PAH Patients Research Articles

Abstract 4123631: Significance of collagen triple helix repeat-containing protein 1 as a right ventricular biomarker in pulmonary hypertension

Background: Right ventricular failure is a major prognostic determinant of pulmonary hypertension and progresses with myocardial fibrosis. Extracellular matrix proteins play a major role in myocardial fibrosis. Right ventricular biomarkers for right ventricular function and fibrosis are poorly examined in pulmonary hypertension. This study investigated the significance of collagen triple helix repeat-containing protein 1 (CTHRC1), one of the extracellular matrix proteins, as a right ventricular biomarker. Methods and Results: A monocrotaline-induced pulmonary hypertension rat model was used in this study. CTHRC1 expression in the right ventricle was higher in rats with monocrotaline-induced pulmonary hypertension than in controls. CTHRC1 was associated with fibrosis in the rat's right ventricle. Next, human circulating CTHRC1 levels were evaluated in controls (n = 20), pulmonary arterial hypertension (PAH, n = 46), and chronic thromboembolic pulmonary hypertension (CTEPH) patients (n = 64). Human circulating CTHRC1 levels were higher in PAH (P = 0.006) and CTEPH patients (P = 0.011) than in controls (Figure). Human circulating CTHRC levels were correlated with tricuspid lateral annular peak systolic velocity (R = -0.213, P = 0.029), right ventricular fractional area change (R = -0.225, P = 0.017), and right ventricular global longitudinal strain evaluated by magnetic resonance imaging (R = 0.429, P = 0.009). In addition, human circulating CTHRC1 levels were decreased after balloon pulmonary angioplasty (P < 0.001) in CTEPH patients. Conclusions: CTHRC1 could be a novel biomarker associated with right ventricular failure and fibrosis in pulmonary hypertension patients.

Abstract 4115669: Single-cell and Spatial Transcriptomics Identified Fatty Acid-binding Proteins Controlling Endothelial Glycolytic and Arterial Programming in Pulmonary Hypertension

We are seeking to elucidate the endothelial fatty acid metabolism role for obstructive vascular remodeling in the pathogenesis of PAH. In this study, we bred a severe mouse model of PH Egln1 Tie2Cre mice with Fabp45 -/- mice to generate Egln1 Tie2Cre / Fabp45 -/- mice. We applied single-cell RNA sequencing (scRNA-seq) to profile the pulmonary cells in Egln1 Tie2Cre mice and Egln1 Tie2Cre / Fabp45 -/- mice. Human hPAEC from idiopathic PAH patients and healthy donors were used to measure fatty acid-binding protein 4 and 5 (FABP4 and FABP5) expression via sc-RNA seq and spatial transcriptomics. siRNA-mediated knockdown of FABP4 and FABP5 and lentivirus-mediated FABP4 and 5 overexpression were performed to study cell proliferation, apoptosis, and glycolysis. Our scRNA-seq analysis demonstrated that both FABP4 and 5 were highly induced in the ECs of Egln1 Tie2Cre mice. PAECs from IPAH patients also showed higher expression of FABP4 and 5. Knockdown of FABP4-5 reduced EC proliferation, starvation-induced Caspase 3/7 activity, and glycolysis. Overexpression of FABP4-5 promoted EC glycolysis and proliferation. Genetic deletion of Fabp4 and 5 in Egln1 Tie2Cre mice exhibited a reduction of RVSP, RV hypertrophy, and reduction of EC glycolysis gene programming compared to Egln1 Tie2Cre mice. In conclusion, we found that FABP4 and 5 control EC glycolysis and contribute to the development of PAH.

Identification and experimental verification of senescence-related gene signatures and molecular subtypes in idiopathic pulmonary arterial hypertension.

Evidences illustrate that cell senescence contributes to the development of pulmonary arterial hypertension. However, the molecular mechanisms remain unclear. Since there may be different senescence subtypes between PAH patients, consistent senescence-related genes (SRGs) were utilized for consistent clustering by unsupervised clustering methods. Senescence is inextricably linked to the immune system, and the immune cells in each cluster were estimated by ssGSEA. To further screen out more important SRGs, machine learning algorithms were used for identification and their diagnostic value was assessed by ROC curves. The expression of hub genes were verified in vivo and in vitro. Transcriptome analysis was used to assess the effects of silence of hub gene on different pathways. Three senescence molecular subtypes were identified by consensus clustering. Compared with cluster A and B, most immune cells and checkpoint genes were higher in cluster C. Thus, we identified senescence cluster C as the immune subtype. The ROC curves of IGF1, HOXB7, and YWHAZ were remarkable in both datasets. The expression of these genes was increased in vitro. Western blot and immunohistochemical analyses revealed that YWHAZ expression was also increased. Our transcriptome analysis showed autophagy-related genes were significantly elevated after silence of YWHAZ. Our research provided several prospective SRGs and molecular subtypes. Silence of YWHAZ may contribute to the clearance of senescent endothelial cells by activating autophagy.

