Pulmonary Arterial Hypertension Cohort Research Articles

Four-Strata Risk Assessment in Patients with Pulmonary Arterial Hypertension Treated with Selexipag in Real-World Settings (EXPOSURE Study).

Risk assessment can aid management of pulmonary arterial hypertension (PAH) and clinical decision-making. This analysis describes characteristics, treatment patterns and outcomes of patients with PAH, categorised by risk status at time of treatment escalation with selexipag in clinical settings. Patients initiating selexipag in the ongoing multicentre, prospective EXPOSURE (EUPAS19085) study were grouped as low, intermediate-low, intermediate-high or high risk of 1-year mortality according to the ESC/ERS 4-strata method. As of November 2022, 77% (535/698) of patients initiating selexipag had data allowing for risk calculation; 14% (N = 76) were low, 31% (N = 168) intermediate-low, 34% (N = 182) intermediate-high and 20% (N = 109) high risk of 1-year mortality. Overall, patients were predominantly female (71%), with idiopathic/heritable PAH (56%) or PAH associated with connective tissue disease (CTD-PAH; 27%), median age of 60years and prevalent (2years) disease. From low to high risk, proportion of CTD-PAH and age increased (from 12%-40% and 46-68years, respectively); time from diagnosis decreased and presence of cardiovascular risk factors increased. Most patients across risk groups (74-81%) initiated selexipag as part of triple oral combination therapy. Overall median (Q1, Q3) selexipag exposure duration was 10.1 (3.5, 24.1) months. Proportions of hospitalised patients increased with increasing risk group (16-42% from low to high, respectively); more hospitalisations were PAH-related for the high risk (71%) versus other risk groups (47-54%). Kaplan-Meier survival estimates were 98%, 98%, 93% and 80% at 1-year and 98%, 92%, 81% and 67% at 2-years, from low to high risk, respectively. In clinical settings, selexipag is initiated across all risk groups, predominantly as triple therapy. Only 45% of patients being at low/intermediate-low risk at selexipag initiation suggests an opportunity for more frequent patient monitoring and earlier treatment escalation, given that 4-strata risk assessment was prognostic for hospitalisations and survival in this contemporary PAH cohort. A graphical abstract is available with this article.

Novel Liver Injury Phenotypes and Outcomes in Clinical Trial Participants with Pulmonary Hypertension.

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) cause right ventricular dysfunction which can impact other solid organs. However, the profiles and consequences of hepatic injury due to PAH and CTEPH have not been well-studied. We aimed to identify underlying patterns of liver injury in a cohort of PAH and CTEPH patients enrolled in 15 randomized clinical trials conducted between 1998 and 2014. We used unsupervised machine learning to identify liver injury clusters in 13 trials and validated the findings in two additional trials. We then determined whether these liver injury clusters were associated with clinical outcomes or treatment effect heterogeneity. Our training dataset included 4,219 patients and our validation dataset included 1,756 patients with serum total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and albumin data. Using k-means clustering, we identified phenotypes with no liver injury, hepatocellular injury, cholestatic injury, and combined injury patterns. Patients in the cholestatic injury liver cluster had the shortest time to clinical worsening and the highest risk of mortality. The cholestatic injury group also experienced the greatest placebo-corrected treatment effect on six-minute walk distance. Randomization to the experimental arm transitioned patients to a healthier liver status. Liver injury was associated with adverse outcomes in patients with PAH and CTEPH. Randomization to active treatment had beneficial effects on liver health compared to placebo. The role of liver disease (often subclinical) in determining outcomes warrants prospective studies.

Evaluation of the European Society of Cardiology Risk Assessment Score in Incident Systemic Sclerosis-Associated Pulmonary Arterial Hypertension.

