The effects of oxygenation on acute vasodilator challenge in pulmonary arterial hypertension.

Identification of long-term calcium channel blocker (CCB) responders with acute vasodilator challenge is critical in the evaluation of patients with pulmonary arterial hypertension. Currently there is no standardized approach for use of supplemental oxygen during acute vasodilator challenge. In this retrospective analysis of patients identified as acute vasoresponders, treated with CCBs, all patients had hemodynamic measurements in three steps: (1) at baseline; (2) with 100% fractional inspired oxygen; and (3) with 100% fractional inspired oxygen plus inhaled nitric oxide (iNO). Those meeting the definition of acute vasoresponsiveness only after first normalizing for the effects of oxygen in step 2 were labeled "iNO Responders." Those who met the definition of acute vasoresponsiveness from a combination of the effects of 100% FiO2 and iNO were labeled "oxygen responders." Survival, hospitalization for decompensated right heart failure, duration of CCB monotherapy, and functional data were collected. iNO responders, when compared to oxygen responders, had superior survival (100% vs. 50.1% 5-year survival, respectively), fewer hospitalizations for acute decompensated right heart failure (0% vs. 30.4% at 1 year, respectively), longer duration of CCB monotherapy (80% vs. 52% at 1 year, respectively), and superior 6-min walk distance. Current guidelines for acute vasodilator testing do not standardize oxygen coadministration with iNO. This study demonstrates that adjusting for the effects of supplemental oxygen before assessing for acute vasoresponsiveness identifies a cohort with superior functional status, tolerance of CCB monotherapy, and survival while on long-term CCB therapy.

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.

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.

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.).

Pulmonary artery compliance in different forms of pulmonary hypertension.

OBJECTIVE: Pulmonary artery compliance (PAC), estimated as stroke volume (SV) divided by pulmonary artery pulse pressure (PP), may be a predictor of survival in pulmonary arterial hypertension (PAH). Resistance-compliance (RC) time, the product of PAC and pulmonary vascular resistance, is reported to be a physiological constant. We investigated if differences in PAC and RC time exist between pulmonary hypertension (PH) subgroups and examined whether PAC is an independent predictor of transplant-free survival in PAH. METHODS: This was a retrospective analysis of adult PAH (n=532) and chronic thromboembolic PH (CTEPH, n=84) patients enrolled in the US Pulmonary Hypertension Association Registry from 2015 to 2019. PAC and RC time were compared between PH subgroups (connective tissue disease-PAH (CTD-PAH), idiopathic/heritable-PAH (i/h-PAH), drug/toxin-PAH (d/t-PAH)). Cox proportional hazards models were constructed for transplant-free survival, adjusting for REVEAL 2.0 risk score. RESULTS: There were no differences in estimated PAC between PAH subgroups, nor between PAH and CTEPH. RC time was shorter in CTEPH compared with PAH (median 0.55 (IQR 0.45-0.64) vs 0.62 (0.52-0.73) s, p<0.0001). RC time was shortest in CTD-PAH when compared with i/h-PAH and d/t-PAH ((0.59±0.18) vs (0.65±0.20) vs (0.73±0.25) s, p=0.0001). PAC was associated with transplant-free survival (HR 0.72, 95% CI 0.55 to 0.94, p=0.02) but was not an independent predictor of outcome after adjustment for REVEAL 2.0 score. CONCLUSION: PAC was similar between PH groups and was not an independent predictor of transplant-free survival in PAH. RC time was different between PH subgroups, challenging RC time constancy. TRIAL REGISTRATION NUMBER: NCT04071327.

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.

Erratum: Health disparities and treatment approaches in portopulmonary hypertension and idiopathic pulmonary arterial hypertension: An analysis of the Pulmonary Hypertension Association Registry.

[This corrects the article DOI: 10.1177/20458940211020913.].

Prediction of patient outcomes through social determinants of health: The Pulmonary Hypertension Association Registry (PHAR) evaluation.