Association of PH-Targeted Therapy and Survival in Precapillary PH with mPAP between 21 and 24 mmHg

Introduction. Pulmonary hypertension (PH) definition was recently changed and led to a new subset of PH patients with mildly impaired pulmonary hemodynamics, characterized by a mean pulmonary artery pressure of 21–24 mmHg and with a pulmonary vascular resistance >2Wood Units. We evaluated the association of PH-targeted therapy and outcome in mild precapillary PH using the PVRI GoDeep meta-registry.Methods. All patients with mild precapillary PH (mPAP 21–24 mmHg, PAWP ≤15 mmHg, PVR >2WU) diagnosed with PAH and CTEPH were enrolled. Patients were considered treated if PH-targeted therapy was initiated within 6 months of diagnostic right heart catheterization. Various statistical models, including in-depth sensitivity analyses, were used to examine the association between PH-targeted therapy and transplant-free survival.Results. 132 patients with group 1 or group 4 mild PH were identified, of whom 34 patients received PH-targeted therapy. There were no differences in baseline hemodynamics between untreated and treated groups, while treated patients suffered more frequently from renal comorbidities and required long-term oxygen treatment more often. Most prescribed were phosphodiesterase-5-inhibitors. PH-targeted therapy was associated with significantly higher survival rates, compared to those without treatment. Cox-regression analysis revealed significantly reduced hazard ratios among treated patients in Cox-regression analyses adjusted for various confounders. Subgroup analyses in PAH (n=78) similarly indicated higher survival rates and reduced hazard ratios in treated patients.Conclusion. PH-targeted therapy may be associated with improved survival in PAH and CTEPH patients with mild PH. To mitigate potential bias of the results due to the retrospective study design, randomized controlled trials are warranted.

The role of immune cells in the pathogenesis of connective tissue diseases-associated pulmonary arterial hypertension.

Connective tissue diseases-related pulmonary arterial hypertension (CTD-PAH) is a disease characterized by an elevated pulmonary artery pressure that arises as a complication of connective tissue diseases. The number of patients with CTD-PAH accounts for 25.3% of all PAH patients. The main pathological features of CTD-PAH are thickening of intima, media and adventitia of pulmonary arterioles, increased pulmonary vascular resistance, autoimmune activation and inflammatory reaction. It is worth noting that abnormal immune activation will produce autoantibodies and release cytokines, and abnormal immune cell recruitment will promote inflammatory environment and vascular remodeling. Therefore, almost all forms of connective tissue diseases are related to PAH. In addition to general therapy and targeted drug therapy for PAH, high-dose glucocorticoid combined with immunosuppressant can quickly alleviate and stabilize the basic CTD-PAH disease. Given this, the development of therapeutic approaches targeting immune dysregulation and heightened inflammation is recognized as a promising strategy to prevent or reverse the progression of CTD-PAH. This review explores the potential mechanisms by which immune cells contribute to the development of CTD-PAH and examines the clinical application of immunosuppressive therapies in managing CTD-PAH.

Comparative Effectiveness of Sotatercept and Approved Add-On Pulmonary Arterial Hypertension Therapies: A Systematic Review and Network Meta-Analysis.

Background: There are no direct comparisons of sotatercept to add-on therapies approved for pulmonary arterial hypertension (PAH). Objective: This study aimed to compare the efficacy and safety of add-on sotatercept versus other add-on therapies using a network meta-analysis. Data Sources: We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and clinicaltrials.gov until April 15, 2023, for randomized trials involving patients with PAH who were treated with add-on sotatercept or other add-on PAH therapies. Data Extraction: Data extraction and risk-of-bias assessments were performed independently and in duplicate using the Cochrane RoB 2.0 tool. We performed a frequentist random-effects network meta-analysis using the restricted maximum-likelihood estimator and assessed the certainty of evidence using the GRADE (grading of recommendations assessment development, and evaluation) approach. Synthesis: Our search found 18 trials (5,777 patients) eligible for analysis. Sotatercept reduces clinical worsening as compared with placebo (relative risk [RR], 0.21; 95% confidence interval [CI] = 0.11-0.41; with high certainty). Sotatercept probably reduces clinical worsening more, compared with add-on endothelin receptor antagonists (RR, 0.28; 95% CI = 0.14-0.55), inhaled prostanoid (RR, 40.21; 95% CI = 0.07-0.67), and prostanoid taken orally (RR, 0.32; 95% CI = 0.16-0.67; all with moderate certainty). Sotatercept probably improves 6-minute-walk distance compared with placebo (mean difference [MD], 36.89 m; 95% CI = 25.26-48.51). Although sotatercept probably improves 6-minute-walk distance more than add-on endothelin receptor antagonists (MD, 18.38 m; 95% CI = 5.92-30.84) and prostanoid taken orally (MD, 25.66 m; 95% CI = 13.71-37.61), it did not exceed the minimal clinically important difference of 33 m (both with moderate certainty). Conclusions: Sotatercept is an effective add-on therapy for PAH, likely superior to many approved add-on PAH therapies in reducing clinical worsening.

