Pulmonary Arterial Hypertension Therapy Research Articles

The Clinical Course of Portopulmonary Hypertension and Outcomes With Endothelin Receptor Antagonist Treatment: Observational Study of Data From the US Organ Procurement and Transplantation Network

Background. Portopulmonary hypertension (PoPH) occurs in patients with advanced liver disease and can be a contraindication to liver transplant (LT). Improvement of hemodynamic parameters with pulmonary arterial hypertension (PAH) therapies (including endothelin receptor antagonists [ERAs]) may help some patients to become eligible for LT. Methods. We conducted a retrospective secondary data analysis to describe the clinical course and management of PoPH in patients on a US registry LT waitlist and outcomes in patients receiving an ERA. Results. At the time of LT waitlist entry (1996–2019), patient characteristics and disease severity were similar in the 685 patients with PoPH enrolled overall (LT waitlist data set) and the 420 of them who underwent LT (LT data set). Most patients (92.0%) had a model for end-stage liver disease exception granted before entering the LT waitlist. Patients spent a median of 8.9 mo (interquartile range, 3.7–19.7) on the LT waitlist before undergoing LT. Overall, 77.1% of patients received PAH treatment at LT waitlist entry (ERAs, 30.1%). Hemodynamic parameters improved in ≥95% of patients between the first assessment versus the second (median interval, 9 mo) and last assessments (median interval, 14 mo). At the first assessment, 49.6% of patients had mean pulmonary arterial pressure ≥45 mm Hg versus 2.6% and 1.8% of patients at the second and last assessments, respectively; 47.5% of patients had pulmonary vascular resistance >450 dynes·s/cm5 versus 0.9% and 0.2% of patients at the second and last assessments. One-year survival was 90.6% (95% confidence interval [CI], 87.6-92.9) following LT waitlist entry and was 86.4% (95% CI, 82.6-89.5) after LT; 5-y survival was 67.4% (95% CI, 60.0-73.8) while on the LT waitlist (before LT) and was 75.6% (95% CI, 70.4-80.0) following LT. Conclusions. This large US study of patients with PoPH on an LT waitlist confirms that effective PAH treatments can help patients achieve acceptable hemodynamics, providing the opportunity to undergo LT.

A novel interaction between aquaporin 1 and caspase-3 in pulmonary arterial smooth muscle cells.

Pulmonary hypertension (PH) is a condition in which remodeling of the pulmonary vasculature leads to hypertrophy of the muscular vascular wall and extension of muscle into nonmuscular arteries. These pathological changes are predominantly due to the abnormal proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), enhanced cellular functions that have been linked to increases in the cell membrane protein aquaporin 1 (AQP1). However, the mechanisms underlying the increased AQP1 abundance have not been fully elucidated. Here we present data that establishes a novel interaction between AQP1 and the proteolytic enzyme caspase-3. In silico analysis of the AQP1 protein reveals two caspase-3 cleavage sites on its C-terminal tail, proximal to known ubiquitin sites. Using biotin proximity ligase techniques, we establish that AQP1 and caspase-3 interact in both human embryonic kidney (HEK) 293A cells and rat PASMCs. Furthermore, we demonstrate that AQP1 levels increase and decrease with enhanced caspase-3 activity and inhibition, respectively. Ultimately, further work characterizing this interaction could provide the foundation for novel PH therapeutics.NEW & NOTEWORTHY Pulmonary arterial smooth muscle cells (PASMCs) are integral to pulmonary vascular remodeling, a characteristic of pulmonary arterial hypertension (PAH). PASMCs isolated from robust animal models of disease demonstrate enhanced proliferation and migration, pathological functions associated with increased abundance of the membrane protein aquaporin 1 (AQP1). We present evidence of a novel interaction between the proteolytic enzyme caspase-3 and AQP1, which may control AQP1 abundance. These data suggest a potential new target for novel PAH therapies.

