Survival in patients with idiopathic, familial, and anorexigen-associated pulmonary arterial hypertension in the modern management era

Dysregulation of the Long Noncoding RNA X-Inactive-Specific Transcript Expression in Male Patients with Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a sex-biased disease with female sex as a significant risk factor. Increased expression of the long noncoding RNA X-inactive-specific transcript (Xist), as induced by an intersectin-1s protein fragment with proliferative potential (EHITSN), may explain the sexual dimorphism of female pulmonary artery endothelial cells (ECs) and at least in part, the imbalance sex/ratio of PAH. Xist is essential for X-chromosome inactivation and dosage compensation of X-linked genes. Herein, increased Xist expression was detected in a subset of ECs and lung tissue samples of male patients with PAH. The role of different Xist expression levels in ECs of male patients with PAH (ECPAH) was studied in several lines of male ECPAH in conjunction with molecular, biochemical, morphologic, and functional approaches. Male ECPAH showed on average 10.3-fold increase in high Xist versus low Xist, a significant association between Xist levels and their proliferative potential, and a heterogeneous methylation of the Xist/XIST antisense RNA (Tsix) locus. Interestingly, Xist up-regulation in male ECPAH decreased the expression of Krueppel-like factor 2 (Klf2), via EHITSN interaction with enhancer of zeste polycomb repressive complex 2 subunit (EZH2), the catalytic subunit of the polycomb repressive complex 2. Moreover, the studies demonstrate that EHITSN-triggered p38/ETS domain-containing protein Elk1/AP-1 transcription factor subunit (c-Fos) signaling is a pathologic mechanism central to ECPAH proliferation and the dynamic crosstalk with cell cycle regulatory proteins cyclin A1/cyclin D2 and Xist-EZH2-Klf2 interaction participate directly and differentially in establishing the proliferative profile of male ECPAH.

MicroRNA-210 mediates hypoxia-induced pulmonary hypertension by targeting mitochondrial bioenergetics and mtROS flux

AIM

Chronic hypoxia is a common cause of pulmonary hypertension (PH). We test the hypothesis that microRNA-210 (miR-210) mediates hypoxia-induced PH by targeting mitochondrial metabolism and increasing reactive oxygen species (mtROS) production in the lungs.

METHODS

Adult wildtype (WT) or miR-210 knockout (KO) mice were exposed to hypoxia (10.5% O2) or normoxia for 4 weeks. We measured miR-210 levels, right ventricular systolic pressure (RVSP), and histological changes in heart and lung tissues. Mitochondrial bioenergetics and mtROS production were assessed in isolated lung mitochondria.

RESULTS

Hypoxia increased right ventricular wall thickness and pulmonary vessel wall muscularization in WT, but not miR-210 KO mice. No sex differences were observed. In male mice, hypoxia increased miR-210 levels in the lung and RVSP, which were abrogated by miR-210 deficiency. Hypoxia upregulated mitochondrial oxygen consumption rate and mtROS flux, which were negated in miR-210 KO animals. In addition, chronic hypoxia increased macrophage accumulation in lungs of WT, but not miR-210 KO mice. Moreover, miR-210 overexpression in lungs of WT animals recapitulated the effects of hypoxia and increased mitochondrial oxygen consumption rate, mtROS flux, right ventricular wall thickness, pulmonary vessel wall muscularization and RVSP. MitoQ revoked the effects of miR-210 on lung mitochondrial bioenergetics, right ventricular and pulmonary vessel remodeling and RVSP.

CONCLUSION

Our findings with loss-of-function and gain-of-function approaches provide explicit evidence that miR-210 mediates hypoxia-induced PH by upregulating mitochondrial bioenergetics and mtROS production in a murine model, revealing new insights into the mechanisms and therapeutic targets for treatment of PH.

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.

Exploring the pathogenesis of pulmonary vascular disease

Pulmonary hypertension (PH) is a complex cardiopulmonary disorder impacting the lung vasculature, resulting in increased pulmonary vascular resistance that leads to right ventricular dysfunction. Pulmonary hypertension comprises of 5 groups (PH group 1 to 5) where group 1 pulmonary arterial hypertension (PAH), results from alterations that directly affect the pulmonary arteries. Although PAH has a complex pathophysiology that is not completely understood, it is known to be a multifactorial disease that results from a combination of genetic, epigenetic and environmental factors, leading to a varied range of symptoms in PAH patients. PAH does not have a cure, its incidence and prevalence continue to increase every year, resulting in higher morbidity and mortality rates. In this review, we discuss the different pathologic mechanisms with a focus on epigenetic modifications and their roles in the development and progression of PAH. These modifications include DNA methylation, histone modifications, and microRNA dysregulation. Understanding these epigenetic modifications will improve our understanding of PAH and unveil novel therapeutic targets, thus steering research toward innovative treatment strategies.

A real-world analysis of safety profile of selexipag by using FDA adverse Event Reporting System (FAERS)

BACKGROUND

The current investigation sought to conduct a real-world analysis of adverse events (AEs) associated with selexipag by utilizing data from the Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

The Reporting Odds Ratios (ROR) and the Medicines Healthcare Products Regulatory Agency (MHRA) method were employed to assess the potential associations between selexipag and AEs. Case reports of adverse drug reaction (ADR) related to selexipag were systematically sourced from PubMed, Embase, and Web of Science databases.

RESULTS

Our analysis identified 281 Preferred Terms (PTs) signals across 20 System Organ Classes (SOCs) were found to meet the screening threshold. The most common AEs were consistent with instructions, randomized controlled trials (RCTs), and case reports. Of significant note, unexpected AEs principally target SOCs of infections and infestations, blood and lymphatic system, renal and urinary disorders, hepatobiliary disorders, including pneumonia, metapneumovirus, decreased hemoglobin. transfusion, iron-deficiency anemia, dialysis hypotension, abnormal creatinine renal clearance, liver function test increased, hepatic function abnormal, hepatic enzyme increased. Within the pediatric population, unexpected signals such as pyrexia, pneumonia, and intussusception necessitate special precautionary measures.

CONCLUSIONS

The findings contribute valuable insights to clinical practice, reinforcing the importance of vigilant monitoring, and can be instrumental in guiding both therapeutic applications and safety assessments of this particular medication.

Omega-3 polyunsaturated fatty acids and pulmonary arterial hypertension: Insights and perspectives

Pulmonary arterial hypertension (PAH) is a rare and progressive disorder that affects the pulmonary vasculature. Although recent developments in pharmacotherapy have extended the life expectancy of PAH patients, their 5-year survival remains unacceptably low, underscoring the need for multitarget and more comprehensive approaches to managing the disease. This should incorporate not only medical, but also lifestyle interventions, including dietary changes and the use of nutraceutical support. Among these strategies, n-3 polyunsaturated fatty acids (n-3 PUFAs) are emerging as promising agents able to counteract the inflammatory component of PAH. In this narrative review, we aim at analysing the preclinical evidence for the impact of n-3 PUFAs on the pathogenesis and the course of PAH. Although evidence for the role of n-3 PUFAs deficiencies in the development and progression of PAH in humans is limited, preclinical studies suggest that these dietary components may influence several aspects of the pathobiology of PAH. Further clinical research should test the efficacy of n-3 PUFAs on top of approved clinical management. These studies will provide evidence on whether n-3 PUFAs can genuinely serve as a valuable tool to enhance the efficacy of pharmacotherapy in the treatment of PAH.

Investigating the "sex paradox" in pulmonary arterial hypertension: Results from the Pulmonary Hypertension Association Registry (PHAR)

BACKGROUND

Female sex is a significant risk factor for pulmonary arterial hypertension (PAH), yet males with PAH have worse survival - a phenomenon referred to as the "sex paradox" in PAH.

METHODS

All adult PAH patients in the Pulmonary Hypertension Association Registry (PHAR) with congruent sex and gender were included. Baseline differences in demographics, hemodynamics, functional parameters, and quality of life were assessed by sex. Kaplan-Meier survival analysis was used to evaluate survival by sex. Mediation analysis was conducted with Cox proportional hazards regression by comparing the unadjusted hazard ratios for sex before and after adjustment for covariates. The plausibility of collider-stratification bias was assessed by modeling how large an unmeasured factor would have to be to generate the observed sex-based mortality differences. Subgroup analysis was performed on idiopathic and incident patients.

RESULTS

Among the 1,891 patients included, 75% were female. Compared to men, women had less favorable hemodynamics, lower 6-minute walk distance, more PAH therapies, and worse functional class; however, sex-based differences were less pronounced when accounting for body surface area or expected variability by gender. On multivariate analysis, women had a 48% lower risk of death compared to men (Hazard Ratio 0.52, 95% Confidence interval 0.36 - 0.74, p < 0.001). Modeling found that under reasonable assumptions collider-stratification could account for sex-based differences in mortality.

CONCLUSIONS

In this large registry of PAH patients new to a care center, men had worse survival than women despite having more favorable baseline characteristics. Collider-stratification bias could account for the observed greater mortality among men.

