Racial and ethnic differences in pulmonary arterial hypertension

Macitentan in Pulmonary Arterial Hypertension Associated with Connective Tissue Disease (CTD-PAH): Real-World Evidence from the Combined OPUS/OrPHeUS Dataset

INTRODUCTION

Data on real-world clinical practice and outcomes of patients with pulmonary arterial hypertension associated with connective tissue disease (CTD-PAH) are scarce. The OPUS/OrPHeUS studies enrolled patients newly initiating macitentan, including those with CTD-PAH. This analysis describes patient characteristics, treatment patterns, outcomes, and safety profiles of patients with CTD-PAH newly initiating macitentan in the US using the OPUS/OrPHeUS combined dataset.

METHODS

OPUS was a prospective, US, multicenter, long-term, observational drug registry (April 2014-June 2020). OrPHeUS was a retrospective, US, multicenter medical chart review (October 2013-March 2017). The characteristics, treatment patterns, safety, and outcomes during macitentan treatment of patients with CTD-PAH and its subgroups systemic sclerosis (SSc-PAH), systemic lupus erythematosus (SLE-PAH), and mixed CTD (MCTD-PAH) were descriptively compared to patients with idiopathic/heritable PAH (I/HPAH).

RESULTS

The combined OPUS/OrPHeUS population included 2498 patients with I/HPAH and 1192 patients with CTD-PAH (708 SSc-PAH; 159 SLE-PAH; 124 MCTD-PAH, and 201 other CTD-PAH etiologies). At macitentan initiation for patients with I/HPAH and CTD-PAH, respectively: 61.2 and 69.3% were in World Health Organization functional class (WHO FC) III/IV; median 6-min walk distance was 289 and 279 m; and 58.1 and 65.2% received macitentan as combination therapy. During follow-up, for patients with I/HPAH and CTD-PAH, respectively: median duration of macitentan exposure observed was 14.0 and 15.8 months; 79.0 and 83.0% experienced an adverse event; Kaplan-Meier estimates (95% confidence limits [CL]) of patients free from all-cause hospitalization at 1 year were 60.3% (58.1, 62.4) and 59.3% (56.1, 62.3); and Kaplan-Meier estimates (95% CL) of survival at 1 year were 90.5% (89.1, 91.7) and 90.6% (88.6, 92.3).

CONCLUSIONS

Macitentan was used in clinical practice in patients with CTD-PAH and its subgroups, including as combination therapy. The safety and tolerability profile of macitentan in patients with CTD-PAH was comparable to that of patients with I/HPAH.

TRIAL REGISTRATION

OPsumit® Users Registry (OPUS): NCT02126943; Opsumit® Historical Users cohort (OrPHeUS): NCT03197688; www.

CLINICALTRIALS

gov Graphical abstract available for this article.

Pulmonary Hypertension in Underrepresented Minorities: A Narrative Review

Minoritized racial and ethnic groups suffer disproportionately from the incidence and morbidity of pulmonary hypertension (PH), as well as its associated cardiovascular, pulmonary, and systemic conditions. These disparities are largely explained by social determinants of health, including access to care, systemic biases, socioeconomic status, and environment. Despite this undue burden, minority patients remain underrepresented in PH research. Steps should be taken to mitigate these disparities, including initiatives to increase research participation, combat inequities in access to care, and improve the treatment of the conditions associated with PH.

Evolution and optimization of clinical trial endpoints and design in pulmonary arterial hypertension

Selection of endpoints for clinical trials in pulmonary arterial hypertension (PAH) is challenging because of the small numbers of patients and the changing expectations of patients, clinicians, and regulators in this evolving therapy area. The most commonly used primary endpoint in PAH trials has been 6-min walk distance (6MWD), leading to the approval of several targeted therapies. However, single surrogate endpoints such as 6MWD or hemodynamic parameters may not correlate with clinical outcomes. Composite endpoints of clinical worsening have been developed to reflect patients' overall condition more accurately, although there is no standard definition of worsening. Recently there has been a shift to composite endpoints assessing clinical improvement, and risk scores developed from registry data are increasingly being used. Biomarkers are another area of interest, although brain natriuretic peptide and its N-terminal prohormone are the only markers used for risk assessment or as endpoints in PAH. A range of other genetic, metabolic, and immunologic markers is currently under investigation, along with conventional and novel imaging modalities. Patient-reported outcomes are an increasingly important part of evaluating new therapies, and several PAH-specific tools are now available. In the future, alternative statistical techniques and trial designs, such as patient enrichment strategies, will play a role in evaluating PAH-targeted therapies. In addition, modern sequencing techniques, imaging analyses, and high-dimensional statistical modeling/machine learning may reveal novel markers that can play a role in the diagnosis and monitoring of PAH.

The impact of right atrial pressure on outcomes in patients undergoing TIPS, an ALTA group study

BACKGROUND AND AIMS

Single-center studies in patients undergoing TIPS suggest that elevated right atrial pressure (RAP) may influence survival. We assessed the impact of pre-TIPS RAP on outcomes using the Advancing Liver Therapeutic Approaches (ALTA) database.