Haemolytic Anaemia-Related Pulmonary Hypertension.

Haemolytic anaemia represents a risk factor for the development of pulmonary hypertension (PH), currently classified as World Health Organization group 5 PH, and data regarding appropriate therapeutic strategy are limited. A total of 28 patients, 85.7% with thalassaemia and 14.3% with sickle cell disease, with a diagnosis of PH confirmed by right heart catheterization were included in the study. The patients were divided into three groups according to the PH haemodynamic definition and overall diagnostic approach: 42.9% had precapillary PH (pulmonary arterial hypertension-PAH group), 25% had post-capillary PH, and 32.1% had chronic thromboembolic PH (CTEPH) (29% of b-thalassemia and 50% of SCD patients). The therapeutic approach in each group and its impact on the outcome and haemodynamics were recorded. PAH-specific drug therapy received 82.1% of patients, and balloon pulmonary angioplasty (BPA) was performed in six patients with CTEPH. There were statistically significant differences in baseline mPAP and PVR values between the CTEPH-haemolytic anaemia group and other groups. PAH-specific drug therapy resulted in haemodynamic improvement for the PAH group. Patients who underwent BPA had improved pulmonary haemodynamics. The median survival time was 162 months, and the survival rate was 1 year-100%; 2, 3, 4, 5, and 6 years-96%; 9 years-90%; and 13 years-78%. In patients with haemolytic anaemia, the wide spectrum of induced PH highlighted the importance of a correct predominant diagnosis. BPA in CTEPH patients and specific-PAH drug therapy for PAH patients represent potential therapeutic strategies; however, the management should be offered in expert PH centres under individualized approaches for patients.

Abstract 147: Monocyte-derived Extracellular Delta-like 4 Contributes To Pulmonary Hypertension Progression By Inhibiting Endothelial Notch1 Activation

Background: We published that reduced Notch1 cleavage in lung endothelial cells (ECs) contributes to pulmonary hypertension (PH) development. However, the underlying mechanism of Notch1 inactivation remains elusive. We recently found enhanced circulating extracellular Delta-like ligand 4 (exDll4) from monocytes in HIV patients, the population with persistent systemic inflammation. Mobilized Notch ligands have demonstrated the ability to inhibit Notch signaling in both in vitro and in vivo studies. Hence, we hypothesize that inflammation increases monocyte-derived exDll4 and diminishes Notch1 cleavage in lung ECs, subsequently promoting the progression of PH. Methods and Results: Tumor necrosis factor-alpha (TNFα) is a major cytokine increase in the plasma of PAH patients and mouse models. Our in vitro studies revealed that TNFα induced a 17.1-fold and 23.6-fold increase of Dll4 mRNA and protein in human monocytes and a 7.2-fold elevation in exDll4 secretion. In PH mouse models induced by chronic hypoxia, Dll4 protein expression in circulating monocytes increased by 4.2 folds, and plasma exDll4 levels rose by 2.6 folds. In PAH patients, serum exDll4 was elevated by 3 folds compared to non-PAH patients. Mimicking enhanced exDll4 in PH patients; we found that exDll4 injection exacerbated PH progression in hypoxia-treated mice, accompanied by inhibited EC-Notch1 cleavage, leaky EC cell-cell junctions, and increased immune cell infiltration in the lungs. Notably, specific knock-out monocyte Dll4 in mice (mDll4 KO mice) significantly attenuated PH progression, indicated by reduced right ventricular systolic pressure and right ventricular remodeling. Mechanistically, exDll4 treatment significantly inhibited Notch1 activation and Notch target gene expression in human pulmonary microvascular ECs (HPMECs) and led to cell apoptosis, cell arrest, impaired barrier function, and enhanced inflammation. Conclusion: Our study demonstrates the role of monocyte-derived exDll4 in PH progression by inducing EC arrest and apoptosis and impairing barrier function in lung ECs through inhibition of Notch1 signaling. These findings imply that monocyte-derived Dll4 could be a potential therapeutic target and biomarker for PH.

"Efficacy and safety of ralinepag, a novel oral IP agonist, in PAH patients on mono or dual background therapy: results from a phase 2 randomised, parallel group, placebo-controlled trial." F. Torres, H. Farber, A. Ristic, et al. Eur Respir J 2019; 54: 1901030.