Patients with pulmonary arterial hypertension (PAH) may be stratified as low, intermediate, or high risk of 1-year mortality. In 2022, the European Society of Cardiology (ESC) updated and simplified its risk stratification tool, based on three variables: World Health Organization functional class, serum N-terminal pro-brain type natriuretic peptide and six-minute walk distance, applied at follow-up visits, intended to guide therapy over time. We applied the 2022 ESC risk assessment tool at baseline and follow-up (within 2 years) to a multinational incident cohort of systemic sclerosis-associated PAH (SSc-PAH). Kaplan-Meier curves, Cox hazards regression, and accelerated failure time models were used to evaluate survival by risk score. At baseline (n = 260), the majority of SSc-PAH (72.2%) were graded as intermediate risk of death according to the 2022 tool. At follow-up, according to 2022 tool, half (55.5%) of the cohort were classified as low or intermediate-low risk. The 2022 risk model at follow-up was able to differentiate survival between risk strata. All three individual parameters (World Health Organization functional class, N-terminal pro-brain type natriuretic peptide, six-minute walk distance) were significantly associated with mortality at baseline and/or follow-up. The 2022 ESC risk assessment strategy applied at baseline and follow-up predicts survival in SSc-PAH. Treatment decisions for SSc-PAH should include risk assessments, aiming to achieve low-risk status according to the 2022 ESC guidelines.

Excess healthcare resource utilization and costs for commercially insured patients with pulmonary arterial hypertension: A real-world data analysis.

This retrospective study was conducted to evaluate all-cause healthcare resource utilization (HCRU) and costs in commercially insured patients living with pulmonary arterial hypertension (PAH) and explore end-of-life (EOL)-related HCRU and costs. Data from the IQVIA PharMetrics® Plus database (October 2014 to May 2020) were analyzed to identify adults (≥18 years) with PAH (PAH cohort) and those without PH (non-PH cohort). Patients were required to have data for ≥12 months before (baseline) and ≥6 months after (follow-up) the first observed PH diagnosis (index date) for PAH cohort or pseudo index date for non-PH cohort. A PAH EOL cohort was similarly constructed using a broader data window (October 2014 to March 2022) and ≥1 month of follow-up. Annualized all-cause HCRU and costs during follow-up were compared between PAH and non-PH cohorts after 1:1 matching on propensity scores derived from patient characteristics. EOL-related HCRU and costs were explored within 30 days and 6 months before the death date and estimated by a claims-based algorithm in PAH EOL cohort. The annual all-cause total ($183,616 vs. $20,212) and pharmacy ($115,926 vs. $7862; both p < 0.001) costs were 8 and 14 times higher, respectively, in the PAH cohort versus matched non-PH cohort (N = 386 for each). In PAH EOL cohort (N = 28), the mean EOL-related costs were $48,846 and $167,524 per patient within 30 days and 6 months before the estimated death, respectively. Hospitalizations contributed 58.8%-70.8% of the EOL-related costs. The study findings indicate substantial HCRU and costs for PAH. While pharmacy costs were one of the major sources, hospitalization was the primary driver for EOL-related costs.

Insights Into Differences in Pulmonary Hemodynamics in Hispanic Patients With Pulmonary Arterial Hypertension.

Emerging data suggest that Hispanic patients with pulmonary arterial hypertension (PAH) exhibit improved survival rates compared to individuals of other ethnicities with similar baseline hemodynamics. However, the underlying reasons for this survival advantage remain unclear. This study focused on comparing pulmonary hemodynamics in Hispanic and non-Hispanic PAH patients and how these differences may contribute to varied clinical outcomes. A retrospective analysis of right heart catheterization data was conducted on a treatment-naive PAH patient cohort from a single center. Over a 10-year period, a total of 226 PAH patients were identified, of which 138 (61%) were Hispanic and 88 (39%) were non-Hispanic. Hispanic patients presented with lower pulmonary artery pressures, lower pulmonary vascular resistance, and exhibited significantly higher pulmonary arterial compliance (PAc). Hispanic patients had better 5-year survival rates. This study highlights the importance of exploring phenotypic differences in ethnically diverse PAH cohorts.

Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants.

