PH (19%), group 3 PH (8%), and combined pre- and post-capillary PH (4%). PAH associated with congenital heart disease (APAH-CHD) was the most frequent subgroup (47%) of PAH. Most of the patients' functional class (FC) at the time of diagnosis was III. The right heart catheterization (RHC) rate was 11.9±11.6 per month. Most frequently used vasoreactivity agent was intravenous adenosine (60%). All patients under targeted treatments were periodically for FC, six-minute walking test, and echo measures at 3-month intervals. AdCCs repeated RHC in case of clinical worsening (CW). The annual rate of hospitalization was 14.9±19.5. In-hospital use of intravenous iloprost reported from 16 AdCCs in CWs. Bosentan and ambrisentan, as monotreatment or combination treatment (CT), were noted in 845 and 28 patients, respectively, and inhaled iloprost, subcutaneous treprostinil, and intravenous epoprostenol were noted in 283, 30, and four patients, respectively. Bosentan was the first agent used for CT in all AdCCs and iloprost was the second. Routine use of antiaggregant, anticoagulant, and pneumococcal and influenza prophylaxis were restricted in only two AdCCs.

CONCLUSION

Our nationwide data illustrate the current status of PH regarding clinical characteristics and practice patterns.

Ethnicity in Pulmonary Arterial Hypertension: Possibilities for Novel Phenotypes in the Age of Personalized Medicine

In the past decade and a half, the introduction of new therapeutic agents has revolutionized the management of pulmonary arterial hypertension (PAH). These new treatment options have improved the quality of life and survival in PAH. With an armamentarium of options available, the identification of unique phenotypes can help practitioners choose tailored treatment regimens. Experts in other cardiovascular diseases, such as congestive heart failure and hypertension, have recommended race-specific treatments in their fields based on data highlighting variations in response to therapies. With this perspective, we review evidence supporting the hypothesis that ethnicity or race plays an important role in the management of PAH. Preliminary research suggests that races/ethnicities have differences in the presentation and outcome of PAH and could respond to PAH-specific medications with varying efficacy. Genetic, physiological, and anatomic differences exist between races, particularly regarding the structure and function of the right ventricle. Unfortunately, clinical trials have not adequately included minorities, and registry data often omit inclusion of this demographic information. Further studies are needed to characterize the role that ethnicity plays in the prevalence, presentation, outcomes, and optimal treatment of PAH.

Anastrozole in Pulmonary Arterial Hypertension. A Randomized, Double-Blind, Placebo-controlled Trial

RATIONALE

The aromatase inhibitor anastrozole blocks the conversion of androgens to estrogen and blunts pulmonary hypertension in animals, but its efficacy in treating patients with pulmonary arterial hypertension (PAH) is unknown.

OBJECTIVES

We aimed to determine the safety and efficacy of anastrozole in PAH.

METHODS

We performed a randomized, double-blind, placebo-controlled trial of anastrozole in patients with PAH who received background therapy at two centers.

MEASUREMENTS AND MAIN RESULTS

A total of 18 patients with PAH were randomized to anastrozole 1 mg or matching placebo in a 2:1 ratio. The two co-primary outcomes were percent change from baseline in 17β-estradiol levels (E2) and tricuspid annular plane systolic excursion (TAPSE) at 3 months. Anastrozole significantly reduced E2 levels compared with placebo (percent change: -40%; interquartile range [IQR], -61 to -26% vs. -4%; IQR, -14 to +4%; P = 0.003), but there was no difference in TAPSE. Anastrozole significantly increased the 6-minute-walk distance (median change = +26 m) compared with placebo (median change = -12 m) (median percent change: anastrozole group, 8%; IQR, 2 to 17% vs. placebo -2%; IQR, -7 to +1%; P = 0.042). Anastrozole had no effect on circulating biomarkers, functional class, or health-related quality of life. There was no difference in adverse events.

CONCLUSIONS

Anastrozole significantly reduced E2 levels in patients with PAH but had no effect on TAPSE. Anastrozole was safe, well tolerated, and improved 6-minute-walk distance in this small "proof-of-principle" study. Larger and longer phase II clinical trials of anastrozole may be warranted in patients with PAH. Clinical trial registered with www.clinicaltrials.gov (NCT 1545336).