"Efficacy and safety of ralinepag, a novel oral IP agonist, in PAH patients on mono or dual background therapy: results from a phase 2 randomised, parallel group, placebo-controlled trial." F. Torres, H. Farber, A. Ristic, et al. Eur Respir J 2019; 54: 1901030.

Prognostic value of tricuspid valve regurgitation in patients with pulmonary arterial hypertension and CTEPH: A longitudinal study

AimsThe prognostic value of functional tricuspid valve regurgitation (TR) in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (CTEPH) remains undetermined. This study primarily aims to quantify the prognostic role of TR in relation to right ventricle (RV) dysfunction on clinical outcomes and secondarily the evolution of TR and RV dysfunction over time. MethodsAdult PAH or CTEPH patients diagnosed by right heart catheterization were included. Exclusion criteria were prevalent patients and age < 18 years.The primary endpoint was a composite of death or lung transplantation. Longitudinal evolution of TR and RV dysfunction were modelled with generalized mixed-effect models, which were inserted in a cox model under the joint-modelling framework in order to investigate the association of TR and RV dysfunction with the endpoint. ResultsWe included 76 PAH and 44 CTEPH patients (median age:59, females:62 %), with a mean follow-up of 3.2 ± 2.1 years. 31 patients reached the endpoint (2 transplant, 29 mortality). On average the probability of moderate-to-severe TR decreased during follow-up, whereas the probability of moderate-to-severe RV dysfunction remained stable. The cumulative effect of moderate-to-severe TR (HRper day 1.01 95 %CI[1.00–1.01],P < 0.001) and moderate-to-severe RV dysfunction (HRper day: 1.01 95 %CI[1.00–1.01],P < 0.001) was associated with the endpoint in univariable joint-models. In a multivariable joint-model with both the evolutions of TR and RV dysfunction only TR remained significant (HR per day: 1.01 95 %CI[1.00–1.01],P < 0.001). ConclusionPersistent moderate-to-severe tricuspid valve regurgitation during follow-up predicts adverse outcomes and might be a better predictor of lung transplantation and mortality compared to right ventricle dysfunction.

Up-regulated expression of two-pore domain K+ channels, KCNK1 and KCNK2, is involved in the proliferation and migration of pulmonary arterial smooth muscle cells in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a severe and rare disease in the cardiopulmonary system. Its pathogenesis involves vascular remodeling of the pulmonary artery, which results in progressive increases in pulmonary arterial pressure. Chronically increased pulmonary arterial pressure causes right ventricular hypertrophy and subsequent right heart failure. Pulmonary vascular remodeling is attributed to the excessive proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), which are induced by enhanced Ca2+ signaling following the up-/down-regulation of ion channel expression. In the present study, the functional expression of two-pore domain potassium KCNK channels was investigated in PASMCs from idiopathic PAH (IPAH) patients and experimental pulmonary hypertensive (PH) animals. In IPAH-PASMCs, the expression of KCNK1/TWIK1 and KCNK2/TREK1 channels was up-regulated, whereas that of KCNK3/TASK1 and KCNK6/TWIK2 channels was down-regulated. The similar up-regulated expression of KCNK1 and KCNK2 channels was observed in the pulmonary arterial smooth muscles of monocrotaline-induced PH rats, Sugen 5416/hypoxia-induced PH rats, and hypoxia-induced PH mice. The facilitated proliferation of IPAH-PASMCs was suppressed by the KCNK channel blockers, quinine and tetrapentylammonium. The migration of IPAH-PASMCs was also suppressed by these channel blockers. Furthermore, increases in the proliferation and migration were inhibited by the siRNA knockdown of KCNK1 or KCNK2 channels. The siRNA knockdown also caused membrane depolarization and subsequent decrease in cytosolic [Ca2+]. The phosphorylated level of c-Jun N-terminal kinase (JNK) was elevated in IPAH-PASMCs compared to normal-PASMCs. The increased phosphorylation was significantly reduced by the siRNA knockdown of KCNK1 or KCNK2 channels. Collectively, these findings indicate that the up-regulated expression of KCNK1 and KCNK2 channels facilitates the proliferation and migration of PASMCs via enhanced Ca2+ signaling and JNK signaling pathway, which is associated with vascular remodeling in PAH.

Application of a modified clinical classification for pulmonary arterial hypertension associated with congenital heart disease in children: emphasis on atrial septal defects and transposition of the great arteries. An analysis from the TOPP registry.