Long-term safety and tolerability of ambrisentan treatment for pediatric patients with pulmonary arterial hypertension: An open-label extension study

This open-label, extension study assessed long-term safety, tolerability, and efficacy of ambrisentan in a pediatric population (age 8– < 18 years) with pulmonary arterial hypertension (PAH). Following completion of a 6-month, randomized study, participants entered the long-term extension at individualized ambrisentan dosages (2.5/5/7.5 or 10 mg/day). Safety assessments included adverse events (AEs), AEs of special interest, and serious AEs (SAEs); efficacy outcomes included 6-min walking distance (6MWD) and World Health Organization functional class (WHO FC). Thirty-eight of 41 (93%) randomized study participants entered the extension; 21 (55%) completed (reaching age 18 years). Most participants received concomitant phosphodiesterase-5 inhibitors (n = 25/38, 66%). Median ambrisentan exposure was 3.5 years. Most participants experienced ≥ 1 AE (n = 34/38, 89%), and 21 (55%) experienced SAEs, most commonly worsening PAH (n = 3/38, 8%), acute cardiac failure, pneumonia, or anemia (n = 2/38; 5% each); none considered ambrisentan-related. Seven participants (18%) died, with recorded reasons (MedDRA preferred term): cardiac failure (n = 2), PAH (n = 2), COVID-19 (n = 1), acute right ventricular failure (n = 1), and failure to thrive (n = 1); median time to death: 5.2 years. Anemia and hepatotoxicity AEs were generally mild to moderate and did not require ambrisentan dose adjustment. Assessed at study end in 29 participants (76%), mean 6MWD improved by 17% (standard deviation: 34.3%), and all (29/29, 100%) had improved or unchanged WHO FC. Conclusion: Long-term weight-based ambrisentan dosing, alone or combined with other PAH therapies in children with PAH aged 8– < 18 years, exhibited tolerability and clinical improvements consistent with prior randomized study results. Trial registration: NCT01342952, April 27, 2011.What is Known:•The endothelin receptor antagonist, ambrisentan, is indicated for treatment of pulmonary arterial hypertension (PAH). Previous studies have shown similar efficacy and tolerability in pediatric patients as in adults.What is New:• This open-label extension study assessed the long-term use of ambrisentan in pediatric patients (8–<18 years) with PAH, most of whom were also receiving recommended background PAH treatment. • Weight-based dosing of ambrisentan, given alone or in combination with other PAH therapies, was well tolerated with clinical improvements consistent with prior randomized study results.

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

BackgroundFemale 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. MethodsAll 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. ResultsAmong the 1,891 patients included, 75% were female. Compared to men, women had less favorable hemodynamics, lower six-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. ConclusionsIn 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.

Triple vasodilator therapy in pulmonary arterial hypertension associated with congenital heart disease

ObjectiveThis study assessed the long-term effects of triple therapy with prostanoids on patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD), as there is limited information on the...

Hydroxy-Safflower Yellow A Mitigates Vascular Remodeling in Rat Pulmonary Arterial Hypertension.

The underlying causes of pulmonary arterial hypertension (PAH) often remain obscure. Addressing PAH with effective treatments presents a formidable challenge. Studies have shown that Hydroxysafflor yellow A (HSYA) has a potential role in PAH, While the mechanism underlies its protective role is still unclear. The study was conducted to investigate the potential mechanisms of the protective effects of HSYA. Using databases such as PharmMapper and GeneCards, we identified active components of HSYA and associated PAH targets, pinpointed intersecting genes, and constructed a protein-protein interaction (PPI) network. Core targets were singled out using Cytoscape for the development of a model illustrating drug-component-target-disease interactions. Intersection targets underwent analysis for Gene Ontology (GO) functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Selected components were then modeled for target interaction using Autodock and Pymol. In vivo validation in a monocrotaline-induced PAH (MCT-PAH) animal model was utilized to substantiate the predictions made by network pharmacology. We associated HSYA with 113 targets, and PAH with 1737 targets, identifying 34 mutual targets for treatment by HSYA. HSYA predominantly affects 9 core targets. Molecular docking unveiled hydrogen bond interactions between HSYA and several PAH-related proteins such as ANXA5, EGFR, SRC, PPARG, PGR, and ESR1. Utilizing network pharmacology and molecular docking approaches, we investigated potential targets and relevant human disease pathways implicating HSYA in PAH therapy, such as the chemical carcinogenesis receptor activation pathway and the cancer pathway. Our findings were corroborated by the efficacious use of HSYA in an MCT-induced rat PAH model, confirming its therapeutic potential.