APPROACH AND RESULTS

Total 883 patients in ALTA multicenter TIPS database from 2010 to 2015 from 9 centers with measured pre-TIPS RAP were included. Primary outcome was mortality. Secondary outcomes were 48-hour post-TIPS complications, post-TIPS portal hypertension complications, and post-TIPS inpatient admission for heart failure. Adjusted Cox Proportional hazards and competing risk model with liver transplant as a competing risk were used to assess RAP association with mortality. Restricted cubic splines were used to model nonlinear relationship. Logistic regression was used to assess RAP association with secondary outcomes.Pre-TIPS RAP was independently associated with overall mortality (subdistribution HR: 1.04 per mm Hg, 95% CI, 1.01, 1.08, p =0.009) and composite 48-hour complications. RAP was a predictor of TIPS dysfunction with increased odds of post-90-day paracentesis in outpatient TIPS, hospital admissions for renal dysfunction, and heart failure. Pre-TIPS RAP was positively associated with model for end-stage liver disease, body mass index, Native American and Black race, and lower platelets.

CONCLUSIONS

Pre-TIPS RAP is an independent risk factor for overall mortality after TIPS insertion. Higher pre-TIPS RAP increased the odds of early complications and overall portal hypertensive complications as potential mechanisms for the mortality impact.

RASA3 is a candidate gene in sickle cell disease-associated pulmonary hypertension and pulmonary arterial hypertension

Pulmonary hypertension (PH) is associated with significant morbidity and mortality. RASA3 is a GTPase activating protein integral to angiogenesis and endothelial barrier function. In this study, we explore the association of RASA3 genetic variation with PH risk in patients with sickle cell disease (SCD)-associated PH and pulmonary arterial hypertension (PAH). Cis-expression quantitative trait loci (eQTL) were queried for RASA3 using whole genome genotype arrays and gene expression profiles derived from peripheral blood mononuclear cells (PBMC) of three SCD cohorts. Genome-wide single nucleotide polymorphisms (SNPs) near or in the RASA3 gene that may associate with lung RASA3 expression were identified, reduced to 9 tagging SNPs for RASA3 and associated with markers of PH. Associations between the top RASA3 SNP and PAH severity were corroborated using data from the PAH Biobank and analyzed based on European or African ancestry (EA, AA). We found that PBMC RASA3 expression was lower in patients with SCD-associated PH as defined by echocardiography and right heart catheterization and was associated with higher mortality. One eQTL for RASA3 (rs9525228) was identified, with the risk allele correlating with PH risk, higher tricuspid regurgitant jet velocity and higher pulmonary vascular resistance in patients with SCD-associated PH. rs9525228 associated with markers of precapillary PH and decreased survival in individuals of EA but not AA. In conclusion, RASA3 is a novel candidate gene in SCD-associated PH and PAH, with RASA3 expression appearing to be protective. Further studies are ongoing to delineate the role of RASA3 in PH.

Long-term impact of add-on sequential triple combination therapy in pulmonary arterial hypertension: real world experience

BACKGROUND

Sequential triple combination therapy is recommended for pulmonary arterial hypertension (PAH) patients who are not at therapeutic goal on dual therapy, but long-term data on efficacy and safety is scarce.

OBJECTIVE

To assess the long-term impact of sequential triple combination therapy in patients with PAH who are not at goal on dual combination therapy.

STUDY DESIGN AND METHODS

We performed a retrospective observational study in a racially/ethnically diverse cohort of consecutive PAH patients on a stable dual therapy regimen who remained in intermediate- or high-risk category and were subsequently initiated on sequential triple combination therapy. We studied interval change in functional, echocardiographic, and hemodynamic parameters, REVEAL 2.0 risk category and ERS/ESC 2022 simplified four-strata risk category. Multivariate logistic regression analysis was performed to identify independent predictors of successful risk reduction (achievement or maintenance of REVEAL 2.0 low-risk category). Kaplan-Meier survival curves were created to assess the effect of risk reduction on survival.

RESULTS

Out of 414 PAH patients seen in our program, 55 patients received add-on sequential triple combination regimen and had follow-up hemodynamic data. The mean age was 57 years, with 85% women. The most common etiology of PAH was idiopathic/heritable (41.8%). Most patients were WHO functional class III (76.4%), and 34.5% of patients were in high-risk category (REVEAL 2.0). On a median follow-up of 68 weeks, there was a significant improvement in WHO Functional Class (p < 0.001), six-minute walk distance (35 m) with 61.8% of patients achieving low-risk status by REVEAL 2.0, and a 28% of patients' improvement in pulmonary vascular resistance. Female gender was identified as a strong predictor of successful risk reduction, whereas Hispanic ethnicity estimated right atrial pressure on echocardiogram and pericardial effusion predicted lower probability of risk reduction. Patients who achieved or maintained low-risk status had significantly improved survival.

CONCLUSION

Add-on sequential triple combination therapy significantly increased functional, echocardiographic, and hemodynamic parameters with improvement in risk category and survival.

