Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension is a progressive disease involving proliferative remodeling of the pulmonary vessels. Despite therapeutic advances, the disease-associated morbidity and mortality remain high. Sotatercept is a fusion protein that traps activins and growth differentiation factors involved in pulmonary arterial hypertension. METHODS: We conducted a multicenter, double-blind, phase 3 trial in which adults with pulmonary arterial hypertension (World Health Organization [WHO] functional class II or III) who were receiving stable background therapy were randomly assigned in a 1:1 ratio to receive subcutaneous sotatercept (starting dose, 0.3 mg per kilogram of body weight; target dose, 0.7 mg per kilogram) or placebo every 3 weeks. The primary end point was the change from baseline at week 24 in the 6-minute walk distance. Nine secondary end points, tested hierarchically in the following order, were multicomponent improvement, change in pulmonary vascular resistance, change in N-terminal pro-B-type natriuretic peptide level, improvement in WHO functional class, time to death or clinical worsening, French risk score, and changes in the Pulmonary Arterial Hypertension-Symptoms and Impact (PAH-SYMPACT) Physical Impacts, Cardiopulmonary Symptoms, and Cognitive/Emotional Impacts domain scores; all were assessed at week 24 except time to death or clinical worsening, which was assessed when the last patient completed the week 24 visit. RESULTS: A total of 163 patients were assigned to receive sotatercept and 160 to receive placebo. The median change from baseline at week 24 in the 6-minute walk distance was 34.4 m (95% confidence interval [CI], 33.0 to 35.5) in the sotatercept group and 1.0 m (95% CI, -0.3 to 3.5) in the placebo group. The Hodges-Lehmann estimate of the difference between the sotatercept and placebo groups in the change from baseline at week 24 in the 6-minute walk distance was 40.8 m (95% CI, 27.5 to 54.1; P<0.001). The first eight secondary end points were significantly improved with sotatercept as compared with placebo, whereas the PAH-SYMPACT Cognitive/Emotional Impacts domain score was not. Adverse events that occurred more frequently with sotatercept than with placebo included epistaxis, dizziness, telangiectasia, increased hemoglobin levels, thrombocytopenia, and increased blood pressure. CONCLUSIONS: In patients with pulmonary arterial hypertension who were receiving stable background therapy, sotatercept resulted in a greater improvement in exercise capacity (as assessed by the 6-minute walk test) than placebo. (Funded by Acceleron Pharma, a subsidiary of MSD; STELLAR ClinicalTrials.gov number, NCT04576988.).

Sotatercept for the Treatment of Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension is characterized by pulmonary vascular remodeling, cellular proliferation, and poor long-term outcomes. Dysfunctional bone morphogenetic protein pathway signaling is associated with both hereditary and idiopathic subtypes. Sotatercept, a novel fusion protein, binds activins and growth differentiation factors in the attempt to restore balance between growth-promoting and growth-inhibiting signaling pathways. METHODS: In this 24-week multicenter trial, we randomly assigned 106 adults who were receiving background therapy for pulmonary arterial hypertension to receive subcutaneous sotatercept at a dose of 0.3 mg per kilogram of body weight every 3 weeks or 0.7 mg per kilogram every 3 weeks or placebo. The primary end point was the change from baseline to week 24 in pulmonary vascular resistance. RESULTS: Baseline characteristics were similar among the three groups. The least-squares mean difference between the sotatercept 0.3-mg group and the placebo group in the change from baseline to week 24 in pulmonary vascular resistance was -145.8 dyn · sec · cm-5 (95% confidence interval [CI], -241.0 to -50.6; P = 0.003). The least-squares mean difference between the sotatercept 0.7-mg group and the placebo group was -239.5 dyn · sec · cm-5 (95% CI, -329.3 to -149.7; P<0.001). At 24 weeks, the least-squares mean difference between the sotatercept 0.3-mg group and the placebo group in the change from baseline in 6-minute walk distance was 29.4 m (95% CI, 3.8 to 55.0). The least-squares mean difference between the sotatercept 0.7-mg group and the placebo group was 21.4 m (95% CI, -2.8 to 45.7). Sotatercept was also associated with a decrease in N-terminal pro-B-type natriuretic peptide levels. Thrombocytopenia and an increased hemoglobin level were the most common hematologic adverse events. One patient in the sotatercept 0.7-mg group died from cardiac arrest. CONCLUSIONS: Treatment with sotatercept resulted in a reduction in pulmonary vascular resistance in patients receiving background therapy for pulmonary arterial hypertension. (Funded by Acceleron Pharma; PULSAR ClinicalTrials.gov number, NCT03496207.).

