Phenotypes in pulmonary hypertension.

The clinical classification of pulmonary hypertension (PH) has guided diagnosis and treatment of patients with PH for several decades. Discoveries relating to underlying mechanisms, pathobiology and responses to treatments for PH have informed the evolution in this clinical classification to describe the heterogeneity in PH phenotypes. In more recent years, advances in imaging, computational science and multi-omic approaches have yielded new insights into potential phenotypes and sub-phenotypes within the existing clinical classification. Identification of novel phenotypes in pulmonary arterial hypertension (PAH) with unique molecular profiles, for example, could lead to new precision therapies. Recent phenotyping studies have also identified groups of patients with PAH that more closely resemble patients with left heart disease (group 2 PH) and lung disease (group 3 PH), which has important prognostic and therapeutic implications. Within group 2 and group 3 PH, novel phenotypes have emerged that reflect a persistent and severe pulmonary vasculopathy that is associated with worse prognosis but still distinct from PAH. In group 4 PH (chronic thromboembolic pulmonary disease) and sarcoidosis (group 5 PH), the current approach to patient phenotyping integrates clinical, haemodynamic and imaging characteristics to guide treatment but applications of multi-omic approaches to sub-phenotyping in these areas are sparse. The next iterations of the PH clinical classification are likely to reflect several emerging PH phenotypes and improve the next generation of prognostication tools and clinical trial design, and improve treatment selection in clinical practice.

Definition, classification and diagnosis of pulmonary hypertension.

Pulmonary hypertension (PH) is a haemodynamic condition characterised by elevation of mean pulmonary arterial pressure (mPAP) >20 mmHg, assessed by right heart catheterisation. Pulmonary arterial wedge pressure (PAWP) and pulmonary vascular resistance (PVR) distinguish pre-capillary PH (PAWP ≤15 mmHg, PVR >2 Wood Units (WU)), isolated post-capillary PH (PAWP >15 mmHg, PVR ≤2 WU) and combined post- and pre-capillary PH (PAWP >15 mmHg, PVR >2 WU). Exercise PH is a haemodynamic condition describing a normal mPAP at rest with an abnormal increase of mPAP during exercise, defined as a mPAP/cardiac output slope >3 mmHg/L/min between rest and exercise. The core structure of the clinical classification of PH has been retained, including the five major groups. However, some changes are presented herewith, such as the re-introduction of "long-term responders to calcium channel blockers" as a subgroup of idiopathic pulmonary arterial hypertension, the addition of subgroups in group 2 PH and the differentiation of group 3 PH subgroups based on pulmonary diseases instead of functional abnormalities. Mitomycin-C and carfilzomib have been added to the list of drugs with "definite association" with PAH. For diagnosis of PH, we propose a stepwise approach with the main aim of discerning those patients who need to be referred to a PH centre and who should undergo invasive haemodynamic assessment. In case of high probability of severe pulmonary vascular disease, especially if there are signs of right heart failure, a fast-track referral to a PH centre is recommended at any point during the clinical workup.

Impact of an expert-derived, quick hands-on tool on classifying pulmonary hypertension in chest computed tomography: a study on inexperienced readers using RAPID-CT-PH.