Asians have a higher carrier rate of pulmonary arterial hypertension (PAH)-related genetic variants than Caucasians do. This study aimed to identify PAH-related genetic variants using whole exome sequencing (WES) in Asian idiopathic and heritable PAH cohorts. A WES library was constructed, and candidate variants were further validated by polymerase chain reaction and Sanger sequencing in the PAH cohort. In a total of 69 patients, the highest incidence of variants was found in the BMPR2, ATP13A3, and GDF2 genes. Regarding the BMPR2 gene variants, there were two nonsense variants (c.994C>T, p. Arg332*; c.1750C>T, p. Arg584*), one missense variant (c.1478C>T, p. Thr493Ile), and one novel in-frame deletion variant (c.877_888del, p. Leu293_Ser296del). Regarding the GDF2 variants, there was one likely pathogenic nonsense variant (c.259C>T, p. Gln87*) and two missense variants (c.1207G>A, p. Val403Ile; c.38T>C, p. Leu13Pro). The BMPR2 and GDF2 variant subgroups had worse hemodynamics. Moreover, the GDF2 variant patients were younger and had a significantly lower GDF2 value (135.6 ± 36.2 pg/mL, p = 0.002) in comparison to the value in the non-BMPR2/non-GDF2 mutant group (267.8 ± 185.8 pg/mL). The BMPR2 variant carriers had worse hemodynamics compared to the patients with the non-BMPR2/non-GDF2 mutant group. Moreover, there was a significantly lower GDF2 value in the GDF2 variant carriers compared to the control group. GDF2 may be a protective or corrected modifier in certain genetic backgrounds.

Impact of Left Heart Disease Risk Factors on Outcomes in Pulmonary Arterial Hypertension Therapy

BackgroundCurrent guidelines recommend initial monotherapy for pulmonary arterial hypertension (PAH) with ‘cardiopulmonary comorbidities’, despite limited available evidence to guide management. Research QuestionDo left heart disease (LHD) risk factors have an impact on treatment response and influence applicability of risk assessment in a real-world cohort of PAH patients? Study Design and MethodsThe AMBITION trial criteria was used to define the phenotype of PAH patients with risk factors for LHD. Treatment strategy, functional outcome, long term survival and risk discrimination were compared with a reference PAH cohort using the PHSANZ registry. Results487 incident PAH patients diagnosed between 2011-2020 were included. Of these, 103 (21.1%) fulfilled the definition of PAH with LHD risk factors with 384 (78.9%) remaining as reference group. PAH with LHD risk factors were older (66±13 vs. 58±19years, p<0.001), had lower pulmonary vascular resistance (393±266 vs 708±391dynes/sec/cm-5, p=0.031) and worse 6-minute walk distance (286±130 vs. 327±136m, p=0.005) at diagnosis. PAH with LHD risk factors were less likely to receive less initial combination therapy (27% vs. 44%, p=0.02). Changes in 6-minute walk distance at 12-months were similar in both groups, 43±77 in PAH with LHD risk factors and 50±90m in reference group (p=0.5), including when stratified by initial treatment strategy (monotherapy: 40±81 vs. 38±95m p=0.87 and combination therapy: 53±78 vs. 64±106m, p=0.511; PAH with LHD risk factors vs. reference PAH). Functional class improvements were also similar in both groups. REVEAL 2.0 risk score effectively discriminated risk in both populations (C-statistic=0.756 for PAH with LHD risk factors and C-statistic=0.750 for reference PAH). There was no difference in survival between the two groups (log-rank test p=0.29). InterpretationIn a real-word cohort, PAH patients with LHD risk factors were less likely to be exposed to initial combination therapy. Nevertheless, selected PAH patients with LHD risk factors who were treated with initial combination therapy derived similar functional response compared to reference group. Further studies are needed to phenotype PAH patients with cardiopulmonary comorbidities who may benefit from initial combination therapy.

Association Study Identified HLA-DQA1 as a Novel Genetic Risk of Systemic Lupus Erythematosus-Associated Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a severe complication of systemic lupus erythematosus (SLE). However, the genetic signatures of SLE-associated PAH have not been well studied. We aimed to identify genetic variants implicated in SLE-associated PAH susceptibility within the major histocompatibility complex (MHC) region and assess the contribution to clinical outcomes. A total of 172 patients with SLE-associated PAH confirmed by right heart catheterization, 1,303 patients with SLE without PAH, and 9,906 healthy controls were included. Deep sequencing of the MHC region was performed to identify alleles, single-nucleotide polymorphisms, and amino acids. We compared patients with SLE-associated PAH with patients with SLE without PAH and healthy controls. Clinical association study was conducted to explore the contribution to phenotypes. A total of 19,881 genetic variants were identified within the MHC region. HLA-DQA1*03:02 was identified as a novel genetic variant associated with SLE-associated PAH in the discovery cohort (P = 5.68 × 10-12 ) and authenticated in an independent replication cohort (P = 1.30 × 10-9 ). The strongest associated amino acid position was mapped to HLA-DQα1 in the region affecting MHC/peptide-CD4+ T cell receptor affinity and antigen binding. Clinical association study demonstrated that patients with SLE-associated PAH with HLA-DQA1*03:02 had significantly lower rates of target role achievement (P = 0.005) and survival (P = 0.04). This study, based on the largest cohort of SLE-associated PAH, is the first to investigate how MHC region genetic variants contribute to SLE-associated PAH susceptibility. HLA-DQA1*03:02 is a novel genetic risk factor and a prognostic factor in SLE-associated PAH. Patients with SLE with this allele require regular monitoring and careful follow-up for early diagnosis and interventions for potential PAH.