Effects of sotatercept on haemodynamics and right heart function: analysis of the STELLAR trial.

BACKGROUND: In the phase 3 STELLAR trial, sotatercept, an investigational first-in-class activin signalling inhibitor, demonstrated beneficial effects on 6-min walk distance and additional efficacy endpoints in pre-treated participants with pulmonary arterial hypertension (PAH). METHODS: This post hoc analysis evaluated data from right heart catheterisation (RHC) and echocardiography (ECHO) obtained from the STELLAR trial. Changes from baseline in RHC and ECHO parameters were assessed at 24 weeks. An analysis of covariance (ANCOVA) model was used to estimate differences in least squares means with treatment and randomisation stratification (mono/double versus triple therapy; World Health Organization functional class II versus III) as fixed factors, and baseline value as covariate. RESULTS: Relative to placebo, treatment with sotatercept led to significant (all p<0.0001 except where noted) improvements from baseline in mean pulmonary artery (PA) pressure (-13.9 mmHg), pulmonary vascular resistance (-254.8 dyn·s·cm-5), mean right atrial pressure (-2.7 mmHg), mixed venous oxygen saturation (3.84%), PA elastance (-0.42 mmHg·mL-1·beat-1), PA compliance (0.58 mL·mmHg-1), cardiac efficiency (0.48 mL·beat-1·mmHg-1), right ventricular (RV) work (-0.85 g·m) and RV power (-32.70 mmHg·L·min-1). ECHO showed improvements in tricuspid annular plane systolic excursion (TAPSE) to systolic pulmonary artery pressure ratio (0.12 mm·mmHg-1), end-systolic and end-diastolic RV areas (-4.39 cm2 and -5.31 cm2, respectively), tricuspid regurgitation and RV fractional area change (2.04% p<0.050). No significant between-group changes from baseline were seen for TAPSE, heart rate, cardiac output, stroke volume or their indices. CONCLUSION: In pre-treated patients with PAH, sotatercept demonstrated substantial improvements in PA pressures, PA compliance, PA-RV coupling and right heart function.

Sotatercept for the treatment of pulmonary arterial hypertension: PULSAR open-label extension.

BACKGROUND: In participants with pulmonary arterial hypertension, 24 weeks of sotatercept resulted in a significantly greater reduction from baseline in pulmonary vascular resistance than placebo. This report characterises the longer-term safety and efficacy of sotatercept in the PULSAR open-label extension. We report cumulative safety, and efficacy at months 18-24, for all participants treated with sotatercept. METHODS: PULSAR was a phase 2, randomised, double-blind, placebo-controlled study followed by an open-label extension, which evaluated sotatercept on top of background pulmonary arterial hypertension therapy in adults. Participants originally randomised to placebo were re-randomised 1:1 to sotatercept 0.3 or 0.7 mg·kg-1 (placebo-crossed group); those initially randomised to sotatercept continued the same sotatercept dose (continued-sotatercept group). Safety was evaluated in all participants who received ≥1 dose of sotatercept. The primary efficacy endpoint was change from baseline to months 18-24 in pulmonary vascular resistance. Secondary endpoints included 6-min walk distance and functional class. Two prespecified analyses, placebo-crossed and delayed-start, evaluated efficacy irrespective of dose. RESULTS: Of 106 participants enrolled in the PULSAR study, 97 continued into the extension period. Serious treatment-emergent adverse events were reported in 32 (30.8%) participants; 10 (9.6%) reported treatment-emergent adverse events leading to study discontinuation. Three (2.9%) participants died, none considered related to study drug. The placebo-crossed group demonstrated significant improvement across primary and secondary endpoints and clinical efficacy was maintained in the continued-sotatercept group. CONCLUSION: These results support the longer-term safety and durability of clinical benefit of sotatercept for pulmonary arterial hypertension.

