Mendelian randomization study on causal association of TEF and circadian rhythm with pulmonary arterial hypertension.

BACKGROUND: Previous research has revealed the potential impact of circadian rhythms on pulmonary diseases; however, the connection between circadian rhythm-associated Thyrotroph Embryonic Factor (TEF) and Pulmonary Arterial Hypertension (PAH) remains unclear. We aim to assess the genetic causal relationship between TEF and PAH by utilizing two sets of genetic instrumental variables (IV) and publicly available Pulmonary Arterial Hypertension Genome-Wide Association Studies (GWAS). METHODS: Total of 23 independent TEF genetic IVs from recent MR reports and PAH GWAS including 162,962 European individuals were used to perform this two-sample MR study. Gain- and loss-of-function experiments were used to demonstrate the role of TEF in PAH. RESULTS: Our analysis revealed that as TEF levels increased genetically, there was a corresponding increase in the risk of PAH, as evidenced by IVW (OR = 1.233, 95% CI: 1.054-1.441; P = 0.00871) and weighted median (OR = 1.292, 95% CI for OR: 1.064-1.568; P = 0.00964) methods. Additionally, the up-regulation of TEF expression was associated with a significantly higher likelihood of abnormal circadian rhythm (IVW: P = 0.0024733, ß = 0.05239). However, we did not observe a significant positive correlation between circadian rhythm and PAH (IVW: P = 0.3454942, ß = 1.4980398). In addition, our in vitro experiments demonstrated that TEF is significantly overexpressed in pulmonary artery smooth muscle cells (PASMCs). And overexpression of TEF promotes PASMC viability and migratory capacity, as well as upregulates the levels of inflammatory cytokines. CONCLUSION: Our analysis suggests a causal relationship between genetically increased TEF levels and an elevated risk of both PAH and abnormal circadian rhythm. Consequently, higher TEF levels may represent a risk factor for individuals with PAH.

Circulating High Mobility Group Box-1 Does Not Predict Pulmonary Arterial Hypertension in Children with Congenital Heart Disease: A Prospective Cohort Study.

OBJECTIVES: Pulmonary arterial hypertension (PAH) is a devastating complication of pediatric congenital heart disease (CHD). A recent study has identified the protein high mobility group box-1 (HMGB1) as a diagnostic tool in adults with CHD-associated PAH. HMGB1 levels in adults with CHD-associated PAH correlated with mean pulmonary artery pressure and pulmonary vascular resistance, and HGMB1 levels fell in response to sildenafil therapy. We wanted to assess if HGMB1 was a biomarker of pediatric CHD-PAH. DESIGN: Prospective cohort study. SETTING: Quaternary pediatric academic hospital PARTICIPANTS: Children ≤18 years with CHD with and without known pulmonary hypertension. Controls were children undergoing dental or urologic surgery with no known heart disease. INTERVENTIONS: Pulmonary hemodynamics, echocardiographic assessment, and biomarker measurement. Controls had biomarker measurement only. MEASUREMENTS AND MAIN RESULTS: Patients with CHD-PAH had mean pulmonary vascular resistance index of 10 Wood units/m2. Neither HGMB1 nor N-terminal pro-brain-type natriuretic peptide levels were significantly different between the groups. Neither marker correlated with pulmonary hypertension. CONCLUSIONS: Unlike in adults, HGMB1 is not a biomarker of PAH in pediatric CHD. Further work will continue to explore for biomarkers for this high-risk population.

Identification of TFRC as a biomarker for pulmonary arterial hypertension based on bioinformatics and experimental verification.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a life-threatening chronic cardiopulmonary disease. However, there is a paucity of studies that reflect the available biomarkers from separate gene expression profiles in PAH. METHODS: The GSE131793 and GSE113439 datasets were combined for subsequent analyses, and batch effects were removed. Bioinformatic analysis was then performed to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) and a protein-protein interaction (PPI) network analysis were then used to further filter the hub genes. Functional enrichment analysis of the intersection genes was performed using Gene Ontology (GO), Disease Ontology (DO), Kyoto encyclopedia of genes and genomes (KEGG) and gene set enrichment analysis (GSEA). The expression level and diagnostic value of hub gene expression in pulmonary arterial hypertension (PAH) patients were also analyzed in the validation datasets GSE53408 and GSE22356. In addition, target gene expression was validated in the lungs of a monocrotaline (MCT)-induced pulmonary hypertension (PH) rat model and in the serum of PAH patients. RESULTS: A total of 914 differentially expressed genes (DEGs) were identified, with 722 upregulated and 192 downregulated genes. The key module relevant to PAH was selected using WGCNA. By combining the DEGs and the key module of WGCNA, 807 genes were selected. Furthermore, protein-protein interaction (PPI) network analysis identified HSP90AA1, CD8A, HIF1A, CXCL8, EPRS1, POLR2B, TFRC, and PTGS2 as hub genes. The GSE53408 and GSE22356 datasets were used to evaluate the expression of TFRC, which also showed robust diagnostic value. According to GSEA enrichment analysis, PAH-relevant biological functions and pathways were enriched in patients with high TFRC levels. Furthermore, TFRC expression was found to be upregulated in the lung tissues of our experimental PH rat model compared to those of the controls, and the same conclusion was reached in the serum of the PAH patients. CONCLUSIONS: According to our bioinformatics analysis, the observed increase of TFRC in the lung tissue of human PAH patients, as indicated by transcriptomic data, is consistent with the alterations observed in PAH patients and rodent models. These data suggest that TFRC may serve as a potential biomarker for PAH.