Pulmonary hypertension associated with congenital portosystemic shunts as a new form of portopulmonary hypertension in children and adults

Pulmonary arterial hypertension (PAH) associated with portal hypertension, or portopulmonary hypertension, is a severe, life-threatening complication of portal hypertension and/or portocaval shunt surgery. Congenital portocaval shunts (CPSSs) are rare vascular anomalies of the portal system, leading to severe pathophysiological reactions and multisystem damage, including PAH, liver nodules, cognitive, metabolic, immune, hematological and hormonal disorders. Severe cardiopulmonary complications are detected in more than a third of patients with CPSSs, which is the main cause of their death. The article describes the pathophysiology, clinical characteristics, diagnostic features and possibilities of modern targeted therapy for CPSS-associated PAH. Patients with CPSS-associated PAH require comprehensive specialized care in an expert center. For long-term successful management of patients, continuous targeted therapy for PAH, in combination with surgical treatment of CPSSs, is crucial.

Pulmonary arterial hypertension associated with type II Abernethy malformation in an adolescent: a case report

The article provides a case of pulmonary arterial hypertension (PAH) associated with congenital extrahepatic portocaval shunt (CEPS), or Abernethy malformation, in a 17-year-old female patient. CEPS, which remained undiagnosed for a long time, manifested with severe encephalopathy at an early age. By the age of 6 years, it was complicated by PAH, and by the age of 9 years — by hepatic focal nodular hyperplasia. In the absence of timely surgical treatment and adequate therapy of CEPS, PAH progressed. Combined dual therapy for PAH, prescribed only at age 14, was ineffective. Despite the potential for clinical and functional improvement documented with combination triple therapy at 17 years of age, the patient continued to meet criteria for a high risk of adverse events, including mortality. Two months after the initiation of triple therapy for PAH, not achieving the target hemodynamic characteristics that would reduce operative and perioperative risks lead to an attempt of surgical treatment of CEPS, which led to the patient death in the early postoperative period. The description of this case report shows the difficulties of diagnosing a rare form of portopulmonary hypertension, the modern possibilities of drug therapy for a severe, potentially curable PAH in the early stages.

An overview of treatment for atrial septal defect with pulmonary hypertension

Background: Atrial Septal Defect (ASD) is a congenital heart defect which can be the cause of comorbidities in the form of Pulmonary Arterial Hypertension (PAH) and therapy cannot be done simply by correcting the ASD but requires further study and evaluation.Purpose: Describe the treatment given to patients with ASD and PAH and the correlation between the administration of interventional therapy and the patient's probability of PH.Method: This study is a descriptive quantitative using a cross-sectional research design. The sampling technique was total sampling method. The samples were 41 ASD patients with PAH at Prof. Ngoerah General Hospital in Denpasar in 2022. Patients under 18 years of age and those with other congenital heart disease will be excluded. The demographic characteristics assessed were the patient's age and gender. The therapy data included information on medical therapy and intervention therapy.Results: Focus of medical therapy was supportive therapy rather than specific PAH therapy. Percutaneous ASD closure was the most widely-used intervention therapy compared to surgical ASD closure. Based on statistical analysis, the p value &gt; 0.05 is 0.284, so there is no significant correlation between the probability of the patient's pH and the provision of intervention therapy.Conclusion: At Prof Ngoerah General Hospital Denpasar, the majority of ASD patients with complications of pulmonary hypertension were females aged between 21 to 30 years. The medical therapy given is adjusted based on the severity of PH as assessed through echocardiography examination. Majority of patients received supportive therapy compared to specific therapy for PAH. Medical therapy is prioritized for patients who have contraindication criteria for interventional therapy. Percutaneous ASD Closure was found to be the largest percentage in interventional therapy regardless of the severity, except for patients who were indicated to undergo surgical ASD closure. There is no significant relationship between the patient's PH probability level and the choice of intervention therapy.

Pulmonary hypertension and insulin resistance: a mechanistic overview.

