Benza, Raymond L.

Abstract Despite numerous therapeutic advances in pulmonary arterial hypertension, patients continue to suffer high morbidity and mortality, particularly considering a median age of 50 years. This article explores whether early, robust reduction of right ventricular afterload would facilitate substantial improvement in right ventricular function and thus whether afterload reduction should be a treatment goal for pulmonary arterial hypertension. The earliest clinical studies of prostanoid treatment in pulmonary arterial hypertension demonstrated an important link between lowering mean pulmonary arterial pressure (or pulmonary vascular resistance) and improved survival. Subsequent studies of oral monotherapy or sequential combination therapy demonstrated smaller reductions in mean pulmonary arterial pressure and pulmonary vascular resistance. More recently, retrospective reports of initial aggressive prostanoid treatment or initial combination oral and parenteral therapy have shown marked afterload reduction along with significant improvements in right ventricular function. Some data suggest that reaching threshold levels for pressure or resistance (components of right ventricular afterload) may be key to interrupting the self-perpetuating injury of pulmonary vascular disease in pulmonary arterial hypertension and could translate into improved long-term clinical outcomes. Based on these clues, the authors postulate that improved clinical outcomes might be achieved by targeting significant afterload reduction with initial oral combination therapy and early parenteral prostanoids.

Aberrant kinase signaling that involves platelet‐derived growth factor receptor (PDGFR) α/β, colony stimulating factor 1 receptor (CSF1R), and stem cell factor receptor (c‐KIT) pathways may be responsible for vascular remodeling in pulmonary arterial hypertension. Targeting these specific pathways may potentially reverse the pathological inflammation, cellular proliferation, and fibrosis associated with pulmonary arterial hypertension progression. Seralutinib (formerly known as GB002) is a novel, potent, clinical stage inhibitor of PDGFRα/β, CSF1R, and c‐KIT delivered via inhalation that is being developed for patients with pulmonary arterial hypertension. Here, we report on an ongoing Phase 2 randomized, double‐blind, placebo‐controlled trial (NCT04456998) evaluating the efficacy and safety of seralutinib in subjects with World Health Organization Group 1 Pulmonary Hypertension who are classified as Functional Class II or III. A total of 80 subjects will be enrolled and randomized to receive either study drug or placebo for 24 weeks followed by an optional 72‐week open‐label extension study. The primary endpoint is the change from baseline to Week 24 in pulmonary vascular resistance by right heart catheterization. The secondary endpoint is the change in distance from baseline to Week 24 achieved in the 6‐min walk test. A computerized tomography sub‐study will examine the effect of seralutinib on pulmonary vascular remodelling. A separate heart rate monitoring sub‐study will examine the effect of seralutinib on cardiac effort during the 6‐min walk test.

Abstract 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.

Background Data about anticoagulation in pulmonary arterial hypertension (PAH) patients are inconsistent. The objective of this study was to examine the impact of adjunctive oral anticoagulants in patients with PAH through meta-analysis, and to further assess whether response differs by PAH subtype. Methods and Results Cochrane CENTRAL, Medline, and Scopus databases were searched for randomized or nonrandomized studies that assessed the association between anticoagulation and outcomes in patients with PAH. Hazard ratios (HRs) for mortality were pooled using the random effects model. Subgroup analyses were performed for type of PAH and study design. Twelve nonrandomized studies, at moderate risk of bias, were included. These consisted of 2512 patients (1342 receiving anticoagulation and 1170 controls). Anticoagulation significantly reduced mortality in the overall PAH cohort (HR, 0.73 [0.57, 0.93]; P =0.001; I 2 =64%). On subgroup analysis, a significant mortality reduction was seen in idiopathic PAH patients (HR, 0.73 [0.56, 0.95]; P =0.02; I 2 =46%), whereas no significant difference was observed in connective tissue disease–related PAH (HR, 1.16 [0.58, 2.32]; P =0.67; I 2 =71%). Sensitivity analysis specific to scleroderma-associated PAH demonstrated a significant increase in mortality with anticoagulant use (HR, 1.58 [1.08, 2.31]; P =0.02; I 2 =9%). Conclusions This meta-analysis shows that use of anticoagulation may improve survival in idiopathic PAH patients, while increasing mortality when used in scleroderma-associated-PAH patients. Currently, no randomized clinical trials have been published, and until randomized data are available, anticoagulant use in PAH should be tailored to PAH subtype.