Incidence of pulmonary hypertension and determining factors in patients with systemic sclerosis

A scoping review of the epidemiology of systemic sclerosis and its organ manifestations: 2018-2024

PURPOSE OF REVIEW

Updates from large, observational cohorts and new statistical techniques have resulted in new data on the epidemiology of systemic sclerosis (SSc). This scoping review uses data from 2018 to 2024 to describe the current understanding of the epidemiology of SSc and several of its organ- manifestations.

RECENT FINDINGS

Our review identified new estimates for the global incidence and prevalence of SSc (1.4-8.6 per 100 000 person-years and 17.6-18.9 per 100 000 individuals, respectively). Mortality rates remain high, though mortality at younger ages has decreased. interstitial lung disease and pulmonary arterial hypertension remain the most common causes of death for patients with SSc. Literature on gastrointestinal (GI) manifestations of SSc was scarce, and we identified significant heterogeneity in results. Furthermore, data on the epidemiology of racial, ethnic and sex-based disparities was lacking.

SUMMARY

New techniques for the evaluation of the epidemiology of SSc highlight the high morbidity and mortality of SSc, and a growing prevalence rate compared with prior eras. Further research is needed to address notable heterogeneity in the reporting of epidemiological data and understudied disease manifestations, including GI disease and health disparities in disease outcomes.

Shifting Paradigms in the Management of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a long-term condition characterised by increased resistance to blood flow in the pulmonary circulation. The disease has a progressive course and is associated with a poor prognosis. Without treatment, PAH is associated with mortality in <3 years. Over the past decade, many advances have been made in revising the haemodynamic definition, clinical classification, risk calculation score, treatment options etc. Suggestions from the Sixth World Symposium on Pulmonary Hypertension were incorporated into a literature review that was included in the European Society of Cardiology/European Respiratory Society (ESC/ERS)'s most recent iteration of their guidelines in 2022. The traditional cut-off for pulmonary hypertension (PH), i.e., mean pulmonary artery pressure (mPAP) >25 mm Hg, has been challenged by observational cohort studies, which have shown poor outcomes for values of 21-24 mmHg; the new consensus is that PH is defined at mPAP >20 mm Hg. Although the gold standard for diagnosis and the major source of therapy guidance continues to be right cardiac catheterisation, echocardiography remains the initial test of choice. A multidisciplinary approach is highly recommended when treating PH patients and careful evaluation of patients will aid in proper diagnosis and prognosis. Pharmacotherapy for PAH has seen a paradigm shift with the successful use of newer agents in more extensive, longer and more inclusive trials driven by hard endpoints. Macitentan, selexipag and riociguat are three oral agents that have shown astounding success in PAH randomised studies in the past decade. Upfront combination therapy with two agents is now becoming the norm (following the AMBITION, OPTIMA and ITALY trials) and the momentum is shifting towards triple therapy as for essential hypertension. More recently, inhaled treprostinil was shown to improve exercise capacity in PH associated with interstitial lung disease in the phase III INCREASE study and has been granted regulatory approval for World Health Organization group 3 PH. A new class of drug, sotatercept (a tumour growth factor-β signalling inhibitor), has also been recently approved by the Food and Drug Administration for management of PAH based on positive results from the phase III STELLAR study. Pulmonary artery denervation and balloon pulmonary angioplasty have emerged as viable alternatives in PH that are resistant to drug therapy. This article aims to summarise the key changes and recent advances in diagnosis and managing PH in general, with an emphasis on certain subgroups.

Prevalence of pulmonary hypertension and its associated factors among chronic obstructive pulmonary diseases patients at public hospitals of Addis Ababa, Ethiopia, 2024: a facility-based cross-sectional study

Background

Pulmonary hypertension (PH) is a serious medical condition characterized by elevated pressure in the lung blood vessels, with chronic heart and lung diseases being the most common causes worldwide. However, there is a dearth of studies on the prevalence of pulmonary hypertension and its associated factors among chronic obstructive pulmonary disease (COPD) patients in Ethiopia and the study area.

Objective

This study aimed to assess the prevalence of pulmonary hypertension and its associated factors among patients with chronic obstructive pulmonary disease at public hospitals in Addis Ababa, Ethiopia, 2024.

Methods

A facility-based cross-sectional study involving 422 COPD patients charted in Addis Ababa town, Ethiopia from May - June 2024 was conducted. Respondents' records were chosen using simple random numbers. Structured, and pretested questionnaires, were used to collect data. The data were coded and entered into EpiData 3.1 before being exported to SPSS version 25 for analysis. Logistic regression was employed to identify factors influencing the prevalence of pulmonary hypertension. Statistical significance was set at p < 0.05 with a 95% confidence interval.

Results

The study found the prevalence of pulmonary hypertension was 52% (95% CI: 49, 54.4%). Aged above 55 years [Adjusted Odds Ratio (AOR): 2.45 (1.55-3.9), Being male (AOR): 2.5 (1.5-4.1)]. Furthermore, having a history of alcohol [(AOR): 5.5 (2.4-13)], a history of smoking [(AOR): 4.6 (2.7-7.8), and congestive heart failure (AOR): 2.65 (1.5-4.6)], all increase the likelihood of pulmonary hypertension.

Conclusion

The study revealed a higher prevalence of pulmonary hypertension among COPD patients. Significant associations were found with being male, belonging to an older age group, and having a history of alcohol use, smoking, and congestive heart disease. Implementing screening programs, smoking cessation programs, educational initiatives, and counseling patients on lifestyle modifications were recommended.

Towards a Better Prognosis in Patients with Systemic Sclerosis-Related Pulmonary Arterial Hypertension: Recent Developments and Perspectives

Precapillary pulmonary hypertension (PH) is a significant complication of systemic sclerosis (SSc). It represents one of the leading causes of morbidity and mortality, correlating with a significantly dismal prognosis and quality of life. Despite advancements in the management of patients with pulmonary arterial hypertension associated with SSc (SSc-PAH), no significant improvement has been reported in survival of patients with precapillary SSc-PH associated with extensive lung parenchyma disease. International expert consensus and guidelines for the management of PH recommend annual screening of SSc patients for early detection of pre-capillary PH. The implementation of screening algorithms capable of identifying patients with a high likelihood of developing PH could help limit unnecessary right-heart catheterization procedures and prevent significant delay in diagnosis. Furthermore, early initiation of up-front combination targeted therapy in patients with PAH has shown increase in survival rates, indicating that timely and aggressive medical therapy is key for stabilizing and even improving functional class, hemodynamic parameters and 6 min walking distance (6MWD) in this population. Further research is warranted into the benefit of PAH-targeted therapies in patients with PH associated with lung disease. Lastly, we discuss the potential role of immunosuppression using biologic agents in the therapeutic management of precapillary PH in SSc patients.

The latest definition and classification of pulmonary hypertension

Pulmonary hypertension (PH) is a serious potential complication of some congenital heart diseases (CHDs). PH encompasses a range of diseases which may be idiopathic or inherited, or secondary to cardiac, respiratory, systemic or thromboembolic conditions, amongst others. Our increasing understanding of the normal ranges of pulmonary haemodynamics, as well as evidence supporting the benefits of early treatment, has resulted in a number of recent revisions to the haemodynamic definition of PH. In this Review Article, we report on the recent updates to haemodynamic definitions and classification of PH, as reflected in the 2022 Pulmonary Hypertension Guidelines and particularly focus on the CHD related sub-type of PH, where the aetiology is often multi-factorial.

