Treatment patterns and factors associated with adherence in pulmonary arterial hypertension.

OBJECTIVE: Improving understanding of actual pulmonary hypertension (PH) treatment adherence patterns is crucial to properly treating these patients. We aimed to primarily assess adherence to treatments used for pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) specific therapies, identify potential factors related to it and secondly describe its treatment patterns. METHODS: A 6-month observational cross-sectional study in a tertiary care hospital was conducted. Patients with PH-targeted therapy who picked it up in the ambulatory hospital pharmacy and who had been on treatment with the same drug for at least 1 year were included. Adherence was assessed as: 1) Proportion of days covered (PDC); and 2) Simplified Medication Adherence Questionnaire (SMAQ). PDC ≥80% was considered adherent. Statistical analyses were performed to evaluate the study outcomes. Logistic regressions were estimated to identify the association between baseline characteristics and factors associated with adherence. P < 0.05 indicated statistical significance. RESULTS: A total of 63 patients with 127 different treatments were included, 71.4% were females with a mean age (SD) of 59 (15) years. PAH was the most common diagnosis (74.6%). Double therapy was used in 39.7% of patients, being the combination of Macitentan + Tadalafil and Ambrisentan + Tadalafil the most prescribed. Endothelin receptor antagonists were the most used treatment (40.2%). Adherence according to PDC was 93.7%, showing no great differences depending on the targeted drug used, and according to SMAQ 61.9%. The agreement degree of both methods was slight (65.1%; Kappa 0.12). Only female sex (OR: 0.23, 95% CI: 0.06-0.90; p = 0.035) was associated with worse adherence in the SMAQ method but not in the PDC. Adverse events were reported by a 55.6% of participants and the perception of effective treatment was high (95.2%). CONCLUSIONS: Adherence to PH therapy differs depending on the assessment method; PDC showed greater adherence rate than SMAQ. According to SMAQ, female sex may have a negative impact on adherence in this cohort, but PDC revealed no factors influencing it. No notable differences in adherence between treatment types were found and generally patients felt the treatments were effective in controlling their disease.

Contemporary Treatment of Pulmonary Arterial Hypertension: A US Perspective.

Pulmonary arterial hypertension (PAH) is a complex fatal condition which requires aggressive treatment with close monitoring. Significant progress has been made over the last three decades in the treatment of PAH but despite this progress, survival has remained unacceptably low. In the quest to improve survival, therapeutic interventions play a central role. In the last few years, there have been remarkable attempts to identify novel treatments. Finally, we have had a breakthrough with the discovery of the fourth treatment pathway in PAH. Activin signaling inhibition distinguishes itself as a potential antiproliferative intervention as opposed to the traditional therapies which mediate their effect primarily by vasodilatation. With this novel treatment pathway, we stand at an important milestone with an exciting future ahead and the natural question of when to utilize Activin signaling inhibitor (ASI) for the treatment of PAH. In this state-of-the-art review, we focus on the placement of this novel agent in the PAH treatment paradigm based on the available evidence, with special focus on the US patient population. This review also provides an expert opinion of the current treatment algorithm on important subgroups of patients with comorbidities from the US perspective.

Intervention control of aerobic exercise in maintaining quality of life and pulmonary hypertension in hemodialysis patients.

BACKGROUND: Pulmonary hypertension is a serious complication in the treatment of maintenance hemodialysis patients, which seriously affects the quality of life of patients and threatens their life safety. Prevention, treatment and improvement of pulmonary hypertension are of great significance to improve the quality of life of patients. AIM: To investigate the intervention and control of pedal-powered bicycle in maintaining quality of life and pulmonary hypertension in hemodialysis patients. METHODS: 73 patients with maintenance hemadialysis combined with pulmonary arterial hypertension at a hemodialysis center in a certain hospital from May 2021 to May 2022 are selected. Patients are divided into two groups, 37 cases in the control group (group C) and 36 cases in the intervention group (group I). Patients are divided into two groups, group C is treated with oral administration of betaglandin sodium combined with routine nursing care. Based on group C, group I conducts power cycling exercises. RESULTS: After treatment, group I patients had higher muscle strength, 36-Item Short Form Health Survey scores, and Kidney Disease Targets Areas scores; The 6-minute walk distance test index level was higher and the Borg score was lower; The group I had lower systolic blood pressure, greater vital capacity, higher positive emotion, lower systolic pulmonary artery pressure index level, higher arterial partial oxygen pressure level, lower pulmonary vascular resistance index level, and higher blood oxygen saturation level [158.91 ± 11.89 vs 152.56 ± 12.81, 1795.01 ± 603.18 vs 1907.20 ± 574.15, 24.00 (22.00, 29.00) vs 24.00 (22.00, 28.00), P < 0.001]. CONCLUSION: Aerobic exercise combined with Western medicine treatment can effectively improve patients' pulmonary hypertension, alleviate their negative emotions, and enable them to achieve a higher level of quality of life.