Association Between the Pulmonary Artery Pulsatility Index and Prognosis in Pulmonary Arterial Hypertension: A Multicentre Study

BackgroundRisk stratification is fundamental in the management of pulmonary arterial hypertension (PAH). Pulmonary artery pulsatility index (PAPi), defined as pulmonary arterial pulse pressure divided by right atrial pressure (RAP), is a hemodynamic index shown to predict acute right ventricular (RV) dysfunction in several settings. Our objective was to test the prognostic utility of PAPi in a diverse multicentre cohort of patients with PAH. MethodsA multicentre retrospective cohort study of consecutive adult patients with a new diagnosis of PAH on right heart catheterization between January 2016 and December 2020 was undertaken across 4 major centres in Canada. Hemodynamic data, clinical data, and outcomes were collected. The association of PAPi and other hemodynamic variables with mortality was assessed by receiver-operating characteristic curves and Cox proportional hazards modeling. ResultsWe identified 590 patients with a mean age of 61.4 ± 15.5 years, with 66.3% being female. A low PAPi (defined as < 5.3) was associated with higher mortality at 1 year: 10.2% vs 5.2% (P = 0.02). In a multivariable model including age, sex, body mass index, and functional class, a low PAPi was associated with mortality at 1 year (area under the curveof 0.64 (95% confidence interval 0.55-0.74). However, high RAP (> 8 mm Hg) was similarly predictive of mortality, with an area under the curve of 0.65. ConclusionPAPi was associated with mortality in a large incident PAH cohort. However, the discriminative value of PAPi was not higher than that of RAP alone.

Economic burden of illness among patients with pulmonary arterial hypertension (PAH) associated with connective tissue disorders (CTD)

Pulmonary arterial hypertension (PAH) is commonly associated with connective tissue disorders (CTDs). This study provides a contemporary assessment of the economic burden of CTD + PAH and PAH in the United States. Eligible adult patients identified from Optum's deidentified Clinformatics® Data Mart Database (10/01/2015-09/30/2021) were classified into mutually exclusive cohorts based on recorded diagnoses: (1) CTD + PAH, (2) PAH, (3) CTD, (4) control without CTD/PAH. The index date was a randomly selected diagnosis date for PAH (CTD + PAH, PAH cohorts) or CTD (CTD cohort), or a random date (control cohort). Entropy balancing was used to balance characteristics across cohorts. Healthcare costs and healthcare resource utilization (HRU) per patient per month (PPPM) were assessed for ≤12 months postindex and compared among balanced cohorts. A total of 552,900 patients were included (CTD + PAH: n = 1876; PAH: n = 8177; CTD: n = 209,156; control: n = 333,691). Average total all-cause costs were higher for CTD + PAH than PAH cohort ($16,854 vs. $15,686 PPPM; p = 0.02); both cohorts incurred higher costs than CTD and control cohorts ($4476 and $2170 PPPM; all p < 0.001). Average HRU PPPM was similar between CTD + PAH and PAH cohorts (inpatient stay: 0.15 vs. 0.15, outpatient visits: 4.23 vs. 4.11; all p > 0.05), while CTD and control cohorts incurred less HRU (inpatient stay: 0.07 and 0.03, outpatient visits: 2.67 and 1.69; all p < 0.001). CTD + PAH and PAH are associated with a substantial economic burden. The incremental burden attributable to PAH versus the general population and patients with CTD without PAH highlights significant unmet needs among PAH patients.