The Management of Mild Pulmonary Hypertension in Clinical Practice

The definition of pulmonary hypertension (PH) has been revised recently, with the mean pulmonary artery pressure (mPAP) threshold (assessed by right heart catheterization) reduced from ⩾25 mm Hg to >20 mm Hg. This change reflects the mPAP upper limit of normal and a lower limit that is independently associated with adverse outcomes. To improve the specificity of diagnosing pathogenic increases in mPAP, however, a diagnosis of precapillary PH now also includes pulmonary vascular resistance >2.0 Wood units (WU) (lowered from >3.0 WU). These changes are positioned to capture approximately 55% more patients with PH. Because all clinical trials showing a benefit of pulmonary vasodilator therapy in precapillary PH used the classical hemodynamic definition, the approach to the diagnosis and management of patients with mild PH (i.e., mPAP 21-24 mm Hg and pulmonary vascular resistance 2-3 WU) requires particular consideration. Here, we use a question/answer format to discuss key areas in the management of mild PH, including practical information tailored to clinicians without training in PH.

Pulmonary Hypertension Associated with Connective Tissue Disease

Pulmonary hypertension (PH), a syndrome characterized by elevated pulmonary pressures, commonly complicates connective tissue disease (CTD) and is associated with increased morbidity and mortality. The incidence of PH varies widely between CTDs; patients with systemic sclerosis are most likely to develop PH. Several different types of PH can present in CTD, including PH related to left heart disease and respiratory disease. Importantly, CTD patients are at risk for developing pulmonary arterial hypertension, a rare form of PH that is associated with high morbidity and mortality. Future therapies targeting pulmonary vascular remodeling may improve outcomes for patients with this devastating disease.

Exercise pulmonary hypertension in patients with systemic sclerosis based on updated guidelines

Recent European guidelines have introduced the concept of exercise pulmonary hypertension (ex-PH). However, the clinical characteristics of ex-PH in systemic sclerosis (SSc) remains unknown. We aimed to investigate the characteristics of exercise pulmonary hypertension (ex-PH) in patients with systemic sclerosis (SSc), which are unknown. We retrospectively examined 77 patients with SSc who underwent symptom-limited exercise testing using a cycle ergometer with right heart catheterization at our hospital. Nineteen patients with postcapillary PH were excluded. Fifty-eight patients (median age, 63 years; 55 women) were divided into the overt-PH (n = 18, mean pulmonary arterial pressure [PAP] > 20 mmHg and pulmonary vascular resistance > 2 Wood units at rest), ex-PH (n = 19, mean PAP/cardiac output slope > 3), and non-PH (n = 21) groups. Exercise tolerance and echocardiography results were compared among the groups. Peak oxygen consumption was high in the non-PH group, intermediate in the ex-PH group, and low in the overt-PH group (14.5 vs. 13.0 vs. 12.5 mL/kg/min, p = 0.043), and the minute ventilation/peak carbon dioxide production slope was also intermediate in the ex-PH group (32.2 vs. 32.4 vs. 43.0, p = 0.003). The tricuspid annular plane systolic excursion/systolic PAP ratio decreased from non-PH to ex-PH to overt-PH (0.73 vs. 0.69 vs. 0.55 mm/mmHg, p = 0.018). In patients with SSc, exercise PH may represent an intermediate condition between not having PH and overt PH, according to the new guidelines.

Endothelial cell clonality, heterogeneity and dysfunction in pulmonary arterial hypertension

Our understanding of the pathophysiology of pulmonary arterial hypertension (PAH) has evolved over recent years, with the recognition that endothelial cell (EC) dysfunction and inflammation play an integral role in the development of this disease. ECs within the pulmonary vasculature play a unique role in maintaining vascular integrity and barrier function, regulating gas exchange, and contributing to vascular tone. Using single-cell transcriptomics, research has shown that there are multiple, unique EC subpopulations with different phenotypes. In response to injury or certain stressors such as hypoxia, there can be a dysregulated response with aberrant endothelial injury repair involving other pulmonary vascular cells and even immune cells. This aberrant signaling cascade is potentially a primary driver of pulmonary arterial remodeling in PAH. Recent studies have examined the role of EC clonal expansion, immune dysregulation, and genetic mutations in the pathogenesis of PAH. This review summarizes the existing literature on EC subpopulations and the intricate mechanisms through which ECs develop aberrant physiologic phenotypes and contribute to PAH. Our goal is to provide a framework for understanding the unique pulmonary EC biology and pathophysiology that is involved in the development of PAH.

[Diagnostic Algorithm and Screening of Pulmonary Hypertension]

The new guidelines for the diagnosis and treatment of pulmonary hypertension include a new diagnostic algorithm and provide specific recommendations for the required diagnostic procedures, including screening methods. These recommendations are commented on by national experts under the auspices of the DACH. These comments provide additional decision support and background information, serving as a further guide for the complex diagnosis of pulmonary hypertension.

Significance of Hypocapnia in the Risk Assessment of Patients with Pulmonary Hypertension

Blood gas analysis is part of the diagnostic work-up for pulmonary hypertension (PH). Although some studies have found that the partial pressure of carbon dioxide (PaCO2) is an independent marker of mortality in individuals with pulmonary arterial hypertension (PH Group 1), there is a lack of data regarding the significance of PaCO2 in individuals with different types of PH based on the new 2022 definitions. Therefore, this study analyzed data from 157 individuals who were undergoing PH work-up, including right heart catheterization, using PH definitions from the 2022 European Society of Cardiology/European Respiratory Society guidelines. At diagnosis, N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels were significantly higher, but the time-course of NT-pro-BNP levels during treatment was significantly more favorable in individuals with pulmonary arterial hypertension (PH Group 1) who did versus did not have hypocapnia (p = 0.026 and p = 0.017, respectively). These differences based on the presence of hypocapnia were not seen in individuals with PH Groups 2, 3, or 4. In conclusion, using the new definition of PH, hypocapnia may correlate with worse risk stratification at diagnosis in individuals with pulmonary arterial hypertension. However, hypocapnic individuals with pulmonary arterial hypertension may benefit more from disease-specific therapy than those without hypocapnia.

Pulmonary hypertension in systemic sclerosis with usual interstitial pneumonia

Retrospective study comparing pulmonary hypertension risk in systemic sclerosis (SSc) and non-SSc interstitial lung disease patients with usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP). Retrospective analysis of 144 interstitial lung disease patients, 53 SSc (32 UIP and 21 NSIP) and 91 non-SSc (47 UIP and 44 NSIP). Pulmonary hypertension was diagnosed as pulmonary systolic artery pressure (PAPs) > 25 mmHg. All SSc and non-SSc patients with pulmonary hypertension were classified WHO Group 3. Pulmonary hypertension was identified in 21/32 (65.6%), 9/21 (42.8%), 14/47 (29.7%), and 28/44 (45.4%) SSc-UIP, SSc-NSIP, control-UIP, and control-NSIP groups, respectively. PAPs mean of SSc-UIP group was higher than control-UIP group (32.6 ± 9.8 vs 28.5 ± 6.6, p-value = 0.02). PAPs mean of SSc-NSIP group was lower than control-NSIP group (27.0 ± 7.1 vs 33.9 ± 8.8, p = 0.002). Frequency of patients with PAP > 25 mmHg in SSc-UIP group was 60% higher in comparison to control-UIP (OR = 1.62, 95% CI 0.51-5.16) and SSc-NSIP (OR = 1.60, 95% CI 0.45-5.70) groups. Logistic regression analysis estimating the linear trend per ten-unit increase in PAPs levels demonstrated an increment for the SSc-UIP group compared to the control-UIP (OR = 2.64, 95% CI 1.25-5.58, p = 0.01) and the control-NSIP (OR = 6.34, 95% CI 2.82-14.3, p < 0.001) groups. The case-control study confirms that pulmonary hypertension is frequently found in SSc patients and demonstrates, for the first time, a significant increased risk of pulmonary hypertension among SSc-UIP patients.