A proportion of patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) do not fit in the current classification. We aimed to analyse the applicability of an adapted clinical classification of PAH-CHD to pediatric patients using the TOPP-1 registry (Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension) and focus on atrial septal defects (ASD) and transposition of the great arteries (TGA). Hemodynamic and clinical data of all patients with PAH-CHD in the TOPP cohort were reviewed. Patients were classified according to predefined ABCDE categories (A: Eisenmenger syndrome, B: left-to-right shunt, C: coincidental defects, including all ASDs, D: corrected CHD, E: TGA), or as complex CHD (group 5), by 2 independent investigators. In case of disagreement, a third reviewer could either settle a final decision, or the patient was deemed not classifiable. Survival curves were calculated for each group and compared to idiopathic PAH patients of the registry. A total of 223 out of 531 patients in the registry had PAH-CHD, and 193 were categorized to the following groups: A 39(20%), B 27(14%), C 62(32%) including 43 ASDs, D 58(30%), E 7(4%), whereas 6 patients were categorized as group 5, and 10 patients were unable to be classified. No survival difference could be demonstrated between the groups. This modified classification seems to be more applicable to pediatric PAH-CHD patients than the previous classification, but some patients with PAH-CHD who never had a shunt remain unclassifiable. The role of ASD in pediatric PH should be reconsidered.

A multimodal approach identifies lactate as a central feature of right ventricular failure that is detectable in human plasma.

In PAH metabolic abnormalities in multiple pathways are well-recognized features of right ventricular dysfunction, however, prior work has focused mainly on the use of a single "omic" modality to describe a single deranged pathway. We integrated metabolomic and epigenomic data using transcriptomics in failing and non-failing RVs from a rodent model to provide novel mechanistic insight and translated these findings to accessible human specimens by correlation with plasma from PAH patients. Study was conducted in a doxycycline-inducible BMPR2 mutant mouse model of RV failure. Plasma was collected from controls and PAH patients. Transcriptomic and metabolomic analyses were done on mouse RV tissue and human plasma. For mouse RV, we layered metabolomic and transcriptomic data for multiple metabolic pathways and compared our findings with metabolomic and transcriptomic data obtained for human plasma. We confirmed our key findings in cultured cardiomyocyte cells with BMPR2 mutation. In failing mouse RVs, (1) in the glycolysis pathway, glucose is converted to lactate via aerobic glycolysis, but may also be utilized for glycogen, fatty acid, and nucleic acid synthesis, (2) in the fatty acid pathway, FAs are accumulated in the cytoplasm because the transfer of FAs to mitochondria is reduced, however, the ß-oxidation pathway is likely to be functional. (3) the TCA cycle is altered at multiple checkpoints and accumulates citrate, and the glutaminolysis pathway is not activated. In PAH patients, plasma metabolic and transcriptomic data indicated that unlike in the failing BMPR2 mutant RV, expression of genes and metabolites measured for the glycolysis pathway, FA pathway, TCA cycle, and glutaminolysis pathway were increased. Lactate was the only metabolite that was increased both in RV and circulation. We confirmed using a stable isotope of lactate that cultured cardiomyocytes with mutant BMPR2 show a modest increase in endogenous lactate, suggesting a possibility of an increase in lactate production by cardiomyocytes in failing BMPR2 mutant RV. In the failing RV with mutant BMPR2, lactate is produced by RV cardiomyocytes and may be secreted out, thereby increasing lactate in circulation. Lactate can potentially serve as a marker of RV dysfunction in PAH, which warrants investigation.

Identification of hub genes based on integrated analysis of single-cell and microarray transcriptome in patients with pulmonary arterial hypertension

BackgroundPulmonary arterial hypertension (PAH) is a devastating chronic cardiopulmonary disease without an effective therapeutic approach. The underlying molecular mechanism of PAH remains largely unexplored at single-cell resolution.MethodsSingle-cell RNA sequencing (scRNA-seq) data from the Gene Expression Omnibus (GEO) database (GSE210248) was included and analyzed comprehensively. Additionally, microarray transcriptome data including 15 lung tissue from PAH patients and 11 normal samples (GSE113439) was also obtained. Seurat R package was applied to process scRNA-seq data. Uniform manifold approximation and projection (UMAP) was utilized for dimensionality reduction and cluster identification, and the SingleR package was performed for cell annotation. FindAllMarkers analysis and ClusterProfiler package were applied to identify differentially expressed genes (DEGs) for each cluster in GSE210248 and GSE113439, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) were used for functional enrichment analysis of DEGs. Microenvironment Cell Populations counter (MCP counter) was applied to evaluate the immune cell infiltration. STRING was used to construct a protein-protein interaction (PPI) network of DEGs, followed by hub genes selection through Cytoscape software and Veen Diagram.ResultsNineteen thousand five hundred seventy-six cells from 3 donors and 21,896 cells from 3 PAH patients remained for subsequent analysis after filtration. A total of 42 cell clusters were identified through UMAP and annotated by the SingleR package. 10 cell clusters with the top 10 cell amounts were selected for consequent analysis. Compared with the control group, the proportion of adipocytes and fibroblasts was significantly reduced, while CD8+ T cells and macrophages were notably increased in the PAH group. MCP counter revealed decreased distribution of CD8+ T cells, cytotoxic lymphocytes, and NK cells, as well as increased infiltration of monocytic lineage in PAH lung samples. Among 997 DEGs in GSE113439, module 1 with 68 critical genes was screened out through the MCODE plug-in in Cytoscape software. The top 20 DEGs in each cluster of GSE210248 were filtered out by the Cytohubba plug-in using the MCC method. Eventually, WDR43 and GNL2 were found significantly increased in PAH and identified as the hub genes after overlapping these DEGs from GSE210248 and GSE113439.ConclusionWDR43 and GNL2 might provide novel insight into revealing the new molecular mechanisms and potential therapeutic targets for PAH.