Endothelial Function in Pulmonary Arterial Hypertension: From Bench to Bedside

Pulmonary arterial hypertension is a complex pathology whose etiology is still not completely well clarified. The pathogenesis of pulmonary arterial hypertension involves different molecular mechanisms, with endothelial dysfunction playing a central role in disease progression. Both individual genetic predispositions and environmental factors seem to contribute to its onset. To further understand the complex relationship between endothelial and pulmonary hypertension and try to contribute to the development of future therapies, we report a comprehensive and updated review on endothelial function in pulmonary arterial hypertension.

Perception towards palliative care among patients with pulmonary hypertension in malaysia: a correlation with disease status

OBJECTIVES

This study aimed to describe the perception of Malaysian patients with pulmonary hypertension towards palliative care and their receptivity towards palliative care.

METHODS

This was a cross-sectional, single-centre study conducted via questionnaire. Patients aged 18 years old and above, who were diagnosed with non-curable pulmonary hypertension were recruited and given the assessment tool - perceptions of palliative care instrument electronically. The severity of pulmonary hypertension was measured using WHO class, N-terminal pro B-type natriuretic peptide and the 6-minute walking test distance.

RESULTS

A total of 84 patients [mean age: 35 ±11 years, female: 83.3%, median N-terminal pro B-type natriuretic peptide: 491 pg/ml (interquartile range: 155,1317.8), median 6-minute walking test distance: 420m (interquartile range: 368.5, 480m)] completed the questionnaires. Patients with a higher WHO functional class and negative feelings (r = 0.333, p = 0.004), and cognitive reaction to palliative care: hopeless (r = 0.340, p = 0.003), supported (r = 0.258, p = 0.028), disrupted (r = 0.262, p = 0.025), and perception of burden (r = 0.239, p = 0.041) are more receptive to palliative care. WHO class, N-terminal pro B-type natriuretic peptide, and 6-minute walking test distance were not associated with higher readiness for palliative care. In logistic regression analyses, patients with positive feelings (β = 2.240, p = < 0.05), and practical needs (β = 1.346, p = < 0.05), were more receptive to palliative care.

CONCLUSIONS

Disease severity did not directly influence patients' readiness for palliative care. Patients with a positive outlook were more receptive to palliative care.

Pulmonary arterial hypertension: Sex matters

Pulmonary arterial hypertension (PAH) is a complex disease of multifactorial origin. While registries have demonstrated that women are more susceptible to the disease, females with PAH have superior right ventricle (RV) function and a better prognosis than their male counterparts, a phenomenon referred to as the 'estrogen paradox'. Numerous pre-clinical studies have investigated the involvement of sex hormones in PAH pathobiology, often with conflicting results. However, recent advances suggest that abnormal estrogen synthesis, metabolism and signalling underpin the sexual dimorphism of this disease. Other sex hormones, such as progesterone, testosterone and dehydroepiandrosterone may also play a role. Several non-hormonal factor including sex chromosomes and epigenetics have also been implicated. Though the underlying pathophysiological mechanisms are complex, several compounds that modulate sex hormones levels and signalling are under investigation in PAH patients. Further elucidation of the estrogen paradox will set the stage for the identification of additional therapeutic targets for this disease.

Right ventricle-pulmonary artery coupling in pulmonary artery hypertension its measurement and pharmacotherapy

The right ventricular (RV) function correlates with prognosis in severe pulmonary artery hypertension (PAH) but which metric of it is most clinically relevant is still uncertain. Clinical methods to estimate RV function from simplified pressure volume loops correlate with disease severity but the clinical relevance has not been assessed. Evaluation of right ventricle pulmonary artery coupling in pulmonary hypertensive patients may help to elucidate the mechanisms of right ventricular failure and may also help to identify patients at risk or guide the timing of therapeutic interventions in pulmonary hypertension. Complete evaluation of RV failure requires echocardiographic or magnetic resonance imaging, and right heart catheterization measurements. Treatment of RV failure in PAH relies on decreasing afterload with drugs targeting pulmonary circulation; fluid management to optimize ventricular diastolic interactions; and inotropic interventions to reverse cardiogenic shock. The ability to relate quantitative metrics of RV function in pulmonary artery hypertension to clinical outcomes can provide a powerful tool for management. Such metrics could also be utilized in the future as surrogate endpoints for outcomes and evaluation of response to therapies. This review of literature gives an insight on RV-PA coupling associated with PAH, its types of measurement and pharmacological treatment.

Early identification of SOX17 deficiency in infants to guide management of heritable pulmonary arterial hypertension using PDA stent to create reverse Potts shunt physiology

Heritable pulmonary arterial hypertension (HPAH) is a rare progressive condition that includes patients with an identified genetic cause of pulmonary arterial hypertension (PAH). HPAH and idiopathic PAH (IPAH) have an estimated combined incidence of 0.5-0.9 cases per million children-years. Several pathogenic variants have been associated with HPAH in children and adults, including genes BMPR2, TBX4, and ACVRL1, and more rarely with variants in genes such as SOX17. HPAH is often difficult to manage and has poor prognosis despite advances in medical therapy with many patients progressing to lung transplantation, right heart failure and death. Surgical and transcatheter Potts shunt creation can reduce systolic burden and has shown reduction in morbidity and mortality in children. Early genetic testing can provide both diagnostic and prognostic value in managing and counseling children with severe PAH and it can guide transcatheter or surgical management in refractory cases despite maximal medical therapies. We describe a patient with HPAH (SOX17 mutation) who underwent percutaneous patent ductus arteriosus stent for right ventricle decompression at 2 months of age with clinical management guidance by genetic testing results.

Pulmonary Hypertension in Women

Pulmonary arterial hypertension (PAH) is a rare devastating disease characterized by elevated pulmonary artery pressure and increased pulmonary vascular resistance. Females have a higher incidence of PAH, which is reflected globally across registries in the United States, Europe, and Asia. However, despite female predominance, women had better outcomes compared with male patients, a finding that has been labeled the "estrogen paradox." Special considerations should be given to women with PAH regarding sexual health, contraception, family planning, and treatment before, during, and after pregnancy. Pregnant women with PAH should be referred to a pulmonary hypertension care center; a multidisciplinary team approach is recommended, and Cesarean section is the preferred mode of delivery. While pregnancy outcomes have improved over the years with PAH-specific therapy, pregnancy portends a high-risk for those with PAH. Continued research is needed to tailor PAH treatment for women.

Molecular recognition and activation of the prostacyclin receptor by anti-pulmonary arterial hypertension drugs

The prostacyclin (PGI2) receptor (IP) is a Gs-coupled receptor associated with blood pressure regulation, allergy, and inflammatory response. It is a main therapeutic target for pulmonary arterial hypertension (PAH) and several other diseases. Here we report cryo-electron microscopy (cryo-EM) structures of the human IP-Gs complex bound with two anti-PAH drugs, treprostinil and MRE-269 (active form of selexipag), at global resolutions of 2.56 and 2.41 angstrom, respectively. These structures revealed distinct features governing IP ligand binding, receptor activation, and G protein coupling. Moreover, comparison of the activated IP structures uncovered the mechanism and key residues that determine the superior selectivity of MRE-269 over treprostinil. Combined with molecular docking and functional studies, our structures provide insight into agonist selectivity, ligand recognition, receptor activation, and G protein coupling. Our results provide a structural template for further improving IP-targeting drugs to reduce off-target activation of prostanoid receptors and adverse effects.

Prognostic value of right ventricular free-wall longitudinal strain in patients with pulmonary hypertension: systematic review and meta-analyses

BACKGROUND

Right ventricular (RV) dysfunction is associated with adverse outcomes in patients with pulmonary hypertension (PH). This systematic review and meta-analysis evaluated the prognostic value of RV free-wall longitudinal strain (RVfwLS), compared with other RV parameters in PH.

METHODS

We searched for articles presenting the HR of two-dimensional RVfwLS in PH. HRs were standardised using the within-study SD. The ratio of HRs of a 1 SD change in RVfwLS versus systolic pulmonary arterial pressure (SPAP), systolic tricuspid annular velocities (s'-TV), RV fractional area change (FAC) or tricuspid annular plane systolic excursion (TAPSE) was calculated for each study, after which we conducted a random model meta-analysis. Subgroup analysis regarding the type of outcome, aetiology of PH and software vendor was also performed.

RESULTS

Twenty articles totalling 2790 subjects were included. The pooled HR of a 1 SD decrease of RVfwLS was 1.80 (95% CI: 1.62 to 2.00, p<0.001), and there was a significant association with all-cause death (ACD) and composite endpoints (CEs). The ratio of HR analysis revealed that RVfwLS has a significant, strong association with ACD and CE per 1 SD change, compared with corresponding values of SPAP, s'-TV, RVFAC or TAPSE. RVfwLS was a significant prognostic factor regardless of the aetiology of PH. However, significant superiority of RVfwLS versus other parameters was not observed in group 1 PH.

CONCLUSIONS

The prognostic value of RVfwLS in patients with PH was confirmed, and RVfwLS is better than other RV parameters and SPAP. Further accumulation of evidence is needed to perform a detailed subgroup analysis for each type of PH.

TRIAL REGISTRATION NUMBER

UMIN Clinical Trials Registry (UMIN000052679).