Inference following multiple imputation for generalized additive models: an investigation of the median p-value rule with applications to the Pulmonary Hypertension Association Registry and Colorado COVID-19 hospitalization data.

BACKGROUND: Missing data prove troublesome in data analysis; at best they reduce a study's statistical power and at worst they induce bias in parameter estimates. Multiple imputation via chained equations is a popular technique for dealing with missing data. However, techniques for combining and pooling results from fitted generalized additive models (GAMs) after multiple imputation have not been well explored. METHODS: We simulated missing data under MCAR, MAR, and MNAR frameworks and utilized random forest and predictive mean matching imputation to investigate a variety of rules for combining GAMs after multiple imputation with binary and normally distributed outcomes. We compared multiple pooling procedures including the "D2" method, the Cauchy combination test, and the median p-value (MPV) rule. The MPV rule involves simply computing and reporting the median p-value across all imputations. Other ad hoc methods such as a mean p-value rule and a single imputation method are investigated. The viability of these methods in pooling results from B-splines is also examined for normal outcomes. An application of these various pooling techniques is then performed on two case studies, one which examines the effect of elevation on a six-minute walk distance (a normal outcome) for patients with pulmonary arterial hypertension, and the other which examines risk factors for intubation in hospitalized COVID-19 patients (a dichotomous outcome). RESULTS: In comparison to the results from generalized additive models fit on full datasets, the median p-value rule performs as well as if not better than the other methods examined. In situations where the alternative hypothesis is true, the Cauchy combination test appears overpowered and alternative methods appear underpowered, while the median p-value rule yields results similar to those from analyses of complete data. CONCLUSIONS: For pooling results after fitting GAMs to multiply imputed datasets, the median p-value is a simple yet useful approach which balances both power to detect important associations and control of Type I errors.

Development of the Pulmonary Arterial Hypertension-Symptoms and Impact (PAH-SYMPACT®) questionnaire: a new patient-reported outcome instrument for PAH.

BACKGROUND: Regulators and clinical experts increasingly recognize the importance of incorporating patient-reported outcomes (PROs) in clinical studies of therapies for pulmonary arterial hypertension (PAH). No PAH-specific instruments have been developed to date in accordance with the 2009 FDA guidance for the development of PROs as endpoints in clinical trials. A qualitative research study was conducted to develop a new instrument assessing PAH symptoms and their impacts following the FDA PRO guidance. METHODS: A cross-sectional study was conducted at 5 centers in the US in symptomatic PAH patients aged 18-80 years. Concept elicitation was based on 5 focus group discussions, after which saturation of emergent concepts was reached. A PRO instrument for PAH symptoms and their impacts was drafted. To assess the appropriateness of items, instructions, response options, and recall periods, 2 rounds of one-on-one cognitive interviews were conducted, with instrument revisions following each round. Additional interviews tested the usability of an electronic version (ePRO). PRO development considered input from an international Steering Committee, and translatability and lexibility assessments. RESULTS: Focus groups comprised 25 patients (5 per group); 20 additional patients participated in cognitive interviews (10 per round); and 10 participated in usability interviews. Participants had a mean ± SD age of 53.1 ± 15.8 years, were predominantly female (93 %), and were diverse in race/ethnicity, WHO functional class (FC I/II: 56 %, III/IV: 44 %), and PAH etiology (idiopathic: 56 %, familial: 2 %, associated: 42 %). The draft PRO instrument (PAH-SYMPACT®) was found to be clear, comprehensive, and relevant to PAH patients in cognitive interviews. Items were organized in a draft conceptual framework with 16 symptom items in 4 domains (respiratory symptoms, tiredness, cardiovascular symptoms, other symptoms) and 25 impact items in 5 domains (physical activities, daily activities, social impact, cognition, emotional impact). The recall period is the past 24 h for symptoms, and the past 7 days for impacts. CONCLUSIONS: The PAH-SYMPACT® was shown to capture symptoms and their impacts relevant to PAH patients, demonstrating content saturation, concept validity, and ePRO usability. Final content and psychometric validation of the instrument will be based on the results of an ongoing Phase IIIb clinical trial in PAH patients.