Social Determinants of Health in Pulmonary Arterial Hypertension Patients in the United States: Clinician Perspective and Health Policy Implications

Social determinants of health (SDoH) can impact the vulnerable pulmonary arterial hypertension (PAH) population, especially during the COVID‐19 pandemic. Providers' understanding of SDoH at the point of care and their impact is unknown. We conducted semi‐structured virtual interviews with US clinicians at 17 pulmonary hypertension (PH) centers and one patient advocate from the Pulmonary Hypertension Association. We sought participants' perspective on SDoH in PAH and their impact. Transcripts were developed and analyzed for key themes to assess potential policy implications. Participants served a large PAH population and demonstrated high awareness of SDoH and its impact on treatment and outcomes. They reported that patients' SDoH, including socioeconomic status, health insurance, access to health care, education levels, health literacy, employment status, and insecurities associated with housing, food, transportation, and family support, impacted health and well‐being. COVID‐19‐related social isolation, mental health, and substance abuse contributed to significant inequities in care provision and outcomes. While telemedicine helped clinicians manage patients remotely during the pandemic, there was a concern for patients with limited access to this medium. Participants reported no formal screening for SDoH at the point of care. With the recognition and the desire to act upon health inequities associated with SDoH, participants felt that it was vital for their centers to have a dedicated PH social worker and support staff to optimize care and outcomes. An approach that integrates SDoH in PAH care management, streamlined through institutional policy, could address health disparities leading to improved healthcare access, outcomes, and quality of care.

Impact of Sex, Race, and Socioeconomic Status on Survival after Pulmonary Thromboendarterectomy for Chronic Thromboembolic Pulmonary Hypertension

OBJECTIVE

Pulmonary thromboendarterectomy (PTE) is a definitive treatment for chronic thromboembolic pulmonary hypertension (CTEPH). Demographic-based disparities in PTE outcomes have not been well studied.

METHODS

We reviewed all patients who underwent PTE for CTEPH between 2009 and 2019 at our institution, tracking demographic information including self-identified race, preoperative characteristics, and 2-year survival. Socioeconomic status (SES) was assessed using the zip code-linked Distressed Communities Index, a validated holistic measure of community well-being. Survival was estimated using Kaplan-Meier method and factors associated with mortality were estimated using Cox regression.

RESULTS

Of 235 PTE patients, 101 (42.9%) were white and 87 (37.0%) were black. White patients had a higher median age at surgery (57 vs. 51 years, P = 0.035) and a lower degree of economic distress (33.6 vs. 61.2 percentile, P < 0.001). Regarding sex, 106 (45.1%) patients were male and 129 (53.6%) were female. Male patients had a higher median age (59 vs. 50 years, P = 0.004), greater rates of dyslipidaemia (34% vs. 20.2%, P = 0.025), a lower ejection fraction (55% vs. 57%, P = 0.046), and longer cross-clamp (77 vs. 67.50 min, P = 0.004) and circulatory arrest times (42 vs. 37.50 min, P = 0.007). No difference was observed in unadjusted 2-year survival after PTE between patients stratified by race and sex (P = 0.35). After adjustment for clinically relevant variables, neither SES, sex, or race were associated with mortality in Cox proportional hazard analysis.

CONCLUSIONS

Sex, SES, and race were not associated with adverse outcomes after PTE in our single center experience.

Disease-Specific Health Disparities: A Targeted Review Focusing on Race and Ethnicity

Background: Wide disparities in health status exist in the United States across race and ethnicity, broadly driven by social determinants of health—most notably race and ethnic group differences in income, education, and occupational status. However, disparities in disease frequency or severity remain underappreciated for many individual diseases whose distribution in the population varies. Such information is not readily accessible, nor emphasized in treatment guidelines or reviews used by practitioners. Specifically, a summary on disease-specific evidence of disparities from population-based studies is lacking. Our goal was to summarize the published evidence for specific disease disparities in the United States so that this knowledge becomes more widely available “at the bedside”. We hope this summary stimulates health equity research at the disease level so that these disparities can be addressed effectively. Methods: A targeted literature review of disorders in Pfizer’s current pipeline was conducted. The 38 diseases included metabolic disorders, cancers, inflammatory conditions, dermatologic disorders, rare diseases, and infectious targets of vaccines under development. Online searches in Ovid and Google were performed to identify sources focused on differences in disease rates and severity between non-Hispanic Whites and Black/African Americans, and between non-Hispanic Whites and Hispanics. As a model for how this might be accomplished for all disorders, disparities in disease rates and disease severity were scored to make the results of our review most readily accessible. After primary review of each condition by one author, another undertook an independent review. Differences between reviewers were resolved through discussion. Results: For Black/African Americans, 29 of the 38 disorders revealed a robust excess in incidence, prevalence, or severity. After sickle cell anemia, the largest excesses in frequency were identified for multiple myeloma and hidradenitis suppurativa. For Hispanics, there was evidence of disparity in 19 diseases. Most notable were metabolic disorders, including non-alcoholic steatohepatitis (NASH). Conclusions: This review summarized recent disease-specific evidence of disparities based on race and ethnicity across multiple diseases, to inform clinicians and health equity research. Our findings may be well known to researchers and specialists in their respective fields but may not be common knowledge to health care providers or public health and policy institutions. Our hope is that this effort spurs research into the causes of the many disease disparities that exist in the United States.