The Co-pathogenic Target Gene CNTN1 Involved in Coronary Artery Disease and Pulmonary Arterial Hypertension Has Potential for Diagnosis of Coronary Artery Disease.

BACKGROUND: We aimed to find a gene for coronary artery disease (CAD) early diagnosis by detecting co-pathogenic target gene involved in CAD and pulmonary arterial hypertension (PAH). Methods: Datasets were obtained from the Gene Expression Omnibus (GEO) database, including GSE113079, GSE113439, and GSE12288, to investigate gene expression patterns in cardiovascular diseases. Weighted Gene Co-expression Network Analysis (WGCNA) was performed to identify gene modules associated with clinical traits. Differential gene expression analysis and functional enrichment analysis were carried out. Protein-protein interaction (PPI) networks were constructed. JASPAR database and FIMO tool were utilized to predict transcription factor (TF) binding sites. Results: Fifteen key genes were identified in CAD and PAH, with CNTN1 being prioritized for further investigation due to its high connectivity degree. Upstream regulation analysis identified potential TFs (DRGX, HOXD3, and RAX) and 7 miRNAs targeting CNTN1. The expression profile of CNTN1 was significantly upregulated in CAD samples, and ROC analysis indicated potential diagnostic value for CAD. CMap database analysis predicted potential targeted drugs for CAD. Conclusion: CNTN1 was detected as a co-pathogenetic gene for CAD and PAH. It is highly expressed in CAD patients and has potential value for CAD diagnosis. CNTN1 is potentially regulated by 3 TFs and 7 miRNAs.

Predictive accuracy of the ASIG algorithm in a prospective systemic sclerosis cohort undergoing annual screening for pulmonary arterial hypertension.

The Australian Scleroderma Interest Group (ASIG) algorithm for screening pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc) requires only respiratory function tests and serum N-terminal pro-brain natriuretic peptide as first-tier tests, and is recommended in international guidelines. In this communication, we present the findings of the application of the ASIG screening algorithm to a Singaporean cohort undergoing prospective annual screening for PAH, which shows a high negative predictive value. The ASIG algorithm may offer an alternative to more complex and costly SSc-PAH screening algorithms.

Using Sotatercept in the Care of Patients With Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a rare disease of the pulmonary microvasculature leading to elevated precapillary pulmonary hypertension. Pulmonary vascular remodeling, a characteristic of PAH, is driven by dysfunctions in the signaling between the pulmonary smooth muscle and endothelial cells with abnormalities that affect cell proliferation and immune dysregulation. Sotatercept, an activin signaling inhibitor, has recently been approved by the US Food and Drug Administration for the treatment of PAH based on two pivotal clinical trials. Evidence-based clinical trials have provided a framework to guide clinicians treating the disease; however, they are not tailored to the individual patient. Often, recommendations from these data are unclear or too general, due to remaining gaps in knowledge. In this edition of "How I Do It," we provide a case-based discussion of common clinical decisions regarding diagnostic testing, choice of first-line agents, escalation of therapy, potential timing of sotatercept, safety awareness, practical use, potential management changes, and the future use of sotatercept in other pulmonary hypertension cohorts.

Predicting high-risk pre-capillary pulmonary hypertension: an echocardiographic multiparameter scoring index.