Anticoagulation in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is characterized by molecular and pathologic alteration to the pulmonary circulation, resulting in increased pulmonary vascular resistance, right ventricular failure, and eventual death. Pharmacologic treatment of PAH consists of use of a multitude of pulmonary vasodilators, sometimes in combination. PAH has been associated with increased thrombosis and disrupted coagulation and fibrinolysis, making anticoagulation an attractive and frequently employed therapeutic modality. Observational studies have provided some insight into the therapeutic potential of anticoagulation in idiopathic PAH, but there is a distinct lack of well-controlled prospective trials. Due to the conflicting evidence, there is a large amount of heterogeneity in the application of therapeutic anticoagulation in PAH and further well-controlled prospective trials are needed to clarify its role in treating PAH.

Validation of two predictive models for survival in pulmonary arterial hypertension.

The French Pulmonary Hypertension Network (FPHN) registry and the Registry to Evaluate Early And Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) have developed predictive models for survival in pulmonary arterial hypertension (PAH). In this collaboration, we assess the external validity (or generalisability) of the FPHN ItinérAIR-HTAP predictive equation and the REVEAL risk score calculator. Validation cohorts approximated the eligibility criteria defined for each model. The REVEAL cohort comprised 292 treatment-naïve, adult patients diagnosed <1 year prior to enrolment with idiopathic, familial or anorexigen-induced PAH. The FPHN cohort comprised 1737 patients with group 1 PAH. Application of FPHN parameters to REVEAL and REVEAL risk scores to FPHN demonstrated estimated hazard ratios that were consistent between studies and had high probabilities of concordance (hazard ratios of 0.72, 95% CI 0.64-0.80, and 0.73, 95% CI 0.70-0.77, respectively). The REVEAL risk score calculator and FPHN ItinérAIR-HTAP predictive equation showed good discrimination and calibration for prediction of survival in the FPHN and REVEAL cohorts, respectively, suggesting prognostic generalisability in geographically different PAH populations. Once prospectively validated, these may become valuable tools in clinical practice.

An official American Thoracic Society clinical practice guideline: diagnosis, risk stratification, and management of pulmonary hypertension of sickle cell disease.

BACKGROUND: In adults with sickle cell disease (SCD), an increased tricuspid regurgitant velocity (TRV) measured by Doppler echocardiography, an increased serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) level, and pulmonary hypertension (PH) diagnosed by right heart catheterization (RHC) are independent risk factors for mortality. METHODS: A multidisciplinary committee was formed by clinician-investigators experienced in the management of patients with PH and/or SCD. Clinically important questions were posed, related evidence was appraised, and questions were answered with evidence-based recommendations. Target audiences include all clinicians who take care of patients with SCD. RESULTS: Mortality risk stratification guides decision making. An increased risk for mortality is defined as a TRV equal to or greater than 2.5 m/second, an NT-pro-BNP level equal to or greater than 160 pg/ml, or RHC-confirmed PH. For patients identified as having increased mortality risk, we make a strong recommendation for hydroxyurea as first-line therapy and a weak recommendation for chronic transfusions as an alternative therapy. For all patients with SCD with elevated TRV alone or elevated NT-pro-BNP alone, and for patients with SCD with RHC-confirmed PH with elevated pulmonary artery wedge pressure and low pulmonary vascular resistance, we make a strong recommendation against PAH-specific therapy. However, for select patients with SCD with RHC-confirmed PH who have elevated pulmonary vascular resistance and normal pulmonary capillary wedge pressure, we make a weak recommendation for either prostacyclin agonist or endothelin receptor antagonist therapy and a strong recommendation against phosphodiesterase-5 inhibitor therapy. CONCLUSIONS: Evidence-based recommendations for the management of patients with SCD with increased mortality risk are provided, but will require frequent reassessment and updating.

Two formulations of epoprostenol sodium in the treatment of pulmonary arterial hypertension: EPITOME-1 (epoprostenol for injection in pulmonary arterial hypertension), a phase IV, open-label, randomized study.