Transcriptomics and proteomics revealed sex differences in human pulmonary microvascular endothelial cells

Marked sexual dimorphism is displayed in the onset and progression of pulmonary hypertension (PH). Females more commonly develop pulmonary arterial hypertension, yet females with pulmonary arterial hypertension and other types of PH have better survival than males. Pulmonary microvascular endothelial cells play a crucial role in pulmonary vascular remodeling and increased pulmonary vascular resistance in PH. Given this background, we hypothesized that there are sex differences in the pulmonary microvascular endothelium basally and in response to hypoxia that are independent of the sex hormone environment. Human pulmonary microvascular endothelial cells (HPMECs) from healthy male and female donors, cultured under physiological shear stress, were analyzed using RNA sequencing and label-free quantitative proteomics. Gene set enrichment analysis identified a number of sex-different pathways in both normoxia and hypoxia, including pathways that regulate cell proliferation. In vitro, the rate of proliferation in female HPMECs was lower than in male HPMECs, a finding that supports the omics results. Interestingly, thrombospondin-1, an inhibitor of proliferation, was more highly expressed in female cells than in male cells. These results demonstrate, for the first time, important differences between female and male HPMECs that persist in the absence of sex hormone differences and identify novel pathways for further investigation that may contribute to sexual dimorphism in pulmonary hypertensive diseases.NEW & NOTEWORTHY There is marked sexual dimorphism in the development and progression of pulmonary hypertension. We show differences in RNA and protein expression between female and male human pulmonary microvascular endothelial cells grown under conditions of physiological shear stress, which identify sex-different cellular pathways both in normoxia and hypoxia. Importantly, these differences were detected in the absence of sex hormone differences. The pathways identified may provide novel targets for the development of sex-specific therapies.

The ALPHA phase 1 study: pulmonary ArteriaL hypertension treated with CardiosPHere-Derived allogeneic stem cells

BACKGROUND

Pulmonary Arterial Hypertension (PAH) is a progressive condition with no cure. Even with pharmacologic advances, survival remains poor. Lung pathology on PAH therapies still shows impressive occlusive arteriolar remodelling and plexiform lesions. Cardiosphere-derived cells (CDCs) are heart-derived progenitor cells exhibiting anti-inflammatory and immunomodulatory effects, are anti -fibrotic, anti-oxidative and anti-apoptotic to potentially impact several aspects of PAH pathobiology. In preclinical trials CDCs reduced right ventricular (RV) systolic pressure, RV hypertrophy, pulmonary arteriolar wall thickness and inflammation.

METHODS

The ALPHA study was a Phase 1a/b study in which CDCs were infused into patients with Idiopathic (I)PAH, Heritable (H) HPAH, PAH-connective tissue disease (CTD) and PAH-human immunodeficiency virus (HIV). The study was IRB approved and DSMB monitored. Phase 1a, was an open label study (n = 6). Phase 1b was a double-blind placebo-controlled study (n = 20) in which half received 100 million CDCs (the maximum feasible dose from manufacturing perspective) and half placebo (PLAC) infusions. Right heart catheterization (RHC) and cardiac MR imaging (cMR) were performed at baseline and at 4 months post infusion. Patients were followed over a year.

FINDINGS

No short-term clinical safety adverse events (AE) were related to the IP, the primary outcome measure. There were no adverse hemodynamic, gas exchange, rhythm or other clinical events following infusion and in the 1st 23 h monitored in hospital. There were no long-term AEs over 12 months noted, including unrelated limited hospitalizations. No immunologic short or long-term AEs were noted. We examined exploratory outcomes across multiple domains to determine encouraging signals to motivate future advanced phase testing. Phase 1a data showed encouraging observations for both 50 and 100 million CDC doses. Several encouraging findings favouring CDCs (n = 16) compared to placebo (n = 10) were noted. On cMR, the RV end diastolic volume (RVEDV) and index (RVEDVI) decreased with CDCs with a rise in the PLAC group. The 6-min walk distance was increased 2 months post infusion in the CDC group compared with PLAC. With PLAC, diffusing capacity (DLCO) decreased at 4 months but was unchanged with CDCs. Serum creatinine decreased with CDCs at 4 months. Encouraging observations favouring CDCs were also noted for RV fractional area change on echo and RV ejection fraction (RVEF) on cMR at 4 months. No differences were observed for mean pulmonary artery pressures or pulmonary vascular resistance. Review of long-term data to 12 months showed continued decline in DLCO for the PLAC cohort at 6 months with no change through 12 months. By contrast, CDC subjects showed an unchanged DLCO over 12-months. For parameters exhibiting early encouraging exploratory findings in CDC subjects, no further improvement was noted in long-term follow up through 12 months.

INTERPRETATION

Intravenous CDCs were safe in both the short and long term in PAH subjects and thus may be safe in larger cohorts, in line with our extensive track record of safety in clinical trials for other conditions. Further, CDCs exhibited encouraging exploratory findings across several domains. Repeat dosing (quarterly, over one year) of intravenous CDCs has been reported to yield highly significant sustained disease-modifying bioactivity in subjects with advanced Duchenne muscular dystrophy. Because only single CDC doses were used here, the findings represent a lower limit estimate of CDC's potential in PAH. Upcoming phase 2 studies would logically use a repeat dosing paradigm.

FUNDING

California Institute for Regenerative Medicine (CIRM). Project Number: CLIN2-09444.

Disease characteristics, treatments, and outcomes of patients with pulmonary arterial hypertension treated with selexipag in real-world settings from the SPHERE registry (SelexiPag: tHe usErs dRug rEgistry)

BACKGROUND

Selexipag is an oral prostacyclin receptor agonist, indicated for pulmonary arterial hypertension to delay disease progression and reduce the risk of pulmonary arterial hypertension-related hospitalization. SelexiPag: tHe usErs dRug rEgistry (NCT03278002) was a US-based, prospective, real-world registry of selexipag-treated patients.

METHODS

Adults with pulmonary hypertension (enrolled 2016-2020) prescribed selexipag were followed for ≤18 months, with data collected at routine clinic visits. Patients were defined as newly or previously initiated if they had started selexipag ≤60 days or >60 days, respectively, before enrollment.

RESULTS

The registry included 829 patients (430 newly initiated, 399 previously initiated; 759 with pulmonary arterial hypertension), of whom 55.6% were World Health Organization functional class (FC) 3/4; 57.3% were intermediate or high risk per Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0. In patients with pulmonary arterial hypertension, 18-month discontinuation rates for adverse events were 22.0%, 32.0%, and 11.9%, and 18-month survival rates were 89.4%, 84.2%, and 94.5% in the overall, newly, and previously initiated patient populations, respectively. From baseline to month 18, most patients had stable or improved FC and stable or improved REVEAL 2.0 risk category status. Discontinuation for adverse events, hospitalization, and survival were similar regardless of patients' individually tolerated selexipag maintenance dose. No new safety signals were identified.

CONCLUSIONS

In this real-world analysis of patients initiating selexipag, most patients had stable or improved FC and REVEAL 2.0 risk category. Similar to the GRIPHON trial, outcomes with selexipag in this real-world study were comparable across maintenance dose strata, with no new safety signals.

Pulmonary veno-occlusive disease: illustrative cases and literature review

Pulmonary veno-occlusive disease (PVOD), also known as "pulmonary arterial hypertension (PAH) with overt features of venous/capillary involvement", is a rare cause of PAH characterised by substantial small pulmonary vein and capillary involvement, leading to increased pulmonary vascular resistance and right ventricular failure. Environmental risk factors have been associated with the development of PVOD, such as occupational exposure to organic solvents and chemotherapy, notably mitomycin. PVOD may also be associated with a mutation in the EIF2AK4 gene in heritable forms of disease. Distinguishing PVOD from PAH is critical for guiding appropriate management. Chest computed tomography typically displays interlobular septal thickening, ground-glass opacities and mediastinal lymphadenopathy. Life-threatening pulmonary oedema is a complication of pulmonary vasodilator therapy that can occur with any class of PAH drugs in PVOD. Early referral to a lung transplant centre is essential due to the poor response to therapy when compared with other forms of PAH. Histopathological analysis of lung explants reveals microvascular remodelling with typical fibrous veno-occlusive lesions. This review covers the main features distinguishing PVOD from PAH and two clinical cases that illustrate the challenges of PVOD management.

Pulmonary hypertension

Pulmonary hypertension encompasses a range of conditions directly or indirectly leading to elevated pressures within the pulmonary arteries. Five main groups of pulmonary hypertension are recognized, all defined by a mean pulmonary artery pressure of >20 mmHg: pulmonary arterial hypertension (rare), pulmonary hypertension associated with left-sided heart disease (very common), pulmonary hypertension associated with lung disease (common), pulmonary hypertension associated with pulmonary artery obstructions, usually related to thromboembolic disease (rare), and pulmonary hypertension with unclear and/or multifactorial mechanisms (rare). At least 1% of the world's population is affected, with a greater burden more likely in low-income and middle-income countries. Across all its forms, pulmonary hypertension is associated with adverse vascular remodelling with obstruction, stiffening and vasoconstriction of the pulmonary vasculature. Without proactive management this leads to hypertrophy and ultimately failure of the right ventricle, the main cause of death. In older individuals, dyspnoea is the most common symptom. Stepwise investigation precedes definitive diagnosis with right heart catheterization. Medical and surgical treatments are approved for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. There are emerging treatments for other forms of pulmonary hypertension; but current therapy primarily targets the underlying cause. There are still major gaps in basic, clinical and translational knowledge; thus, further research, with a focus on vulnerable populations, is needed to better characterize, detect and effectively treat all forms of pulmonary hypertension.