Biventricular intraventricular mechanical and electrical dyssynchrony in pulmonary arterial hypertension

BackgroundPulmonary arterial hypertension (PAH) leads to myocardial remodeling, manifesting as mechanical dyssynchrony (M-dys) and electrical dyssynchrony (E-dys), in both right (RV) and left ventricles (LV). However, the impacts of layer-specific intraventricular M-dys on biventricular functions and its association with E-dys in PAH remain unclear. MethodsSeventy-nine newly diagnosed patients with PAH undergoing cardiac magnetic resonance scanning were consecutively recruited between January 2011 and December 2017. The biventricular volumetric and layer-specific intraventricular M-dys were analyzed. The QRS duration z-scores were calculated after adjusting for age and sex. Results77.22 % of patients were female (mean age 30.30 ± 9.79 years; median follow-up 5.53 years). Further, 29 (36.71 %) patients succumbed to all-cause mortality by the end of the study. At the baseline, LV layer–specific intraventricular M-dys had apparent transmural gradients compared with RV in the radial and circumferential directions. However, deceased patients lost the transmural gradients. The LV longitudinal strain rate time to late diastolic peak in the myocardial region (LVmyoLSRTTLDPintra) predicted long-term survival. The Kaplan–Meier curve revealed that patients with PAH with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. Larger right ventricle (RV) intraventricular M-dys resulted in worse RV ejection fraction. However, larger LV intraventricular M-dys in the late diastolic phase indicated remarkable exercise capacity and higher LV stroke volume index. E-dys and intraventricular M-dys had no direct correlations. ConclusionsThe layer-specific intraventricular M-dys had varying impacts on biventricular functions in PAH. PAH patients with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. LV intraventricular M-dys in the late diastolic phase needs more attention to precisely evaluate LV function.

Pulmonary Hypertension-Associated Right Ventricular Cardiomyocyte Remodelling Reduces Treprostinil Function.

(1) Pulmonary hypertension (PH)-associated right ventricular (RV) failure is linked to a reduction in pulmonary vasodilators. Treprostinil has shown effectiveness in PAH patients with cardiac decompensation, hinting at potential cardiac benefits. We investigated treprostinil's synergy with isoprenaline in RV and LV cardiomyocytes. We hypothesised that disease-related RV structural changes in cardiomyocytes would reduce contractile responses and cAMP/PKA signalling activity. (2) We induced PH in male Sprague Dawley rats using monocrotaline and isolated their ventricular cardiomyocytes. The effect of in vitro treprostinil and isoprenaline stimulation on contraction was assessed. FRET microscopy was used to study PKA activity associated with treprostinil stimulation in AKAR3-NES FRET-based biosensor-expressing cells. (3) RV cells exhibited maladaptive remodelling with hypertrophy, impaired contractility, and calcium transients compared to control and LV cardiomyocytes. Combining treprostinil and isoprenaline failed to enhance inotropy in PH RV cardiomyocytes. PH RV cardiomyocytes displayed an aberrant contractile behaviour, which the combination treatment could not rectify. Finally, we observed decreased PKA activity in treprostinil-treated PH RV cardiomyocytes. (4) PH-associated RV cardiomyocyte remodelling reduced treprostinil sensitivity, inotropic support, and impaired relaxation. Overall, this study highlights the complexity of RV dysfunction in advanced PH and suggests the need for alternative therapeutic strategies.