BACKGROUND: Epoprostenol sodium with arginine-mannitol excipients (epoprostenol AM; Veletri [Actelion Pharmaceuticals Ltd, Allschwil, Switzerland]) and epoprostenol sodium with glycine-mannitol excipients (epoprostenol GM; Flolan [GlaxoSmithKline, Triangle Park, NC]) are intravenous treatments for pulmonary arterial hypertension (PAH). Epoprostenol AM contains different inactive excipients, resulting in greater stability at room temperature compared with epoprostenol GM. METHODS: In this prospective, multicenter, open-label, randomized, phase IV exploratory study, epoprostenol-naïve patients in need of injectable prostanoid therapy were randomized 2:1 to open-label epoprostenol AM or epoprostenol GM. The study period was 28 days, followed by a 30-day safety follow-up. Study aims were to descriptively compare the safety, tolerability, drug metabolite levels, and treatment effects of epoprostenol AM and epoprostenol GM in PAH. Statistical analysis was descriptive only because of the exploratory nature of the study. RESULTS: Thirty patients with PAH (18-70 years, 24 women, 20 idiopathic PAH) were randomized to epoprostenol AM (n = 20) or epoprostenol GM (n = 10). Most frequently reported adverse events included jaw pain, headache, nausea, and flushing. Two deaths occurred during the study period, and 1 death occurred during the 30-day safety follow-up period, all in patients receiving epoprostenol AM. All deaths were classified by the treating physician as unrelated to epoprostenol AM. The median (range) change from baseline to day 28 in 6-minute walk distance was 36 m (-127 to 210 m) and 49 m (-44 to 110 m) for the epoprostenol AM and epoprostenol GM groups, respectively. CONCLUSIONS: In this randomized clinical study of epoprostenol AM in PAH, use of this novel preparation with greater room temperature stability was well tolerated.

[Definitions and diagnosis of pulmonary hypertension]. / Pulmoner hipertansiyon tani ve tanimlar.

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure 25 mm Hg at rest, measured during right heart catheterization. There is still insufficient .evidence to add an exercise criterion to this definition. The term pulmonary arterial hypertension (PAH) describes a subpopulation of patients with PH characterized hemodynamically by the presence of pre-capillary PH including an end-expiratory pulmonary artery wedge pressure (PAWP) 15 mm Hg and a pulmonary vascular resistance >3 Wood units. Right heart catheterization remains essential for a diagnosis of PH or PAH. This procedure requires further standardization, including uniformity of the pressure transducer zero level at the midthoracic line, which is at the level of the left atrium. One of the most common problems in the diagnostic workup of patients with PH is the distinction between PAH and PH due to left heart failure with preserved ejection fraction (HFpEF). A normal PAWP does not rule out the presence of HFpEF. Volume or exercise challenge during right heart catheterization may be useful to unmask the presence of left heart disease, but both tools require further evaluation before their use in general practice can be recommended. Early diagnosis of PAH remains difficult, and screening programs in asymptomatic patients are feasible only in high-risk populations, particularly in patients with systemic sclerosis, for whom recent data suggest that a combination of clinical assessment and pulmonary function testing including diffusion capacity for carbon monoxide, biomarkers, and echocardiography has a higher predictive value than echocardiography alone. (J Am Coll Cardiol 2013;62: D42-50) ©2013 by the American College of Cardiology Foundation.

Hospitalization for pain in patients with sickle cell disease treated with sildenafil for elevated TRV and low exercise capacity.

In adults with sickle cell disease (SCD), an increased tricuspid regurgitation velocity (TRV) by Doppler echocardiography is associated with increased morbidity and mortality. Although sildenafil has been shown to improve exercise capacity in patients with pulmonary arterial hypertension, it has not been evaluated in SCD. We therefore sought to determine whether sildenafil could improve exercise capacity in SCD patients with increased TRV and a low exercise capacity. A TRV ≥ 2.7 m/s and a 6-minute walk distance (6MWD) between 150 and 500 m were required for enrollment in this 16-week, double-blind, placebo-controlled sildenafil trial. After 74 of the screened subjects were randomized, the study was stopped early due to a higher percentage of subjects experiencing serious adverse events in the sildenafil arm (45% of sildenafil, 22% of placebo, P = .022). Subject hospitalization for pain was the predominant cause for this difference: 35% with sildenafil compared with 14% with placebo (P = .029). There was no evidence of a treatment effect on 6MWD (placebo-corrected effect -9 m; 95% confidence interval [95% CI] -56-38; P = .703), TRV (P = .503), or N-terminal pro-brain natriuretic peptide (P = .410). Sildenafil appeared to increase hospitalization rates for pain in patients with SCD. This study is registered at www.clinicaltrials.gov as NCT00492531.