PURPOSE: To test the inter-reader agreement in classifying pulmonary hypertension (PH) on chest contrast-enhanced computed tomography (CECT) between a consensus of two cardio-pulmonary-devoted radiologists (CRc) and inexperienced readers (radiology residents, RRs) when using a CECT-based quick hands-on tool built upon PH imaging literature, i.e., the "Rapid Access and Practical Information Digest on Computed Tomography for PH-RAPID-CT-PH". MATERIAL AND METHODS: The observational study retrospectively included 60 PH patients who underwent CECT between 2015 and 2022. Four RRs independently reviewed all CECTs and classified each case into one of the five PH groups per the 2022 ESC/ERS guidelines. While RR3 and RR4 (RAPID-CT-PH group) used RAPID-CT-PH, RR1 and RR2 (control group) did not. RAPID-CT-PH and control groups' reports were compared with CRc using unweighted Cohen's Kappa (k) statistics. RRs' report completeness and reporting time were also compared using the Wilcoxon-Mann-Whitney test. RESULTS: The inter-reader agreement in classifying PH between the RAPID-CT-PH group and CRc was substantial (k = 0.75 for RR3 and k = 0.65 for RR4); while, it was only moderate for the control group (k = 0.57 for RR1 and k = 0.49 for RR2). Using RAPID-CT-PH resulted in significantly higher report completeness (all p < 0.0001) and significantly lower reporting time (p < 0.0001) compared to the control group. CONCLUSION: RRs using RAPID-CT-PH showed a substantial agreement with CRc on CECT-based PH classification. RAPID-CT-PH improved report completeness and reduced reporting time. A quick hands-on tool for classifying PH on chest CECT may help inexperienced radiologists effectively contribute to the PH multidisciplinary team.

Molecular Profiling of Vascular Remodeling in Chronic Pulmonary Disease.

Pulmonary hypertension and pulmonary vascular remodeling (PVR) are common in many lung diseases leading to right ventricular dysfunction and death. Differences in PVR result in significant prognostic divergences in both the pulmonary arterial and venous compartments, as in pulmonary arterial hypertension (PAH) and pulmonary veno-occlusive disease (PVOD), respectively. Our goal was to identify compartment-specific molecular hallmarks of PVR, considering the risk of life-threatening pulmonary edema in PVOD, if treated by conventional pulmonary hypertension therapy. Formalin-fixed and paraffin-embedded tissues from fresh explanted human lungs of patients with PVOD (n = 19), PAH (n = 20), idiopathic pulmonary fibrosis (n = 13), and chronic obstructive pulmonary disease (n = 15), were analyzed for inflammation and kinome-related gene regulation. The generated neuronal network differentiated PVOD from PAH samples with a sensitivity of 100% and a specificity of 92% in a randomly chosen validation set, a level far superior to established diagnostic algorithms. Further, various alterations were identified regarding the gene expression of explanted lungs with PVR, compared with controls. Specifically, the dysregulation of microtubule-associated serine/threonine kinase 2 and protein-o-mannose kinase SGK196 in all disease groups suggests a key role in pulmonary vasculopathy for the first time. Our findings promise to help develop novel target-specific interventions and innovative approaches to facilitate clinical diagnostics in an elusive group of diseases.

Development of the Pulmonary Hypertension Functional Classification Self-Report: a patient version adapted from the World Health Organization Functional Classification measure.

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterized by progressive limitations on physical activity, right heart failure, and premature death. The World Health Organization functional classification (WHO-FC) is a clinician-rated assessment used widely to assess PAH severity and functioning, but no equivalent patient-reported version of PAH symptoms and activity limitations exists. We developed a version of the WHO-FC for self-completion by patients: the Pulmonary Hypertension Functional Classification Self-Report (PH-FC-SR). METHODS: Semistructured interviews were conducted with three health care providers (HCPs) via telephone to inform development of the draft PH-FC-SR. Two rounds of semi-structured interviews were conducted with 14 US patients with a self-reported PAH diagnosis via telephone/online to elicit concepts and iteratively refine the PH-FC-SR. RESULTS: HCPs reported that the WHO-FC was a useful tool for evaluating patients' PAH severity over time and for making treatment decisions but acknowledged that use of the measure is subjective. Patients in round 1 interviews (n = 6) reported PAH symptoms, including shortness of breath (n = 6), fatigue (n = 5), syncope (n = 5), chest pains (n = 3), and dizziness (n = 3). Round 1 patients identified challenges with the original WHO-FC, including comprehensibility of clinical terms and overlapping descriptions of class II and III, and preferred the Draft 1 PH-FC-SR over the original WHO-FC. After minor changes were made to Draft 2, round 2 interviews (n = 8) confirmed patients understood the PH-FC-SR class descriptions, interpreting them consistently. CONCLUSIONS: The HCP and patient interviews identified and confirmed certain limitations inherent within the clinician-rated WHO-FC, including subjective assessment and overlapping definitions for class II and III. The PH-FC-SR includes patient-appropriate language, symptoms, and physical activity impacts relevant to patients with PAH. Future research is recommended to validate the PH-FC-SR and explore its correlation with the physician-assessed WHO-FC and other outcomes.