Outcomes of patients with pulmonary arterial hypertension (PAH) may be associated with social determinants of health (SDOH) and other baseline patient characteristics. At present, there is no prognostic model to predict important patient outcomes in PAH based on SDOH. Utilizing information from the Pulmonary Hypertension Association Registry (PHAR), we derive a model (PHAR Evaluation or PHARE) to predict an important composite patient outcomes based on SDOH and other patient characteristics. Baseline data regarding SDOH from adult patients with PAH enrolled in the PHAR between 2015 and March 23, 2020, were included for analysis. We performed repeated measures logistic regression modeling with dichotomous outcome data (0 for no events, 1 for one or more events) to derive the PHARE. Here, 1275 consecutive adult patients enrolled in the PHAR from 47 participating centers were included. Variables included in our model are race, gender, ethnicity, household income, level of education, age, body mass index, drug use, alcohol use, marital status, and type of health insurance. Interaction effect between variables was analyzed and several interactions were also included in the PHARE. The PHARE shows a c-statistic of 0.608 (p < 0.0001) with 95% confidence intervals (0.583, 0.632). Using SDOH and baseline characteristics from the PHAR, the PHARE correlates with our composite patient outcome. Further work evaluating the role of SDOH in prognostic modeling of PAH is indicated.

INSPIRE: Safety and tolerability of inhaled Yutrepia (treprostinil) in pulmonary arterial hypertension (PAH).

The INSPIRE trial was a Phase 3, open-label, multicenter trial (LTI-301) that enrolled patients with pulmonary arterial hypertension (PAH) ≥ 18 years of age who transitioned to Yutrepia from nebulized treprostinil (Transition) or added Yutrepia to prostacyclin naïve patients on ≤2 nonprostacyclin oral therapies. The objectives of the trial were to evaluate the safety and tolerability of Yutrepia (dry-powder formulation of treprostinil) in patients with PAH. The primary safety measures were the incidence of adverse events (AEs) and serious AEs. Exploratory efficacy measures were also assessed during the trial. Transition patients initiated Yutrepia at a dose comparable to their nebulized treprostinil dose while prostacyclin naïve patients received 26.5-mcg QID; up-titration in 26.5-mcg increments was permitted for both groups. A total of 121 patients were enrolled, of which 29 patients discontinued from the trial, with the most common reason being AEs. Eighty percent of the Transition group and 96% of the prostacyclin naïve group titrated to a dose ≥79.5 mcg QID at Day 360, respectively, with one patient achieving a dose of 212-mcg QID. The most common AEs were cough, headache, upper respiratory tract infection, dyspnea, dizziness, throat irritation, diarrhea, chest discomfort, fatigue, and nasopharyngitis. Most of these events were considered treatment-related though mild to moderate in severity and expected for prostacyclin therapy administered by inhalation. In an evaluation of exploratory efficacy measures, patients remained stable or improved over the 1 year of treatment. Yutrepia was found to be a convenient, safe, and well-tolerated inhaled prostacyclin treatment option for PAH patients.

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.

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.

Health-related quality of life and hospitalizations in chronic thromboembolic pulmonary hypertension versus idiopathic pulmonary arterial hypertension: an analysis from the Pulmonary Hypertension Association Registry (PHAR).

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare, morbid, potentially curable subtype of pulmonary hypertension that negatively impacts health-related quality of life (HRQoL). Little is known about differences in HRQoL and hospitalization between CTEPH patients and idiopathic pulmonary arterial hypertension (IPAH) patients. Using multivariable linear regression and mixed effects models, we examined differences in HRQoL assessed by emPHasis-10 (E10) and SF-12 between CTEPH and IPAH patients in the Pulmonary Hypertension Association Registry, a prospective multicenter cohort of patients newly evaluated at a Pulmonary Hypertension Care Center. Multivariable negative binomial regression models were used to estimate incidence rate ratios (IRR) for hospitalization amongst the two groups. We included 461 IPAH patients and 169 CTEPH patients. Twenty-one percent of CTEPH patients underwent pulmonary thromboendarterectomy (PTE) before the end of follow-up. At baseline, patients with CTEPH had significantly worse HRQoL (higher E10 scores) (ß 2.83, SE 1.11, p = 0.01); however, differences did not persist over time. CTEPH patients had higher rates of hospitalization (excluding the hospitalization for PTE) compared to IPAH patients after adjusting for age, sex, body mass index, WHO functional class and six-minute walk distance (IRR 1.66, 95%CI 1.04-2.65, p = 0.03). CTEPH patients who underwent PTE had improved HRQoL as compared to those who were medically managed, but patients who underwent PTE were younger, had higher cardiac outputs and greater six-minute walk distances. In this large, prospective, multicenter cohort, CTEPH patients had significantly worse baseline HRQoL and higher rates of hospitalizations than those with IPAH. CTEPH patients who underwent PTE had significant improvements in HRQoL.