Impact of the COVID-19 pandemic on chronic disease management and patient reported outcomes in patients with pulmonary hypertension: The Pulmonary Hypertension Association Registry.

To better understand the impact of the COVID-19 pandemic on the care of patients with pulmonary hypertension, we conducted a retrospective cohort study evaluating health insurance status, healthcare access, disease severity, and patient reported outcomes in this population. Using the Pulmonary Hypertension Association Registry (PHAR), we defined and extracted a longitudinal cohort of pulmonary arterial hypertension (PAH) patients from the PHAR's inception in 2015 until March 2022. We used generalized estimating equations to model the impact of the COVID-19 pandemic on patient outcomes, adjusting for demographic confounders. We assessed whether insurance status modified these effects via covariate interactions. PAH patients were more likely to be on publicly-sponsored insurance during the COVID-19 pandemic compared with prior, and did not experience statistically significant delays in access to medications, increased emergency room visits or nights in the hospital, or worsening of mental health metrics. Patients on publicly-sponsored insurance had higher healthcare utilization and worse objective measures of disease severity compared with privately insured individuals irrespective of the COVID-19 pandemic. The relatively small impact of the COVID-19 pandemic on pulmonary hypertension-related outcomes was unexpected but may be due to pre-established access to high quality care at pulmonary hypertension comprehensive care centers. Irrespective of the COVID-19 pandemic, patients who were on publicly-sponsored insurance seemed to do worse, consistent with prior studies highlighting outcomes in this population. We speculate that previously established care relationships may lessen the impact of an acute event, such as a pandemic, on patients with chronic illness.

A claims-based, machine-learning algorithm to identify patients with pulmonary arterial hypertension.

Many patients with pulmonary arterial hypertension (PAH) experience substantial delays in diagnosis, which is associated with worse outcomes and higher costs. Tools for diagnosing PAH sooner may lead to earlier treatment, which may delay disease progression and adverse outcomes including hospitalization and death. We developed a machine-learning (ML) algorithm to identify patients at risk for PAH earlier in their symptom journey and distinguish them from patients with similar early symptoms not at risk for developing PAH. Our supervised ML model analyzed retrospective, de-identified data from the US-based Optum® Clinformatics® Data Mart claims database (January 2015 to December 2019). Propensity score matched PAH and non-PAH (control) cohorts were established based on observed differences. Random forest models were used to classify patients as PAH or non-PAH at diagnosis and at 6 months prediagnosis. The PAH and non-PAH cohorts included 1339 and 4222 patients, respectively. At 6 months prediagnosis, the model performed well in distinguishing PAH and non-PAH patients, with area under the curve of the receiver operating characteristic of 0.84, recall (sensitivity) of 0.73, and precision of 0.50. Key features distinguishing PAH from non-PAH cohorts were a longer time between first symptom and the prediagnosis model date (i.e., 6 months before diagnosis); more diagnostic and prescription claims, circulatory claims, and imaging procedures, leading to higher overall healthcare resource utilization; and more hospitalizations. Our model distinguishes between patients with and without PAH at 6 months before diagnosis and illustrates the feasibility of using routine claims data to identify patients at a population level who might benefit from PAH-specific screening and/or earlier specialist referral.

Societal costs associated with pulmonary arterial hypertension: A study utilizing linked national registries.

Pulmonary arterial hypertension (PAH) is a progressive disease with no cure. Healthcare resource utilization (HCRU; hospitalization, outpatient visits, and drug utilization) before diagnosis and productivity loss (sick leave and disability pension) before and after PAH diagnosis are not well known. By linking several Swedish national databases, this study have estimated the societal costs in a national PAH cohort (n = 749, diagnosed with PAH in 2008-2019) 5years before and 5years after diagnosis and compared to an age, sex, and geographically matched control group (n = 3745, 1:5 match). HCRU and productivity loss were estimated per patient per year. The PAH group had significantly higher HCRU and productivity loss compared to the control group starting already 3and 5years before diagnosis, respectively. HCRU peaked the year after diagnosis in the PAH group with hospitalizations (mean ± standard deviation; 2.0 ± 0.1 vs. 0.2 ± 0.0), outpatient visits (5.3 ± 0.3 vs. 0.9 ± 0.1), and days on sick leave (130 ± 10 vs. 13 ± 1) significantly higher compared to controls. Total costs during the entire 10-year period were six times higher for the PAH group than the control group. In the 5years before diagnosis the higher costs were driven by productivity loss (76%) and hospitalizations (15%), while the 5years after diagnosis the main cost drivers were drugs (63%), hospitalizations (16%), and productivity loss (16%). In conclusion, PAH was associated with large societal costs due to high HCRU and productivity loss, starting several years before diagnosis. The economic and clinical burden of PAH suggests that strategies for earlier diagnosis and more effective treatments are warranted.