Hispanic Ethnicity and Social Determinants of Health in Pulmonary Arterial Hypertension: The Pulmonary Hypertension Association Registry

Rationale There is a noticeable underrepresentation of minorities in clinical trials and registries in pulmonary arterial hypertension (PAH). Prior studies evaluating the association between Hispanic ethnicity and clinical outcomes in patients with PAH have not assessed the socioeconomic profile of Hispanic individuals or the significance of social determinants of health in clinical outcomes. Objective To determine the association between Hispanic ethnicity, social determinants of health, and clinical outcomes in PAH. Methods Prospective cohort study of adult participants with PAH enrolled in the Pulmonary Hypertension Association Registry, a multicenter US-based registry of patients treated at Pulmonary Hypertension Care Centers. Participants were classified as Hispanics and non-Hispanic Whites, based on self-reported ethnicity. A comparison of baseline clinical and sociodemographic characteristics between groups was performed as well using absolute standardized differences (ASD). The primary outcome of the study was to assess transplant-free survival between Hispanics and non-Hispanic Whites. A Cox proportional hazards model was used for the multivariable analysis after adjusting for age, sex, PAH etiology, annual income, education level and health insurance. Results A total of 683 individuals were included, 98 (14.3%) of Hispanic ethnicity. Hispanic patients had impaired access to health care (31.6% vs. 12.9% Medicaid/uninsured; ASD 0.35), lower education level (72.6% vs. 94.0% high school graduates or higher; ASD 0.60) and lower annual income (32.0% vs. 17.4% with income <20,000 US dollars; ASD 0.47), as compared with non-Hispanic Whites. Hispanic patients had a higher frequency of ER visits and a higher number of hospitalizations, despite having similar disease severity (incidence rate ratio 1.452, 95% CI 1.326 - 1.590 and 1.428, 95% CI 1.292 - 1.577, respectively). While the unadjusted analysis showed a lower transplant/death hazard ratio for Hispanics (HR 0.47, 95% CI 0.24-0.94; p=0.032), there was no association between Hispanic ethnicity and outcome in the multivariable model after adjusting for social determinants of health and other covariates (HR 0.76, 95% CI 0.35-1.62; p=0.474). Conclusions Hispanic ethnicity was not associated with differences in survival after adjusting for social determinants of health and other factors. Social determinants of health are important to consider when assessing the association between ethnicity and outcomes in PAH.

Noninvasive Risk Score to Screen for Pulmonary Hypertension With Elevated Pulmonary Vascular Resistance in Diseases of Chronic Volume Overload

Volume overload promotes pulmonary hypertension (PH) through pulmonary venous hypertension. However, PH with elevated pulmonary vascular resistance (hereafter PH-PVR) may develop in patients with diseases of volume overload, such as heart failure or chronic kidney disease (CKD). In such cases, volume management alone may be insufficient to slow PH progression. An accurate, noninvasive method to screen for PH-PVR in these diseases would facilitate early targeted therapy. We integrated invasive hemodynamic and echocardiography data collected from a single-center clinical cohort and identified patients with CKD or heart failure at the time of assessment. We applied penalized regression to derive a risk score of clinical parameters and echocardiography data associated with PH-PVR and categorized patients into low- (≤5 points), intermediate- (6-10 points), or high-risk (>10 points) groups. Using an internal validation strategy, we evaluated the ability of this risk score to predict PH-PVR and determined the association of this risk classification with 3-year all-cause mortality. Of 2422 patients, 42.4% had PH-PVR. In adjusted analyses, tricuspid regurgitant velocity, right ventricular function, BMI, heart rate, and hemoglobin most strongly associated with PH-PVR. The risk score significantly associated with PH-PVR (age-adjusted odds ratio 11.69 for the highest-risk group, 95% confidence interval [CI] 6.54-20.92). The high-risk group also associated with a significantly higher risk of 3-year all-cause mortality in adjusted analyses (hazard ratio 1.85, 95% CI 1.50-2.27). In conclusion, a noninvasive risk score derived from echocardiography and clinical parameters significantly associated with PH-PVR and all-cause mortality in a cohort of patients with CKD and heart failure.

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 Arterial Pruning and Longitudinal Change in Percent Emphysema and Lung Function: The Genetic Epidemiology of COPD Study

BACKGROUND

Pulmonary endothelial damage has been shown to precede the development of emphysema in animals, and vascular changes in humans have been observed in COPD and emphysema.

RESEARCH QUESTION

Is intraparenchymal vascular pruning associated with longitudinal progression of emphysema on CT imaging or decline in lung function over 5 years?

STUDY DESIGN AND METHODS

The Genetic Epidemiology of COPD Study enrolled ever smokers with and without COPD from 2008 through 2011. The percentage of emphysema-like lung, or "percent emphysema," was assessed at baseline and after 5 years on noncontrast CT imaging as the percentage of lung voxels < -950 Hounsfield units. An automated CT imaging-based tool assessed and classified intrapulmonary arteries and veins. Spirometry measures are postbronchodilator. Pulmonary arterial pruning was defined as a lower ratio of small artery volume (< 5 mm2 cross-sectional area) to total lung artery volume. Mixed linear models included demographics, anthropomorphics, smoking, and COPD, with emphysema models also adjusting for CT imaging scanner and lung function models adjusting for clinical center and baseline percent emphysema.