Risk assessment in pulmonary arterial hypertension

Regular patient assessment is essential for the management of chronic diseases, such as pulmonary arterial hypertension (PAH). Comprehensive patient assessment and risk stratification in PAH are important to guide treatment decisions and to monitor disease progression as well as patients' response to treatment. Approaches for assessing risk in PAH patients include the use of risk variables, as recommended in the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) pulmonary hypertension (PH) guidelines, and the application of risk equations and scores, such as the French registry risk equation and the REVEAL registry risk score. Risk stratification and risk scores are both useful predictors of survival on a population basis, and provide an estimate for individual patients' risk. The 2015 ESC/ERS PH guidelines recommend regular assessment of multiple variables at an expert centre. The respective merits and limitations of different risk assessment methods in PAH are discussed in this article, as well as some considerations that can be taken into account in the future development of risk assessment tools.

Regular risk assessment with multiple parameters evaluates PAH disease progression and treatment responsehttp://ow.ly/Nq0I305kgpU

Estrogen receptor-dependent attenuation of hypoxia-induced changes in the lung genome of pulmonary hypertension rats

17β-estradiol (E2) exerts complex and context-dependent effects in pulmonary hypertension. In hypoxia-induced pulmonary hypertension (HPH), E2 attenuates lung vascular remodeling through estrogen receptor (ER)-dependent effects; however, ER target genes in the hypoxic lung remain unknown. In order to identify the genome regulated by the E2-ER axis in the hypoxic lung, we performed a microarray analysis in lungs from HPH rats treated with E2 (75 mcg/kg/day) ± ER-antagonist ICI182,780 (3 mg/kg/day). Untreated HPH rats and normoxic rats served as controls. Using a false discovery rate of 10%, we identified a significantly differentially regulated genome in E2-treated versus untreated hypoxia rats. Genes most upregulated by E2 encoded matrix metalloproteinase 8, S100 calcium binding protein A8, and IgA Fc receptor; genes most downregulated by E2 encoded olfactory receptor 63, secreted frizzled-related protein 2, and thrombospondin 2. Several genes affected by E2 changed in the opposite direction after ICI182,780 co-treatment, indicating an ER-regulated genome in HPH lungs. The bone morphogenetic protein antagonist Grem1 (gremlin 1) was upregulated by hypoxia, but found to be among the most downregulated genes after E2 treatment. Gremlin 1 protein was reduced in E2-treated versus untreated hypoxic animals, and ER-blockade abolished the inhibitory effect of E2 on Grem1 mRNA and protein. In conclusion, E2 ER-dependently regulates several genes involved in proliferative and inflammatory processes during hypoxia. Gremlin 1 is a novel target of the E2-ER axis in HPH. Understanding the mechanisms of E2 gene regulation in HPH may allow for selectively harnessing beneficial transcriptional activities of E2 for therapeutic purposes.

World Health Organization Group I Pulmonary Hypertension: Epidemiology and Pathophysiology

Pulmonary arterial hypertension (PAH) is a debilitating disease characterized by pathologic remodeling of the resistance pulmonary arteries, ultimately leading to right ventricular (RV) failure and death. In this article we discuss the definition of PAH, the initial epidemiology based on the National Institutes of Health Registry, and the updated epidemiology gleaned from contemporary registries, pathogenesis of pulmonary vascular dysfunction and proliferation, and RV failure in PAH.

Comparison of hemodynamic parameters in treatment-naïve and pre-treated patients with pulmonary arterial hypertension in the randomized phase III PATENT-1 study

BACKGROUND

Detailed hemodynamic data from the phase III PATENT-1 study of riociguat in patients with pulmonary arterial hypertension (PAH) were investigated.

METHODS

Patients with PAH who were treatment naïve or pre-treated with endothelin receptor antagonists or non-intravenous prostanoids were randomly assigned to riociguat up to 2.5 mg 3 times a day or placebo. Hemodynamic parameters were assessed at baseline and week 12.

RESULTS

Riociguat significantly decreased pulmonary vascular resistance in treatment-naïve (n = 221; least squares [LS] mean difference -266 dyne∙sec∙cm^-5 [95% confidence interval (CI) -357 to -175; p < 0.0001]) and pre-treated (n = 222; LS mean difference -186 dyne∙sec ∙cm^-5 [95% CI -252 to -120; p < 0.0001]) patients and significantly increased cardiac index (LS mean difference +0.7 [95% CI 0.5 to 0.8] and +0.5 [95% CI 0.3 to 0.7], respectively [both p < 0.0001]). Mean pulmonary artery pressure (p = 0.0056 and p = 0.0019 for treatment-naïve and pre-treated patients, respectively), mean arterial pressure (both p < 0.0001), and systemic vascular resistance (both p < 0.0001) were significantly reduced, and there was an increase in mixed venous oxygen saturation (p < 0.0001 and p = 0.0004, respectively). Results were similar in patients pre-treated with endothelin receptor antagonists and patients pre-treated with non-intravenous prostanoids. Improvements in 6-minute walking distance correlated very weakly with improvements in pulmonary vascular resistance (r = -0.21 [95% CI -0.30 to -0.11; p < 0.0001]) and cardiac index (r = 0.16 [95% CI 0.06 to 0.25; p < 0.0016]).