Pulmonary arterial hypertension (PAH) is a vascular remodeling disease, characterized by increased blood pressure levels in pulmonary circulation, leading to a restriction in the circulation flow and heart failure. Although the emergence of new PAH therapies has increased survival rates, this disease still has a high mortality and patients that receive diagnosis die within a few years. The pathogenesis of PAH involves multiple pathways, with a complex interaction of local and distant cytokines, hormones, growth factors, and transcription factors, leading to an inflammation that changes the vascular anatomy in PAH patients. These abnormalities involve more than just the lungs, but also other organs, and between these affected organs there are different metabolic dysfunctions implied. Recently, several publications demonstrated in PAH patients a disturbance in glucose metabolism, demonstrated by higher levels of glucose, insulin, and lipids in those patients. It is possible that a common molecular mechanism can have a significant role in this connection. In this regard, this narrative review intends to focus on the recent papers that mainly discuss the molecular determinants between insulin resistance (IR) associated PAH, which included obesity subclinical inflammation induced IR, PPAR gamma and Adiponectin, BMPR2, mitochondrial dysfunction and endoplasmic reticulum stress. Therefore, the following review will summarize some of the existing data for IR associated PAH, focusing on the better understanding of PAH molecular mechanisms, for the development of new translational therapies.

Actigraphy methodology in the Kids Mod PAH trial: Physical activity as a functional endpoint in pediatric clinical trials.

Pulmonary vasodilator treatment can improve hemodynamics, right ventricular function, symptoms, and survival in pediatric pulmonary hypertension (PH). However, clinical trial data are lacking due to many constraints. One major limitation is the lack of relevant trial endpoints reflective of hemodynamics or functional status in patients in whom standard exercise testing is impractical, unreliable, or not reproducible. The Kids Mod PAH trial (Mono- vs. Duo Therapy for Pediatric Pulmonary Arterial Hypertension) is an ongoing multicenter, Phase III, randomized, open-label, pragmatic trial to compare the safety and efficacy of first-line combination therapy (sildenafil and bosentan) to first-line monotherapy (sildenafil alone) in 100 pediatric patients with PH across North America. Investigators will measure participants' physical activity with a research-grade, wrist-worn actigraphy device at multiple time points as an exploratory secondary outcome. Vector magnitude counts per minute and activity intensity will be compared between the treatment arms. By directly and noninvasively measuring physical activity in the ambulatory setting, we aim to identify a novel, simple, inexpensive, and highly reproducible approach for quantitative assessment of exercise tolerance in pediatric PH. These data will increase the field's understanding of the effect of pulmonary vasodilator treatment on daily activity - a quantitative measure of functional status and wellbeing in pediatric PH and a potential primary outcome for future clinical trials in children with cardiopulmonary disorders.

Hemodynamic response to inhaled nitric oxide in patients with pulmonary hypertension and chronic kidney disease: A retrospective cohort study.

Pulmonary hypertension (PH) associated with chronic kidney disease (CKD) (PH-CKD) affects approximately 20%-40% of CKD patients and is associated with increased morbidity and mortality. PH and CKD are both pathophysiologically associated with nitric oxide (NO) deficiency. The NO pathway, an important therapeutic domain in pulmonary arterial hypertension (PAH), is an intriguing but unexplored target in PH-CKD. We sought to improve understanding of the clinical significance of the NO pathway in patients with PH-CKD by assessing the hemodynamic response to inhaled NO (iNO) during right heart catheterization (RHC). In this retrospective cohort study, patients with diagnosis codes of PH and stage IV/V CKD or end-stage renal disease and estimated glomerular filtration rate < 60 mL/min/body surface areawho underwent RHC and hemodynamic drug study between July 2011 and June 2021 were eligible. Patients with mean pulmonary artery pressure (mPAP) > 20 mmHg and pulmonary vascular resistance (PVR) > 3Wood unitswere included. The final cohort included 37 patients (45.9% female, mean age 72.5 ± 9.7 years). A total of 56.7%of the cohort (21/37) had precapillary PH, while 43.2% (16/37) had combined precapillary postcapillary PH (Cpc-PH). Median survival was 3.1 years after RHC. iNO was associated with a significant decrease in both mPAP and PVR. Hemodynamic changes in mPAP and PVR were similar in precapillary and Cpc-PH groups. Among a small subset (n = 14) who were subsequently treated with PAH-targeted therapy, treatment response was mixed and did not reveal significant benefit. Further studies are warranted to better define the potential role of PAH therapy in PH-CKD.