RESULTS

At baseline, the 4,227 participants were 60 ± 9 years of age, 50% were women, 28% were Black, 47% were current smokers, and 41% had COPD. Median percent emphysema was 2.1 (interquartile range, 0.6-6.3) and progressed 0.24 percentage points/y (95% CI, 0.22-0.26 percentage points/y) over 5.6 years. Mean FEV1 to FVC ratio was 68.5 ± 14.2% and declined 0.26%/y (95% CI, -0.30 to -0.23%/y). Greater pulmonary arterial pruning was associated with more rapid progression of percent emphysema (0.11 percentage points/y per 1-SD increase in arterial pruning; 95% CI, 0.09-0.16 percentage points/y), including after adjusting for baseline percent emphysema and FEV1. Arterial pruning also was associated with a faster decline in FEV1 to FVC ratio (-0.04%/y per 1-SD increase in arterial pruning; 95% CI, -0.008 to -0.001%/y).

INTERPRETATION

Pulmonary arterial pruning was associated with faster progression of percent emphysema and more rapid decline in FEV1 to FVC ratio over 5 years in ever smokers, suggesting that pulmonary vascular differences may be relevant in disease progression.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.

Epidemiology of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: identification of the most accurate estimates from a systematic literature review

This systematic review of literature and online reports critically appraised incidence and prevalence estimates of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension to identify the most accurate estimates. Medline® and Embase® databases were searched for articles published between 1 January 2003 and 31 August 2020. Studies were grouped according to whether they were registries (population-based estimates), clinical databases (hospital-based estimates) or claims/administrative databases. Registries were classified into systematic and non-systematic registries, according to whether every national centre participated. Of 7309 publications identified, 5414 were screened after removal of duplicates and 33 were included. Inclusion was based on study type, availability of a clear numerator (diagnosed population) and a population- or hospital-based denominator, or all primary data required to calculate estimates. Only the most recent publication from a database was included. Most studies were based on European data and very few included children. In adults, the range of estimates per million was approximately 20-fold for pulmonary arterial hypertension incidence (1.5-32) and prevalence (12.4-268) and of similar magnitude for chronic thromboembolic pulmonary hypertension incidence (0.9-39) and prevalence (14.5-144). Recent (≤5 years) national systematic registry data from centralised healthcare systems provided the following ranges in adult estimates per million: approximately 5.8 for pulmonary arterial hypertension incidence, 47.6-54.7 for pulmonary arterial hypertension prevalence, 3.1-6.0 for chronic thromboembolic pulmonary hypertension incidence and 25.8-38.4 for chronic thromboembolic pulmonary hypertension prevalence. These estimates were considered the most reliable and consistent for the scientific community to plan for resource allocation and improve detection rates.

Impact of patient characteristics and perceived barriers on referral to exercise rehabilitation among patients with pulmonary hypertension in the United States

Exercise rehabilitation is underutilized in patients with pulmonary arterial hypertension despite improving exercise capacity and quality of life. We sought to understand the association between (1) patient characteristics and (2) patient-perceived barriers and referral to exercise rehabilitation. We performed a cross-sectional survey of patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension attending an International PAH meeting. Predictors of referral considered included gender, body mass index, subjective socioeconomic status, insurance type, age, and World Health Organization functional class and perceived barriers assessed using the Cardiac Rehabilitation Barriers Scale. Among 65 participants, those in the lowest subjective socioeconomic status tertile had reduced odds of referral compared to the highest tertile participants (odds ratio 0.22, 95% confidence interval: 0.05–0.98, p = 0.047). Several patient-perceived barriers were associated with reduced odds of referral. For every 1-unit increase in a reported barrier on a five-point Likert scale, odds of referral were reduced by 85% for my doctor did not feel it was necessary; 85% for prefer to take care of my health alone, not in a group; 78% many people with heart and lung problems don’t go, and they are fine; and 78% for I didn’t know about exercise therapy. The lack of perceived need subscale and overall barriers score were associated with a 92% and 77% reduced odds of referral, respectively. These data suggest the need to explore interventions to promote referral among low socioeconomic status patients and address perceived need for the therapy.