Investigation into the role of H2-Ab1 in vascular remodeling in pulmonary arterial hypertension via Bioinformatics.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive disease of vascular remodeling characterized by persistent pulmonary arterial pressure elevation, which can lead to right heart failure and premature death. Given the complex pathogenesis and poor prognosis of PAH, the identification and investigation of biomarkers become increasingly critical for advancing further understanding of the disease. METHODS: PAH-related datasets, GSE49114, GSE180169 and GSE154959, were downloaded from the publicly available GEO database. By performing WGCNA on the GSE49114 dataset, a total of 906 PAH-related key module genes were screened out. By carrying out differential analysis on the GSE180169 dataset, a total of 576 differentially expressed genes were identified. Additionally, the GSE154959 single-cell sequencing dataset was also subjected to differential analysis, leading to the identification of 34 DEGs within endothelial cells. By taking intersection of the above three groups of DEGs, five PAH-related hub genes were screened out, namely Plvap, Cyp4b1, Foxf1, H2-Ab1, and H2-Eb1, among which H2-Ab1 was selected for subsequent experiments. RESULTS: A SuHx mouse model was prepared using the SU5416/hypoxia method, and the successful construction of the model was evaluated through Hematoxylin-Eosin staining, hemodynamic detection, fulton index, and Western Blot (WB). The results of WB and qRT-PCR demonstrated a significant upregulation of H2-Ab1 expression in SuHx mice. Consistent with the results of bioinformatics analysis, a time-dependent increase was observed in H2-Ab1 expression in hypoxia-treated mouse pulmonary artery endothelial cells (PAECs). To investigate whether H2-Ab1 affects the development and progression of PAH, we knocked down H2-Ab1 expression in PAECs, and found that its knockdown inhibited the viability, adhesion, migration, and angiogenesis, while concurrently promoted the apoptosis of PAECs. CONCLUSION: H2-Ab1 could regulate the proliferation, apoptosis, adhesion, migration, and angiogenesis of PAECs.

Cardiac arrest during deep brain stimulation: A case report.

We present the case of a 54-year-old male with severe Parkinson's disease and chronic, non-reversible pulmonary artery hypertension who had seizures and a cardiorespiratory arrest during surgery for deep brain stimulation, a minimally invasive procedure usually associated with a low risk of complications. This case illustrates how perioperative changes in antiparkinsonian therapy in patient with multiple comorbidities may significantly affect the risk profile.

Interrelation of daily blood pressure profile with left ventricular myocardial hypertrophy in men of working age with hypertension.

OBJECTIVE: Aim: To analyze the relationship between daily blood pressure biorhythms and left ventricular myocardial hypertrophy in working-age men with arterial hypertension. PATIENTS AND METHODS: Materials and Methods: Fifty-seven men with AH (mean age: 44.6±1.3 years) underwent Echo-CG and daily ABPM. Non-dipper and night-peaker patterns indicated BP biorhythm disturbances, while normal dipper and over-dipper patterns indicated undisturbed BP biorhythms. LVH was defined as LMMI > 115 g/m^2. RESULTS: Results: About 60% of participants exhibited diurnal BP rhythm disorders, with a higher prevalence of LVH in this group compared to those with normal BP biorhythms (32% vs. 22%, p>0,05). Patients with normal daily BP biorhythms had significantly higher circadian indices of HR, systolic and diastolic BP, and double product compared to those with disturbed BP rhythms. CONCLUSION: Conclusions: In young men with "non-dipper" and "night-peaker" patterns, LVH appears to be more pronounced than in those with normal daily BP biorhythms. This approach may optimize the timing of antihypertensive drug administration.

LOXL2 inhibition ameliorates pulmonary artery remodeling in pulmonary hypertension.