Pulmonary Hypertension Subtypes and Mortality in CKD.

RATIONALE & OBJECTIVE: Pulmonary hypertension (PH) contributes to cardiovascular disease and mortality in patients with chronic kidney disease (CKD), but the pathophysiology is mostly unknown. This study sought to estimate the prevalence and consequences of PH subtypes in the setting of CKD. STUDY DESIGN: Observational retrospective cohort study. SETTING & PARTICIPANTS: We examined 12,618 patients with a right heart catheterization in the Duke Databank for Cardiovascular Disease from January 1, 2000, to December 31, 2014. EXPOSURES: Baseline kidney function stratified by CKD glomerular filtration rate category and PH subtype. OUTCOMES: All-cause mortality. ANALYTICAL APPROACH: Multivariable Cox proportional hazards analysis. RESULTS: In this cohort, 73.4% of patients with CKD had PH, compared with 56.9% of patients without CKD. Isolated postcapillary PH (39.0%) and combined pre- and postcapillary PH (38.3%) were the most common PH subtypes in CKD. Conversely, precapillary PH was the most common subtype in the non-CKD cohort (35.9%). The relationships between mean pulmonary artery pressure, pulmonary capillary wedge pressure, and right atrial pressure with mortality were similar in both the CKD and non-CKD cohorts. Compared with those without PH, precapillary PH conferred the highest mortality risk among patients without CKD (HR, 2.27; 95% CI, 2.00-2.57). By contrast, in those with CKD, combined pre- and postcapillary PH was associated with the highest risk for mortality in CKD in adjusted analyses (compared with no PH, HRs of 1.89 [95% CI, 1.57-2.28], 1.87 [95% CI, 1.52-2.31], 2.13 [95% CI, 1.52-2.97], and 1.63 [95% CI, 1.12-2.36] for glomerular filtration rate categories G3a, G3b, G4, and G5/G5D). LIMITATIONS: The cohort referred for right heart catheterization may not be generalizable to the general population. Serum creatinine data in the 6 months preceding catheterization may not reflect true baseline CKD. Observational design precludes assumptions of causality. CONCLUSIONS: In patients with CKD referred for right heart catheterization, PH is common and associated with poor survival. Combined pre- and postcapillary PH was common and portended the worst survival for patients with CKD.

Which Functional Classification Scale is Optimal for Children with Pulmonary Hypertension (PAH)?

Functional status assessed by the WHO-FC scale derived from adults is a known prognostic factor for pulmonary hypertension. Data on the usefulness of the Panama-FC scale in assessing children with pulmonary hypertension are limited. The study was performed to compare functional status results (WHO-FC and Panama-FC) and to assess the usefulness of these scales in various clinical situations. The reliability of the Panama-FC questionnaire method for facilitating patient evaluation was also examined. 26 functional status assessments (7 in disease progression/after treatment intensification) in both scales were analyzed in 19 patients with PAH confirmed in RHC. WHO-FC, Panama-FC scales, and questionnaire-based on Panama-FC were conducted independently by three different physicians. Results of assessments were compared with each other and with 6MWD, NTproBNP level, and echo parameters (TAPSE, RV/LV ratio). The Panama-FC scale results obtained using the medical interview method and questionnaire did not differ. Both WHO-FC and Panama-FC classes well-reflected disease advancement confirmed by non-invasive parameters (NTproBNP, 6MWD, TAPSE, RV/LV ratio). Differences between grading the class in both scales were observed: 5pts were classified to II (Panama-FC) vs I (WHO-FC), 2pts were in lower risk group in WHO-FC (II) vs Panama (IIIa). Worsening or improvement after treatment intensification in functional status in both scales was connected with the significant change of NTproBNP level. The 6-min walking distance did not change. TAPSE, RV/LV ratio changed significantly in 3pts with IPAH, accordingly to change in WHO-FC and Panama-FC. WHO-FC and Panama-FC well reflect the disease advancement. The questionnaire method simplified the use of the Panama-FC scale. The Panama-FC scale appears to be better for assessing functional status during long-term follow-up, while the WHO-FC scale was more useful in short-term treatment monitoring.