Use of the National Cancer Institute Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events to assess treatment tolerability in pulmonary arterial hypertension: qualitative patient research findings in current and former users of oral selexipag

BackgroundUnderstanding patients’ perspectives regarding drug tolerability, in addition to effectiveness, provides a complete picture of the patient experience and supports more informed therapeutic decision-making. The item library of the National Cancer Institute’s Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) was developed to measure patient-reported frequency, severity, and interference of adverse events (AEs) associated with cancer therapies. This qualitative interview study assessed the suitability of items selected from the PRO-CTCAE library for assessing tolerability of selexipag, a medication targeting the prostacyclin pathway for patients with pulmonary arterial hypertension (PAH).MethodsTwo rounds of 10 qualitative, web-assisted telephone interviews following a semi-structured guide were conducted in individuals with recent experience taking oral selexipag for PAH. Each interview included concept elicitation to gather participants’ perspectives on symptomatic AEs (type, frequency, severity, and interference) and cognitive debriefing of PRO-CTCAE items addressing the most frequently reported AEs of oral selexipag.ResultsInterviews were conducted with 20 participants with PAH (mean [range] age 50 [24–68] years; 75% female; 85% in World Health Organization Functional Class II–III), comprising different races/ethnicities, levels of education, and employment status. Fifteen participants were currently treated with selexipag; five had taken selexipag for ≥ 6 months before discontinuing. The most frequently reported AEs included headache, jaw pain, and nausea (n = 15, 12, and 10 participants, respectively). Diarrhea and headache were identified as the most bothersome AEs by 5 and 4 participants, respectively. Some AEs were transitory (e.g., jaw pain); others were long-lasting (e.g., muscle pain). Based on findings from Round 1 interviews, a flushing item was added and the PRO-CTCAE general pain item was modified to be specific to jaw pain for testing in Round 2. Interview findings identified the following AEs as relevant to assess in a PAH clinical trial: nausea, vomiting, diarrhea, flushing, jaw pain, headache, aching muscles, and aching joints.ConclusionsThe PRO-CTCAE items selected in this study and the additional symptomatic AEs identified as patient-relevant have the potential to be included in assessments capturing the patient perspective on tolerability in future studies of selexipag and possibly other PAH therapies.

Hub gene ELK3-mediated reprogramming lipid metabolism regulates phenotypic switching of pulmonary artery smooth muscle cells to develop pulmonary arterial hypertension induced by PM2.5

Fine particulate matter (PM2.5) as an environmental pollutant is related with respiratory and cardiovascular diseases. Pulmonary arterial hypertension (PAH) was characterized by incremental pulmonary artery pressure and pulmonary arterial remodeling, leading to right ventricular hypertrophy, and finally cardiac failure and death. The adverse effects on pulmonary artery and the molecular biological mechanism underlying PM2.5-caused PAH has not been elaborated clearly. In the current study, the ambient PM2.5 exposure mice model along with HPASMCs models were established. Based on bioinformatic methods and machine learning algorithms, the hub genes in PAH were screened and then adverse effects on pulmonary artery and potential mechanism was studied. Our results showed that chronic PM2.5 exposure contributed to increased pulmonary artery pressure, pulmonary arterial remodeling and right ventricular hypertrophy in mice. In vitro, PM2.5 induced phenotypic switching in HPASMCs, which served as the early stage of PAH. In mechanism, we investigated that PM2.5-mediated mitochondrial dysfunction could induce phenotypic switching in HPASMCs, which was possibly through reprogramming lipid metabolism. Next, we used machine learning algorithm to identify ELK3 as potential hub gene for mitochondrial fission. Besides, the effect of DNA methylation on ELK3 was further detected in HPASMCs after PM2.5 exposure. The results provided novel directions for protection of pulmonary vasculature injury, against adverse environmental stimuli. This work also provided a new idea for the prevention of PAH, as well as provided experimental evidence for the targeted therapy of PAH.

Dissecting molecular mechanisms underlying ferroptosis in human umbilical cord mesenchymal stem cells: Role of cystathionine γ-lyase/hydrogen sulfide pathway.

