Frantz, Robert P.

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.

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.

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.

While parenteral prostacyclin (pPCY) therapy, delivered either subcutaneously or intravenously, is recommended for pulmonary arterial hypertension patients with severe or rapidly developing disease, some patients refuse this treatment. This study aimed to understand, directly from patients with pulmonary arterial hypertension, why pPCY was refused and, in some cases, later accepted. Interviews were conducted with 25 pulmonary arterial hypertension patients who previously refused pPCY therapy (Group A: Refused/Never initiated (n = 9) and Group B: Refused/Initiated (n = 16)). Patients in both groups believed that pPCY could improve their symptoms, slow disease progression, and provide them a greater ability to perform activities. Reasons for refusal included concern over side effects and the perceived limitations of pPCY on daily activities. Group A perceived their decision as a balance between quality of life and prolonging life and most acknowledged they would reconsider pPCY if other treatment options were exhausted. Group B cited they initiated therapy due to a worsening of symptoms, disease progression, to improve quality of life, to be there for their family, or a desire to live. Following initiation, Group B indicated their experience met expectations with reduced symptoms, slowed disease progression, and perception of improved survival; concerns related to pPCY were described as manageable. Given the efficacy of pPCY therapy, clinicians should apply knowledge of these findings in clinical practice. Patients noted improvements to parenteral pump technologies to include smaller size, water resistance, and implantability may increase their acceptance of this modality. Development efforts should focus on technologies that increase the acceptance of pPCY when indicated.

Current guidelines suggest screening all patients with idiopathic pulmonary arterial hypertension for genetic aberrations, particularly mutations in Bone Morphogenic Protein Receptor Type II (BMPR2), the gene most commonly implicated in the pathogenesis of PAH. Herein, we present a novel technique used to identify a pathogenic germline BMPR2 alteration in a 36‐year‐old female and family members with hereditary pulmonary arterial hypertension who each screened negative by standard cytogenetics and molecular genetics testing.

The ability to work efficiently at altitude is impaired by the reduced arterial oxygen tension. Acetazolamide may improve systemic saturation (SaO 2 ) by stimulating ventilation but increases the work of breathing. Efforts have focused on the potential role of sildenafil in improving exercise performance in high altitude environment. The purpose of this study was to determine the effects of acetazolamide and sildenafil on oxygen uptake (VO 2 ) and breathing efficiency during submaximal hypoxic exercise. Sixteen volunteers received sildenafil 40 mg (S), acetazolamide 125 mg (A) or matching placebo (P) tid × four doses in double‐blind fashion starting 8 hours prior to hypoxic exposure over 3 separate overnight stays in an altitude tent with an O 2 concentration of 12.5%, and then performed hypoxic submaximal exercise on a stationary bicycle for 10 min at a workload of 40% of VO 2 peak. SaO 2 decreased with exercise but there was no difference in exercising SaO 2 or VO 2 between conditions. As expected, acetazolamide increased ventilation compared to placebo and sildenafil. Breathing efficiency as measured by Ve/VCO 2 decreased with acetazolamide in comparison to placebo and sildenafil (P: 42.6±1.2, S: 41.9±1.6, A: 46.7±1.1, p<0.01). Sildenafil did not change breathing efficiency while acetazolamide reduced breathing efficiency during hypoxic exercise. This study was funded by Mayo Foundation and NIH Grant No. HL71478.

Background Heart failure (HF) is associated with impaired exercise pulmonary gas exchange (PGX) that is likely related to the development and severity of pulmonary hypertension (PH). Purpose To determine whether PGX measures differentiate HF patients with reactive PH from patients with passive PH or no PH. Methods/Results Pulmonary arterial pressure (P AP ), pulmonary wedge pressure (P WP ), transpulmonary pressure gradient (TPG) and PGX indices [end‐tidal CO 2 (P ET CO 2 ), ventilatory efficiency (V E /VCO 2 ), O 2 pulse, estimated pulmonary arterial capacitance (GX CAP )] were assessed simultaneously at rest and during cycle exercise in 38 HF patients undergoing right heart catheterization. Post hemodynamic evaluation, patients were classified as having no PH ( n = 12), passive PH ( n = 10) or reactive PH ( n = 16). TPG increased during exercise in all groups but was greater at end exercise in the reactive PH vs. the passive PH and no PH patients (21±9 vs. 14±7 vs. 12±7 mmHg). At an equivalent VO 2 , P ET CO 2 , O 2 pulse and GX CAP were higher and V E /VCO 2 ratio lower in the no PH and, to a lesser extent, in the passive PH vs. the reactive PH subjects (Figure 1). Conclusion Noninvasive measures of PGX during exercise appear to differentiate HF patients with reactive PH from patients with passive PH or no PH and may be a useful adjunct to invasive catheterization in assessing PH type and severity. HL71478, AHA12POST12070084, Gilead Science