BACKGROUND: Conduit pulmonary arterial stiffening and the resultant increase in pulmonary vascular impedance has emerged as an important underlying driver of pulmonary arterial hypertension (PAH). Given that matrix deposition is central to vascular remodeling, we evaluated the role of the collagen crosslinking enzyme lysyl oxidase like 2 (LOXL2) in this study. METHODS AND RESULTS: Human pulmonary artery smooth muscle cells (PASMCs) subjected to hypoxia showed increased LOXL2 secretion. LOXL2 activity and expression were markedly higher in primary PASMCs isolated from pulmonary arteries of the rat Sugen5416 + hypoxia (SuHx) model of severe PH. Similarly, LOXL2 protein and mRNA levels were increased in pulmonary arteries (PA) and lungs of rats with PH (SuHx and monocrotaline (MCT) models). Pulmonary arteries (PAs) isolated from rats with PH exhibited hypercontractility to phenylephrine and attenuated vasorelaxation elicited by acetylcholine, indicating severe endothelial dysfunction. Tensile testing revealed a a significant increase in PA stiffness in PH. Treatment with PAT-1251, a novel small-molecule LOXL2 inhibitor, improved active and passive properties of the PA ex vivo. There was an improvement in right heart function as measured by right ventricular pressure volume loops in-vivo with PAT-1251. Importantly PAT-1251 treatment ameliorated PH, resulting in improved pulmonary artery pressures, right ventricular remodeling, and survival. CONCLUSION: Hypoxia induced LOXL2 activation is a causal mechanism in pulmonary artery stiffening in PH, as well as pulmonary artery mechanical and functional decline. LOXL2 inhibition with PAT-1251 could be a promising approach to improve pulmonary artery pressures, right ventricular elastance, cardiac relaxation, and survival in PAH.

Characteristics of the Basel Postpartum Hypertension Cohort (Basel-PPHT Cohort): An Interim Analysis.

Postpartum hypertension (PPHT) is hypertension that persists or develops after delivery and is a frequent cause of readmission, affecting 10% of pregnancies. This interim analysis aims to describe the cohort and to determine the feasibility and acceptance of a home-based telemonitoring management strategy (HBTMS) in PPHT patients. Enrollment at the University Hospital Basel began during the 2020 SARS-CoV-2 pandemic. Maternity-ward patients were screened for preexisting hypertension, hypertensive disorders of pregnancy, and de novo PPHT. In this pragmatic non-randomized prospective trial, the participants chose the HBTMS or standard of care (SOC), which consisted of outpatient hypertension clinic appointments. The HBTMS was a smartphone application or a programmed spreadsheet to report blood pressure (BP), followed by telephone consultations. Three months postpartum, the participants underwent a 24 h BP measurement and a blood, biomarker, and urine analysis. A total of 311 participants were enrolled between 06/20 and 08/23. The mean age was 34 (±5.3) years. The current pregnancy history demonstrated the following (≥1 diagnosis possible): 10% had preexisting hypertension, 27.3% gestational hypertension, 53% preeclampsia (PE), 0.3% eclampsia, 6% HELLP (hemolysis, elevated liver enzymes, and low platelets), and 18.3% de novo PPHT. A family history of cardiovascular disease and PE was reported in 49.5% and 7.5%, respectively. In total, 23.3% were high-risk for PE. A total of 68.5% delivered via c-section, the mean hospitalization was 6.3 days (±3.9), and newborn intrauterine growth restriction occurred in 21%. A total of 99% of the participants chose the HBTMS. This analysis demonstrated that the HBTMS was accepted. This is vital in the immediate postpartum period and pertinent when the exposure of hospital visits should be avoided.

How We Do It: Using Sotatercept in the Care of Patients with Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a rare disease of the pulmonary microvasculature leading to elevated pre-capillary pulmonary hypertension. Pulmonary vascular remodeling, a characteristic of PAH, is driven by dysfunctions in the signaling between the pulmonary smooth muscle and endothelial cells with abnormalities that affect cell proliferation and immune dysregulation. Sotatercept, an activin signaling inhibitor, has been recently approved by the Food and Drug Administration for the treatment of PAH, based on two pivotal clinical trials. Evidence based clinical trials have provided a framework to guide clinicians treating the disease; however, they are not tailored to the individual patient. Often, recommendations from these data are unclear or too general, due to remaining gaps in knowledge. In this edition of "How I Do It", we provide a case-based discussion of common clinical decisions regarding diagnostic testing, choice of first line agents, escalation of therapy, potential timing of sotatercept, safety awareness, practical use, potential management changes, and the future use of sotatercept in other pulmonary hypertension cohorts.