The relationship between the severity of hemolysis, clinical manifestations and risk of death in 415 patients with sickle cell anemia in the US and Europe.

The intensity of hemolytic anemia has been proposed as an independent risk factor for the development of certain clinical complications of sickle cell disease, such as pulmonary hypertension, hypoxemia and cutaneous leg ulceration. A composite variable derived from several individual markers of hemolysis could facilitate studies of the underlying mechanisms of hemolysis. In this study, we assessed the association of hemolysis with outcomes in sickle cell anemia. A hemolytic component was calculated by principal component analysis from reticulocyte count, serum lactate dehydrogenase, aspartate aminotransferase and total bilirubin concentrations in 415 hemoglobin SS patients. Association of this component with direct markers of hemolysis and clinical outcomes was assessed. As primary validation, both plasma red blood cell microparticles and cell-free hemoglobin concentration were higher in the highest hemolytic component quartile compared to the lowest quartile (P≤0.0001 for both analyses). The hemolytic component was lower with hydroxyurea therapy, higher hemoglobin F, and alpha-thalassemia (P≤0.0005); it was higher with higher systemic pulse pressure, lower oxygen saturation, and greater values for tricuspid regurgitation velocity, left ventricular diastolic dimension and left ventricular mass (all P<0.0001). Two-year follow-up analysis showed that a high hemolytic component was associated with an increased risk of death (hazard ratio, HR 3.44; 95% confidence interval, CI: 1.2-9.5; P=0.02). The hemolytic component reflects direct markers of intravascular hemolysis in patients with sickle cell disease and allows for adjusted analysis of associations between hemolytic severity and clinical outcomes. These results confirm associations between hemolytic rate and pulse pressure, oxygen saturation, increases in Doppler-estimated pulmonary systolic pressures and mortality (Clinicaltrials.gov identifier: NCT00492531).

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.

Echocardiographic markers of elevated pulmonary pressure and left ventricular diastolic dysfunction are associated with exercise intolerance in adults and adolescents with homozygous sickle cell anemia in the United States and United Kingdom.

BACKGROUND: Noninvasively assessed pulmonary pressure elevations and left ventricular (LV) diastolic dysfunction are associated with increased mortality in adults with sickle cell disease, but their relationship to exercise intolerance has not been evaluated prospectively. METHODS AND RESULTS: Echocardiography, 6-minute walk distance, hemolytic rate, and serum concentrations of ferritin and erythropoietin were evaluated in a cohort of 483 subjects with homozygous hemoglobin S in the U.S. and U.K. Walk-Treatment of Pulmonary Hypertension and Sickle Cell Disease with Sildenafil Therapy (Walk-PHaSST) study. Tricuspid regurgitation velocity, which reflects systolic pulmonary artery pressure, was 2.7 to <3.0 m/s (mean±SD, 2.8±0.1) in 26% of the subjects and ≥3.0 m/s (mean±SD, 3.4±0.4) in 11%. The LV lateral E/e' ratio, which has been shown to reflect LV filling pressure in other conditions but has not been studied in sickle cell disease, was significantly higher in the groups with tricuspid regurgitation velocity ≥2.7 m/s. Increased hemolysis (P<0.0001), LV lateral E/e' ratio (P=0.0001), blood urea nitrogen (P=0.0002), and erythropoietin (P=0.002) were independently associated with an increased tricuspid regurgitation velocity. Furthermore, female sex (P<0.0001), older age (P<0.0001), LV lateral E/e' ratio (P=0.014), and tricuspid regurgitation velocity (P=0.019) were independent predictors of a shorter 6-minute walk distance. CONCLUSIONS: Echocardiography-estimated elevated pulmonary artery systolic pressure and LV lateral E/e' ratio were independently associated with poor exercise capacity in a large cohort of patients with sickle cell anemia. Controlled trials investigating whether strategies to prevent or delay pulmonary hypertension and/or LV diastolic dysfunction will improve exercise capacity and long-term outcomes in sickle cell anemia should be considered. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00492531.