Veno-Arterial Extracorporeal Membrane Oxygenation Rescue in a Patient With Pulmonary Hypertension Presenting for Revision Total Hip Arthroplasty: A Case Report and Narrative Review

Patients with pulmonary hypertension (PH) are at an increased risk of perioperative morbidity and mortality when undergoing non-cardiac surgery. We present a case of a 57-year-old patient with severe PH, who developed cardiac arrest as the result of right heart failure, undergoing a revision total hip arthroplasty under combined spinal epidural anesthesia. Emergent veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) was undertaken as rescue therapy during the pulmonary hypertensive crisis and a temporizing measure to provide circulatory support in an intensive care unit (ICU). We present a narrative review on perioperative management for patients with PH undergoing non-cardiac surgery. The review goes through the updated hemodynamic definition, clinical classification of PH, perioperative morbidity, and mortality associated with PH in non-cardiac surgery. Pre-operative assessment evaluates the type of surgery, the severity of PH, and comorbidities. General anesthesia (GA) is discussed in detail for patients with PH regarding the benefits of and unsubstantiated arguments against GA in non-cardiac surgery. The literature on risks and benefits of regional anesthesia (RA) in terms of neuraxial, deep plexus, and peripheral nerve block with or without sedation in patients with PH undergoing non-cardiac surgery is reviewed. The choice of anesthesia technique depends on the type of surgery, right ventricle (RV) function, pulmonary artery (PA) pressure, and comorbidities. Given the differences in pathophysiology and mechanical circulatory support (MCS) between the RV and left ventricle (LV), the indications, goals, and contraindications of VA-ECMO as a rescue in cardiopulmonary arrest and pulmonary hypertensive crisis in patients with PH are discussed. Given the significant morbidity and mortality associated with PH, multidisciplinary teams including anesthesiologists, surgeons, cardiologists, pulmonologists, and psychological and social worker support should provide perioperative management.

[Cardiopulmonary exercise testing in the management of systemic sclerosis]

Cardiopulmonary complications are the leading cause of mortality in patients with systemic sclerosis (SSc) requiring an early identification. The complexity of the overlapping aetiologies of dyspnoea in SSc often requires a global and comprehensive approach. Through its integrative approach of ventilatory, metabolic, cardiovascular, skeletal muscular and gas exchange findings, cardiopulmonary exercise testing (CPET) has been known to identify and sort competing mechanisms of exercise limitation in scleroderma patients presenting with dyspnoea. CPET may be used to screen for pulmonary arterial hypertension, suspect interstitial lung disease and guide therapeutic strategies including exercise rehabilitation. This review focuses on the clinical value of CPET in the decision-making processes for a more personalised diagnostic approach to SSc-related complications.

Paraclinical Aspects in Systemic Sclerosis

Systemic sclerosis (SSc) is a chronic inflammatory disease with an autoimmune substrate that affects the skin and a large number of internal organs. The chronic inflammatory process is sustained by a wide range of cytokines and chemokines, which are discharged by inflammatory cells, with fibrosis and nail bed vascular changes (disorganized vasculature architecture with microhemorrhages, megacapillaries and areas without capillaries). Confocal microscopy contributes to the understanding of the molecular mechanism involved in chronic inflammation and mainly targets the field of research. Coherent optical tomography, capillaroscopy, and skin biopsy are useful for the differential diagnosis of SSc with other sclerodermoid syndromes. The immunological profile is a classification criterion for SSc and directs the diagnosis to the two subsets of the disease. Multisystemic damage requires evaluation with the help of a set of investigations specific to each affected organ, such as: diffusing capacity for carbon monoxide, forced vital capacity, 6-minute walk test, high-resolution computed tomography standard and reduced sequential, cardiac ultrasound and right cardiac catheterization. The current possibilities of diagnosis, treatment and monitoring are permanently adapting to new medical discoveries.

High prevalence of occult left ventricular diastolic dysfunction detected by exercise stress test in systemic sclerosis

Despite the poor prognosis of systemic sclerosis (SSc) due to the co-occurrence of left ventricular diastolic dysfunction (LVDD), presence of occult LVDD has not been sufficiently investigated. This retrospective study aimed to reveal the prevalence and determinants of occult LVDD in patients with SSc by exercise stress test. Forty-five SSc patients (age, 63 ± 13 years; men/women, 6/39) with normal pulmonary artery pressure and pulmonary artery wedge pressure (PAWP) at rest underwent a symptom-limited exercise test with right heart catheterization using a supine cycle ergometer; haemodynamic parameters at rest, leg raise and during exercise were evaluated. Occult LVDD defined PAWP ≥ 25 mmHg during exercise was seen in 13 patients (29%). Higher PAWP, lower pulmonary vascular resistance and diastolic pulmonary pressure gradient, larger left atrium at rest, and higher PAWP during leg raise (15 ± 4 vs 10 ± 4 mmHg in non-LVDD group, p < 0.001) were observed in the occult LVDD group. The area under the ROC curve for PAWP after leg raise was largest at 0.83 (95% CI: 0.70–0.95, p = 0.001). About one-third (29%) of SSc patients with normal haemodynamics at rest showed occult LVDD. A higher PAWP after leg raise could be useful for detecting occult LVDD.

Pulmonary Hypertension Associated with Connective Tissue Disease

Pulmonary hypertension (PH), a syndrome characterized by elevated pulmonary pressures, commonly complicates connective tissue disease (CTD) and is associated with increased morbidity and mortality. The incidence of PH varies widely between CTDs; patients with systemic sclerosis are most likely to develop PH. Several different types of PH can present in CTD, including PH related to left heart disease and respiratory disease. Importantly, CTD patients are at risk for developing pulmonary arterial hypertension, a rare form of PH that is associated with high morbidity and mortality. Future therapies targeting pulmonary vascular remodeling may improve outcomes for patients with this devastating disease.

Pulmonary hypertension phenotypes in patients with systemic sclerosis

Pulmonary hypertension (PH) commonly affects patients with systemic sclerosis (SSc) and is associated with significant morbidity and increased mortality. PH is a heterogenous condition and several different forms can be associated with SSc, including pulmonary arterial hypertension (PAH) resulting from a pulmonary arterial vasculopathy, PH due to left heart disease and PH due to interstitial lung disease. The incidence of pulmonary veno-occlusive disease is also increased. Accurate and early diagnosis to allow optimal treatment is, therefore, essential. Recent changes to diagnostic haemodynamic criteria at the 6th World Symposium on Pulmonary Hypertension have resulted in therapeutic uncertainty regarding patients with borderline pulmonary haemodynamics. Furthermore, the optimal pulmonary vascular resistance threshold for diagnosing PAH and the role of exercise in identifying early disease require further elucidation. In this article we review the epidemiology, diagnosis, outcomes and treatment of the spectrum of pulmonary vascular phenotypes associated with SSc.