The Role of Hypertension for Maternal Outcomes of Women with HELLP Syndrome - a Retrospective Study from a Tertiary Obstetric Center.

Introduction: HELLP syndrome is a serious disorder that can occur in pregnancy; it has many possible complications and is associated with adverse maternal outcome. Due to the lack of predictive parameters for HELLP syndrome, finding the right time for delivery is challenging. In contrast to preeclampsia, hypertension is not an essential part of the diagnosis; nevertheless, many women with HELLP syndrome are hypertensive. The role and possible implications of hypertension in HELLP syndrome are not fully understood. Material and Methods: In this retrospective cohort study, we analyzed the maternal outcomes of 59 patients diagnosed with HELLP syndrome. The patients were divided into three groups according to their blood pressure levels during their stay in hospital. These three groups were compared in terms of patient characteristics and maternal outcomes. A combined endpoint for adverse maternal outcome was defined which included blood pressure and antihypertensive medication at discharge from hospital, severe postpartum anemia, and eclampsia. Results: Women with hypertensive crises had an unfavorable outcome compared to women with lower blood pressure levels. Patients with higher blood pressure during pregnancy were more likely to be hypertensive at discharge and needed a combination of antihypertensive agents significantly more often. The risk of an adverse maternal outcome increased with the severity of hypertension. An increase in systolic blood pressure by 10 mmHg raised the risk of an adverse outcome by 74% (95% CI: 1.22-2.66). Conclusion: Hypertension not only plays an important role in preeclampsia but also affects the outcomes of patients with HELLP syndrome. These patients need to be identified quickly and treated accordingly as they are at risk of cardiovascular impairment. Patients should be followed up closely after delivery to reduce cardiovascular morbidity.

Pulmonary Hypertension Induced by Right Pulmonary Artery Occlusion: Hemodynamic Consequences of Bmpr2 Mutation.

BACKGROUND: The primary genetic risk factor for heritable pulmonary arterial hypertension is the presence of monoallelic mutations in the BMPR2 gene. The incomplete penetrance of BMPR2 mutations implies that additional triggers are necessary for pulmonary arterial hypertension occurrence. Pulmonary artery stenosis directly raises pulmonary artery pressure, and the redirection of blood flow to unobstructed arteries leads to endothelial dysfunction and vascular remodeling. We hypothesized that right pulmonary artery occlusion (RPAO) triggers pulmonary hypertension (PH) in rats with Bmpr2 mutations. METHODS AND RESULTS: Male and female rats with a 71 bp monoallelic deletion in exon 1 of Bmpr2 and their wild-type siblings underwent acute and chronic RPAO. They were subjected to full high-fidelity hemodynamic characterization. We also examined how chronic RPAO can mimic the pulmonary gene expression pattern associated with installed PH in unobstructed territories. RPAO induced precapillary PH in male and female rats, both acutely and chronically. Bmpr2 mutant and male rats manifested more severe PH compared with their counterparts. Although wild-type rats adapted to RPAO, Bmpr2 mutant rats experienced heightened mortality. RPAO induced a decline in cardiac contractility index, particularly pronounced in male Bmpr2 rats. Chronic RPAO resulted in elevated pulmonary IL-6 (interleukin-6) expression and decreased Gdf2 expression (corrected P value<0.05 and log2 fold change>1). In this context, male rats expressed higher pulmonary levels of endothelin-1 and IL-6 than females. CONCLUSIONS: Our novel 2-hit rat model presents a promising avenue to explore the adaptation of the right ventricle and pulmonary vasculature to PH, shedding light on pertinent sex- and gene-related effects.

An adult patient with pulmonary arterial hypertension, a NOTCH3 mutation, and leflunomide exposure.

Pulmonary arterial hypertension (PAH) is a poorly understood disease of the small pulmonary arteries. Pulmonary vascular remodeling and progressively rising pulmonary vascular resistance are hallmarks of the disease that ultimately result in right heart failure. Several genetic mutations, most notably in bone morphogenetic protein receptor type 2, have a causal association with heritable forms of PAH. Mutations in neurogenic locus notch homolog protein 3 (NOTCH3) have been reported in adults and children with PAH, but whether NOTCH3 is causally associated with PAH is debated. With this case report, we describe the clinical characteristics, comorbidities, and exposure history of an adult patient with PAH and multiple sclerosis who was found to have a NOTCH3 missense mutation and exposure to leflunomide.