Health disparities and treatment approaches in portopulmonary hypertension and idiopathic pulmonary arterial hypertension: an analysis of the Pulmonary Hypertension Association Registry.

Compared to idiopathic pulmonary arterial hypertension (IPAH), patients with portopulmonary hypertension (POPH) have worse survival. Health disparities may contribute to these differences but have not been studied. We sought to compare socioeconomic factors in patients with POPH and IPAH and to determine whether socioeconomic status and/or POPH diagnosis were associated with treatment and health-care utilization. We performed a cross-sectional study of adults enrolled in the Pulmonary Hypertension Association Registry. Patients with IPAH (n = 344) and POPH (n = 57) were compared. Compared with IPAH, patients with POPH were less likely to be college graduates (19.6% vs. 34.9%, p = 0.02) and more likely to be unemployed (54.7% vs. 30.5%, p < 0.001) and have an annual household income below poverty level (45.7% vs. 19.0%, p < 0.001). Patients with POPH had similar functional class, quality of life, 6-min walk distance, and mean pulmonary arterial pressure with a higher cardiac index. Compared with IPAH, patients with POPH were less likely to receive combination therapy (46.4% vs. 62.2%, p = 0.03) and endothelin receptor antagonists (28.6% vs. 55.1%, p < 0.001) at enrollment with similar treatment at follow-up. Patients with POPH had more emergency department visits (1.7 ± 2.1 vs. 0.9 ± 1.2, p = 0.009) and hospitalizations in the six months preceding enrollment (1.5 ± 2.1 vs. 0.8 ± 1.1, p = 0.02). Both POPH diagnosis and lower education level were independently associated with a higher number of emergency department visits. Compared to IPAH, patients with POPH have lower socioeconomic status, are less likely to receive initial combination therapy and endothelin receptor antagonists but have similar treatment at follow-up, and have increased health-care utilization.

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.).

Safety and Efficacy of B-Cell Depletion with Rituximab for the Treatment of Systemic Sclerosis-associated Pulmonary Arterial Hypertension: A Multicenter, Double-Blind, Randomized, Placebo-controlled Trial.

Rationale: Systemic sclerosis (SSc)-pulmonary arterial hypertension (PAH) is one of the most prevalent and deadly forms of PAH. B cells may contribute to SSc pathogenesis. Objectives: We investigated the safety and efficacy of B-cell depletion for SSc-PAH. Methods: In an NIH-sponsored, multicenter, double-blinded, randomized, placebo-controlled, proof-of-concept trial, 57 patients with SSc-PAH on stable-dose standard medical therapy received two infusions of 1,000 mg rituximab or placebo administered 2 weeks apart. The primary outcome measure was the change in 6-minute-walk distance (6MWD) at 24 weeks. Secondary endpoints included safety and invasive hemodynamics. We applied a machine learning approach to predict drug responsiveness. Measurements and Main Results: We randomized 57 subjects from 2010 to 2018. In the primary analysis, using data through Week 24, the adjusted mean change in 6MWD at 24 weeks favored the treatment arm but did not reach statistical significance (23.6 ± 11.1 m vs. 0.5 ± 9.7 m; P = 0.12). Although a negative study, when data through Week 48 were also considered, the estimated change in 6MWD at Week 24 was 25.5 ± 8.8 m for rituximab and 0.4 ± 7.4 m for placebo (P = 0.03). Rituximab treatment appeared to be safe and well tolerated. Low levels of RF (rheumatoid factor), IL-12, and IL-17 were sensitive and specific as favorable predictors of a rituximab response as measured by an improved 6MWD (receiver operating characteristic area under the curve, 0.88-0.95). Conclusions: B-cell depletion therapy is a potentially effective and safe adjuvant treatment for SSc-PAH. Future studies in these patients can confirm whether the identified biomarkers predict rituximab responsiveness. Clinical trial registered with www.clinicaltrails.gov (NCT01086540).

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.

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.