Focused Update on Pulmonary Hypertension in Children-Selected Topics of Interest for the Adult Cardiologist.

Pulmonary hypertensive vascular disease (PHVD), and pulmonary hypertension (PH), which is a broader term, are severe conditions associated with high morbidity and mortality at all ages. Treatment guidelines in childhood are widely adopted from adult data and experience, though big differences may exist regarding aetiology, concomitant conditions and presentation. Over the past few years, paediatric aspects have been incorporated into the common guidelines, which currently address both children and adults with pulmonary hypertension (PH). There are multiple facets of PH in the context of cardiac conditions in childhood. Apart from Eisenmenger syndrome (ES), the broad spectrum of congenital heart disease (CHD) comprises PH in failing Fontan physiology, as well as segmental PH. In this review we provide current data and novel aspects on the pathophysiological background and individual management concepts of these conditions. Moreover, we focus on paediatric left heart failure with PH and its challenging issues, including end stage treatment options, such as mechanical support and paediatric transplantation. PH in the context of rare congenital disorders, such as Scimitar Syndrome and sickle cell disease is discussed. Based on current data, we provide an overview on multiple underlying mechanisms of PH involved in these conditions, and different management strategies in children and adulthood. In addition, we summarize the paediatric aspects and the pros and cons of the recently updated definitions of PH. This review provides deeper insights into some challenging conditions of paediatric PH in order to improve current knowledge and care for children and young adults.

Haemodynamic definitions and updated clinical classification of pulmonary hypertension.

Since the 1st World Symposium on Pulmonary Hypertension (WSPH) in 1973, pulmonary hypertension (PH) has been arbitrarily defined as mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest, measured by right heart catheterisation. Recent data from normal subjects has shown that normal mPAP was 14.0±3.3 mmHg. Two standard deviations above this mean value would suggest mPAP >20 mmHg as above the upper limit of normal (above the 97.5th percentile). This definition is no longer arbitrary, but based on a scientific approach. However, this abnormal elevation of mPAP is not sufficient to define pulmonary vascular disease as it can be due to an increase in cardiac output or pulmonary arterial wedge pressure. Thus, this 6th WSPH Task Force proposes to include pulmonary vascular resistance ≥3 Wood Units in the definition of all forms of pre-capillary PH associated with mPAP >20 mmHg. Prospective trials are required to determine whether this PH population might benefit from specific management.Regarding clinical classification, the main Task Force changes were the inclusion in group 1 of a subgroup "pulmonary arterial hypertension (PAH) long-term responders to calcium channel blockers", due to the specific prognostic and management of these patients, and a subgroup "PAH with overt features of venous/capillaries (pulmonary veno-occlusive disease/pulmonary capillary haemangiomatosis) involvement", due to evidence suggesting a continuum between arterial, capillary and vein involvement in PAH.

Sildenafil Use in Children with Pulmonary Hypertension.