Genetic Admixture and Survival in Diverse Populations with Pulmonary Arterial Hypertension

Rationale: Limited information is available on racial/ethnic differences in pulmonary arterial hypertension (PAH).Objectives: Determine effects of race/ethnicity and ancestry on mortality and disease outcomes in diverse patients with PAH.Methods: Patients with Group 1 PAH were included from two national registries with genome-wide data and two local cohorts, and further incorporated in a global meta-analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for transplant-free, all-cause mortality in Hispanic patients with non-Hispanic white (NHW) patients as the reference group. Odds ratios (ORs) for inpatient-specific mortality in patients with PAH were also calculated for race/ethnic groups from an additional National Inpatient Sample dataset not included in the meta-analysis.Measurements and Main Results: After covariate adjustment, self-reported Hispanic patients (n = 290) exhibited significantly reduced mortality versus NHW patients (n = 1,970) after global meta-analysis (HR, 0.60 [95% CI, 0.41-0.87]; P = 0.008). Although not significant, increasing Native American genetic ancestry appeared to account for part of the observed mortality benefit (HR, 0.48 [95% CI, 0.23-1.01]; P = 0.053) in the two national registries. Finally, in the National Inpatient Sample, an inpatient mortality benefit was also observed for Hispanic patients (n = 1,524) versus NHW patients (n = 8,829; OR, 0.65 [95% CI, 0.50-0.84]; P = 0.001). An inpatient mortality benefit was observed for Native American patients (n = 185; OR, 0.38 [95% CI, 0.15-0.93]; P = 0.034).Conclusions: This study demonstrates a reproducible survival benefit for Hispanic patients with Group 1 PAH in multiple clinical settings. Our results implicate contributions of genetic ancestry to differential survival in PAH.

Serum High-Density Lipoprotein Cholesterol is Significantly Associated with the Presence and Severity of Pulmonary Arterial Hypertension: A Retrospective Cross-Sectional Study

INTRODUCTION

To explore the relationship between serum high-density lipoprotein cholesterol (HDL-C) levels and the presence and severity of pulmonary arterial hypertension (PAH).

METHODS

A total of 177 patients with PAH and 103 patients without pulmonary hypertension (PH) were enrolled in this study. All patients underwent right heart catheterization (RHC) for diagnosing and assessing the severity of PAH. Demographics, comorbidities, and laboratory data including serum HDL-C levels were collected.

RESULTS

Plasma HDL-C levels in patients with PAH were significantly lower compared with patients without PH (1.08 ± 0.36 vs 1.49 ± 0.36, p < 0.001). HDL-C levels positively correlated with cardiac output (r = 0.360, p < 0.001), cardiac index (r = 0.337, p < 0.001), and mixed venous oxygen saturation (r = 0.426, p < 0.001), and negatively with mean pulmonary arterial pressure (r = - 0.529, p < 0.001), right atrial pressure (r = - 0.421, p < 0.001), and pulmonary vascular resistance (r = - 0.583, p < 0.001). Multivariate logistic regression analysis indicated that HDL-C was a significant independent predictor of PAH (OR 0.042, 95% CI 0.006-0.304, p = 0.002). The receiver operating characteristic curve analysis showed that the optimal cutoff value of the serum HDL-C concentration for predicting PAH was 1.32 mmol/L, with a sensitivity of 83.6% and a specificity of 72.8% (area under the curve 0.803, 95% confidence interval 0.750-0.856, p < 0.001).

CONCLUSIONS

Serum HDL-C is a simple biomarker that might be used for prediction and assessment of PAH in Chinese Han ethnicity, and the mechanism underlying the association needs further study.

Impact of race on survival in pulmonary arterial hypertension: Results from the REVEAL registry

BACKGROUND

Prior research has suggested that the prevalence and outcomes of pulmonary arterial hypertension (PAH) may vary by race or ethnicity. However, these studies have been limited by small sample size or methodological techniques relying on epidemiologic data. The purpose of this study is to evaluate the relationship between race/ethnicity and survival in a large U.S.-based prospective multicenter registry.

METHODS

Patients in the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL), a 5-year observational study of Group 1 PAH, were categorized by race/ethnicity. Baseline hemodynamic characteristics, clinical characteristics, and medication use was described. The relationship between race/ethnicity and outcome was evaluated by Kaplan-Meier and Cox proportional hazards modeling techniques. Left-truncation analysis, which adjusted for time from diagnosis to study enrollment, was used to minimize the effect of survivor bias.

RESULTS

This analysis included 3,046 patients; 2,202 identified as white, 393 as black, 263 as Hispanic, 100 as Asian or Pacific Islander, and 88 as other. Unadjusted Kaplan-Meier survival analysis indicated that white patients had the lowest survival rates. After adjusting for variables of prognostic impact, race/ethnicity was no longer significantly associated with survival. Other results showed that black patients were more likely to have connective tissue disease-associated PAH, Hispanic patients were more likely to have portopulmonary hypertension, and Asian patients were more likely to have congenital heart disease-associated PAH.

CONCLUSIONS

Analysis of the REVEAL registry did not find race/ethnicity to be a significant predictor of mortality. This is the largest analysis to date evaluating the role of race/ethnicity on outcomes in PAH.

The role of cardiopulmonary exercise testing and training in patients with pulmonary hypertension: making the case for this assessment and intervention to be considered a standard of care

Introduction: Pulmonary hypertension (PH) is a broad pathophysiological disorder primarily characterized by increased pulmonary vascular resistance due to multiple possible etiologies. Patients typically present with multiple complaints that worsen as disease severity increases. Although initially discouraged due to safety concerns, exercise interventions for patients with PH have gained wide interest and multiple investigations have established the effective role of exercise training in improving the clinical profile, exercise tolerance, and overall quality of life.Areas covered: In this review, we discuss the pathophysiology of PH during rest and exercise, the role of cardiopulmonary exercise testing (CPX) in the diagnosis and prognosis of PAH, the role of exercise interventions in this patient population, and the expected physiological adaptations to exercise training.Expert opinion: Exercise testing, in particular CPX, provides a wealth of clinically valuable information in the PH population. Moreover, the available evidence strongly supports the safety and efficacy of exercise training as a clinical tool in improving exercise tolerance and quality of life. Although clinical trials investigating the role of exercise in this PH population are relatively few compared to other chronic conditions, current available evidence supports the clinical implementation of exercise training as a safe and effective treatment modality.