Effects of empagliflozin on right ventricular adaptation to pressure overload

Background

Right ventricular (RV) failure is the prime cause of death in patients with pulmonary arterial hypertension. Novel treatment strategies that protect the RV are needed. Empagliflozin, a sodium-glucose co-transporter-2 inhibitor, shows cardioprotective effects on the left ventricle in clinical and preclinical studies, but its direct effects on RV remain elusive. We investigated the effects of empagliflozin on RV dysfunction induced by pulmonary trunk banding (PTB).

Methods

Male Wistar rats (116 ± 10 g) were randomized to PTB or sham surgery. One week after surgery, PTB animals received empagliflozin mixed into the chow (300 mg empagliflozin/kg chow; PTB-empa, n = 10) or standard chow (PTB-control, n = 10). Sham rats (Sham, n = 6) received standard chow. After five weeks, RV function was evaluated by echocardiography, cardiac MRI, and invasive pressure-volume measurements.

Results

PTB caused RV failure evident by decreased cardiac output compared with sham. PTB-empa rats had a 49% increase in water intake compared with PTB-control yet no differences in hematocrit or blood glucose. Treatment with empagliflozin decreased RV end-systolic pressures without any changes in RV cardiac output or ventricular-arterial coupling (Ees/Ea). The decrease in RV end-systolic pressure was complemented by a slight reduction in RV cross sectional area as a sign of reduced hypertrophy. Load-independent measures of RV systolic and diastolic function were not affected in PTB-empa rats compared with PTB-control.

Conclusion

Empagliflozin treatment reduced RV end-systolic pressure in RV failure induced by pressure overload. Further studies are needed to elucidate whether this simply relates to a diuretic effect and/or additional independent beneficial RV effects.

The Association Between Non-Clinically Apparent Liver Fibrosis and Pulmonary Arterial Hypertension in Hispanic Patients

Background

Pulmonary arterial hypertension (PAH) is a deadly cardiopulmonary disease with multi-organ involvement including impaired liver function. Liver dysfunction in PAH is poorly understood but significantly associated with morbidity and mortality. Hispanics have a significantly higher prevalence of non-alcoholic fatty liver disease (NAFLD) and evidence of more advanced disease in comparison to other ethnic groups. The clinical impact of NAFLD in Hispanic PAH patients is unknown. We aimed to investigate the impact of a validated scoring system, non-alcoholic fatty liver disease fibrosis score (NFS), to predict the degree of liver fibrosis in a Hispanic PAH population and its relationship to hemodynamics, functional class, and outcomes.

Methods

A retrospective review of all treatment-naive Hispanic patients with group I World Health Organization (WHO) pulmonary hypertension (PH) at a single academic center between February 2016 and March 2021 was performed. Patients with history of substance or alcohol abuse, non-group I WHO PH, pre-existent liver disease, chronic kidney disease, atrial fibrillation, thyroid disease, and warfarin use were excluded from the study. The diagnosis of group I WHO PH was determined by cardiac catheterization after the exclusion of other etiologies. NFS was calculated for each patient and correlated with functional capacity, hemodynamics, N-terminal-pro-B-type natriuretic peptide (NT-proBNP), and survival.

Results

A total of 96 Hispanic patients were included in our study. The median age of patients in our cohort was 49 years (interquartile range: 15) and 69% of our cohort were females. Higher NFSs indicating advanced hepatic fibrosis (F3-F4) were found to correlate with elevated right-sided cardiac filling pressures (r = 0.27, P = 0.03), elevated levels of NT-proBNP (r = 0.32, P = 0.01), lower 6-minute walk distance (6MWD) (r = -0.49, P = 0.001), lower functional capacity (World Health Organization functional class, WHO-FC, r = -0.35, P = 0.051), a higher prevalence of diabetes (21.1% versus 51.9%, P = 0.001), a higher prevalence of risk factors for metabolic syndrome (81.5% versus 65.0%, P = 0.035), and worse 5-year survival rates.

Conclusion

In Hispanic patients with PAH, NFSs correlate with the degree of right-sided pressure overload. In addition, advanced NFSs were independently associated with lower 5-year survival rates and added prognostic information to other established risk parameters in PAH. This study suggests that screening for liver disease in this vulnerable patient population can aid in earlier detection leading to discussion of lifestyle modifications and possible escalation of PAH-targeted therapies, thus leading to potential improvement in survival rates.

Prevalence and Determinants of Delay in Time-to-Diagnosis for Pulmonary Arterial Hypertension Patients in Gansu China: A Observational Cohort Study

Current studies of patients with pulmonary arterial hypertension (PAH) have shown a significant diagnostic delay. However, the causes and risk factors for this delay are not been well explored in Chinese population. This study aimed to assess the status of diagnostic delay in patients with PAH in China. Additionally, we identified factors associated with the delay. Demographic and clinical data were collected from 153 PAH patients admitted to three tertiary hospitals in Gansu, China, from March 2020 to October 2022. Based on the recorded date, the diagnostic delay was divided into patient delay and health system delay. For analysis, we divided diagnostic delay into 2 groups (≤3 years and >3 years). Factors associated with delay were identified by binary logistic regression. The median diagnostic delay was 3 years (IQR: 0.25-5.88). Binary logistic regression analysis showed that male (OR = 2.48, 95% CI: 1.10-5.58), those with junior high school or below (OR = 3.65, 95% CI: 1.36-9.78), living far away from the tertiary hospital (OR = 2.66, 95% CI: 1.14-6.18), initially visit hospital before 2018 (OR = 3.82, 95% CI: 1.68-8.71), and visit hospital at county level or below (OR = 3.80, 95% CI: 1.42-10.18) were risk factor for diagnostic delay (>3 years). Despite increased awareness, most patients with PAH in Gansu, China still experienced a delay in diagnosis of more than 3 years. Male sex, lower educational background, and being away from tertiary hospitals are risk factors for delay. Furthermore, factors impacting time-to-diagnosis and its impact should be continuously evaluated as therapeutic strategies continue to evolve and improve.

Unleashing the Potential of Nrf2: A Novel Therapeutic Target for Pulmonary Vascular Remodeling

Pulmonary vascular remodeling, characterized by the thickening of all three layers of the blood vessel wall, plays a central role in the pathogenesis of pulmonary hypertension (PH). Despite the approval of several drugs for PH treatment, their long-term therapeutic effect remains unsatisfactory, as they mainly focus on vasodilation rather than addressing vascular remodeling. Therefore, there is an urgent need for novel therapeutic targets in the treatment of PH. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor that regulates endogenous antioxidant defense and emerges as a novel regulator of pulmonary vascular remodeling. Growing evidence has suggested an involvement of Nrf2 and its downstream transcriptional target in the process of pulmonary vascular remodeling. Pharmacologically targeting Nrf2 has demonstrated beneficial effects in various diseases, and several Nrf2 inducers are currently undergoing clinical trials. However, the exact potential and mechanism of Nrf2 as a therapeutic target in PH remain unknown. Thus, this review article aims to comprehensively explore the role and mechanism of Nrf2 in pulmonary vascular remodeling associated with PH. Additionally, we provide a summary of Nrf2 inducers that have shown therapeutic potential in addressing the underlying vascular remodeling processes in PH. Although Nrf2-related therapies hold great promise, further research is necessary before their clinical implementation can be fully realized.

Untangling the mechanisms of pulmonary arterial hypertension-induced right ventricular stiffening in a large animal model

Pulmonary hypertension (PHT) is a devastating disease with low survival rates. In PHT, chronic pressure overload leads to right ventricle (RV) stiffening; thus, impeding diastolic filling. Multiple mechanisms may contribute to RV stiffening, including wall thickening, microstructural disorganization, and myocardial stiffening. The relative importance of each mechanism is unclear. Our objective is to use a large animal model to untangle these mechanisms. Thus, we induced pulmonary arterial hypertension (PAH) in sheep via pulmonary artery banding. After eight weeks, the hearts underwent anatomic and diffusion tensor MRI to characterize wall thickening and microstructural disorganization. Additionally, myocardial samples underwent histological and gene expression analyses to quantify compositional changes and mechanical testing to quantify myocardial stiffening. Finally, we used finite element modeling to disentangle the relative importance of each stiffening mechanism. We found that the RVs of PAH animals thickened most at the base and the free wall and that PAH induced excessive collagen synthesis, increased cardiomyocyte cross-sectional area, and led to microstructural disorganization, consistent with increased expression of fibrotic genes. We also found that the myocardium itself stiffened significantly. Importantly, myocardial stiffening correlated significantly with collagen synthesis. Finally, our computational models predicted that myocardial stiffness contributes to RV stiffening significantly more than other mechanisms. Thus, myocardial stiffening may be the most important predictor for PAH progression. Given the correlation between myocardial stiffness and collagen synthesis, collagen-sensitive imaging modalities may be useful for estimating myocardial stiffness and predicting PAH outcomes. STATEMENT OF SIGNIFICANCE: Ventricular stiffening is a significant contributor to pulmonary hypertension-induced right heart failure. However, the mechanisms that lead to ventricular stiffening are not fully understood. The novelty of our work lies in answering this question through the use of a large animal model in combination with spatially- and directionally sensitive experimental techniques. We find that myocardial stiffness is the primary mechanism that leads to ventricular stiffening. Clinically, this knowledge may be used to improve diagnostic, prognostic, and therapeutic strategies for patients with pulmonary hypertension.