Evaluation of patients engagement with a digital intervention for daily disease management in pulmonary arterial hypertension

Abstract Introduction Pulmonary arterial hypertension (PAH) is a chronic rare disease with a complex treatment that affects the daily life of patients and requires ongoing monitoring and assessment. In comparison with other chronic diseases, the application of digital health approaches to address patients’ needs in disease self-management has not been comprehensively studied [1], [2]. Within the framework of a clinical study, PAH patients’ engagement level and adherence to using a digital health platform have been studied. The platform allows patients to log health and lifestyle information while also providing structured content for patient education, medication reminders, and lifestyle coaching from a remote HC. Purpose The study aimed to measure the impact of the use of the platform on the Health-Related Quality of Life of the patients (HRQoL) and other clinical endpoints (patient’s functional status, signs and symptoms of PAH, patient costs and healthcare resource utilization) and also to assess patients’ engagement and satisfaction with the use of the platform. Method 53 PAH patients enrolled in a prospective, single cohort, multicentre study [3] from 5 specialized PAH units of reference public Spanish hospitals. The duration of the study was 6 months and to avoid interferences with routine clinical practice, clinical investigation visits matched the clinical guidelines for PAH patients in Spain, which recommend scheduling monitoring visits every 3-6 months. Questionnaires were administered to assess the QoL and satisfaction and for assessing the engagement levels, the app usage data has been analysed. Results Regarding the impact of platform usage for 6 months on the HRQoL and clinical endpoints of PAH patients, no statistically significant changes have been observed. However, as per the engagement, patients showed a great interest in using the app and connecting to the Health Coach (HC). More than 45% of patients finished 2 out of 4 levels of the structured educational content, 96.1% of patients used the activity logging feature. Over 79% of patients visited the app monthly and on average, the app was launched 1500 times per month. The communication between the patients and HC was steady during the study, another indication of adherence to the program. As per user experience, the overall outcomes of the questionnaire showed that 84.2% of patients considered that their needs have been met suggesting that the purpose of the program is well addressed. Additionally, 92.1% of patients were satisfied with the program and would use it again. Moreover, 94.7% of patients expressed that they would recommend the program to a PAH patient. Conclusion Elevated satisfaction and engagement levels of patients demonstrate that the digital intervention is useful for the patients and supports companionship and knowledge. In this context, the development of digital solutions provides opportunities to ensure continuous PAH patient care and patient empowerment.

Efficacy comparison of prostacyclin analogue and prostacyclin receptor agonist as third line treatment for pulmonary arterial hypertension

Abstract Background Pulmonary arterial hypertension (PAH) is a progressive disease characterized by small pulmonary arteries remodeling that leads to increased pulmonary vascular resistance, dyspnea, fatigue, right heart failure and ultimately death. Prostacyclin analogue drugs, such as epoprostenol or treprostinil, have a vasodilator, antiproliferative and immunomodulatory effect, representing established therapies for cases of severe PAH. Both these drugs improve exercise capacity, functional class and hemodynamic parameters, while epoprostenol also improves survival among patients with PAH. Despite these therapeutic benefits, these treatments need parenteral administration. Recently, the approval of selexipag, an oral selective prostacyclin receptor agonist, may represent a possible alternative option in some PAH patients. Methods Patients with PAH treated as third line therapy with epoprostenol, treprostinil or selexipag, on top of inhibitor of type 5 phosphodiesterases and endothelin-1 receptor antagonists, referred to our center from February 1995 to December 2021 were retrospectively included. All patients noninvasive [6 minutes walking distance (6MWD)] and invasive [mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index (CI), right atrial pressure (RAP) and mixed venous oxygen saturation (SvO2)] parameters were first collected at the baseline right heart catheterization (prior to the beginning of prostacyclin treatment) and then 3-4 months after the beginning of third line therapy. The absolute improvements in these parameters were compared with Dunn’s test. Data are expressed as median (interquartile range). Results 153 PAH patients treated as third line therapy with epoprostenol, treprostenil and selexipag were included (44, 73, 36 patients respectively). At 3 to 4 months after the beginning of the third line therapy, absolute improvements in the different parameters are shown in Figure 1. Conclusions In our study population, epoprostenol, treprostenil and selexipag improve both exercise capacity and haemodynamic parameters in PAH patients when used as third line therapy, with the highest efficacy in the first group and, possibly, the lowest efficacy in the latter. These results confirm the beneficial role of these drugs in PAH patients and may suggest a possible favorable role for selexipag in the management of PAH patients with a less severe disease reserving a more invasive treatment strategy with parenteral prostanoids in patients with a higher risk disease.Figure 1

Hemodynamic changes with pulmonary arterial hypertension targeted therapies: a meta-analysis of 3898 treatment-naive patients