Anticoagulation in pulmonary arterial hypertension: a decision analysis

Systemic anticoagulation may be beneficial in pulmonary arterial hypertension, but there is no randomized clinical trial data to guide therapeutic decision making, and current guidelines do not account for patient preferences or quality of life. Decision analytic models to evaluate the potential risks and benefits of systemic anticoagulation in pulmonary arterial hypertension patients, focusing on the benefit in quality-adjusted life years, may be helpful in clarifying this uncertainty. We constructed a 31-state Markov decision analytic model to explore anticoagulation and no anticoagulation strategies. Modeled patient characteristics included gender, use of central catheter-based pulmonary arterial hypertension therapy, type of pulmonary arterial hypertension (idiopathic, idiopathic pulmonary arterial hypertension, or connective-tissue associated, connective tissue disease-pulmonary arterial hypertension), and use of oral contraceptive medication by females. Modeled events included mortality, thromboembolic complications, atrial fibrillation, stroke, and anticoagulation bleeding. Deterministic and probabilistic sensitivity analyses were performed. Anticoagulation was favored in all idiopathic pulmonary arterial hypertension cases, with a gain of 0.43-0.51 quality-adjusted life years, and detrimental in all connective tissue disease-pulmonary arterial hypertension cases, with a loss of 0.66-1.89 quality-adjusted life years. Anticoagulation would need to demonstrate a hazard ratio for pulmonary arterial hypertension mortality of 0.95 or better to be favored. In our model, idiopathic pulmonary arterial hypertension patients benefit from anticoagulation in terms of quality-adjusted life years, and connective tissue disease-pulmonary arterial hypertension patients were harmed, with a hazard ratio for pulmonary arterial hypertension mortality of 0.95 or better being required to favorably impact quality-adjusted life years. These results suggest that anticoagulation significantly improves quality adjusted life years and should be offered to all idiopathic pulmonary arterial hypertension patients. Shared decision models based on these results may help clarify therapeutic decision-making uncertainty in pulmonary arterial hypertension patients.

Learning from registries in pulmonary arterial hypertension: pitfalls and recommendations

Pulmonary arterial hypertension is a rare and incurable chronic disease characterised by a progressive increase in pulmonary vascular resistance and right heart failure. Patient registries collecting observational data can be of great value in the understanding of clinical problems. While clinical trials provide data in selected patient populations, registries better depict real-life practice. This review aims to reflect the input of patient registries in the general knowledge of the disease. Advances in epidemiology of the different subgroups, including data on incidence and/or prevalence, increasing age at presentation and stagnating diagnostic delay are reported. The importance of haemodynamic definition criteria and cardiac comorbidities are underscored. The review also shows the major transformation that pulmonary arterial hypertension therapeutic management has undergone, with still insufficient use of combination therapies; consecutive improvement in outcome; upcoming evidence in disfavour of anticoagulation; and validity of the available risk-stratification tools derived from large registries. Product registries are also briefly presented. Finally, the benefits of registries and methodological aspects are discussed, including immortal time bias, registry data quality and recommendations from EU organisations (EUCERD and PARENT).

Novel risk genes and mechanisms implicated by exome sequencing of 2572 individuals with pulmonary arterial hypertension

BACKGROUND

Group 1 pulmonary arterial hypertension (PAH) is a rare disease with high mortality despite recent therapeutic advances. Pathogenic remodeling of pulmonary arterioles leads to increased pulmonary pressures, right ventricular hypertrophy, and heart failure. Mutations in bone morphogenetic protein receptor type 2 and other risk genes predispose to disease, but the vast majority of non-familial cases remain genetically undefined.

METHODS

To identify new risk genes, we performed exome sequencing in a large cohort from the National Biological Sample and Data Repository for PAH (PAH Biobank, n = 2572). We then carried out rare deleterious variant identification followed by case-control gene-based association analyses. To control for population structure, only unrelated European cases (n = 1832) and controls (n = 12,771) were used in association tests. Empirical p values were determined by permutation analyses, and the threshold for significance defined by Bonferroni's correction for multiple testing.

RESULTS

Tissue kallikrein 1 (KLK1) and gamma glutamyl carboxylase (GGCX) were identified as new candidate risk genes for idiopathic PAH (IPAH) with genome-wide significance. We note that variant carriers had later mean age of onset and relatively moderate disease phenotypes compared to bone morphogenetic receptor type 2 variant carriers. We also confirmed the genome-wide association of recently reported growth differentiation factor (GDF2) with IPAH and further implicate T-box 4 (TBX4) with child-onset PAH.