Time to diagnosis of pulmonary hypertension and diagnostic burden: A retrospective analysis of nationwide US healthcare data.

The main aim of this analysis was to investigate time from symptom onset (chronic unexplained dyspnoea [CUD]) to diagnosis of Group 1 pulmonary hypertension (PH)-pulmonary arterial hypertension (PAH)-and to characterize healthcare resource utilization leading up to diagnosis using a nationwide US claims and an electronic health record (EHR) database from Optum©. Eligible patients were ≥18 years old at first CUD diagnosis (index event) and had a PAH diagnosis on or after index date. Based on administrative codes, PAH was defined as right heart catheterization (RHC), ≥ 2 PAH diagnoses (1 within a year of RHC), and ≥1 post-RHC prescription for PAH treatment. All values are median (1st quartile-3rd quartile) unless otherwise stated. Of 854,722 patients with CUD in the claims database, 582 (0.1%) had PAH. Time from CUD to PAH diagnosis was 2.26 (0.73-4.22) years. PAH patients experienced 3 (2-4) transthoracic echocardiograms (TTEs), 6 (3-12) specialist visits, and 2 (1-4) hospitalizations during the diagnostic interval. Almost one-third of patients (29%) waited 10 months or more to have a TTE. Findings from the EHR database were broadly similar. Resource utilization during the diagnostic interval was also analyzed in an overall PH cohort: findings were generally similar to the PAH cohort (2 [1-3] TTEs, 4 [2-9] specialist visits and 2 [1-4] hospitalizations). These data indicate a delay in the diagnostic pathway for PAH, and illustrate the burden associated with PAH diagnosis.

Risk stratification, prognosis, and survival in a pulmonary arterial hypertension cohort in Latin America. A multicenter study

BackgroundPulmonary arterial hypertension (PAH) guidelines suggest that achieving a low-risk profile should be the treatment goal. Our aim was to assess a risk assessment strategy based on three non-invasive variables from the ESC/ERS 2015 guidelines in a Latin American cohort. Methods92 incident patients (mean [SD] age 47, 77% female, 53% idiopathic PAH) were included in this retrospective, multicenter study. Patients were stratified at baseline and at early follow-up, within the first year, using three non-invasive variables (WHO functional class, 6-minute walking distance, BNP/NT-proBNP) from the ESC/ERS 2015 risk assessment instrument. Median (IQR) follow-up was 3.11 years (3.01 years). ResultsAt baseline assessment, 25% of patients were at low risk, 61.9% at intermediate-risk, and 13% at high-risk. At early follow-up (median 9.5 months), 56.5% of patients were at low-risk, 40.2% at intermediate-risk, and 3.2% at high-risk (p<0.001 vs. baseline). According to risk stratification at early follow-up, one, three and five-year overall survival was 100% in the low-risk group (no deaths at five-year follow-up), and 100%, 84% (95% CI: 72–98%), and 66% (95% CI: 48–90%) respectively in the intermediate-risk group, p = 0.0003. Mortality in the high-risk patients at early follow-up was 1/3 (33.3%). One, three, and five-year event-free survival (death or transplant or first hospitalization due to worsening PAH) based on early follow-up risk assessment was higher in the low-risk group, p = 0.0003. ConclusionOur study validates a risk assessment strategy based on three non-invasive variables and confirms that early achievement of a low-risk profile should be the treatment goal.

Influence of Iron Deficiency on Clinical and Haemodynamic Parameters in Pulmonary Arterial Hypertension Cohorts.