Management of systemic to pulmonary shunts and elevated pulmonary vascular resistance

Background

Repair of systemic to pulmonary shunts is timed to prevent the development of irreversible pulmonary vascular disease, including in patients with other factors contributing to pulmonary hypertension. This study assessed outcomes of an individualised strategy for managing patients with mild-moderately elevated pulmonary vascular resistance (PVR) deemed borderline eligible for repair.

Methods

A retrospective chart review was conducted of patients with systemic to pulmonary shunts and baseline indexed PVR (PVRi) ≥3 WU·m2 treated at a single centre from 1 January 2005 to 30 September 2019. Data included demographics, World Health Organization functional class (WHO FC), medications and haemodynamic data at baseline and serial follow-up.

Results

30 patients (18 females) met criteria for inclusion. Median age at diagnosis of pulmonary arterial hypertension was 1.3 years (range 0.03-54 years) and at surgery was 4.1 years (range 0.73-56 years). Median follow-up time was 5.8 years (range 0.2-14.6 years) after repair. Most patients received at least one targeted pulmonary arterial therapy prior to repair and the majority (80%) underwent fenestrated shunt closure. There was a significant decrease in mean pulmonary arterial pressure (mPAP) (p<0.01), PVRi (p=0.0001) and PVR/systemic vascular resistance (p<0.01) between baseline and preoperative catheterisation and a decrease in PVRi (p<0.005), mPAP (p=0.0001) and pulmonary to systemic flow ratio (p<0.03) from baseline to most recent catheterisation. WHO FC improved from FC II-III at baseline to FC I post repair in most patients (p<0.003).

Conclusions

In carefully selected patients with systemic to pulmonary shunts and elevated PVR considered borderline for operability, the use of preoperative targeted therapy in conjunction with fenestrated or partial closure of intracardiac shunts is associated with improvement in WHO FC and clinical outcomes.

Impact of Parenteral Prostanoids in Pulmonary Arterial Hypertension: The Relevance of Timing

Parenteral prostanoids are being recommended in pulmonary arterial hypertension (PAH) treatment, but the prognostic relevance of delayed treatment initiation is still debated. This study assessed the impact of the timing of prostacyclin treatment initiation on reducing PVR and achieving a low-risk profile in PAH patients. The study enrolled 151 patients who started on parenteral prostanoids with different treatment strategies. All patients underwent right heart catheterization, clinical evaluation, and risk assessments at baseline and after 1-year follow-up. Patients with an upfront strategy including parenteral prostanoid plus one oral drug had -5.3 ± 6.2 WU (-50 ± 19%) reduction in PVR, patients with an upfront strategy including parenteral prostanoid plus double oral drug had -12.8 ± 5.9 WU (-68 ± 17%) reduction in PVR, while patients with an add-on strategy including parenteral prostanoid after oral drugs had -3.9 ± 3.5 WU (-23 ± 19%) reduction in PVR. An upfront strategy including parenteral prostanoids was independently associated with an increased likelihood of achieving the greater reduction of PVR compared with an add-on strategy. Additionally, the greater the severity of PH at the time of diagnosis, in terms of PVR and RV reverse remodeling, the higher the probability of treatment failure. An upfront strategy including a parenteral prostanoid is associated with the highest likelihood of achieving a low-risk profile and a greater reduction of PVR compared with parenteral prostanoid as an add-on to oral treatment.

Differential drug response in pulmonary arterial hypertension: The potential for precision medicine

Pulmonary arterial hypertension (PAH) is a rare, complex, and deadly cardiopulmonary disease. It is characterized by changes in endothelial cell function and smooth muscle cell proliferation in the pulmonary arteries, causing persistent vasoconstriction, resulting in right heart hypertrophy and failure. There are multiple drug classes specific to PAH treatment, but variation between patients may impact treatment response. A small subset of patients is responsive to pulmonary vasodilators and can be treated with calcium channel blockers, which would be deleterious if prescribed to a typical PAH patient. Little is known about the underlying cause of this important difference in vasoresponsive PAH patients. Sex, race/ethnicity, and pharmacogenomics may also factor into efficacy and safety of PAH-specific drugs. Research has indicated that endothelin receptor antagonists may be more effective in women and there have been some minor differences found in certain races and ethnicities, but these findings are muddled by the impact of socioeconomic factors and a lack of representation of non-White patients in clinical trials. Genetic variants in genes such as CYP3A5, CYP2C9, PTGIS, PTGIR, GNG2, CHST3, and CHST13 may influence the efficacy and safety of certain PAH-specific drugs. PAH research faces many challenges, but there is potential for new methodologies to glean new insights into PAH development and treatment.

Real-world evidence to advance knowledge in pulmonary hypertension: Status, challenges, and opportunities. A consensus statement from the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative's Real-world Evidence Working Group

This manuscript on real-world evidence (RWE) in pulmonary hypertension (PH) incorporates the broad experience of members of the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative Real-World Evidence Working Group. We aim to strengthen the research community's understanding of RWE in PH to facilitate clinical research advances and ultimately improve patient care. Herein, we review real-world data (RWD) sources, discuss challenges and opportunities when using RWD sources to study PH populations, and identify resources needed to support the generation of meaningful RWE for the global PH community.

Pulmonary Arterial Hypertension in the Elderly: Peculiar Features and Challenges for a Proper Phenotyping Approach

(1) Introduction. Although pulmonary arterial hypertension (PAH) usually affects young people with a low cardiovascular risk profile, progressive epidemiologic changes have been providing a codified phenotype of elderly subjects with PAH and increased risk predictors for left heart disease. We therefore conducted a systematic review to describe the current knowledge and characteristics of elderly individuals with PAH and further insights concerning their prognostic outcomes and therapeutic response. (2) Methods. A search was conducted in PubMed, Embase, and Cochrane Library for publications evaluating the epidemiology, diagnostic work-up, and treatment of PAH in elderly subjects. (3) Among the 74 publications initially retrieved, 16 full-text articles were selected for the present systematic review. Compared to their younger counterparts, elderly individuals with PAH showed greater clinical deterioration, reduced exercise capacity, and worse prognostic outcomes, as well as less response to PAH-targeted therapy and higher rates of PAH drug discontinuation. (4) Conclusions. Demographic changes over time contributed to define a peculiar PAH phenotype in elderly patients, with an increased burden of cardiovascular comorbidities and distinctive features compared to young patients. Further investigations are needed in order to better clarify the nosologic criteria, and management in this subset population.

A prognostic model for systemic lupus erythematosus-associated pulmonary arterial hypertension: CSTAR-PAH cohort study

BACKGROUND

Pulmonary arterial hypertension is a major cause of death in systemic lupus erythematosus, but there are no tools specialized for predicting survival in systemic lupus erythematosus-associated pulmonary arterial hypertension.

RESEARCH QUESTION

To develop a practical model for predicting long-term prognosis in patients with systemic lupus erythematosus-associated pulmonary arterial hypertension.

METHODS

A prognostic model was developed from a multicenter, longitudinal national cohort of consecutively evaluated patients with systemic lupus erythematosus-associated pulmonary arterial hypertension. The study was conducted between November 2006 and February 2020. All-cause death was defined as the endpoint. Cox regression and least absolute shrinkage and selection operators were used to fit the model. Internal validation of the model was assessed by discrimination and calibration using bootstrapping.

RESULTS

Of 310 patients included in the study, 81 (26.1%) died within a median follow-up of 5.94 years (interquartile range 4.67-7.46). The final prognostic model included eight variables: modified World Health Organization functional class, 6-min walking distance, pulmonary vascular resistance, estimated glomerular filtration rate, thrombocytopenia, mild interstitial lung disease, N-terminal pro-brain natriuretic peptide/brain natriuretic peptide level, and direct bilirubin level. A 5-year death probability predictive algorithm was established and validated using the C-index (0.77) and a satisfactory calibration curve. Risk stratification was performed based on the predicted probability to improve clinical decision-making.

CONCLUSIONS

This new risk stratification model for systemic lupus erythematosus-associated pulmonary arterial hypertension may provide individualized prognostic probability using readily obtained clinical risk factors. External validation is required to demonstrate the accuracy of this model's predictions in diverse patient populations.

Pulmonary Circulation Under Pressure: Pathophysiological and Therapeutic Implications of BK Channel

The large-conductance Ca2+-activated K+ (BK) channel is widely expressed in the pulmonary blood vessels and plays a significant role in regulating pulmonary vascular tonus. It opens under membrane depolarization, increased intracellular Ca+2 concentration, and chronic hypoxia, resulting in massive K+ efflux, membrane hyperpolarization, decreased L-type Ca+2 channel opening, and smooth muscle relaxation. Several reports have demonstrated an association between BK channel dysfunction and pulmonary hypertension (PH) development. Decreased BK channel subunit expression and impaired regulation by paracrine hormones result in decreased BK channel opening, increased pulmonary vascular resistance, and pulmonary arterial pressure being the cornerstone of PH. The resulting right ventricular pressure overload ultimately leads to ventricular remodeling and failure. Therefore, it is unsurprising that the BK channel has arisen as a potential target for treating PH. Recently, a series of selective, synthetic BK channel agonists have proven effective in attenuating the pathophysiological progression of PH without adverse effects in animal models.