OBJECTIVE: To assess the demographics, treatment algorithm, and outcomes in a large cohort of children treated with sildenafil. STUDY DESIGN: A retrospective cohort study of children with pulmonary hypertension (PH) treated with sildenafil at a single institution between 2004 and 2015. Baseline and follow-up data collected by chart review. RESULTS: There were 269 children included in this study: 47 with idiopathic pulmonary arterial hypertension, 53 with congenital heart disease, 135 with bronchopulmonary dysplasia, 24 with congenital diaphragmatic hernia, and 7 with other causes. Sildenafil was initial monotherapy in 84.8% and add-on therapy in 15.2%. Median follow-up time was 3.1 years (2 weeks-12.4 years). On follow-up, 99 (37%) remained on sildenafil or transitioned to tadalafil, 93 (35%) stopped sildenafil for improvement in PH, 54 (20%) died, and 20 (7%) were lost to follow-up. PH was most likely to improve in those with bronchopulmonary dysplasia, allowing for the discontinuation of sildenafil in 45%. Eighteen deaths were related to PH and 36 from other systemic causes. Two patients stopped sildenafil owing to airway spasm with desaturation. Overall survival was significantly lower in World Health Organization group 3 PH (bronchopulmonary dysplasia and congenital diaphragmatic hernia) vs group 1 (idiopathic pulmonary arterial hypertension and congenital heart disease), P = .02. CONCLUSIONS: In this retrospective experience in children with mainly World Health Organization groups 1 and 3 PH, low-dose sildenafil was well-tolerated, safe, and had an acceptable side effect profile. Although patients with group 3 PH have high mortality, survivors have a high likelihood of PH improving.

Learning a Comorbidity-Driven Taxonomy of Pediatric Pulmonary Hypertension.

RATIONALE: Pediatric pulmonary hypertension (PH) is a heterogeneous condition with varying natural history and therapeutic response. Precise classification of PH subtypes is, therefore, crucial for individualizing care. However, gaps remain in our understanding of the spectrum of PH in children. OBJECTIVE: We seek to study the manifestations of PH in children and to assess the feasibility of applying a network-based approach to discern disease subtypes from comorbidity data recorded in longitudinal data sets. METHODS AND RESULTS: A retrospective cohort study comprising 6 943 263 children (<18 years of age) enrolled in a commercial health insurance plan in the United States, between January 2010 and May 2013. A total of 1583 (0.02%) children met the criteria for PH. We identified comorbidities significantly associated with PH compared with the general population of children without PH. A Bayesian comorbidity network was constructed to model the interdependencies of these comorbidities, and network-clustering analysis was applied to derive disease subtypes comprising subgraphs of highly connected comorbid conditions. A total of 186 comorbidities were found to be significantly associated with PH. Network analysis of comorbidity patterns captured most of the major PH subtypes with known pathological basis defined by the World Health Organization and Panama classifications. The analysis further identified many subtypes documented in only a few case studies, including rare subtypes associated with several well-described genetic syndromes. CONCLUSIONS: Application of network science to model comorbidity patterns recorded in longitudinal data sets can facilitate the discovery of disease subtypes. Our analysis relearned established subtypes, thus validating the approach, and identified rare subtypes that are difficult to discern through clinical observations, providing impetus for deeper investigation of the disease subtypes that will enrich current disease classifications.

Pulmonary Hypertension Associated with Connective Tissue Disease.

Pulmonary hypertension (PH) is common in most forms of connective tissue disease (CTD); the prevalent type of PH depends on the particular CTD. Thus, pulmonary arterial hypertension (PAH) is dominantly associated with scleroderma, while postcapillary PH is most common in rheumatoid arthritis and lung disease-associated PH is typically found in myositis and sarcoidosis.Considerable expertise is required to identify, diagnose, and manage CTD-PH, as the primary physicians providing the majority of care for this population, rheumatologists, need a good working knowledge of CTD-PH, its rather subtle presentation, and how to access the necessary investigations to screen for and identify patients with PH. The role of the rheumatologist does not stop at diagnosis; in some conditions such as lupus, optimizing immunosuppression is key to the management of PH, and unlike simple idiopathic PAH, the natural history of CTD-PH is often punctuated by complications of the CTD rather than just events due to progression of PH or therapy-related adverse events.The aim of this article is to provide an overview of all forms of CTD-PH, and to provide an easy reference source on current best practice.

Lung Disease in Antiphospholipid Syndrome.