CONCLUSIONS

Riociguat significantly improved hemodynamic parameters in pre-treated and treatment-naïve patients with PAH.

Mexican registry of pulmonary hypertension: REMEHIP

OBJECTIVE

REMEHIP is a prospective, multicentre registry on pulmonary hypertension. The main objective will be to identify the clinical profile, medical care, therapeutic trends and outcomes in adult and pediatric Mexican patients with well-characterized pulmonary hypertension.

METHODS

REMEHIP a multicenter registry began in 2015 with a planned recruitment time of 12 months and a 4-year follow-up. The study population will comprise a longitudinal cohort study, collecting data on patients with prevalent and incident pulmonary hypertension. Will be included patients of age >2 years and diagnosis of pulmonary hypertension by right heart catheterization within Group 1 and Group 4 of the World Health Organization classification. The structure, data collection and data analysis will be based on quality current recommendations for registries. The protocol has been approved by institutional ethics committees in all participant centers. All patients will sign an informed consent form. Currently in Mexico, there is a need of observational registries that include patients with treatment in the everyday clinical practice so the data could be validated and additional information could be obtained versus the one from the clinical trials. In this way, REMEHIP emerges as a link among randomized clinical trials developed by experts and previous Mexican experience.

An international physician survey of pulmonary arterial hypertension management

We conducted an international study to evaluate practices in the diagnosis and management of pulmonary arterial hypertension (PAH) globally across different geographic regions. Between July and October 2012, PAH-treating physicians completed a 15-minute online questionnaire and provided patient record data for their 3 or 5 most recent patients with PAH. Overall, 560 physicians (Europe: 278; United States: 160; Argentina: 53; Japan: 69) completed the questionnaire and provided data for 2,618 patients. The proportion of physicians who described themselves as working in or affiliated with a specialized pulmonary hypertension center ranged from 13% in Argentina to 74% in the United States. At the time of diagnosis, patients' New York Heart Association functional class differed significantly between regions. At the time of last assessment, functional class had improved overall, and differences between regions had largely disappeared. A large proportion of patients did not undergo right heart catheterization for the diagnosis of PAH (Europe: 7%-21%; United States: 21%; Japan: 19%; Argentina: 51%). Variations in management included greater use of phosphodiesterase 5 inhibitors in the United States than in Europe and Japan and greater use of triple or greater combination therapy in Japan than in other regions. Results from this study, which includes a global aspect of PAH care, demonstrate that there are significant differences in PAH management between regions and low adherence to guidelines recommending right heart catheterization for the diagnosis of PAH.

Prognostic Factors in Patients With Pulmonary Hypertension-A Nationwide Cohort Study

Background

Pulmonary hypertension (PH) is a rare but fatal condition. Large‐scale studies to examine the prognostic factors are lacking. In the present study, we aimed to investigate the factors associated with overall mortality in PH patients.

Methods and Results

Based on Taiwan's National Health Insurance Database, we identified 1092 newly identified PH patients between 1999 and 2011. These patients were matched with 8736 healthy subjects based on propensity score calculated with age, sex, and chronic cardiovascular risk factors. Overall mortality, death incidence rate ratio, and hazard ratio were calculated. Patients with PH had a higher mortality than controls (56.45 versus 18.51 per 1000 person‐years, P<0.0001), with hazard ratio at 3.3 (95% CI: 2.92–3.73, P<0.001). The long‐term survival rates of the PH patients at 1, 5, and 10 years were 87.9%, 72.5%, and 62.6%, respectively, which were significantly lower than controls with 98.4%, 90.8%, and 83.6% at 1, 5, and 10 years, respectively. Among patients with PH, the mortality rate was higher in the older and male patients. However, after stratifying by age and sex, the younger (<50 years) and female patients had a higher risk. Regarding different etiologies of PH, chronic obstructive pulmonary disease and pulmonary embolism led to most cases of mortality (adjusted hazard ratio: 3.2, 95% CI: 2.76–3.71 and 4.64, 95% CI: 2.74–7.87, P<0.05).