Relationship between obesity and hypertrophic or dilated cardiomyopathy: The role of sex.

Evidence suggests an association between obesity and the risk for cardiomyopathy development; however, robust evidence is still lacking. In this study we sought to explore the relationship of obesity with hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) and possible interactions with sex using large-scale epidemiological real-world data. We analysed data from the Nationwide Inpatient Sample of US hospitalisations for the years 2015-2019. There were a total of 46 934 admissions with diagnosis of HCM and 170 924 with DCM. There was a significant interaction between cardiomyopathies' diagnosis with sex and age subgroups; the rates of both DCM and HCM increased with age (p < .001 for both); DCM diagnosis was significantly higher in males compared with females (0.85% vs. 0.35%, p < .001). After adjustment for age, sex, race and presence of arterial hypertension there was a significant stepwise positive association between obesity and the population rates of both cardiomyopathy subtypes. For hospitalised patients with a body mass index (BMI) ≥30 kg/m2 there was an odds ratio (OR) of 1.68 (95% CI: 1.55-1.81, p < .001) for HCM and OR = 1.82 (95% CI: 1.79-1.84, p < .001) for DCM. More importantly, the positive relationship between a cardiomyopathy diagnosis (HCM or DCM) with increasing BMI was driven by the male sex (p < .001 for both) and it was non-significant in females. The findings from this nationwide observational analysis support a sexual dimorphism in the relationship between obesity and HCM or DCM, which should be further investigated.

Characteristics and risk profiles of patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension living permanently at >2500 m of high altitude in Ecuador.

Over 80 Mio people worldwide live >2500 m, including at least as many patients with pulmonary vascular disease (PVD), defined as pulmonary arterial or chronic thromboembolic pulmonary hypertension (PAH/CTEPH), as elsewhere (estimated 0.1‰). Whether PVD patients living at high altitude have altered disease characteristics due to hypobaric hypoxia is unknown. In a cross-sectional study conducted at the Hospital Carlos Andrade Marin in Quito, Ecuador, located at 2840 m, we included 36 outpatients with PAH or CTEPH visiting the clinic from January 2022 to July 2023. We collected data on diagnostic right heart catheterization, treatment, and risk factors, including NYHA functional class (FC), 6-min walk distance (6MWD), and NT-brain natriuretic peptide (BNP) at baseline and at last follow-up. Thirty-six PVD patients (83% women, 32 PAH, 4 CTEPH, mean ± SD age 44 ± 13 years, living altitude 2831 ± 58 m) were included and had the following baseline values: PaO2 8.2 ± 1.6 kPa, PaCO2 3.9 ± 0.5 kPa, SaO2 91 ± 3%, mean pulmonary artery pressure 53 ± 16 mmHg, pulmonary vascular resistance 16 ± 4 WU, 50% FC II, 50% FC III, 6MWD 472 ± 118 m, BNP 490 ± 823 ng/L. Patients were treated for 1628 ± 1186 days with sildenafil (100%), bosentan (33%), calcium channel blockers (33%), diuretics (69%), and oxygen (nocturnal 53%, daytime 11%). Values at last visit were: FC (II 75%, III 25%), 6MWD of 496 ± 108 m, BNP of 576 ± 5774 ng/L. Compared to European PVD registries, ambulatory PVD patients living >2500 m revealed similar blood gases and relatively low and stable risk factor profiles despite severe hemodynamic compromise, suggesting that favorable outcomes are achievable for altitude residents with PVD. Future studies should focus on long-term outcomes in PVD patients dwelling >2500 m.

Pharmacological Gq inhibition induces strong pulmonary vasorelaxation and reverses pulmonary hypertension.