BACKGROUND: The risk stratification of pulmonary arterial hypertension proposed by the European Society of Cardiology /European Respiratory Society guidelines in 2015 and 2022 included two to three echocardiographic indicators. However, the specific value of echocardiography in risk stratification of pre-capillary pulmonary hypertension (pcPH) has not been efficiently demonstrated. Given the complex geometry of the right ventricular (RV) and influencing factors of echocardiographic parameter, there is no single echocardiographic parameter that reliably informs about PH status. We hypothesize that a multi-parameter comprehensive index can more accurately evaluate the severity of the pcPH. The purpose of this study was to develop and validate an echocardiographic risk score model to better assist clinical identifying high risk of pcPH during initial diagnosis and follow-up. METHODS: We studied 197 consecutive patients with pcPH. A multivariable echocardiographic model was constructed to predict the high risk of pcPH in the training set. Points were assigned to significant risk factors in the final model based on ß-coefficients. We validated the model internally and externally. RESULTS: The echocardiographic score was constructed by multivariable logistic regression, which showed that pericardial effusion, right atrial (RA) area, RV outflow tract proximal diameter (RVOT-Prox), the velocity time integral of the right ventricular outflow tract (TVIRVOT) and S' were predictors of high risk of pcPH. The area under curve (AUC) of the training set of the scoring model was 0.882 (95%CI: 0.809-0.956, p < 0.0001). External validation was tested in a test dataset of 77 patients. The AUC of the external validation set was 0.852. A 10-point score risk score was generated, with scores ranging from 0 to 10 in the training cohort. The estimate risk of high risk of pcPH ranged from 25.1 to 94.6%. CONCLUSIONS: The echocardiographic risk score using five echocardiographic parameters could be comprehensive and useful to predict the high risk of pcPH for initial assessment and follow-up.

Medication adherence, related factors and outcomes among patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension: a systematic review.

INTRODUCTION: Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are life-threatening conditions that can progress to death without treatment. Although strong medication adherence (MA) is known to enhance outcomes in chronic illnesses, its association with PAH and CTEPH was sporadically explored. This study aims to examine the MA of patients with PAH or CTEPH, identify factors associated with low adherence and explore the resulting outcomes. METHODS: A systematic review was conducted by searching multiple databases (Medline, Embase, Cochrane Central, ClinicalTrials.gov, Scopus, Web of Science and Google Scholar) from 6 March 1998 to 6 July 2023. We included studies reporting MA as primary or secondary end-points. Study selection, data extraction and methodological quality assessment were performed in duplicate. RESULTS: 20 studies involving 22 675 patients met the inclusion criteria. Heterogeneity was observed, particularly in the methods employed. MA means ranged from 0.62 to 0.96, with the proportion of patients exhibiting high MA varying from 40% (95% CI 35-45%) to 94% (95% CI 88-97%). Factors associated with low adherence included increased treatment frequency, time since diagnosis and co-payment. High MA seems to be associated with reduced hospitalisation rates, inpatient stays, outpatient visits and healthcare costs. CONCLUSIONS: This systematic review underscores the heterogeneity of MA across studies. Nevertheless, the findings suggest that high MA could improve patients' clinical outcomes and alleviate the economic burden. Identifying factors consistently associated with poor MA could strengthen educational efforts for these patients, ultimately contributing to improved outcomes.

Phenotypes in pulmonary hypertension.

The clinical classification of pulmonary hypertension (PH) has guided diagnosis and treatment of patients with PH for several decades. Discoveries relating to underlying mechanisms, pathobiology and responses to treatments for PH have informed the evolution in this clinical classification to describe the heterogeneity in PH phenotypes. In more recent years, advances in imaging, computational science and multi-omic approaches have yielded new insights into potential phenotypes and sub-phenotypes within the existing clinical classification. Identification of novel phenotypes in pulmonary arterial hypertension (PAH) with unique molecular profiles, for example, could lead to new precision therapies. Recent phenotyping studies have also identified groups of patients with PAH that more closely resemble patients with left heart disease (group 2 PH) and lung disease (group 3 PH), which has important prognostic and therapeutic implications. Within group 2 and group 3 PH, novel phenotypes have emerged that reflect a persistent and severe pulmonary vasculopathy that is associated with worse prognosis but still distinct from PAH. In group 4 PH (chronic thromboembolic pulmonary disease) and sarcoidosis (group 5 PH), the current approach to patient phenotyping integrates clinical, haemodynamic and imaging characteristics to guide treatment but applications of multi-omic approaches to sub-phenotyping in these areas are sparse. The next iterations of the PH clinical classification are likely to reflect several emerging PH phenotypes and improve the next generation of prognostication tools and clinical trial design, and improve treatment selection in clinical practice.