Mortality in Pulmonary Arterial Hypertension in the Modern Era: Early Insights From the Pulmonary Hypertension Association Registry.

Background Current mortality data for pulmonary arterial hypertension (PAH) in the United States are based on registries that enrolled patients prior to 2010. We sought to determine mortality in PAH in the modern era using the PHAR (Pulmonary Hypertension Association Registry). Methods and Results We identified all adult patients with PAH enrolled in the PHAR between September 2015 and September 2020 (N=935). We used Kaplan-Meier survival analysis and Cox proportional hazards models to assess mortality at 1, 2, and 3 years. Patients were stratified based on disease severity by 3 validated risk scores. In treatment-naïve patients, we compared survival based on initial treatment strategy. The median age was 56 years (44-68 years), and 76% were women. Of the 935 patients, 483 (52%) were ≤6 months from PAH diagnosis. There were 121 deaths (12.9%) during a median follow-up time of 489 days (281-812 days). The 1-, 2-, and 3-year mortality was 8% (95% CI, 6%-10%), 16% (95% CI, 13%-19%), and 21% (95% CI, 17%-25%), respectively. When stratified into low-, intermediate-, and high-risk PAH, the mortality at 1, 2, and 3 years was 1%, 4% to 6%, and 7% to 11% for low risk; 7% to 8%, 11% to 16%, and 18% to 20% for intermediate risk; and 12% to 19%, 22% to 38%, and 28% to 55% for high risk, respectively. In treatment-naïve patients, initial combination therapy was associated with better 1-year survival (adjusted hazard ratio, 0.43 [95% CI, 0.19-0.95]; P=0.037). Conclusions Mortality in the intermediate- and high-risk patients with PAH remains unacceptably high in the PHAR, suggesting the importance for early diagnosis, aggressive use of available therapies, and the need for better therapeutics.

Predicting survival in pulmonary arterial hypertension: insights from the Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL).

BACKGROUND: Factors that determine survival in pulmonary arterial hypertension (PAH) drive clinical management. A quantitative survival prediction tool has not been established for research or clinical use. METHODS AND RESULTS: Data from 2716 patients with PAH enrolled consecutively in the US Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) were analyzed to assess predictors of 1-year survival. We identified independent prognosticators of survival and derived a multivariable, weighted risk formula for clinical use. One-year survival from the date of enrollment was 91.0% (95% confidence interval [CI], 89.9 to 92.1). In a multivariable analysis with Cox proportional hazards, variables independently associated with increased mortality included pulmonary vascular resistance >32 Wood units (hazard ratio [HR], 4.1; 95% CI, 2.0 to 8.3), PAH associated with portal hypertension (HR, 3.6; 95% CI, 2.4 to 5.4), modified New York Heart Association/World Health Organization functional class IV (HR, 3.1; 95% CI, 2.2 to 4.4), men >60 years of age (HR, 2.2; 95% CI, 1.6 to 3.0), and family history of PAH (HR, 2.2; 95% CI, 1.2 to 4.0). Renal insufficiency, PAH associated with connective tissue disease, functional class III, mean right atrial pressure, resting systolic blood pressure and heart rate, 6-minute walk distance, brain natriuretic peptide, percent predicted carbon monoxide diffusing capacity, and pericardial effusion on echocardiogram all predicted mortality. Based on these multivariable analyses, a prognostic equation was derived and validated by bootstrapping technique. CONCLUSIONS: We identified key predictors of survival based on the patient's most recent evaluation and formulated a contemporary prognostic equation. Use of this tool may allow the individualization and optimization of therapeutic strategies. Serial follow-up and reassessment are warranted. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00370214.

United States Pulmonary Hypertension Scientific Registry: Baseline Characteristics.