Conclusions

PH has high mortality, especially in females, and patients with younger age and with chronic diseases. Chronic obstructive pulmonary disease and pulmonary embolism contributed to an increased risk of mortality in PH patients.

Systematic Review of Health-Related Quality of Life in Patients with Pulmonary Arterial Hypertension

BACKGROUND

The increasing survival of patients with pulmonary arterial hypertension (PAH) has shifted attention towards the disease burden that PAH imposes on patients and healthcare systems. Most studies emphasize epidemiology and medications, while large observational studies reporting on the health-related quality of life (HRQOL) of patients with PAH are lacking.

OBJECTIVE

Our objective was to study the HRQOL of patients with PAH and to summarize the factors that influence it.

METHODS

We conducted systematic literature searches in English (PubMed, Web of Knowledge, ScienceDirect and OVID) and Chinese (China National Knowledge Infrastructure, Wanfang Data, Chongqing VIP and SinoMed) databases to identify studies published from 2000 to 2015 assessing the HRQOL of patients with PAH. Search results were independently reviewed and extracted by two reviewers.

RESULTS

Of 3392 records identified in the initial search, 20 eligible papers (19 English, 1 Chinese) were finally included. Studies used a range of instruments; the generic 36-item Short Form Survey (SF-36) was the most widely used, and the disease-specific Cambridge Pulmonary Hypertension Outcome Survey (CAMPHOR) was the second mostly widely used. Mean HRQOL scores assessed via the SF-36 (physical component summary [PCS] 25.4-80.1; mental component summary [MCS] 33.2-76.0) and CAMPHOR (symptom scores 3.1-17; total HRQOL 2.8-12.6; activity scores 3.8-18.1) varied across studies, reporting decreased HRQOL in patients. Mental health (depression, anxiety, stress), physical health (exercise capacity, symptoms) and medical therapies were reported to affect HRQOL.

CONCLUSION

We found that PAH places a substantial burden on patients, particularly in terms of HRQOL; however, the paucity of large observational studies in this area requires the attention of researchers, especially in China.

Transforming growth factor beta 1 induced endothelin-1 release is peroxisome proliferator-activated receptor gamma dependent in A549 cells

Background

Endothelin-1 (ET-1) is involved in pulmonary vascular remodeling. The aim of this study was to investigate the biochemical interactions between PPAR-γ, TGF-β1 and ET-1 in vitro.

Methods

A549 cells were pre-treated with S2505 (10 μM), S2871 (10 μM) with/without SB203580 (10 μM) for 60 min following 2 h treatment with 10 ng/mL TGF-β1. A549 cells were also transfected with positive or negative PPAR-γ plasmids for comparison. RT-PCR, ELISA, western blotting and confocal laser scanning microscopy (CLSM) were used to measure the relevant expression of mRNA, protein, mediators of pathways and nuclear factor translocation.

Results

SB203580 inhibited TGF-β1 induced ET-1 expression in A549 cells. S2871 decreased PPAR-γ mRNA and increase TGF-β1-induced ET-1 expression. S2871 increased phosphorylation of p38 MAPK and Smad2. Cells transfected with PPAR-γ negative plasmid increased TGF-β1 induced ET-1 expression, and increased the expression of phospho-p38 MAPK and phospho-Smad2. S2505 increased PPAR-γ mRNA expression, suppressed the increased TGF-β1-induced expression of ET-1. S2505 inhibited TGF-β1 induced phosphorylation of p38 MAPK and Smad2, also the nuclear translocation of Smad2. Cells transfected with PPAR-γ positive plasmid reduced TGF-β1-induced ET-1 expression, and inhibited the expression of phospho-p38 MAPK and phospho-Smad2.

Conclusions

TGF-β1 induced release of endothelin-1 is PPAR-γ dependent in cultured A549 cells.

Systematic Review of the Economic Burden of Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH), as a life-threatening disease with no efficient cure, may impose a tremendous economic burden on patients and healthcare systems. However, most existing studies have mainly emphasised epidemiology and medications, while large observational studies reporting on the economic burden are currently lacking.

OBJECTIVES

To review and evaluate evidence on the costs of PAH and the cost effectiveness of PAH treatments, and to summarise the corresponding cost drivers.

METHODS

Systematic literature searches were conducted in English-language databases (PubMed, Web of Science, ScienceDirect) and Chinese-language databases (China National Knowledge Infrastructure, Wanfang Data, Chongqing VIP) to identify studies (published from 2000 to 2014) assessing the costs of PAH or the cost effectiveness of PAH treatments. The search results were independently reviewed and extracted by two reviewers. Costs were converted into 2014 US dollars.