Pharmacogenomics in the Management of Pulmonary Arterial Hypertension: Current Perspectives

Pulmonary arterial hypertension (PAH) is a rare disease with heterogeneous causes that can lead to right ventricular (RV) failure and death if left untreated. There are currently 10 medications representative of five unique pharmacologic classes that are approved for treatment. These have led to significant improvements in overall clinical outcome. However, substantial variability in dosing requirements and treatment response is evident, leading to suboptimal outcome for many patients. Furthermore, dosing is empiric and iterative and can lead to delays in meeting treatment goals and burdensome adverse effects. Pharmacogenomic (PGx) associations have been reported with certain PAH medications, such as treprostinil and bosentan, and can explain some of the variability in response. Relevant genes associated with treprostinil include CYP2C8, CYP2C9, CAMK2D, and PFAS. CYP2C8 and CYP2C9 are the genes encoding the major metabolizing liver enzymes for treprostinil, and reduced function variants (*2, *3) with CYP2C9 were associated with lower treatment persistence. Additionally, a higher CYP2C9 activity score was associated with a significantly less risk of treatment discontinuation. Other genes of interest that have been explored with treprostinil include CAMK2D, which is associated with right ventricular dysfunction and significantly higher dose requirements. Similarly, PFAS is associated with lower concentrations of cyclic adenosine monophosphate and significantly higher dose requirements. Genes of interest with the endothelin receptor antagonist (ERA) class include GNG2 and CYP2C9. A genetic variant in GNG2 (rs11157866) was linked to a significantly increased rate of clinical improvement with ERAs. The *2 variant with CYP2C9 (encoding for the major metabolizing enzyme for bosentan) was significantly associated with a higher risk for elevations in hepatic aminotransferases and liver injury. In summary, this article reviews the relevant pharmacogenes that have been associated to date with dosing and outcome among patients who received PAH medications.

Emerging pharmacotherapies for the treatment of pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a progressive and life-threatening disease. Approved treatment options currently primarily target abnormal cell signaling pathways involved in vasoconstriction and proliferation, such as those mediated by prostacyclin, cyclic guanosine monophosphate, and endothelin.

AREAS COVERED

Recent advancements have led to new applications and modes of delivery of currently approved PAH medications. At the same time, novel drugs targeting specific molecular pathways involved in PAH pathogenesis have been developed and are being investigated in clinical trials. This review summarizes investigational drug trials for PAH gathered from a comprehensive search using PubMed and ClinicalTrials.gov between 2003 and 2023. It includes both currently approved medications studied at different doses or new administration forms and experimental drugs that have not yet been approved.

EXPERT OPINION

Approved treatments for PAH target imbalances in pulmonary vasoactive pathways that work primarily on enhancing pulmonary vasodilation with less salient effects on pulmonary vascular remodeling. The advent of more locally acting inhaled medications offers additional therapeutic options that may improve the ease of drug delivery and reduce adverse systemic effects. The more recent emphasis on developing and applying therapeutics that directly impact the aberrant signaling pathways implicated in PAH appears more likely to advance the treatment of this devastating disease.

Diagnosis and management of pulmonary veno-occlusive disease

INTRODUCTION

Pulmonary veno-occlusive disease (PVOD) is an orphan disease and uncommon etiology of pulmonary arterial hypertension (PAH) characterized by substantial small pulmonary vein and capillary involvement.

AREAS COVERED

PVOD, also known as 'PAH with features of venous/capillary involvement' in the current ESC/ERS classification.

EXPERT OPINION

In recent years, particular risk factors for PVOD have been recognized, including genetic susceptibilities and environmental factors (such as exposure to occupational organic solvents, chemotherapy, and potentially tobacco). The discovery of biallelic mutations in the EIF2AK4 gene as the cause of heritable PVOD has been a breakthrough in understanding the molecular basis of PVOD. Venous and capillary involvement (PVOD-like) has also been reported to be relatively common in connective tissue disease-associated PAH (especially systemic sclerosis), and in rare pulmonary diseases like sarcoidosis and pulmonary Langerhans cell granulomatosis. Although PVOD and pulmonary arterial hypertension (PAH) exhibit similarities, including severe precapillary PH, it is essential to differentiate between them since PVOD has a worse prognosis and requires specific management. Indeed, PVOD patients are characterized by poor response to PAH-approved drugs, which can lead to pulmonary edema and clinical deterioration. Due to the lack of effective treatments, early referral to a lung transplantation center is crucial.

Serum and Pulmonary Expression Profiles of the Activin Signaling System in Pulmonary Arterial Hypertension

BACKGROUND

Activins are novel therapeutic targets in pulmonary arterial hypertension (PAH). We therefore studied whether key members of the activin pathway could be used as PAH biomarkers.

METHODS

Serum levels of activin A, activin B, α-subunit of inhibin A and B proteins, and the antagonists follistatin and follistatin-like 3 (FSTL3) were measured in controls and in patients with newly diagnosed idiopathic, heritable, or anorexigen-associated PAH (n=80) at baseline and 3 to 4 months after treatment initiation. The primary outcome was death or lung transplantation. Expression patterns of the inhibin subunits, follistatin, FSTL3, Bambi, Cripto, and the activin receptors type I (ALK), type II (ACTRII), and betaglycan were analyzed in PAH and control lung tissues.

RESULTS

Death or lung transplantation occurred in 26 of 80 patients (32.5%) over a median follow-up of 69 (interquartile range, 50-81) months. Both baseline (hazard ratio, 1.001 [95% CI, 1.000-1.001]; P=0.037 and 1.263 [95% CI, 1.049-1.520]; P=0.014, respectively) and follow-up (hazard ratio, 1.003 [95% CI, 1.001-1.005]; P=0.001 and 1.365 [95% CI, 1.185-1.573]; P<0.001, respectively) serum levels of activin A and FSTL3 were associated with transplant-free survival in a model adjusted for age and sex. Thresholds determined by receiver operating characteristic analyses were 393 pg/mL for activin A and 16.6 ng/mL for FSTL3. When adjusted with New York Heart Association functional class, 6-minute walk distance, and N-terminal pro-B-type natriuretic peptide, the hazard ratios for transplant-free survival for baseline activin A <393 pg/mL and FSTL3 <16.6 ng/mL were, respectively, 0.14 (95% CI, 0.03-0.61; P=0.009) and 0.17 (95% CI, 0.06-0.45; P<0.001), and for follow-up measures, 0.23 (95% CI, 0.07-0.78; P=0.019) and 0.27 (95% CI, 0.09-0.78, P=0.015), respectively. Prognostic values of activin A and FSTL3 were confirmed in an independent external validation cohort. Histological analyses showed a nuclear accumulation of the phosphorylated form of Smad2/3, higher immunoreactivities for ACTRIIB, ALK2, ALK4, ALK5, ALK7, Cripto, and FSTL3 in vascular endothelial and smooth muscle layers, and lower immunostaining for inhibin-α and follistatin.

CONCLUSIONS

These findings offer new insights into the activin signaling system in PAH and show that activin A and FSTL3 are prognostic biomarkers for PAH.

Metabolic Deregulation in Pulmonary Hypertension

The high morbidity and mortality rate of pulmonary arterial hypertension (PAH) is partially explained by metabolic deregulation. The present study complements our previous publication in "Genes" by identifying significant increases of the glucose transporter solute carrier family 2 (Slc2a1), beta nerve growth factor (Ngf), and nuclear factor erythroid-derived 2-like 2 (Nfe2l2) in three standard PAH rat models. PAH was induced by subjecting the animals to hypoxia (HO), or by injecting with monocrotaline in either normal (CM) or hypoxic (HM) atmospheric conditions. The Western blot and double immunofluorescent experiments were complemented with novel analyses of previously published transcriptomic datasets of the animal lungs from the perspective of the Genomic Fabric Paradigm. We found substantial remodeling of the citrate cycle, pyruvate metabolism, glycolysis/gluconeogenesis, and fructose and mannose pathways. According to the transcriptomic distance, glycolysis/gluconeogenesis was the most affected functional pathway in all three PAH models. PAH decoupled the coordinated expression of many metabolic genes, and replaced phosphomannomutase 2 (Pmm2) with phosphomannomutase 1 (Pmm1) in the center of the fructose and mannose metabolism. We also found significant regulation of key genes involved in PAH channelopathies. In conclusion, our data show that metabolic dysregulation is a major PAH pathogenic factor.

Inhibition of PCSK9 Improves the Development of Pulmonary Arterial Hypertension Via Down-Regulating Notch3 Expression

BACKGROUND

Pulmonary arterial hypertension (PAH) is a fatal disease characterized by continuous constriction and occlusion of small pulmonary arteries, leading to the development of right ventricular failure and death. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a kind of serine protease enzyme that increases low-density lipoprotein cholesterol (LDLC) levels through degrading low-density lipoprotein cholesterol receptors (LDLr). However, whether inhibition of PCSK9 can alleviate PAH has not been reported.