Pulmonary arterial hypertension (PAH) is a life-threatening disease with limited survival. Herein, we propose the pharmacological inhibition of Gq proteins as a novel concept to counteract pulmonary vasoconstriction and proliferation/migration of pulmonary artery smooth muscle cells (PASMCs) in PAH. We demonstrate that the specific pan-Gq inhibitor FR900359 (FR) induced a strong vasorelaxation in large and small pulmonary arteries in mouse, pig, and human subjects ex vivo. Vasorelaxation by FR proved at least as potent as the currently used triple therapy. We also provide in vivo evidence that local pulmonary application of FR prevented right ventricular systolic pressure increase in healthy mice as well as in mice suffering from hypoxia (Hx)-induced pulmonary hypertension (PH). In addition, we demonstrate that chronic application of FR prevented and also reversed Sugen (Su)Hx-induced PH in mice. We also demonstrate that Gq inhibition reduces proliferation and migration of PASMCs in vitro. Thus, our work illustrates a dominant role of Gq proteins for pulmonary vasoconstriction as well as remodeling and proposes direct Gq inhibition as a powerful pharmacological strategy in PH.

Pericardiocentesis in Severe Pulmonary Arterial Hypertension Guided by a Pulmonary Artery Catheter.

Patients, often with underlying rheumatologic disease, may present with pericardial effusions in the setting of pulmonary hypertension (PHTN). Pericardial drainage in PHTN is associated with significant morbidity and mortality. We describe a patient with PHTN who developed cardiac tamponade that was managed safely and effectively with pulmonary artery catheter-guided pericardiocentesis.

Group 5 Pulmonary Hypertension Associated With T-Cell Large Granular Lymphocytic Leukemia: Hemodynamics and Treatment.

Group 5 pulmonary hypertension (PH) encompasses diverse diseases, with a few cases linking it to T-cell large granular lymphocytic (LGL) leukemia. We report a case of a 76-year-old woman, diagnosed with LGL leukemia and concomitant PH, treated with oral triple pulmonary arterial hypertension (PAH) therapy. She initially presented with dyspnea on exertion; evaluation revealed severe precapillary PH. Implementing cyclophosphamide for leukemia along with tadalafil and macitentan for PH led to sustained symptomatic and hemodynamic improvement for over 3 years. At that time, deterioration in PH prompted the addition of selexipag, resulting in sustained clinical improvement for an additional 5 years. This case exemplifies the potential for sustained benefits of PAH therapy in leukemia-associated PH and highlights the need for continued research on the mechanistic relationship between LGL leukemia and PH, with the hope of identifying new management strategies.

Pulmonary Arterial Hypertension in Neurofibromatosis Type 1: A Case with a Novel NF1 Gene Mutation.

Neurofibromatosis type 1 (NF1) is an autosomal dominant multi-organ disease. The clinical manifestations include not only skin lesions and malignant tumors but also lung complications, including pulmonary arterial hypertension (PAH). However, the association between gene mutations in NF1 and the occurrence of PAH has not yet been elucidated. We herein report a case of isolated PAH in a 67-year-old woman with NF1, presumably caused by a novel heterozygous mutation, c.4485_4486delinsAT (p.Lys1496Ter), in the NF1 gene.

Racial disparities in treatment patterns, healthcare resource use, and outcomes in patients with pulmonary arterial hypertension in the United States.

OBJECTIVE: This retrospective study using claims data compared demographics, clinical characteristics, treatment patterns, healthcare resource utilization, and clinical outcomes in Black and White patients with pulmonary arterial hypertension (PAH) in the United States. METHODS: Patients (aged ≥18 years) had ≥1 pharmacy claim for PAH medication, ≥6 months continuous healthcare plan enrollment, ≥1 inpatient/outpatient medical claim with a pulmonary hypertension diagnosis ≤6 months before first PAH medication, and race recorded. RESULTS: This analysis included 836 Black and 2896 White patients. Black patients were younger, with lower levels of education and annual household income, and higher comorbidity scores versus White patients. Only ∼14% of Black and White patients received index combination therapy. Lower adherence to index treatment was observed in Black patients. Although adjusted regression analysis in the overall population showed no differences in outcomes between groups, Black patients <65 years were 36% less likely to receive index combination therapy (odds ratio [OR] 0.64; 95% confidence interval [CI] 0.41-0.99), and 46% less likely to adhere to index treatment (OR 0.54; 95% CI 0.33-0.90). Other disparities included 24% higher all-cause health care resource utilization, 75% higher all-cause costs, and higher risk of clinical composite outcome. Social determinants of health (education, income, health insurance plan) partially mediated these race effects. CONCLUSIONS: Differences in demographics, clinical characteristics, and treatment patterns between Black and White patients with PAH were observed. Disparities between Black and White patients <65 years were only partially mediated through social determinants of health variables, suggesting other factors may be involved.