RESULTS

Of 1959 citations identified in the initial search, 19 papers were finally included in this analysis: eight on the economic burden of PAH and 11 on economic evaluation of PAH treatments. The economic burden on patients with PAH was rather large, with direct healthcare costs per patient per month varying from $2476 to $11,875, but none of the studies reported indirect costs. Sildenafil was universally reported to be a cost-effective treatment, with lower costs and better efficacy than other medications. Medical costs were reported to be the key cost drivers.

CONCLUSION

The economic burden of patients with PAH is substantial, while the paucity of comprehensive country-specific evidence in this area and the lack of reports on indirect costs of PAH warrant researchers' concern, especially in China.

Where do we go from here? Reappraising the data on anticoagulation in pulmonary arterial hypertension

The use of anticoagulation as part of the treatment regimen in pulmonary arterial hypertension (PAH) remains a topic of debate. A recently published analysis of anticoagulation use in the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) study offers conflicting conclusions regarding the benefit of this therapeutic strategy. There remains no robust randomized trial in PAH weighing the risks versus benefits of including anticoagulation in treatment regimens, leaving clinicians to surmise value in individual patients. Reexamination of available data may help to provide guidance on this controversial topic in the absence of future dedicated investigations.

Clinical characteristics and risk factors of pulmonary hypertension associated with chronic respiratory diseases: a retrospective study

BACKGROUND

Chronic respiratory disease-associated pulmonary hypertension (PH) is an important subtype of PH, which lacks clinical epidemiological data in China.

METHODS

Six hundred and ninety three patients hospitalized from 2010 to 2013 were classified by echocardiography according to pulmonary arterial systolic pressure (PASP): mild (36≤ PASP <50 mmHg); moderate (50≤ PASP <70 mmHg) and severe (PASP ≥70 mmHg).

RESULTS

Dyspnea (93.51%) was the most common symptom. Hemoptysis observed in the severe group (6.42%) was significantly higher than the other two groups (P<0.05). COPD (78.35%), lung bullae (44.16%), tuberculosis (including obsolete pulmonary tuberculosis) (38.82%), and bronchiectasis (30.45%) were frequently present. Mild group occupied the highest proportion (84.7%) in COPD, while severe group occupied the highest proportion (19.3%) in pulmonary embolism (P<0.01). Age, partial pressure of oxygen (PaO2), hematocrit (HCT), partial pressure of carbon dioxide (PaCO2), increase of N-terminal pro brain natriuretic peptide (NT-proBNP) and right ventricular (RV) diameter (>20 mm) were associated with moderate-to-severe PH, while RV [odds ratio (OR) =3.53, 95% CI, 2.17-5.74], NT-proBNP (OR=2.44, 95% CI, 1.51-3.95), HCT (OR=1.03, 95% CI, 1.00-1.07) and PaCO2 (OR=1.01, 95% CI, 1.00-1.03) were independent risk factors.

CONCLUSIONS

PH related to respiratory diseases is mostly mild to moderate, and the severity is associated with the category of respiratory disease. Increased HCT can be an independent risk factor for PH related to chronic respiratory diseases.

The Characteristics of Treated Pulmonary Arterial Hypertension Patients in Ontario

Background. There are no Canadian prevalence studies on pulmonary arterial hypertension (PAH) to date. We described the characteristics of treated PAH patients and the healthcare utilization and costs associated with PAH in a population of public drug plan beneficiaries in Ontario, Canada. Methods. A retrospective cross-sectional analysis was conducted between April 2010 and March 2011 to identify treated PAH patients using population-based health administrative databases. We investigated demographic and clinical characteristics of treated PAH patients and conducted a cohort study to determine treatment patterns, healthcare utilization, and associated costs, over a one-year follow-up period (March 2012). Results. We identified 326 treated PAH cases in Ontario's publicly funded drug plan. Overall mean age was 59.4 years (±20.3 years) and over 77% of cases were women (n = 251). Combination therapy was used to treat 22.9% (n = 69) of cases, costing an average of $4,569 (SD $1,544) per month. Median monthly healthcare costs were $264 (IQR $96-$747) for those who survived and $2,021 (IQR $993-$6,399) for those who died over a one-year period, respectively (p < 0.01). Conclusions. PAH care in Ontario is complex and has high healthcare costs. This data may help guide towards improved patient management.