Systemic sclerosis-associated pulmonary arterial hypertension in children

Systemic sclerosis (SSc) is a rare disease in childhood and is characterized by a combination of vasculopathy, inflammation, autoimmunity, and fibrogenesis with individually varying expression pattern. Pulmonary arterial hypertension (PAH) is a serious complication of SSc and affects approximately 10% of SSc patients. SSc-PAH is complex and difficult to diagnose, as symptoms are non-specific and may be complicated by other SSc-associated diseases such as interstitial lung disease or left heart disease. SSc-PAH patients can deteriorate rapidly, and disease progression can occur even in patients with mild PAH symptoms at diagnosis. Therefore, interdisciplinary care of SSc patients is essential, and treating physicians must be aware of the association between SSc and PAH. In order to detect PAH early, children with SSc should be regularly screened for PAH by pediatric cardiologists. If PAH is detected, a systematic diagnostic approach by trained PH specialists including careful phenotyping of PAH is required. Relevant interstitial lung disease and left heart disease should be ruled out in the differential diagnosis of SSc-PAH before starting any targeted therapy. Due to the progressive character of SSc-PAH known from adult studies, it appears appropriate to initiate targeted PAH-therapy in juvenile SSc-PAH early. Adapted from adult treatment algorithms, combination therapy regimens (addressing at least two pathophysiological pathways) are increasingly used for pediatric PAH patients, and there is growing evidence to support this approach also in SSc-PAH patients.

Pulmonary Hypertension in Heart Failure

Pulmonary hypertension (PH) is traditionally defined as a mean pulmonary arterial pressure (mPAP) ≥25 mmHg. Although various factors cause PH, the most common etiology is PH due to left heart disease (PH-LHD). The underlying LHD is characterized by heart failure (HF) with reduced ejection fraction (HFrEF), HF with preserved ejection fraction (HFpEF), valvular heart disease, cardiomyopathies, or arrhythmic diseases. Regardless of its underlying cause, elevated left atrial (LA) filling pressure is a manifestation of advanced heart disease. High LA pressure then causes persistent backflow to the pulmonary veins, which increases mPAP. PH-LHD at this stage is named isolated postcapillary PH (IpcPH). Further progression of IpcPH is associated with pulmonary vasculature remodeling and hypertrophy, which consists of adding the precapillary component of PH to the pre-existing postcapillary PH. This form of PH-LHD is called combined precapillary and postcapillary PH (CpcPH). To date, therapeutic strategies for PH-LHD have been investigated in the context of HFrEF or HFpEF. Pulmonary arterial hypertension (PAH)-specific drugs have been tested in HFrEF and HFpEF populations, although encouraging results have not been demonstrated. As PAH-specific drugs target the precapillary component of PH-LHD, future studies utilizing such therapeutics in PH-LHD patients with CpcPH appear to have a more robust pathobiological basis. This article reviews the diagnosis, pathophysiology, treatment, and future direction of PH in HF.

How low should we go? Potential benefits and ramifications of the pulmonary hypertension hemodynamic definitions proposed by the 6th World Symposium

PURPOSE OF REVIEW

The 6th World Symposium on Pulmonary Hypertension (WSPH) proposed lowering the mean pulmonary artery pressure (mPAP) threshold that defines pulmonary hypertension from ≥ 25 to > 20 mmHg. The historical context and evolution of the pulmonary hypertension definition and the data used to rationalize recent changes are reviewed here.

RECENT FINDINGS

There are accumulating data on the clinical significance of mildly elevated mPAPs (21-24 mmHg). Studies have demonstrated lower exercise capacity and an increased risk of progression to overt pulmonary hypertension (mPAP ≥ 25 mmHg) in specific at-risk patient populations. Further, large registries across diverse pulmonary hypertension populations have identified increased mortality in patients with mPAPs 21-24 mmHg. Although the clinical sequelae of lowering the mPAP threshold remain unclear, this uncertainty has fueled recent debates within the pulmonary hypertension community.

SUMMARY

The changes to the pulmonary hypertension definition proposed by the 6th WSPH are supported by normative hemodynamic data in healthy individuals as well as studies demonstrating an association between mPAPs above this normal range and increased mortality. Whether the higher mortality observed in patients with mildly elevated mPAPs is directly attributable to pulmonary vascular disease that is amenable to therapeutic intervention remains to be determined.

Screening for the early detection of pulmonary arterial hypertension in patients with systemic sclerosis: A systematic review and meta-analysis of long-term outcomes

BACKGROUND

Systemic sclerosis (scleroderma, SSc) is a chronic multisystem autoimmune disease characterised by fibrosis of the skin and internal organs and vasculopathy. One of the major contributors to mortality in patients with SSc is pulmonary arterial hypertension (PAH). International recommendations advise annual screening for the early detection of PAH in asymptomatic patients with SSc.

OBJECTIVES

To evaluate by systematic review current measures employed for screening for PAH. To summarise by meta-analysis the current evidence for long-term outcomes of screening for PAH in SSc.

METHODS

Manuscripts published until 12th March 2019 were identified through searching Medline, Embase and Cochrane Central Register of Controlled Trials and Database of Systematic Reviews. Eligible studies included abstracts or full reports investigating patients with SSc undergoing screening by any protocol to detect PAH. Risk of bias was assessed with reference to the QUADAS-2 tool.

RESULTS

The review resulted in 580 unique citations with 15 manuscripts included for final systematic review of screening methods, and six for meta-analysis. The systematic review demonstrated that there are varying protocols for screening for PAH. Screened populations were reported to have better risk stratification parameters at PAH diagnosis. Meta-analysis showed improved survival in patients with SSc-PAH diagnosed as a result of screening. There were trends towards having better risk stratification parameters at PAH diagnosis in those screened, although not all of these were statistically significant.

LIMITATIONS

There are no randomised controlled trials of screening for PAH in patients with SSc and the evidence presented in this review is derived from publications of registry data, cross-sectional and cohort studies.

CONCLUSIONS

This review demonstrates long-term benefit through the systematic screening of patients with SSc of varying disease duration for the early detection of PAH. Screened cohorts had improved survival, and were more likely to have better prognostic factors at the time of diagnosis with PAH.

Impact of the new definition of pulmonary hypertension according to world symposium of pulmonary hypertension 2018 on diagnosis of post-capillary pulmonary hypertension

BACKGROUND

The World Symposium on Pulmonary Hypertension (WSPH) in 2018 recommended new definitions of pulmonary hypertension (PH). We investigated the impact of the updated definition on prevalence of PH due to left heart disease (PH-LHD).

METHODS

The data of right heart catheterizations in patients with suspected PH-LHD between January 2008 and July 2015 was retrospectively analyzed applying different definitions. The number of patients diagnosed by the updated WSPH hemodynamic criteria of a mean pulmonary artery pressure (mPAP) > 20 mmHg was compared to the number of patients using mPAP ≥ 25 mmHg. The differentiation between patients with isolated post-capillary (Ipc) and combined post-capillary and pre-capillary (Cpc) PH was analyzed comparing the ESC/ERS guidelines, the recommendation of Cologne Consensus Conference (CCC) and WSPH.