Abstract Background Pulmonary arterial hypertension (PAH)-targeted therapies exert significant hemodynamic changes. We aimed to systematically synthesize these effects and explore the pulmonary pressure and flow changes in relation to the resistance changes. Methods We systematically searched PubMed, CENTRAL, and Web of Science for studies evaluating the hemodynamic effects (mean pulmonary artery pressure [mPAP], cardiac index/output [CI/CO], pulmonary vascular resistance [PVR]) of PAH-targeted therapies (comprising endothelin receptor antagonists [ERA], phosphodiesterase type 5 inhibitors [PDE5i], prostanoids [either i.v./s.c. or p.o./inh], riociguat, and selexipag) either in monotherapy or combinations as assessed by right heart catheterization (RHC) in treatment-naïve PAH patients. We performed a random-effects meta-analysis and used meta-regression to evaluate the contribution of mPAP % reduction and CI/CO % increase on the PVR % reduction across different treatment groups. Results We included 68 studies comprising 90 treatment groups and 4276 patients (age 47.3±13.2, 74% women). PVR reduction as a percentage of the pre-treatment value was more pronounced in the oral + prostanoid i.v./s.c. combination therapy (mean difference [MD] -50.0%, 95% confidence interval [CI] -60.8%; -39.2%), compared to oral combination therapy (MD -41.7%, 95% CI -47.6%; -35.8%), prostanoid i.v./s.c. monotherapy (MD -31.8%, 95% CI -37.6%; -25.9%), and oral monotherapy (MD -21.6%, 95% CI -25.4%; -17.8%) (Figure 1). The contribution of mPAP % reduction and of CI/CO % increase to the PVR % reduction was equally significant in all treatment groups (Figure 2). In the oral combination therapy group CI/CO % increase had superior contribution over mPAP % reduction (R2 90% vs R2 0%), but this difference was driven by an outlier study with n = 8 patients and after the exclusion of the outlier, the contribution of mPAP % reduction and of CI/CO % increase to the PVR % reduction was equally significant also in the oral combination group. The same results applied in a sensitivity analysis including only studies with idiopathic/heritable/drugs-induced/connective tissue disease-associated PAH patients. Conclusion Combination therapies, especially with the inclusion of parenteral prostanoids, lead to remarkable hemodynamic improvement in treatment-naïve PAH patients. The contribution of mPAP and CI/CO % changes to the overall PVR % reduction is equally significant.Figure 1Figure 2

Development of KER-012, a modified ActRIIB ligand trap, for the treatment of pulmonary arterial hypertension

Abstract Background Pulmonary Arterial Hypertension (PAH) is a debilitating disorder characterized by elevated pulmonary vascular resistance (PVR) due to severe constriction obliteration of pulmonary vessels (Tielemans 2019). The pathology of PAH is driven by endothelial dysfunction and vascular remodeling that leads to increased wall thickening and resistance to blood flow. Dysregulated TGF-β, specifically SMAD signaling, is a key molecular defect in proliferative thickening of pulmonary arterioles in PAH leading to increased arterial pressure and compensatory right ventricular hypertrophy, ultimately resulting in decompensated right heart failure. Increased levels of activin A, a TGF-β superfamily ligand, have been found in PAH patients, and in the lungs of hypoxia-induced pulmonary hypertensive mice (Yndestad 2009). KER-012 is an investigational modified ActRIIB ligand trap designed to bind and inhibit activin A, activin B, GDF8 and GDF11 to maximally inhibit SMAD2/3 (pro proliferative), while permitting SMAD1/5/9 (anti-proliferative) signaling. This profile is expected to rebalance defective SMAD signaling in PAH and potentially delay or reverse disease progression. Aim To evaluate safety and tolerability of KER-012 in healthy post-menopausal women (PMW) and present the planned design of a Phase 2 trial in participants with PAH. Methods A two-part Phase 1 study has been conducted with KER-012 in healthy PMW. Participants received either placebo or a single dose of KER-012 ranging between 0.75 and 5.0 mg/kg in Part 1 or multiple doses between 0.75 and 4.5 mg/kg in Part 2 subcutaneously once every 4 weeks over a 12-week period. Safety, PK and biomarkers of activin target engagement were assessed. Results KER-012 was generally well tolerated at dose levels up to 5 mg/kg as a single dose and at dose levels up to 4.5 mg/kg administered Q4W for a total of 3 doses (Table 1). Maximal target engagement of KER-012, as demonstrated by changes in biomarkers of activin inhibition, namely follicle stimulating hormone (FSH) and bone specific alkaline phosphatase (BSAP), was observed in this study. As previous studies with activin receptor type II ligand traps have shown a potentially dose-limiting increase in erythropoiesis, changes in red blood cells (RBC) were closely monitored in this study. KER-012 did not elicit any changes in hemoglobin or RBC count in the Phase 1 study (Figure 1). Summary KER-012 was generally well tolerated in healthy participants. The observed biomarker changes are consistent with inhibition of activins, suggestive of a balance shift in favor of signaling via the anti-proliferative SMAD 1/5/9 pathway. Based on this mechanism, administration of KER-012 could potentially result in reverse vascular remodeling and clinical cardiopulmonary improvements in patients with PAH, without targeting erythropoietic pathways. Given this profile, KER-012 is being advanced for development in patients with PAH in an upcoming Ph2 clinical trial (Figure 2).