BACKGROUND: The treatment, genotyping, and phenotyping of patients with World Health Organization Group 1 pulmonary arterial hypertension (PAH) have evolved dramatically in the last decade. RESEARCH QUESTION: The United States Pulmonary Hypertension Scientific Registry was established as the first US PAH patient registry to investigate genetic information, reproductive histories, and environmental exposure data in a contemporary patient population. STUDY DESIGN AND METHODS: Investigators at 15 US centers enrolled consecutively screened adults diagnosed with Group 1 PAH who had enrolled in the National Biological Sample and Data Repository for PAH (PAH Biobank) within 5 years of a cardiac catheterization demonstrating qualifying hemodynamic criteria. Exposure and reproductive histories were collected by using a structured interview and questionnaire. The biobank provided genetic data. RESULTS: Between 2015 and 2018, a total of 499 of 979 eligible patients with clinical diagnoses of idiopathic PAH (IPAH) or familial PAH (n = 240 [48%]), associated PAH (APAH; n = 256 [51%]), or pulmonary venoocclusive disease/pulmonary capillary hemangiomatosis (n = 3 [1%]) enrolled. The mean age was 55.8 years, average BMI was 29.2 kg/m2, and 79% were women. Mean duration between symptom onset and diagnostic catheterization was 1.9 years. Sixty-six percent of patients were treated with more than one PAH medication at enrollment. Past use of prescription weight loss drugs (16%), recreational drugs (27%), and oral contraceptive pills (77%) was common. Women often reported miscarriage (37%), although PAH was rarely diagnosed within 6 months of pregnancy (1.9%). Results of genetic testing identified pathogenic or suspected pathogenic variants in 13% of patients, reclassifying 18% of IPAH patients and 5% of APAH patients to heritable PAH. INTERPRETATION: Patients with Group 1 PAH remain predominately middle-aged women diagnosed with IPAH or APAH. Delays in diagnosis of PAH persist. Treatment with combinations of PAH-targeted medications is more common than in the past. Women often report pregnancy complications, as well as exposure to anorexigens, oral contraceptives, and/or recreational drugs. Results of genetic tests frequently identify unsuspected heritable PAH.

Clinical Differences and Outcomes between Methamphetamine-associated and Idiopathic Pulmonary Arterial Hypertension in the Pulmonary Hypertension Association Registry.

Rationale: Single-center studies demonstrated that methamphetamine use is associated with pulmonary arterial hypertension (Meth-APAH). We used the Pulmonary Hypertension Association Registry to evaluate the national distribution of Meth-APAH and to compare its impact on patient-reported and clinical outcomes relative to idiopathic PAH.Objectives: To determine if patients with Meth-APAH differ from those with idiopathic PAH in demographics, regional distribution in the United States, hemodynamics, health-related quality of life, PAH-specific treatment, and health care use.Methods: The Pulmonary Hypertension Association Registry is a U.S.-based prospective cohort of patients new to care at a Pulmonary Hypertension Care Center. The registry collects baseline demographics, clinical parameters, and repeated measures of health-related quality of life, World Health Organization functional class, 6-minute walk distance, therapy, and health care use. Repeated measures of functional class, health-related quality of life, type of therapy, emergency department visits, and hospitalizations were compared using generalized estimating equations.Results: Of 541 participants included, 118 had Meth-APAH; 83% of Meth-APAH arose in the western United States. The Meth-APAH group was younger and had a poorer socioeconomic status and lower cardiac index than the idiopathic PAH group, despite no difference in mean pulmonary artery pressure or pulmonary vascular resistance. The Meth-APAH group had a more advanced functional class in longitudinal models (0.22 points greater; 95% confidence interval [CI], 0.07 to 0.37) and worse PAH-specific (emPHasis-10) health-related quality of life (-5.4; 95% CI, -8.1 to -2.8). There was no difference in dual combination therapy; however, participants with Meth-APAH were less likely to be initiated on triple therapy (odds ratio [OR], 0.43; 95% CI, 0.24 to 0.77) or parenteral therapy (OR, 0.10; 95% CI, 0.04 to 0.24). Participants with Meth-APAH were more likely to seek care in the emergency department (incidence rate ratio, 2.30; 95% CI, 1.71 to 3.11) and more likely to be hospitalized (incidence rate ratio, 1.42; 95% CI, 1.10 to 1.83).Conclusions: Meth-APAH represents a unique clinical phenotype of PAH, most common in the western United States. It accounts for a notable proportion of PAH in expert centers. Assessment for methamphetamine use is necessary in patients with PAH.