RESULTS

Of the 726 patients with a suspected PH, 58 patients met the diagnostic criteria of the ESC/ERS guidelines for PH-LHD with 32.8% Ipc-cases, 34.4% Cpc-PH-cases and 32.8% unclassifiable cases. Overall, 58 patients were diagnosed by the CCC criteria, with 34.5% classified as Cpc-PH and 65.5% as Icp-PH. Using the criteria of WSPH, the number of PH-LHD rose by one patient. According to the new definition, 64.4% of the patients were classified as Cpc-PH and had a significantly higher right to left atrial area (RA/LA) ratio than Ipc-PH patients.

CONCLUSION

Applying the new recommendation, the number of diagnosed patients with PH-LHD increases marginally. There is, however, a relevant shift in the number of Cpc-PH cases. An elevated RA/LA ratio might help to identify patients for invasive diagnostic work-up.

Mildly Elevated Pulmonary Arterial Pressure Is Associated With a High Risk of Progression to Pulmonary Hypertension and Increased Mortality: A Systematic Review and Meta-Analysis

Background

Pulmonary hypertension (PH) is defined as a mean pulmonary arterial pressure (PAP) ≥25 mm Hg measured by right heart catheterization. However, the upper limit of a normal mean PAP is 20 mm Hg. There is a gap between the upper limit of normal and the threshold for diagnosing PH. Therefore, we aimed to investigate whether individuals with a mildly elevated PAP, defined as 20 mm Hg < mean PAP <25 mm Hg, are at an increased risk of progression to PH or mortality than those with a normal PAP.

Methods and Results

We reviewed studies evaluating the risk of progression to PH and/or mortality in individuals with a mildly elevated PAP versus those with a normal PAP. The mean PAP value of each participant was confirmed by right heart catheterization. We reviewed 1213 studies and 8 fulfilled our inclusion criteria. Our results indicated that individuals with a mildly elevated PAP were 1.81 to 2.45 times more likely to progress to PH than individuals with a normal PAP. There was a statistically significant difference in mortality between the mildly elevated PAP and normal PAP groups (hazard ratio, 2.48; 95% CI, 1.69–3.64). We also pooled survival probabilities in each arm to obtain a summary survival curve for each group, and the pooled survival rates in the mildly elevated PAP group were numerically lower than those in the normal PAP group.

Conclusions

Our study revealed that individuals with a mildly elevated PAP were at an increased risk of progression to PH and mortality than those with a normal PAP.

Combined pre- and post-capillary pulmonary hypertension: The clinical implications for patients with heart failure

BACKGROUND

The prognostic implications of combined pre- and post-capillary pulmonary hypertension (Cpc-PH) in patients with pulmonary hypertension due to left heart disease (PH-LHD) remain controversial. The aim of this retrospective study was to evaluate the new PH-LHD criteria, recommended by the 6th World Symposium on Pulmonary Hypertension and to determine the prognostic value of Cpc-PH.

METHODS

A total of 701 patients with symptomatic heart failure who had undergone right-heart catheterization were divided into the following four groups: (i) Isolated post-capillary PH (Ipc-PH) group; mean pulmonary artery pressure (mPAP) >20 mmHg, pulmonary artery wedge pressure (PAWP) >15 mmHg, and pulmonary vascular resistance (PVR) <3 Wood units (WU) (ii) Cpc-PH group; mPAP >20 mmHg, PAWP >15 mmHg, and PVR ≥3 WU (iii) borderline-PH group; mPAP >20 mmHg and PAWP ≤15 mmHg (iv) non-PH group; mPAP ≤20 mmHg. Multivariate Cox hazard analysis was used to investigate whether Cpc-PH was associated with cardiac outcomes.

RESULTS

The study subjects were allocated into the Ipc-PH (n = 268), Cpc-PH (n = 54), borderline-PH (n = 112), or non-PH (n = 267) groups. The Cpc-PH group was associated significantly with adverse cardiac events even after adjustment for clinically relevant confounding factors for heart failure prognosis (vs. non-PH group: HR 2.98 [95% CI 1.81-4.90], P <0.001; vs. Ipc-PH group: HR: 1.92 [95% CI 1.19-3.08], P = 0.007).

CONCLUSIONS

The new definitions of PH-LHD stratified patients into 4 categories. Long-term clinical outcomes were significantly different between the four categories, with Cpc-PH having the worst cardiac outcomes.

Recent advances in the management of pulmonary arterial hypertension: lessons from the upfront combination of ambrisentan and tadalafil

INTRODUCTION

The sixth World Symposium of Pulmonary Hypertension (sixth WSPH) brought to the forefront for the first time the value of earlier, aggressive management with an upfront oral combination in patients with pulmonary arterial hypertension (PAH) of low or intermediate risk. This was prompted by results from the AMBITION study (ambrisentan + tadalafil). A literature search was conducted to collect all evidence provided by upfront treatment with this combination, as well as other combinations under investigation at the time the manuscript was prepared.

AREAS COVERED

The value of an upfront oral combination with ambrisentan and tadalafil is reviewed on the basis of topics discussed at the sixth WSPH, such as evidence in different PAH etiologies, according to risk stratification and in so-called 'atypical' patients where monotherapy is still recommended. Evidence in clinical practice is also reviewed. New evidence about the value of the upfront oral combination is also commented. Finally, tendencies in primary endpoints to assess the effect of PAH-targeted therapies (time to clinical worsening and hemodynamics) and their value are also reviewed.

EXPERT OPINION

All above-mentioned aspects are put into perspective with regard to the impact of new advances on improving PAH management in clinical practice.

[Differential Diagnosis of Pulmonary Hypertension Using the Example of Collagenosis-associated PAH in the Context of Chronic Lung and Left Heart Disease]

Pulmonary hypertension (PH) can be diagnosed in the context of connective tissue diseases (CTD) as well as in elderly patients with multiple comorbidities. A correct clinical differential diagnosis and classification is essential before adequate therapeutic decisions can be made. Differential diagnosis of PH in CTD comprises associated pulmonary arterial hypertension (APAH), group 2 or 3 PH (PH arising from left heart or chronic lung disease), chronic thromboembolic PH (PH) and group 5 (e. g. in the context of terminal renal insufficiency). This is also true of elderly patients in whom the decision has to be made if the increasing number of coincident diseases lead to PH or have to be interpreted as comorbidities. In this manuscript, the differential diagnosis of PH is elucidated, focusing on CTD, in the context of left heart disease and chronic lung disease. Furthermore, criteria are presented facilitating an objective approach in this context.

Pulmonary arterial hypertension in systemic sclerosis

Pulmonary arterial hypertension (PAH) is a frequent and severe complication of systemic sclerosis (SSc) due to combined vasculopathy and fibrogenesis. Early diagnosis and treatment are highly challenging in SSc-PAH and require referral to an expert PAH centre. Diagnostic algorithms evolved in the last decade. Novel therapeutic options notably targeting pulmonary vascular remodeling are needed.