METHODS AND RESULTS

We reported that PCSK9 expression was up-regulated in lung tissues of PAH patients. In addition, we used PCSK9 monoclonal antibody subcutaneously to inhibit PCSK9 expression in mice exposed to chronic hypoxia (10%) in combination with SU5416, a VEGF receptor inhibitor. Hypoxia plus SU5416-induced PAH was attenuated in PCSK9 monoclonal antibody-treated mice compared with wild-type mice. PCSK9 inhibited pulmonary vascular remodeling in mice. Moreover, PCSK9 knockdown significantly altered the proliferation and migration of hypoxia-induced PASMCs. We also found that PCSK9 monoclonal antibody inhibited Notch3 expression in vivo and in vitro.

CONCLUSION

Our results suggest that the PCSK9-Notch3 signaling pathway is critical for the proliferation and migration of PASMCs and provides a potential drug target for the treatment of PAH.

The HIF-1α/miR-26a-5p/PFKFB3/ULK1/2 axis regulates vascular remodeling in hypoxia-induced pulmonary hypertension by modulation of autophagy

Pulmonary arterial hypertension (PAH) is a progressive and life-threatening disease characterized by pulmonary vascular remodeling, which may cause right heart failure and even death. Accumulated evidence confirmed that microRNA-26 family play critical roles in cardiovascular disease; however, their function in PAH remains largely unknown. Here, we investigated the expression of miR-26 family in plasma from PAH patients using quantitative RT-PCR, and identified miR-26a-5p as the most downregulated member, which was also decreased in hypoxia-induced pulmonary arterial smooth muscle cell (PASMC) autophagy models and lung tissues of PAH patients. Furthermore, chromatin immunoprecipitation (ChIP) analysis and luciferase reporter assays revealed that hypoxia-inducible factor 1α (HIF-1α) specifically interacted with the promoter of miR-26a-5p and inhibited its expression in PASMCs. Tandem mRFP-GFP-LC3B fluorescence microscopy demonstrated that miR-26a-5p inhibited hypoxia-induced PAMSC autophagy, characterized by reduced formation of autophagosomes and autolysosomes. In addition, results showed that miR-26a-5p overexpression potently inhibited PASMC proliferation and migration, as determined by cell counting kit-8, EdU staining, wound-healing, and transwell assays. Mechanistically, PFKFB3, ULK1, and ULK2 were direct targets of miR-26a-5p, as determined by dual-luciferase reporter gene assays and western blots. Meanwhile, PFKFB3 could further enhance the phosphorylation level of ULK1 and promote autophagy in PASMCs. Moreover, intratracheal administration of adeno-miR-26a-5p markedly alleviated right ventricular hypertrophy and pulmonary vascular remodeling in hypoxia-induced PAH rat models in vivo. Taken together, the HIF-1α/miR-26a-5p/PFKFB3/ULK1/2 axis plays critical roles in the regulation of hypoxia-induced PASMC autophagy and proliferation. MiR-26a-5p may represent as an attractive biomarker for the diagnosis and treatment of PAH.

Untangling the mechanisms of pulmonary hypertension-induced right ventricular stiffening in a large animal model

Background

Pulmonary arterial hypertension (PHT) is a devastating disease with low survival rates. In PHT, chronic pressure overload leads to right ventricle (RV) remodeling and stiffening; thus, impeding diastolic filling and ventricular function. Multiple mechanisms contribute to RV stiffening, including wall thickening, microstructural disorganization, and myocardial stiffening. The relative importance of each mechanism is unclear. Our objective is to use a large animal model as well as imaging, experimental, and computational approaches to untangle these mechanisms.

Methods

We induced PHT in eight sheep via pulmonary artery banding. After eight weeks, the hearts underwent anatomic and diffusion tensor MRI to characterize wall thickening and microstructural disorganization. Additionally, myocardial samples underwent histological and gene expression analyses to quantify compositional changes and mechanical testing to quantify myocardial stiffening. All findings were compared to 12 control animals. Finally, we used computational modeling to disentangle the relative importance of each stiffening mechanism.

Results

First, we found that the RVs of PHT animals thickened most at the base and the free wall. Additionally, we found that PHT induced excessive collagen synthesis and microstructural disorganization, consistent with increased expression of fibrotic genes. We also found that the myocardium itself stiffened significantly. Importantly, myocardial stiffening correlated significantly with excess collagen synthesis. Finally, our model of normalized RV pressure-volume relationships predicted that myocardial stiffness contributes to RV stiffening significantly more than other mechanisms.

Conclusions

In summary, we found that PHT induces wall thickening, microstructural disorganization, and myocardial stiffening. These remodeling mechanisms were both spatially and directionally dependent. Using modeling, we show that myocardial stiffness is the primary contributor to RV stiffening. Thus, myocardial stiffening may be an important predictor for PHT progression. Given the significant correlation between myocardial stiffness and collagen synthesis, collagen-sensitive imaging modalities may be useful for non-invasively estimating myocardial stiffness and predicting PHT outcomes.

A claims-based, machine-learning algorithm to identify patients with pulmonary arterial hypertension

Many patients with pulmonary arterial hypertension (PAH) experience substantial delays in diagnosis, which is associated with worse outcomes and higher costs. Tools for diagnosing PAH sooner may lead to earlier treatment, which may delay disease progression and adverse outcomes including hospitalization and death. We developed a machine-learning (ML) algorithm to identify patients at risk for PAH earlier in their symptom journey and distinguish them from patients with similar early symptoms not at risk for developing PAH. Our supervised ML model analyzed retrospective, de-identified data from the US-based Optum® Clinformatics® Data Mart claims database (January 2015 to December 2019). Propensity score matched PAH and non-PAH (control) cohorts were established based on observed differences. Random forest models were used to classify patients as PAH or non-PAH at diagnosis and at 6 months prediagnosis. The PAH and non-PAH cohorts included 1339 and 4222 patients, respectively. At 6 months prediagnosis, the model performed well in distinguishing PAH and non-PAH patients, with area under the curve of the receiver operating characteristic of 0.84, recall (sensitivity) of 0.73, and precision of 0.50. Key features distinguishing PAH from non-PAH cohorts were a longer time between first symptom and the prediagnosis model date (i.e., 6 months before diagnosis); more diagnostic and prescription claims, circulatory claims, and imaging procedures, leading to higher overall healthcare resource utilization; and more hospitalizations. Our model distinguishes between patients with and without PAH at 6 months before diagnosis and illustrates the feasibility of using routine claims data to identify patients at a population level who might benefit from PAH-specific screening and/or earlier specialist referral.

Phosphodiesterase 5 inhibitor treatment and survival in interstitial lung disease pulmonary hypertension: A Bayesian retrospective observational cohort study

BACKGROUND AND OBJECTIVE

Pulmonary hypertension is a life-limiting complication of interstitial lung disease (ILD-PH). We investigated whether treatment with phosphodiesterase 5 inhibitors (PDE5i) in patients with ILD-PH was associated with improved survival.

METHODS

Consecutive incident patients with ILD-PH and right heart catheterisation, echocardiography and spirometry data were followed from diagnosis to death, transplantation or censoring with all follow-up and survival data modelled by Bayesian methods.

RESULTS

The diagnoses in 128 patients were idiopathic pulmonary fibrosis (n = 74, 58%), hypersensitivity pneumonitis (n = 17, 13%), non-specific interstitial pneumonia (n = 12, 9%), undifferentiated ILD (n = 8, 6%) and other lung diseases (n = 17, 13%). Final outcomes were death (n = 106, 83%), transplantation (n = 9, 7%) and censoring (n = 13, 10%). Patients treated with PDE5i (n = 50, 39%) had higher mean pulmonary artery pressure (median 38 mm Hg [interquartile range, IQR: 34, 43] vs. 35 mm Hg [IQR: 31, 38], p = 0.07) and percentage predicted forced vital capacity (FVC; median 57% [IQR: 51, 73] vs. 52% [IQR: 45, 66], p=0.08) though differences did not reach significance. Patients treated with PDE5i survived longer than untreated patients (median 2.18 years [95% CI: 1.43, 3.04] vs. 0.94 years [0.69, 1.51], p = 0.003) independent of all other prognostic markers by Bayesian joint-modelling (HR 0.39, 95% CI: 0.23, 0.59, p < 0.001) and propensity-matched analyses (HR 0.38, 95% CI: 0.22, 0.58, p < 0.001). Survival difference with treatment was significantly larger if right ventricular function was normal, rather than abnormal, at presentation (+2.55 years, 95% CI: -0.03, +3.97 vs. +0.98 years, 95% CI: +0.47, +2.00, p = 0.04).

CONCLUSION

PDE5i treatment in ILD-PH should be investigated by a prospective randomized trial.