Ferroptosis can induce low retention and engraftment after mesenchymal stem cell (MSC) delivery, which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension (PAH) therapy. Interestingly, the cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway may contribute to mediating ferroptosis. However, the influence of the CSE/H2S pathway on ferroptosis in human umbilical cord MSCs (HUCMSCs) remains unclear. To clarify whether the effect of HUCMSCs on vascular remodelling in PAH mice is affected by CSE/H2S pathway-mediated ferroptosis, and to investigate the functions of the CSE/H2S pathway in ferroptosis in HUCMSCs and the underlying mechanisms. Erastin and ferrostatin-1 (Fer-1) were used to induce and inhibit ferroptosis, respectively. HUCMSCs were transfected with a vector to overexpress or inhibit expression of CSE. A PAH mouse model was established using 4-wk-old male BALB/c nude mice under hypoxic conditions, and pulmonary pressure and vascular remodelling were measured. The survival of HUCMSCs after delivery was observed by in vivo bioluminescence imaging. Cell viability, iron accumulation, reactive oxygen species production, cystine uptake, and lipid peroxidation in HUCMSCs were tested. Ferroptosis-related proteins and S-sulfhydrated Kelch-like ECH-associating protein 1 (Keap1) were detected by western blot analysis. In vivo, CSE overexpression improved cell survival after erastin-treated HUCMSC delivery in mice with hypoxia-induced PAH. In vitro, CSE overexpression improved H2S production and ferroptosis-related indexes, such as cell viability, iron level, reactive oxygen species production, cystine uptake, lipid peroxidation, mitochondrial membrane density, and ferroptosis-related protein expression, in erastin-treated HUCMSCs. In contrast, in vivo, CSE inhibition decreased cell survival after Fer-1-treated HUCMSC delivery and aggravated vascular remodelling in PAH mice. In vitro, CSE inhibition decreased H2S levels and restored ferroptosis in Fer-1-treated HUCMSCs. Interestingly, upregulation of the CSE/H2S pathway induced Keap1 S-sulfhydration, which contributed to the inhibition of ferroptosis. Regulation of the CSE/H2S pathway in HUCMSCs contributes to the inhibition of ferroptosis and improves the suppressive effect on vascular remodelling in mice with hypoxia-induced PAH. Moreover, the protective effect of the CSE/H2S pathway against ferroptosis in HUCMSCs is mediated via S-sulfhydrated Keap1/nuclear factor erythroid 2-related factor 2 signalling. The present study may provide a novel therapeutic avenue for improving the protective capacity of transplanted MSCs in PAH.

ERS International Congress 2023: highlights from the Pulmonary Vascular Diseases Assembly.

Pulmonary vascular diseases such as pulmonary embolism and pulmonary hypertension are important and frequently under-recognised conditions. This article provides an overview of key highlights in pulmonary vascular diseases from the European Respiratory Society International Congress 2023. This includes insights into disease modification in pulmonary arterial hypertension and novel therapies such as sotatercept and seralutinib. Exciting developments in our understanding of the mechanisms underpinning pulmonary hypertension associated with interstitial lung disease are also explored. A comprehensive overview of the complex relationship between acute pulmonary embolism and chronic thromboembolic pulmonary hypertension (CTEPH) is provided along with our current understanding of the molecular determinants of CTEPH. The importance of multidisciplinary and holistic care cannot be understated, and this article also addresses advances beyond medication, with a special focus on exercise training and rehabilitation.

Impact of Left Heart Disease Risk Factors on Outcomes in Pulmonary Arterial Hypertension Therapy

BackgroundCurrent guidelines recommend initial monotherapy for pulmonary arterial hypertension (PAH) with ‘cardiopulmonary comorbidities’, despite limited available evidence to guide management. Research QuestionDo left heart disease (LHD) risk factors have an impact on treatment response and influence applicability of risk assessment in a real-world cohort of PAH patients? Study Design and MethodsThe AMBITION trial criteria was used to define the phenotype of PAH patients with risk factors for LHD. Treatment strategy, functional outcome, long term survival and risk discrimination were compared with a reference PAH cohort using the PHSANZ registry. Results487 incident PAH patients diagnosed between 2011-2020 were included. Of these, 103 (21.1%) fulfilled the definition of PAH with LHD risk factors with 384 (78.9%) remaining as reference group. PAH with LHD risk factors were older (66±13 vs. 58±19years, p<0.001), had lower pulmonary vascular resistance (393±266 vs 708±391dynes/sec/cm-5, p=0.031) and worse 6-minute walk distance (286±130 vs. 327±136m, p=0.005) at diagnosis. PAH with LHD risk factors were less likely to receive less initial combination therapy (27% vs. 44%, p=0.02). Changes in 6-minute walk distance at 12-months were similar in both groups, 43±77 in PAH with LHD risk factors and 50±90m in reference group (p=0.5), including when stratified by initial treatment strategy (monotherapy: 40±81 vs. 38±95m p=0.87 and combination therapy: 53±78 vs. 64±106m, p=0.511; PAH with LHD risk factors vs. reference PAH). Functional class improvements were also similar in both groups. REVEAL 2.0 risk score effectively discriminated risk in both populations (C-statistic=0.756 for PAH with LHD risk factors and C-statistic=0.750 for reference PAH). There was no difference in survival between the two groups (log-rank test p=0.29). InterpretationIn a real-word cohort, PAH patients with LHD risk factors were less likely to be exposed to initial combination therapy. Nevertheless, selected PAH patients with LHD risk factors who were treated with initial combination therapy derived similar functional response compared to reference group. Further studies are needed to phenotype PAH patients with cardiopulmonary comorbidities who may benefit from initial combination therapy.