Association of Lymphangiogenic Factors With Pulmonary Arterial Hypertension in Systemic Sclerosis

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a major complication in systemic sclerosis (SSc), a disease marked by vascular and lymphatic vessel abnormalities. This study was undertaken to assess the role of the lymphangiogenic factors vascular endothelial growth factor C (VEGF-C) and angiopoietin 2 (Ang-2) and the soluble forms of their respective cognate receptors, soluble VEGF receptor 3 (sVEGFR-3) and soluble TIE-2, in patients with SSc, and to evaluate their predictive ability as markers for PAH development in SSc.

METHODS

In this cohort study, we used multiplex bead assays to assess serum levels of lymphangiogenic factors in 2 well-characterized SSc cohorts: an unselected identification cohort of SSc patients from Oslo University Hospital (n = 371), and a PAH-enriched validation cohort of SSc patients from Zurich University Hospital and Oslo University Hospital (n = 149). As controls for the identification and validation cohorts, we obtained serum samples from 100 healthy individuals and 68 healthy individuals, respectively. Patients in whom SSc-related PAH was identified by right-sided heart catheterization (RHC) in both cohorts were studied in prediction analyses. PAH was defined according to the European Society of Cardiology/European Respiratory Society 2015 guidelines for the diagnosis and treatment of PAH. Associations of serum levels of lymphangiogenic factors with the risk of PAH development were assessed in logistic regression and Cox regression analyses. Associations in Cox regression analyses were expressed as the hazard ratio (HR) with 95% confidence interval (95% CI).

RESULTS

In the identification cohort, SSc patients had lower mean serum levels of VEGF-C and higher mean serum levels of Ang-2 compared to healthy controls (for VEGF-C, mean ± SD 2.1 ± 0.5 ng/ml in patients versus 2.5 ± 0.4 ng/ml in controls; for Ang-2, mean ± SD 6.1 ± 7.6 ng/ml in patients versus 2.8 ± 1.8 ng/ml in controls; each P < 0.001); these same trends were observed in SSc patients with PAH compared to those without PAH. The association of serum VEGF-C levels with SSc-PAH was confirmed in the PAH-enriched RHC validation cohort. For prediction analyses, we assembled all 251 cases of SSc-PAH identified by RHC from the identification and validation cohorts. In multivariable Cox regression analyses adjusted for age and sex, the mean serum levels of VEGF-C and sVEGFR-3 were predictive of PAH development in patients with SSc (for VEGF-C, HR 0.53 [95% CI 0.29-0.97], P = 0.04; for sVEGFR-3, HR 1.21 [95% CI 1.01-1.45], P = 0.042).

CONCLUSION

These findings support the notion that lymphangiogenesis is deregulated during PAH development in SSc, and indicate that VEGF-C could be a promising marker for early PAH detection in patients with SSc.

Are troponin and B-type natriuretic peptides useful biomarkers for the diagnosis of systemic sclerosis heart involvement? A systematic literature review

BACKGROUND

Systemic sclerosis (SSc) heart involvement (SHI) is a leading cause of SSc-associated mortality and once clinically overt, carries a very poor prognosis. There remain no established diagnostic criteria for SHI. This study aimed to systematically review the literature regarding the role of cardiac troponin (cTn) and B-type natriuretic peptide (BNP) or N-terminal B-type natriuretic peptide (NT-proBNP) in the diagnosis of SHI.

METHODS

A comprehensive search of the MEDLINE (Ovid), EMBASE and Pubmed databases was performed to identify adult human studies of at least 10 SSc patients with a primary focus of SHI that included data on cTn and BNP or NT-proBNP results. Only cohort studies and case-controlled studies were identified and the quality of the evidence presented in each study was assessed according to the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Of the 2742 studies identified by the database search, 12 articles fulfilled the study inclusion criteria. Three out of four studies evaluating SHI using cardiac magnetic resonance imaging found no association between cardiac biomarkers and imaging changes. By comparison echocardiographic abnormalities, cardiac arrhythmias and congestive cardiac failure were more likely to be associated with elevated cardiac biomarkers. Comparison of results between studies was limited by the highly heterogenous definitions of SHI and inclusion criteria employed across studies.

CONCLUSION

There are insufficient data to draw definitive conclusions about the role of cTn and BNP / NT-proBNP in the diagnosis of SHI. Currently available literature suggests that cardiac biomarkers may have some role, in conjunction with other diagnostic modalities, in identifying SHI; however, this remains a much-needed area of clinical research.

Right Heart Size and Right Ventricular Reserve in Pulmonary Hypertension: Impact on Management and Prognosis

Various parameters reflecting right heart size, right ventricular function and capacitance have been shown to be prognostically important in patients with pulmonary hypertension (PH). In the advanced disease, patients suffer from right heart failure, which is a main reason for an impaired prognosis. Right heart size has shown to be associated with right ventricular function and reserve and is correlated with prognosis in patients with PH. Right ventricular reserve, defined as the ability of the ventricle to adjust to exercise or pharmacologic stress, is expressed by various parameters, which may be determined invasively by right heart catheterization or by stress-Doppler-echocardiography as a noninvasive approach. As the term "right ventricular contractile reserve" may be misleading, "right ventricular output reserve" seems desirable as a preferred term of increase in cardiac output during exercise. Both right heart size and right ventricular reserve have been shown to be of prognostic importance and may therefore be useful for risk assessment in patients with pulmonary hypertension. In this article we aim to display different aspects of right heart size and right ventricular reserve and their prognostic role in PH.

Pulmonary hypertension in patients with interstitial pneumonia with autoimmune features

Pulmonary hypertension in interstitial lung diseases is associated with increased mortality and hospitalizations and reduced exercise capacity. Interstitial pneumonia with autoimmune features (IPAF) is a recently described interstitial lung disease. The characteristics of pulmonary hypertension in IPAF patients are unknown. We sought to characterize patients with IPAF based on their echocardiographic probability of pulmonary hypertension and compare patients with and without pulmonary hypertension identified by right heart catheterization. We conducted a retrospective study of patients seen in the interstitial lung disease clinic from 2015 to 2018. Forty-seven patients with IPAF were identified. Patients were classified into low, intermediate and high echocardiographic pulmonary hypertension probabilities. A sub-group analysis of patients with pulmonary hypertension and without pulmonary hypertension (IPAF-PH vs. IPAF-no PH) identified by right heart catheterization was also performed. Linear regression analysis was performed to study the association between 6-min-walk-distance (6MWD) and pulmonary vascular resistance (PVR) while adjusting for age and body mass index. Right ventricular hypertrophy (>5 mm), right ventricular enlargement (>41 mm) and right ventricular systolic dysfunction defined as fractional area change% ≤35 was present in 76%, 24%, and 39% of patients, respectively. Pulmonary hypertension was identified in 12.7% of patients. IPAF-PH patients had higher mean pulmonary artery pressure and lower cardiac output compared to the IPAF-no PH group (34 mmHg vs. 19 mmHg, p = 0.002 and 4.0 vs. 5.7 L/min, p = 0.023, respectively). Lower 6MWD was associated with higher PVR on regression analysis (p = 0.002). Pulmonologists should be aware that a significant number of IPAF patients may develop pulmonary hypertension. Reduced 6MWD may suggest the presence of pulmonary hypertension in IPAF patients.

circRNA CDR1as Promotes Pulmonary Artery Smooth Muscle Cell Calcification by Upregulating CAMK2D and CNN3 via Sponging miR-7-5p