Iron deficiency (Fedef) has been shown to be common in patients with group 1 or pulmonary arterial hypertension (PAH). Several studies have shown a negative impact of Fedef on clinical and haemodynamic parameters of the disease, but data from individual studies have not been strong enough to lead to incorporation of the finding of Fedef into prognostic or therapeutic algorithms. The goal of this meta-analysis was to combine data from available studies to better define any associations between Fedef and established variables of prognostic importance in PAH. A literature search identified nine studies with extractable data relevant to the study questions. The impact of Fedef upon the following parameters was evaluated: 6-minute walk distance (6MWD), WHO-functional class, N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, echocardiography, and findings from right heart catheterisation (RHC). Pooled results were reported as mean difference or risk difference with 95% confidence intervals utilising a random effects modeling approach. Fedef in the PAH population was common (47% of cases) and was associated with cardiovascular dysfunction (lower tricuspid annular plane systolic excursion [TAPSE], elevated NT-proBNP, and lower mixed venous oxygen saturation) and with reduction in functional capacity (lower 6MWD and higher functional class). This meta-analysis strengthens the relationships between Fedef and several markers of poor outcome in PAH. Fedef in patients with PAH warrants further scrutiny and merits consideration as a cause of clinical deterioration. Even though causation and longitudinal relationships between Fedef and PAH could not be identified, effect of Fedef on factors that affect disease prognosis is noteworthy and worthy of more focussed studies.

Early selexipag initiation and long-term outcomes: insights from randomised controlled trials in pulmonary arterial hypertension.

Further understanding of when to initiate therapies in pulmonary arterial hypertension (PAH) is important to improve long-term outcomes. Post hoc analyses of GRIPHON (NCT01106014) and exploratory analyses of TRITON (NCT02558231) suggested benefit of early selexipag initiation on long-term outcomes, despite no additional benefit versus initial double combination on haemodynamic and functional parameters in TRITON. Post hoc analyses investigated the effect of early selexipag initiation on disease progression and survival in a large, pooled PAH cohort. Data from newly diagnosed (≤6 months) PAH patients from GRIPHON and TRITON were pooled. Patients on active therapy with selexipag (pooled selexipag group) were compared with those on control therapy with placebo (pooled control group). Disease progression end-points were defined as per the individual studies. Hazard ratios (HR) and 95% CI for time to first disease progression event up to end of double-blind treatment (selexipag/placebo) +7 days and time to all-cause death up to end of study were estimated using Cox regression models. The pooled dataset comprised 649 patients, with 44% on double background therapy. Selexipag reduced the risk of disease progression by 52% versus control (HR: 0.48; 95% CI: 0.35-0.66). HR for risk of all-cause death was 0.70 (95% CI: 0.46-1.10) for the pooled selexipag versus control group. Sensitivity analyses accounting for the impact of PAH background therapy showed consistent results, confirming the appropriateness of data pooling. These post hoc, pooled analyses build on previous insights, further supporting selexipag use within 6 months of diagnosis, including as part of triple therapy, to delay disease progression.

Abstract 9439: Association of Renal Function With Abnormal Hemodynamics and Severity of Pulmonary Arterial Hypertension

Introduction: Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary vascular pressure and resistance that ultimately resulted in right heart failure and the deterioration of related hemodynamic parameters, precipitating the alternation of renal function and prognosis. However, which hemodynamic parameter associating the severity of PAH might alter renal function remains uncertain. Methods: The PAH cohort were extracted from the TAIPANS, a multicenter, prospective, observational registry of the clinical course and disease management of PAH patients. The COMPERA risk assessment strategy was used to grading the severity of PAH into low, intermediate, or high risk. The calculation of eGFR by using the MDRD formula. Results: A total 353 PAH diagnosed patients were included from TAIPANS registry. The higher risks group had been significantly older, higher WHO Fc, higher NT-pro BNP level, worse right hemodyanmic parameters (Table 1). The higher risk group carried lower eGFR. After adjustment, the intermediate and high risk groups were significantly decreased eGFR (p trend=0.01) (Table 2). The component of COMPERA risk factors, especially RAP level, showed significant negative correlation with eGFR (Figure A). Conclusions: The renal dysfunction is associated with PAH severity and associated with worse hemodynamic, especially elevated RAP.