Evaluating the safety and long-term efficacy of triple vasodilator therapy for pulmonary arterial hypertension associated with congenital heart disease

Abstract Background Pulmonary arterial hypertension (PAH) affects 5-10% of congenital heart disease (CHD) patients, but there is limited information on the safety and efficacy of triple combination therapy for PAH-CHD. The aim of this study was to assess the long-term effects of triple therapy (TT) with prostacyclins on PAH-CHD patients. Methods A retrospective, longitudinal, cohort study of patients with PAH-CHD under active follow-up in our center. All patients were receiving baseline dual therapy at maximum doses. Clinical characteristics, including functional class (FC), 6-minute walk test distance (6MWTd), and NT-ProBNP were recorded before initiating TT and during annual follow-ups during 2 years. Results 60 patients were included (median age 41, 31 women 61%). 32 had Eisenmenger syndrome, 9 had coincidental shunts, 18 had postoperative PAH, and 1 had a significant L-R shunt. TT was initiated based on the clinical situation, existence of shunt and ease of administration (epoprostenol 20%, treprostinil 41%, selexipag 32%, iloprost 7%). A significant improvement in the 6MWTd was observed one year after the initiation of TT (p&amp;lt;0.05), which was maintained at two-year follow-up, with an average improvement of 44 metres. An improvement of FC was observed in 79% of patients at one year, maintained at 2 years in 76%. A NT- proBNP levels decreased from the start, and reached significancy two years after the initiation of TT, with an average decrease of 199 ng/l (Figure 1). Twenty patients (33.3%) experienced side effects after drug initiation. Most were mild and well-controlled with symptomatic treatment. Only 3 (5%) had to change the administration route (Figure 2). By subgroups, patients without Eisenmenger and with pre-tricuspid defects had a more marked benefit. Conclusions TT has been shown to be safe and effective in patients with PAH-CHD, improving FC, 6MWTd, and NT-proBNP levels, particularly in pre-tricuspid defects and non-Eisenmenger PAH-CHD.Changes after initiation of TTType of treatment and side-effects

Triple therapy for incident pulmonary arterial hypertension in Finland between 2008 and 2020. A descriptive real-world FINPAH cohort study