Emerging evidence has suggested that circular RNAs (circRNAs) are involved in multiple physiological processes and participate in a variety of human diseases. However, the underlying biological function of circRNAs in pulmonary hypertension (PH) is still ambiguous. Herein, we investigated the implication and regulatory effect of a typical circRNA, CDR1as, in the pathological process of vascular calcification in PH. Human pulmonary artery smooth muscle cell (HPASMC) calcification was analyzed by western blotting, immunofluorescence, alizarin red S staining, alkaline phosphatase activity analysis, and calcium deposition quantification. CDR1as targets were identified by bioinformatics analysis and validated by dual-luciferase reporter and RNA antisense purification assays. We identified that CDR1as was upregulated in hypoxic conditions and promoted a phenotypic switch of HPASMCs from a contractile to an osteogenic phenotype. Moreover, microRNA (miR)-7-5p was shown to be a target of CDR1as, and calcium/calmodulin-dependent kinase II-delta (CAMK2D) and calponin 3 (CNN3) were suggested to be the putative target genes and regulated by CDR1as/miR-7-5p. The results showed that the CDR1as/miR-7-5p/CNN3 and CAMK2D regulatory axis mediates HPASMC osteoblastic differentiation and calcification induced by hypoxia. This evidence reveals an approach to the treatment of PH.

The prevalence and incidence rate of pulmonary arterial hypertension in systemic sclerosis: Systematic review and meta-analysis

The present study aimed to assess the prevalence and incidence rate of pulmonary arterial hypertension (PAH) in Systemic Sclerosis (SSc). The review was undertaken using MEDLINE and SCOPUS from June 1962 to May 2019 and the terms: ("Scleroderma, Systemic"[MesH]) AND "Hypertension, Pulmonary"[MesH]. The Newcastle-Ottawa Scale (NOS) was used for the qualifying assessment. The inverse variance-weighted method was performed. Twenty-four studies were included in the global PAH prevalence study. They comprised data from 9804 SSc patients. The overall PAH prevalence found was 6.4% (95%CI 5%-8.3%). Fourteen studies were included in the PAH prevalence study for lcSSc. They comprised data from 4987 lcSSc patients. The PAH prevalence found in lcSSc was 7.7% (95%CI 5.3%-11.1%). Twelve studies were included in the PAH prevalence study for dcSSc. They comprised data from 1790 dcSSc patients. The PAH prevalence found in dcSSc was 6.3% (95%CI 4.5%-8.9%). Fifteen studies showed PAH incidence of an entire SSc cohort. They comprised data from 5926 SSc patients. The overall PAH incidence found was 18.2 cases per 1000 person-years (95%CI 12-27.4). Eight studies showed PAH incidence for lcSSc. They comprised data from 2721 patients. The overall PAH incidence found in lcSSc was 20.4 cases per 1000 person-years (95%CI 10.1-41.1). Seven studies showed PAH incidence for dcSSc. They comprised data from 942 dcSSc patients. The overall PAH incidence found in dcSSc was 16.6 cases per 1000 person-years (95%CI 8.5-32.1). CONCLUSION: The overall PAH prevalence found was 6.4% (95%CI 5%-8.3%) and the overall PAH incidence 18.2 cases per 1000 person-years (95%CI 12-27.4).

Impact of the updated hemodynamic definitions on diagnosis rates of pulmonary hypertension

We evaluated whether updated pulmonary hypertension definitive criteria proposed in sixth World Symposium on Pulmonary Hypertension had an impact on diagnosis of overall pulmonary hypertension and pre-capillary and combined pre- and post-capillary phenotypes as compared to those in European Society of Cardiology/European Respiratory Society 2015 pulmonary hypertension Guidelines. Study group comprised the retrospectively evaluated 1300 patients (age 53.1 ± 18.8 years, female 807, 62.1%) who underwent right heart catheterization with different indications between 2006 and 2018. Mean pulmonary arterial pressure ≥25 mmHg (European Society of Cardiology) and PAMP (mean pulmonary arterial pressure) >20 mmHg (World Symposium on Pulmonary Hypertension) right heart catheterization definitions criteria were used, respectively. For pre-capillary pulmonary hypertension, pulmonary artery wedge pressure ≤15 mmHg and pulmonary vascular resistance ≥3 Wood units criteria were included in the both definitions. Normal mean pulmonary arterial pressure (<21 mmHg), borderline mean pulmonary arterial pressure elevation (21–24 mmHg), and overt pulmonary hypertension (≥25 mmHg) were documented in 21.1, 9.8, and 69.1% of the patients, respectively. The pre-capillary and combined pre- and post-capillary pulmonary hypertension were noted in 2.9 and 1.1%, 8.7 and 2.5%, and 34.6 and 36.6% of the patients with normal mean pulmonary arterial pressure, borderline, and overt pulmonary hypertension subgroups, respectively. The World Symposium on Pulmonary Hypertension versus European Society of Cardiology/European Respiratory Society definitions resulted in a net 9.8% increase in the diagnosis of overall pulmonary hypertension whereas increases in the pre-capillary pulmonary hypertension and combined pre- and post-capillary pulmonary hypertension diagnosis were only 0.8 and 0.3%, respectively. The re-definition of mean pulmonary arterial pressure threshold seems to increase the frequency of the overall pulmonary hypertension diagnosis. However, this increase was mainly originated from those in post-capillary pulmonary hypertension subgroup whereas its impact on pre-capillary and combined pre- and post-capillary pulmonary hypertension was negligible. Moreover, criteria of pre-capillary pulmonary vascular disease and combined pre- and post-capillary phenotypes were still detectable even in the presence of normal mean pulmonary arterial pressure. The obligatory criteria of pulmonary vascular resistance ≥3 Wood units seems to keep specificity for discrimination between pre-capillary versus post-C pulmonary hypertension after lowering the definitive mean pulmonary arterial pressure threshold to 20 mmHg.

Incidence, predictors, and survival of pulmonary hypertension determined by echocardiography in Thai patients with early systemic sclerosis (SSc): inception cohort study

OBJECTIVES

We investigated the incidence, predictors, and survival of pulmonary hypertension (PH) determined by Doppler echocardiography in Thai patients with early SSc (systemic sclerosis), in which the majority were diffuse cutaneous SSc (DcSSc) with anti-topoisomerase I-positive.

METHODS

We used an inception cohort study of patients with early SSc seen at the Rheumatology Clinic, Maharaj Nakorn Chiang Mai Hospital. All patients were assessed for clinical data and underwent Doppler echocardiography at the study entry and then annually.

RESULTS

A total of 133 patients (81 female, 106 DcSSc, 103 anti-topoisomerase I-positive) with a mean disease duration of 11.9 months were recruited. During the mean observational period of 4.2 years, 14 patients developed PH concurrent with ILD and 6 with left heart disease. The incidence rate for the development of PH was 3.95 per 100 person years. The multivariate Cox regression analysis indicated higher NYHA class (HR 6.90, 95% CI 2.28-20.94, p = 0.001), telangiectasia (HR 4.18, 95% CI 1.25-13.92, p = 0.020), and enlarged LA diameter (HR 1.16, 95% CI 1.05-1.28, p = 0.005) as predictors of PH. Raynaud's phenomenon (HR 0.22, 95% CI 0.06-0.84, p = 0.026) and high oxygen saturation (HR 0.80, 95% CI 0.65-0.99, p = 0.047) were protective factors. The survival rate after PH diagnosis at 1, 3, and 5 years were 88.9%, 82.3%, and 48.0%, respectively.