Abstract 10096: Genetic Control of Lysosomal Dysfunction Reprograms Sterol Metabolism in Pulmonary Arterial Hypertension

Background : Vascular inflammation critically regulates endothelial pathophenotypes, yet causative mechanisms remain incompletely defined, particularly in pulmonary arterial hypertension (PAH). Immune dysregulation and metabolic reprogramming are recognized tenets of PAH pathogenesis, but a unifying theory connecting the two has not been established. Methods &amp; Results: Guided by an unbiased, metabolome-wide association study from the multicenter PAH Biobank cohort (N=2,666) that identified a proinflammatory sterol and bile acid metabolite plasma signature significantly associated with PAH mortality (adjusted P values&lt;1.1x10 -6 ), we found in pulmonary arterial endothelial cells (ECs) that induction of the nuclear receptor coactivator 7 (NCOA7) tempered the generation of proinflammatory sterols by bolstering lysosomal acidification and constraining EC immunoactivation. Conversely, reduced NCOA7 promoted lysosomal dysfunction, resulting in sterol- and bile acid-driven inflammation and EC phenotypes consistent with PAH. Notably, the common variant intronic SNP rs11154337 in NCOA7 was found to control NCOA7 levels, lysosome activity, sterol and bile acid production, and EC immunoactivation in isogenic, CRISPR-Cas9, SNP-edited, iPSC-derived ECs, indicating a potentially widespread genetic predisposition to NCOA7 deficiency. Correspondingly, SNP rs11154337 was associated with PAH severity as noted by six-minute walk distance ( P =0.0130, β=58.15, 95% CI [14.45-119.36]) and mortality ( P =0.0250; hazard ratio=0.4368, 95% CI [0.21-0.90]) in an independent, single-center PAH cohort (N=93). In vivo , mice deficient for Ncoa7 or treated with exogenous 7α-hydroxy-3-oxo-4-cholestenoic acid (7HOCA)—chosen as a representative metabolite from the sterol signature associated with mortality in the PAH Biobank—demonstrated worsened hemodynamic and histological indices of PAH. Conclusions: Our work establishes a genetic and metabolic paradigm that links lysosomal biology and sterol and bile acid processes with EC inflammation. This paradigm carries broad implications not only on molecular diagnostic and therapeutic development in PAH but also in other vascular disorders dependent upon acquired and innate immune regulation.

Abstract 10474: Long-Term Daily Activity is Associated With Exercise Capacity and Quality of Life in Pulmonary Arterial Hypertension

Introduction: Reduced functional capacity is a hallmark of pulmonary arterial hypertension (PAH). Six minute walk distance (6MWD) is a common measure of functional capacity. Unlike the 6MWD, daily activity monitoring integrates behavioral aspects of physical capacity. We hypothesized that daily activity is associated with 6MWD and quality of life (QOL) in patients with PAH. Methods: This study included patients with PAH from the NHLBI-funded Pulmonary Vascular Disease Phenomics (PVDOMICS) study. PVDOMICS collected 6MWD and QOL surveys (Minnesota Living with Heart Failure [MLHF] and Short Form-36 [SF-36]) data. Daily activity was measured using Fitbit devices which participants wore continuously for 12 weeks. Daily activity was expressed as average daily steps and graded intensity. Results: We enrolled 45 patients with PAH (age, 48.1 + 13.4 years) with median daily steps of 4146 (IQR: 2682-6977). Sedentary, fairly active, and very active minutes/day were 850 (IQR: 774-1093), 5.0 (IQR 2.0-7.6), and 2.1 (IQR 0.7-7.3). The median time between 6MWD and the start of daily activity monitoring was 32 days (IQR 11-53). Average daily steps correlated with 6MWD (r = 0.70, p&lt;0.001), MLHF total score (r = - 0.46, p=0.002), MLHF physical and emotional domains, and the SF-36 physical component score. Among hemodynamic measures, average steps and fairly active minutes were most strongly associated with PA compliance (r=0.46 and r=0.64; both p&lt;0.05). In contrast, 6MWD only correlated with the SF 36 physical component but no MLHF measures. Conclusions: In a geographically diverse PAH cohort, long-term daily step counts are associated with exercise capacity and QOL. Daily activity measures capture behavioral information not captured by the 6MWD and correlated with prognostic hemodynamic measures. Daily activity monitoring and 6MWD represent complementary measures for the assessment of functional capacity in patients with PAH.