CONCLUSIONS

We report robust association of novel genes KLK1 and GGCX with IPAH, accounting for ~ 0.4% and 0.9% of PAH Biobank cases, respectively. Both genes play important roles in vascular hemodynamics and inflammation but have not been implicated in PAH previously. These data suggest new genes, pathogenic mechanisms, and therapeutic targets for this lethal vasculopathy.

Racial and Ethnic Differences in Pediatric Pulmonary Hypertension: An Analysis of the Pediatric Pulmonary Hypertension Network Registry

OBJECTIVE

To investigate racial and ethnic differences in pulmonary hypertension subtypes and survival differences in a pediatric population.

STUDY DESIGN

This was a retrospective analysis of a cohort of patients with pulmonary hypertension (aged ≤18 years) enrolled in the Pediatric Pulmonary Hypertension Network registry between 2014 and 2018, comprising patients at eight Pediatric Centers throughout North America (n = 1417).

RESULTS

Among children diagnosed after the neonatal period, pulmonary arterial hypertension was more prevalent among Asians (OR, 1.83; 95% CI, 1.21-2.79; P = .0045), lung disease-associated pulmonary hypertension among blacks (OR, 2.09; 95% CI, 1.48-2.95; P < .0001), idiopathic pulmonary arterial hypertension among whites (OR, 1.58; 95% CI, 1.06-2.41; P = .0289), and pulmonary veno-occlusive disease among Hispanics (OR, 6.11; 95% CI, 1.34-31.3; P = .0184). Among neonates, persistent pulmonary hypertension of the newborn (OR, 4.07; 95% CI, 1.54-10.0; P = .0029) and bronchopulmonary dysplasia (OR, 8.11; 95% CI, 3.28-19.8; P < .0001) were more prevalent among blacks, and congenital diaphragmatic hernia was more prevalent among whites (OR, 2.29; 95% CI, 1.25-4.18; P = .0070). An increased mortality risk was observed among blacks (HR, 1.99; 95% CI, 1.03-3.84; P = .0396), driven primarily by the heightened mortality risk among those with lung disease-associated pulmonary hypertension (HR, 2.84; 95% CI, 1.15-7.04; P = .0241).

CONCLUSIONS

We found significant racial variability in the prevalence of pulmonary hypertension subtypes and survival outcomes among children with pulmonary hypertension. Given the substantial burden of this disease, further studies to validate phenotypic differences and to understand the underlying causes of survival disparities between racial and ethnic groups are warranted.

Pulmonary Hypertension During Pregnancy in New York State, 2003-2014

Objectives This study examined the prevalence and temporal trends in (a) pulmonary hypertension (PH) during pregnancy and (b) mortality and morbidity during pregnancy with and without PH. Methods This was a retrospective observational study of the 2003-2014 New York State Inpatient Database. PH was categorized as primary or secondary and pregnancy as loss or termination of pregnancy, preterm birth, or term birth. The Centers for Disease Control and Prevention definition of maternal morbidity was used, including 17 diagnoses and 5 procedures. Changes were assessed using Cochran-Armitage trend tests. Results Of 2,940,868 pregnancy-related discharges, 746 indicated a diagnosis of PH (25/100,000; 95% CI 24-27). PH was secondary in 677/746 (91%) discharges and 488/746 were term births (65%). Prevalence of secondary PH increased from 17 to 30/100,000 between 2003- 2004 and 2013-2014 (+ 69%; P < 0.001), with an increase in the prevalence of heart valve disease, obesity, and systemic hypertension. Primary PH decreased 81% (P = 0.002). Term-birth PH discharges increased from 13 to 22/100,000 between 2003-2004 and 2013-2014 (+ 66%; P = 0.003), without change in preterm births and loss or termination of pregnancies. No change in morbidity in PH discharges was observed between 2003-2004 and 2013-2014, contrasting with a 64% increase in discharges without PH. Conclusions for Practice Prevalence of secondary PH during pregnancy markedly increased since 2003, underscoring the importance of screening for PH, especially in women with heart valve disease, obesity, or systemic hypertension.

The Use of Risk Assessment Tools and Prognostic Scores in Managing Patients with Pulmonary Arterial Hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a chronic, progressive, and incurable disease with significant morbidity and mortality. Despite increasingly available treatment options, PAH patients continue to experience disease progression and increased rates of hospitalizations due to right heart failure. Physician's ability to comprehensively assess PAH patients, determine prognosis, and monitor disease progression and response to treatment remains critical in optimizing outcomes.

RECENT FINDINGS

Risk assessment in PAH should include a range of clinical, hemodynamic, and exercise parameters, performed in a serial fashion over the course of treatment. Approaches to risk assessment in PAH patients include the use of risk variables, scores, and equations that stratify the impact of both modifiable (e.g., 6-min walk distance, functional class, brain natriuretic peptide), and non-modifiable (e.g., age, gender, PAH etiology) risk factors. Such tools allow physicians to better determine prognosis, allocate treatment resources, and enhance the consistency of treatment approaches across providers. Comprehensive and accurate risk prediction is essential to make individualized treatment decisions and optimizing outcomes in PAH.