CONCLUSIONS

In this study cohort, the majority had early DcSSc, the incidence of PH was modest, and all cases developed concomitantly with ILD or left heart disease, resulting in poor survival. The presence of higher NYHA class, telangiectasia, and enlarged LA diameter was predictors of secondary PH. Further study regarding the treatment strategies for PH associated with ILD and left heart disease in SSc is needed. Key Points • In this cohort of early SSc in which the main subtype was DcSSc, the incidence of PH was modest and all PH was secondary PH associated with ILD and left heart disease, resulting in poor survival. • The presence of higher NYHA functional class, telangiectasia, and enlarged LA diameter was baseline predictors of developing secondary PH. • Effective treatment strategies for secondary PH due to ILD and cardiac involvement in SSc patients are urgently needed.

Pulmonary arterial hypertension with below threshold pulmonary vascular resistance

Pulmonary vascular resistance (PVR) >3 Wood units is a criterion of the haemodynamic definition of pulmonary arterial hypertension (PAH). However, this cut-off is conservative and arbitrarily defined. Data is lacking on the natural history, response to therapy and survival of patients diagnosed with precapillary pulmonary hypertension (PH) with mild or borderline elevation of PVR.In Australia, PAH therapy could be prescribed solely on mean pulmonary arterial pressure (PAP) and pulmonary arterial wedge pressure (PAWP) criteria. Using the Australian and New Zealand Pulmonary Hypertension Registry, we aimed to study a population diagnosed with PAH between January 2004 and December 2017 with the pre-defined haemodynamic characteristics of mean PAP ≥25 mmHg, PAWP ≤15 mmHg and PVR <3 Wood units.Eighty-two patients met the pre-defined haemodynamic inclusion criteria (mean age 63±11 years; 67 females). Underlying aetiologies included idiopathic disease (n=39), connective tissue disease (CTD; n=42) and HIV infection (n=1). At diagnosis, mean PAP was 27 mmHg (interquartile range (IQR) 25-30 mmHg), PAWP 13 mmHg (IQR 11-14 mmHg) and PVR 2.2 Wood units (IQR 1.9-2.7 Wood units). Baseline 6-min walk distance (6MWD) was 352 m (IQR 280-416 m) and 77% of subjects were in New York Heart Association (NYHA) functional class 3 or 4. All patients were commenced on initial monotherapy with an endothelin receptor antagonist (ERA; n=66) or phosphodiesterase type-5 inhibitor (PDE5i; n=16). At first re-evaluation, 6MWD increased by 46 m (IQR 7-96 m) and 35% of subjects demonstrated improvement in NYHA functional class. After a median follow-up of 65 months (IQR 32-101 months), 18 out of 82 subjects (22.0%) had died, with estimated 1-year and 5-year survival rates of 98% and 84%, respectively. Death attributed to PAH occurred in six out of these 18 patients (33.3%, 7% of total cohort).Patients with precapillary PH and "borderline" PVR falling outside the current definition have adverse outcomes. Such patients appear to respond to PAH therapy; however, this requires further study in randomised trials.

Diagnosis and Management of Pulmonary Hypertension in the Modern Era: Insights from the 6th World Symposium

The past 20 years have seen major advances in the diagnosis and management of pulmonary hypertension, a disease associated with significant morbidity and mortality. The 6th World Symposium in Pulmonary Hypertension (WSPH) took place in February 2018 and attempted to consolidate the current knowledge in the field into practical recommendations to help prioritize an action plan to improve patient outcomes and identify future research directions. In this review, we will summarize the highlights of the 6th WSPH proceedings, including revisions to the hemodynamic definitions and classification of the various types of pulmonary hypertension, genetic advances, approaches to risk stratification, and updated treatment algorithms.

Haemodynamic phenotypes and survival in patients with systemic sclerosis: the impact of the new definition of pulmonary arterial hypertension

BACKGROUND

In this study, we investigated the impact of the new haemodynamic definition of pulmonary arterial hypertension (PAH) as proposed by the 6th PH World Symposium on phenotypes and survival in patients with systemic sclerosis (SSc).

METHODS

In SSc patients who were prospectively and consecutively screened for PAH including right heart catheterisation in Heidelberg or Zurich, haemodynamic and clinical variables have been reassessed according to the new PAH definition. Patients have been followed for 3.7±3.7 (median 3.4) years; Kaplan-Meier survival analysis was performed. Patients with significant lung or left heart disease were excluded from comparative analyses.

RESULTS

The final dataset included 284 SSc patients, 146 patients (49.2%) had mean pulmonary arterial pressure (mPAP) ≤20 mm Hg, 19.3% had mPAP 21-24 mm Hg and 29.4% had mPAP ≥25 mm Hg. In the group of mildly elevated mPAP, only four patients (1.4% of the whole SSc cohort) had pulmonary vascular resistance (PVR) values ≥3 Wood Units (WU) and could be reclassified as manifest SSc-APAH. Twenty-eight (9.8%) patients with mPAP of 21-24 mm Hg and PVR ≥2 WU already presented with early pulmonary vascular disease with decreased 6 min walking distance (6MWD) (p<0.001), TAPSE (p=0.004) and pulmonary arterial compliance (p<0.001). A PVR ≥2 WU was associated with reduced long-term survival (p=0.002). PVR and 6MWD were independent prognostic predictors in multivariate analysis.

CONCLUSION

The data of this study show that a PVR threshold ≥3 WU is too high to enable an early diagnosis of PAH. A PVR threshold ≥2 WU was already associated with pulmonary vascular disease, significantly reduced survival and would be more appropriate in SSc patients with mild PAH.

How did the updated hemodynamic definitions affect the frequency of pulmonary hypertension in patients with systemic sclerosis?

OBJECTIVE

Pulmonary hypertension (PH) is a one of the major causes of death in patients with systemic sclerosis (SSc). In this study, we investigated the impact of updated hemodynamic definition proposed by the 6th PH World Symposium (6th WSPH) on the frequency of PH and its subtypes in patients with SSc.

METHODS

Patients with SSc admitted between 2015 and 2019 and who underwent right heart catheterization (RHC) were included. The frequency of PH and its subgroups based on the hemodynamic definitions of both 2015 European Society of Cardiology/European respiratory Society (ESC/ERS) PH guidelines and 6th WSPH was compared.

RESULTS

Of the 65 patients with SSc, 23 (35.4%) had normal mean pulmonary arterial pressure (mPAP), 20 (30.8%) had mildly elevated mPAP (21-24 mm Hg), and 22 (33.8%) had PH [pulmonary arterial hypertension (PAH) (n=16, 24.6%), group 2 PH (n=5, 7.7%), group 3 PH (n=1, 1.5%)] according to the 2015 ESC/ERS PH definition. Based on the updated criteria, 7 (10.8% of total cohort) additional patients were reclassified as having PH [PAH (n=3), group 2 PH (n=3), group 3 PH (n=1)].

CONCLUSION

The impact of the updated definition on the frequency of PH and PAH in our cohort was greater than previously reported, which may be caused by the difference in screening strategies for PAH.