Abstract Background Treatment of pulmonary arterial hypertension (PAH) with triple therapy (TriT) including phosphodiesterase type-5 inhibitors (PDE5), endothelin receptor antagonists (ERA), and prostacyclin receptor agonists (PRA) or analogues (PCA) is indicated in severe PAH. There is evidence of benefit also in intermediate-risk patients. Purpose To describe the real-world use of TriT in a contemporary cohort of Finnish PAH patients. Methods Data was collected via chart review by treating clinicians. Pulmonary hypertension (PH) patients were diagnosed between 2008–19 at the five Finnish university hospitals. Patient characteristics and clinical information were combined with mortality data from Statistics Finland. Persistence and survival were estimated using Kaplan-Meier. Results Out of 493 incident PH patients with medication history available, TriT was recorded for 41 (8%), with a median follow-up of 5.86 years (IQR: 4.12-8.72). TriT patients were predominantly women (73%), mean age 55 years (IQR 46–69) at diagnosis. 35 patients (85%) had PAH (37% iPAH, 27% PAH associated with connective tissue disease and 22% other PAH subclasses), and 6 patients (15%) had other PH types, mostly CTEPH. TriT was started at a median of 2.15 years (IQR: 0.65-3.64) after diagnosis. At the initiation of TriT, 7 patients (17%) had NYHA functional class (FC) IV, 21 (51%) had FC III, 8 (20%) had FC II. Median six-minute walking distance (6MWD) was 360 m (IQR 245-435 m, N=33). Median BNP was 328 pg/mL (IQR 190-723, N=10), and median NT-proBNP was 1082 pg/mL (IQR 745-3420, N=31). Fewer than 3 patients (&amp;lt;7%) were at ESC/ERS 2015 high risk. Initial PRA or PCA in TriT was iloprost (n=21, 51%), selexipag (n=12, 29%), or treprostinil (n=8, 20%). Initial ERA in TriT was macitentan (n=20, 49%), bosentan (n=11, 27%), or ambrisentan (n=10, 24%). Initial PDE5 was sildenafil (n=36, 88%) or tadalafil (n=5, 12%). Estimated persistence with TriT was 88% at 1 year and 84% at 5 years. Selexipag and iloprost were discontinued in &amp;lt;3 (&amp;lt;25% of users) and in 12 (57% of users), respectively, and 10 patients (24%) were switched to treprostinil. 6 TriT patients were listed for lung transplant after start of TriT, and 4 received a lung transplant. Six months after start of TriT, 4 patients (10%) had died and 5 (12%) had discontinued TriT. For the patients with 6 months of recorded TriT use (N=31), NT-proBNP changed by median -184 pg/mL (IQR -689 to +165, N=24), and 6MWD changed by median +20 m (IQR -3 to +35, N=22). In 8 patients (30%) FC improved within 6 months of TriT, was stable in 15 patients (56%) and worsened in 4 patients (15%). After 6 months of TriT, no patient was at high risk. Estimated overall survival was 90% (95%-CI 82-100%) at 6 months and 1 year after start of TriT. Estimated 5-year survival was 52% (95%-CI 38-72%). Conclusion(s) The study shows infrequent use but high persistence of TriT in Finnish PAH patients. TriT patients remained generally stable while on TriT.

Abstract 13431: Safety and Efficacy of Pulmonary Artery Denervation Therapy for the Treatment of Pulmonary Artery Hypertension

Background: Despite recent advances in the treatment of pulmonary arterial hypertension (PAH), the survival rate remains poor in severe PAH. Pulmonary artery denervation (PADN) therapy for PAH is gaining popularity, although the safety and efficacy of PADN were not fully evaluated. Therefore, we conducted an updated systematic review and meta-analysis of the safety and efficacy of PADN in the treatment of patients with PAH. Methods: Using PRISMA guidelines, we searched PubMed, Embase, Cochrane, and the Clinical Trials.gov databases from inception till May 2023 for placebo-controlled outcome studies that compared PADN therapy to placebo in patients with moderate-severe PAH. The literature was screened for appropriate randomized clinical trials (RCT) and prospective studies, and data were extracted and analyzed. Comprehensive meta-analysis software (CMA v3, Biostat Inc. Englewood, NJ, USA) was utilized to perform statistical analyses. Results: The metanalysis included 8 studies (7 RCTs and 1 prospective) with 577 patients (PADN group = 270, placebo = 307). PADN treatment was associated with a significant reduction in mean pulmonary artery pressure [weighted mean difference (WMD) = -6.9 mmHg; 95% CI = -9.7, -4.1; P &lt; 0.01; I 2 = 61] and pulmonary vascular resistance [WMD = -3.2 dyne.s.cm -5 ; 95% CI = -5.4, -0.9; P = 0.005; I 2 = 95]. There was a statistically significant improvement in the cardiac output [WMD = 0.3 l/min; 95% CI = 0.07, 0.6; P=0.012; I 2 = 76] and numerical improvement in 6-minute walking distance [WMD = 67.7m; 95% CI = -3.73, 139.2; P = 0.06; I 2 = 95] in the PADN group. There were fewer side effects in the PADN group as compared to the placebo group. Conclusion: This updated metanalysis supports PADN as a safe and efficacious therapy for moderate-severe PAH. Findings are limited by small sample size, medium-quality literature, and large data heterogeneity, necessitating larger RCT with clinical endpoints comparing PADN therapy with optimal medical treatment.