The association of right ventricular-pulmonary arterial coupling and pulmonary vascular resistance in adult patients with uncorrected atrial septal defect.

BACKGROUND: Atrial septal defects (ASD) are the most common type of adult congenital heart disease (ACHD) associated with a high risk developing of pulmonary arterial hypertension (PAH). ASD closure is not recommended in patients with PAH and Pulmonary Vascular Resistance (PVR) ≥ 5 Wood Unit (WU). Noninvasive methods have been proposed to measure PVR; however, their accuracy remains low. Right Ventricle (RV) - Pulmonary Artery (PA) coupling is defined as the ability of the RV to adapt to high-resistance conditions. Tricuspid Annular Plane Systolic Excursion (TAPSE)/estimated pulmonary artery systolic pressure (ePASP) calculation using echocardiography is a noninvasive technique that has been proposed as a surrogate equation to evaluate RV-PA coupling. Currently, no research has demonstrated a relationship between RV-PA coupling and PVR in patients with ASD. METHODS: The study participants were consecutive eligible patients with ASD who underwent right heart catheterization (RHC) and echocardiography at Hasan Sadikin General Hospital, Bandung. Both the procedures were performed on the same day. RV-PA Coupling, defined as TAPSE/ePASP > 0.31, was assessed using echocardiography. The PVR was calculated during RHC using the indirect Fick method. RESULTS: There were 58 patients with ASD underwent RHC and echocardiography. Among them, 18 had RV/PA Coupling and 40 had RV/PA Uncoupling. The PVR values were significantly different between the two groups (p = 0.000). Correlation test between TAPSE/ePASP with PVR showed moderate negative correlation (r= -0.502, p = 0.001). TAPSE/ePASP ≤ 0.34 is the cutoff point to predict PVR > 5 WU with sensitivity of 91.7% and specificity 63.6%. CONCLUSION: This study showed a moderate negative correlation between TAPSE/ePASP and PVR. TAPSE/ePASP ≤ 0.34 could predict PVR > 5 WU with good sensitivity.

Resistin predicts disease severity and survival in patients with pulmonary arterial hypertension.

BACKGROUND: Abnormal remodeling of distal pulmonary arteries in patients with pulmonary arterial hypertension (PAH) leads to progressively increased pulmonary vascular resistance, followed by right ventricular hypertrophy and failure. Despite considerable advancements in PAH treatment prognosis remains poor. We aim to evaluate the potential for using the cytokine resistin as a genetic and biological marker for disease severity and survival in a large cohort of patients with PAH. METHODS: Biospecimens, clinical, and genetic data for 1121 adults with PAH, including 808 with idiopathic PAH (IPAH) and 313 with scleroderma-associated PAH (SSc-PAH), were obtained from a national repository. Serum resistin levels were measured by ELISA, and associations between resistin levels, clinical variables, and single nucleotide polymorphism genotypes were examined with multivariable regression models. Machine-learning (ML) algorithms were applied to develop and compare risk models for mortality prediction. RESULTS: Resistin levels were significantly higher in all PAH samples and PAH subtype (IPAH and SSc-PAH) samples than in controls (P < .0001) and had significant discriminative abilities (AUCs of 0.84, 0.82, and 0.91, respectively; P < .001). High resistin levels (above 4.54 ng/mL) in PAH patients were associated with older age (P = .001), shorter 6-min walk distance (P = .001), and reduced cardiac performance (cardiac index, P = .016). Interestingly, mutant carriers of either rs3219175 or rs3745367 had higher resistin levels (adjusted P = .0001). High resistin levels in PAH patients were also associated with increased risk of death (hazard ratio: 2.6; 95% CI: 1.27-5.33; P < .0087). Comparisons of ML-derived survival models confirmed satisfactory prognostic value of the random forest model (AUC = 0.70, 95% CI: 0.62-0.79) for PAH. CONCLUSIONS: This work establishes the importance of resistin in the pathobiology of human PAH. In line with its function in rodent models, serum resistin represents a novel biomarker for PAH prognostication and may indicate a new therapeutic avenue. ML-derived survival models highlighted the importance of including resistin levels to improve performance. Future studies are needed to develop multi-marker assays that improve noninvasive risk stratification.