Antiphospholipid syndrome (APS) is an acquired prothrombotic condition characterized by vascular thrombosis and/or obstetric complications, in the persistent positivity of circulating antiphospholipid antibodies (aPLs). The clinical spectrum of manifestations associated with aPL positivity is progressively expanding, including the description of several lung manifestations. The most common pulmonary involvement related to aPL positivity is pulmonary embolism (PE), which has been reported to occur in 14.1% of APS patients during disease course. PE acknowledges a purely thrombotic etiology and thus might be accounted as a criterion for APS, making imperative to test aPL in young subjects with unprovoked PE. Pulmonary hypertension (PH) can manifest in APS patients, being the second most common lung complication of the syndrome, with a prevalence ranging between 1.8 and 3.5%. aPL-positive patients might present PH following a PE, might develop pulmonary arterial hypertension associated with connective tissue disease, or might present pulmonary venous hypertension due to Libman-Sacks endocarditis. Additional lung manifestations, such as diffuse alveolar hemorrhage, acute respiratory distress syndrome, and pulmonary fibrosis, are rarely described in APS patients; it is still not clear whether in these settings aPLs exert a pathogenic role or is a mere epiphenomenon. Hereby we discuss impact, clinical presentation, histopathologic findings, etiology, and treatment of each aPL-associated lung manifestation.

[Pulmonary Hypertension: Diagnostics, Classification and Therapy]. / Pulmonale Hypertonie: Diagnostik, Klassifikation und Therapie.

Pulmonary hypertension is a chronic, incurable disease with poor prognosis. The therapeutic aim is a stabilization of patients showing signs of right heart failure as well as disease progression. A pulmonary hypertension is diagnosed in patients displaying a mean pulmonary arterial pressure of > 25 mmHg in resting state. Invasively measured hemodynamics evaluated by right heart catheterization (mean pulmonary arterial pressure [mPAP], pulmonary arterial wedge pressure [PAWP], diastolic pressure gradient [DPG] and pulmonary vascular resistance [PVR]) allows to differentiate between pre-capillary, post-capillary and combined pulmonary hypertension, which constitutes the basis for classification. Diagnostics and therapy shall occur within a center of expertise. Currently, 10 medications belonging to 5 substance classes are approved. Combination therapy should be introduced early. In accordance with risk stratification, therapy is oriented towards estimated 1-year survival as opposed to single target values. If pulmonary hypertension is associated with left heart disease (group 2) or lung disease (group 3), optimal care of the primary disease should be paramount. These associations make up for a greater proportion of patients than idiopathic pulmonary arterial hypertension (PAH). In isolated cases, patients of group 2 may be treated in centers of expertise within the scope of medical studies. Patients with PAH may be categorized into typical versus atypical PAH. For patients with atypical PAH, an initial monotherapy is to be introduced. In case of chronic thromboembolic pulmonary hypertension, the possibility of an operative pulmonary endarterectomy should be evaluated. To date, the only approved drug is Riociguat, a stimulator of the soluble guanylate cyclase.

Pulmonary Vascular Underperfusion Score in Premature Infants with Bronchopulmonary Dysplasia and Pulmonary Hypertension.

Pulmonary hypertension (PH) is a complication of bronchopulmonary dysplasia (BPD). The underlying pathophysiology of BPD-associated PH is complex and poorly understood. Echocardiogram may underestimate the severity of pulmonary hypertensive vascular disease in severe BPD. Digital subtraction pulmonary angiography (DSPA) is a potentially useful imaging modality for evaluating changes in the pulmonary vasculature of BPD-associated PH. In this study, we objectively quantified the pulmonary hypertensive vascular changes demonstrated by DSPA using a novel pulmonary vascular underperfusion score (PVUS) and correlated the scoring system with echocardiography parameters and cardiac hemodynamics by right heart catheterization.

New insights into the recognition, classification and management of systemic sclerosis-associated pulmonary hypertension.