Astragaloside IV improves pulmonary arterial hypertension by increasing the expression of CCN1 and activating the ERK1/2 pathway

The aim of the present study was to investigate the underlying mechanism of AS-IV and CCN1 in PAH and to evaluate whether the protective effect of AS-IV against PAH is associated with CCN1 and its related signalling pathway. In vivo, male SD rats were intraperitoneally injected with monocrotaline (MCT, 60 mg/kg) or exposed to hypoxia (10% oxygen) and gavaged with AS-IV (20, 40 and 80 mg/kg/day) to create a PAH model. In vitro, human pulmonary artery endothelial cells (hPAECs) were exposed to hypoxia (3% oxygen) or monocrotaline pyrrole (MCTP, 60 μg/mL) and treated with AS-IV (10, 20 and 40 μM), EGF (10 nM, ERK agonist), small interfering CCN1 (CCN1 siRNA) and recombinant CCN1 protein (rCCN1, 100 ng/mL). We identified the differences in the expression of genes in the lung tissues of PAH rats by proteomics. At the same time, we dynamically detected the expression of CCN1 by Western blot both in vivo and in vitro. The Western blot experimental results showed that the expression of CCN1 increased in the early stage of PAH and decreased in the advanced stage of PAH. The results showed that compared with the control group, MCT- and hypoxia-induced increased the hemodynamic parameters and apoptosis. AS-IV can improve PAH, as characterized by decreased hemodynamic parameters, vascular wall area ratio (WA%), vascular wall thickness ratio (WT%) and α-SMA expression and inhibition of cell apoptosis. Moreover, the improvement of PAH by AS-IV was accompanied by increased CCN1 expression, which activated the ERK1/2 signalling pathway. Meanwhile, CCN1 and p-ERK1/2 were inhibited by siCCN1 and promoted by rCCN1. EGF not only activated the ERK1/2 signalling pathway but also induced the expression of CCN1. In conclusion, AS-IV improves PAH by increasing the expression of CCN1 and activating the ERK1/2 signalling pathway. The results of our study provide a theoretical basis for additional study on the protective effect of AS-IV against PAH.

Cytokines as prognostic biomarkers in pulmonary arterial hypertension

BACKGROUND

Risk stratification and assessment of disease progression in patients with pulmonary arterial hypertension (PAH) are challenged by the lack of accurate disease-specific and prognostic biomarkers. To date, brain natriuretic peptide (BNP) and/or its N-terminal fragment (NT-proBNP) are the only markers for right ventricular dysfunction used in clinical practice, in association with echocardiographic and invasive haemodynamic variables to predict outcome in patients with PAH.

METHODS

This study was designed to identify an easily measurable biomarker panel in the serum of 80 well-phenotyped PAH patients with idiopathic, heritable or drug-induced PAH at baseline and at first follow-up. The prognostic value of identified cytokines of interest was secondly analysed in an external validation cohort of 125 PAH patients.

RESULTS

Among the 20 biomarkers studied with the multiplex Ella platform, we identified a three-biomarker panel composed of β-NGF, CXCL9 and TRAIL that were independently associated with prognosis both at the time of PAH diagnosis and at the first follow-up after initiation of PAH therapy. β-NGF and CXCL9 were predictors of death or transplantation, whereas high levels of TRAIL were associated with a better prognosis. Furthermore, the prognostic value of the three cytokines was more powerful for predicting survival than usual non-invasive variables (New York Heart Association Functional Class, 6-min walk distance and BNP/NT-proBNP). The results were validated in a fully independent external validation cohort.

CONCLUSION

The monitoring of β-NGF, CXCL9 and TRAIL levels in serum should be considered in the management and treatment of patients with PAH to objectively guide therapeutic options.

[Comparative assessment of the effects of dobutamine and levosimendan on right ventricular ejection fraction in patients with biventricular heart failure]

Aim    The primary objective of this study was to comparatively assess the effects of levosimendan and dobutamine on RVEF, right ventricular diastolic function, and hormonal balance in patients with biventricular heart failure. The secondary objective was to investigate the relationship between the RVEF and the peak systolic velocity (Sa), an indicator of right ventricular systolic function, as measured by tissue Doppler echocardiography from the tricuspid annulus, and by the tricuspid annular plane systolic excursion (TAPSE).Material and Methods    The population of this cross-sectional, single-center, prospective study was comprised of 81 patients, who between December 2019 and January 2022, applied to the study health institution with diagnosis of ADHF. The study sample included 67 biventricular heart failure patients with left ventricular ejection fraction (LVEF) &lt;35 % and RVEF &lt;50 %, as measured by the ellipsoidal shell model, and who met the other study inclusion criteria. Of these 67 patients, 34 were treated with levosimendan, and 33 were treated with dobutamine. RVEF, LVEF, Sa, peak early (Ea) and peak late (Aa) annular velocities, Ea / Aa ratio, TAPSE, systolic pulmonary artery pressure (SPAP), n-terminal pro-brain natriuretic peptide (NT-pro BNP), and functional capacity (FC) were measured before treatment and at 48 hrs of treatment. The within group pre- and post-treatment differences (Δs) of these variables were compared.Results    RVEF, SPAP, and BNP, and FC significantly improved in both treatment groups (p&lt;0.05 for all). Sa (p&lt;0.01), TAPSE (p&lt;0.01), LVEF (p&lt;0.01), and Ea / Aa (p&lt;0.05) improved only in the levosimendan group. The pre- and post-treatment Δs for RVEF, LVEF, SPAP, Sa, TAPSE, FC, and Ea / Aa were higher in the levosimendan group than in the dobutamine group (p&lt;0.05 for all).Conclusion    Compared to dobutamine, levosimendan produced greater improvement in right ventricular systolic and diastolic function in patients with biventricular heart failure and in need of inotropic therapy support.

Novel Molecular Mechanisms Involved in the Medical Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe condition with a high mortality rate despite advances in diagnostic and therapeutic strategies. In recent years, significant scientific progress has been made in the understanding of the underlying pathobiological mechanisms. Since current available treatments mainly target pulmonary vasodilation, but lack an effect on the pathological changes that develop in the pulmonary vasculature, there is need to develop novel therapeutic compounds aimed at antagonizing the pulmonary vascular remodeling. This review presents the main molecular mechanisms involved in the pathobiology of PAH, discusses the new molecular compounds currently being developed for the medical treatment of PAH and assesses their potential future role in the therapeutic algorithms of PAH.

Krüppel-like Factor 7 inhibits proliferation and migration of pulmonary smooth muscle cells via p21 activation

The aberrant proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) are critical contributors to the pulmonary vascular remodeling that occurs during the development of Pulmonary arterial hypertension (PAH). Krüppel-like Factor 7 (KLF7) has been reported to be involved in the development of certain cardiovascular diseases. However, the role of KLF7 in PAH remains unknown. Here, we aimed to explore whether KLF7 mediates the proliferation and migration of PASMCs and its underlying mechanism. In this study, Sprague Dawley rats were exposed to 60 mg/kg monocrotaline (MCT) for 3 weeks to induce PAH and human PASMCs were stimulated with 20 ng/ml platelet-derived growth factor-BB (PDGF-BB) for 24 h to induce proliferation and migration. The mRNA and protein expression of KLF7 were significantly down-regulated in MCT-induced PAH rats and PDGF-BB-treated PASMCs. Under normal conditions, KLF7 knockdown obviously promoted PASMCs proliferation and migration, whereas KLF7 overexpression exhibited the opposite effects. Furthermore, PDGF-BB promoted the PASMCs proliferation and migration, increased the cell proportion in S phase, which was significantly attenuated by overexpression of KLF7. Mechanistic investigation indicated that KLF7 through activation its target protein, the cell cycle inhibitor p21, which finally leading to the inhibition of PASMCs growth. Consistently, UC2288, a specific inhibitor of p21, partially reversed the PASMCs proliferation inhibited by KLF7 overexpression. Taken collectively, the data suggested that KLF7 inhibits PASMCs proliferation and migration via p21 pathway and it may be used as a new therapeutic target for the PAH.

Sex and Gender in Lung Diseases and Sleep Disorders: A State-of-the-Art Review: Part 2

There is now ample evidence that differences in sex and gender contribute to the incidence, susceptibility, presentation, diagnosis, and clinical course of many lung diseases. Some conditions are more prevalent in women, such as pulmonary arterial hypertension and sarcoidosis. Some life stages-such as pregnancy-are unique to women and can affect the onset and course of lung disease. Clinical presentation may differ as well, such as the higher number of exacerbations experienced by women with cystic fibrosis (CF), more fatigue in women with sarcoidosis, and more difficulty in achieving smoking cessation. Outcomes such as mortality may be different as well, as indicated by the higher mortality in women with CF. In addition, response to therapy and medication safety may also differ by sex, and yet, pharmacogenomic factors are often not adequately addressed in clinical trials. Various aspects of lung/sleep biology and pathobiology are impacted by female sex and female reproductive transitions. Differential gene expression or organ development can be impacted by these biological differences. Understanding these differences is the first step in moving toward precision medicine for all patients. This article is the second part of a state-of-the-art review of specific effects of sex and gender focused on epidemiology, disease presentation, risk factors, and management of selected lung diseases. We review the more recent literature and focus on guidelines incorporating sex and gender differences in pulmonary hypertension, CF and non-CF bronchiectasis, sarcoidosis, restless legs syndrome and insomnia, and critical illness. We also provide a summary of the effects of pregnancy on lung diseases and discuss the impact of sex and gender on tobacco use and treatment of nicotine use disorder.