PURPOSE OF REVIEW: Pulmonary hypertension is a common complication of systemic sclerosis (SSc), and remains a leading cause of morbidity and mortality. We will review recent developments in the recognition, classification and treatment of pulmonary hypertension in SSc. RECENT FINDINGS: Advances in screening for pulmonary arterial hypertension (PAH) and use of exercise haemodynamics may help to identify pulmonary vascular disease earlier in SSc. Recent studies have led to changes in recommendations for adjunct therapy and selection of pulmonary vasodilators for the treatment of SSc-associated PAH. SUMMARY: Recent advances in the diagnosis, classification and management of pulmonary hypertension in SSc have continued to improve our understanding of this challenging disease. Ongoing investigation in the pathogenesis of this disease will afford the opportunity to develop targeted therapies to improve outcomes for SSc patients with pulmonary hypertension.

Risk assessment, prognosis and guideline implementation in pulmonary arterial hypertension.

Current European guidelines recommend periodic risk assessment for patients with pulmonary arterial hypertension (PAH). The aim of our study was to determine the association between the number of low-risk criteria achieved within 1 year of diagnosis and long-term prognosis.Incident patients with idiopathic, heritable and drug-induced PAH between 2006 and 2016 were analysed. The number of low-risk criteria present at diagnosis and at first re-evaluation were assessed: World Health Organization (WHO)/New York Heart Association (NYHA) functional class I or II, 6-min walking distance (6MWD) >440 m, right atrial pressure <8 mmHg and cardiac index ≥2.5 L·min-1·m-21017 patients were included (mean age 57 years, 59% female, 75% idiopathic PAH). After a median follow-up of 34 months, 238 (23%) patients had died. Each of the four low-risk criteria independently predicted transplant-free survival at first re-evaluation. The number of low-risk criteria present at diagnosis (p<0.001) and at first re-evaluation (p<0.001) discriminated the risk of death or lung transplantation. In addition, in a subgroup of 603 patients with brain natriuretic peptide (BNP) or N-terminal pro-brain natriuretic peptide (NT-proBNP) measurements, the number of three noninvasive criteria (WHO/NYHA functional class, 6MWD and BNP/NT-proBNP) present at first re-evaluation discriminated prognostic groups (p<0.001).A simplified risk assessment tool that quantifies the number of low-risk criteria present accurately predicted transplant-free survival in PAH.

Pulmonary arterial hypertension - progress in understanding the disease and prioritizing strategies for drug development.

Pulmonary arterial hypertension (PAH), at one time a largely overlooked disease, is now the subject of intense study in many academic and biotech groups. The availability of new treatments has increased awareness of the condition. This in turn has driven a change in the demographics of PAH, with an increase in the mean age at diagnosis. The diagnosis of PAH in more elderly patients has highlighted the need for careful phenotyping of patients and for further studies to understand how best to manage pulmonary hypertension associated with, for example, left heart disease. The breadth and depth of expertise focused on unravelling the molecular pathology of PAH has yielded novel insights, including the role of growth factors, inflammation and metabolic remodelling. The description of the genetic architecture of PAH is accelerating in parallel, with novel variants, such as those reported in potassium two-pore domain channel subfamily K member 3 (KCNK3), adding to the list of more established mutations in genes associated with bone morphogenetic protein receptor type 2 (BMPR2) signalling. These insights have supported a paradigm shift in treatment strategies away from simply addressing the imbalance of vasoactive mediators observed in PAH towards tackling more directly the structural remodelling of the pulmonary vasculature. Here, we summarize the changing clinical and molecular landscape of PAH. We highlight novel drug therapies that are in various stages of clinical development, targeting for example cell proliferation, metabolic, inflammatory/immune and BMPR2 dysfunction, and the challenges around developing these treatments. We argue that advances in the treatment of PAH will come through deep molecular phenotyping with the integration of clinical, genomic, transcriptomic, proteomic and metabolomic information in large populations of patients through international collaboration. This approach provides the best opportunity for identifying key signalling pathways, both as potential drug targets and as biomarkers for patient selection. The expectation is that together these will enable the prioritization of potential therapies in development and the evolution of personalized medicine for PAH.