Prognostic Significance of Proteomics-Discovered Circulating Inflammatory Biomarkers in Patients With Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) ultimately leads to right ventricular failure and premature death. The identification of circulating biomarkers with prognostic utility is considered a priority. As chronic inflammation is recognized as key pathogenic driver, we sought to identify inflammation-related circulating proteins that add incremental value to current risk stratification models for long-term survival in patients with PAH. METHODS AND RESULTS: Plasma levels of 384 inflammatory proteins were measured with the proximity extension assay technology in patients with PAH (n=60) and controls with normal hemodynamics (n=28). Among these, 51 analytes were significantly overexpressed in the plasma of patients with PAH compared with controls. Cox proportional hazard analyses and C-statistics were performed to assess the prognostic value and the incremental prognostic value of differentially expressed proteins. A panel of 6 proteins (CRIM1 [cysteine rich transmembrane bone morphogenetic protein regulator 1], HGF [hepatocyte growth factor], FSTL3 [follistatin-like 3], PLAUR [plasminogen activator, urokinase receptor], CLSTN2 [calsyntenin 2], SPON1 [spondin 1]) were independently associated with death/lung transplantation at the time of PAH diagnosis after adjustment for the 2015 European Society of Cardiology/European Respiratory Society guidelines, the REVEAL (Registry to Evaluate Early and Long-Term PAH Disease Management) 2.0 risk scores, and the refined 4-strata risk assessment. CRIM1, PLAUR, FSTL3, and SPON1 showed incremental prognostic value on top of the predictive models. As determined by Western blot, FSTL3 and SPON1 were significantly upregulated in the right ventricle of patients with PAH and animal models (monocrotaline-injected and pulmonary artery banding-subjected rats). CONCLUSIONS: In addition to revealing new actors likely involved in cardiopulmonary remodeling in PAH, our screening identified promising circulating biomarkers to improve risk prediction in PAH, which should be externally confirmed.

Prognostic Value of Serial Risk Stratification in Adult and Pediatric Pulmonary Arterial Hypertension: A Systematic Review.

BACKGROUND: In pulmonary arterial hypertension, it is recommended to base therapeutic decisions on risk stratification. This systematic review aims to report the prognostic value of serial risk stratification in adult and pediatric pulmonary arterial hypertension and to explore the usability of serial risk stratification as treatment target. METHODS AND RESULTS: Electronic databases PubMed, Embase, and Web of Science were searched up to January 30, 2023, using terms associated with pulmonary arterial hypertension, pediatric pulmonary hypertension, and risk stratification. Observational studies and clinical trials describing risk stratification at both baseline and follow-up were included. Sixty five studies were eligible for inclusion, including only 2 studies in a pediatric population. C-statistic range at baseline was 0.31 to 0.77 and improved to 0.30 to 0.91 at follow-up. In 53% of patients, risk status changed (42% improved, 12% worsened) over 168 days (interquartile range, 137-327 days; n=22 studies). The average proportion of low-risk patients increased from 18% at baseline to 36% at a median follow-up of 244 days (interquartile range, 140-365 days; n=40 studies). In placebo-controlled drug studies, risk statuses of the intervention groups improved more and worsened less compared with the placebo groups. Furthermore, a low-risk status, but also an improved risk status, at follow-up was associated with a better outcome. Similar results were found in the 2 pediatric studies. CONCLUSIONS: Follow-up risk stratification has improved prognostic value compared with baseline risk stratification, and change in risk status between baseline and follow-up corresponded to a change in survival. These data support the use of serial risk stratification as treatment target in pulmonary arterial hypertension.

The prognosis and management of reclassified systemic lupus erythematosus associated pulmonary arterial hypertension according to 2022 ESC/ERS guidelines.

BACKGROUND AND AIMS: The 2022 European Society of Cardiology/European Respiratory Society (ESC/ERS) guideline has recently revised the hemodynamic definition of pulmonary arterial hypertension. However, there is currently limited research on the prognosis and treatment of system lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH) patients that have been reclassified by the new hemodynamic definition. This study aims to analyze the prognosis of newly reclassified SLE-PAH patients and provide recommendations for the management strategy. METHODS: This retrospective study analyzed records of 236 SLE-PAH patients who visited Peking Union Medical College Hospital (PUMCH) from 2011 to 2023, among whom 22 patients were reclassified into mild SLE-PAH (mean pulmonary arterial pressure (mPAP) of 21-24 mmHg, pulmonary vascular resistance (PVR) of 2-3 WU, and PAWP ≤ 15 mmHg) according to the guidelines and 14 were defined as unclassified SLE-PAH patients (mPAP 21-24 mmHg and PVR ≤ 2 WU). The prognosis was compared among mild SLE-PAH, unclassified SLE-PH, and conventional SLE-PAH patients (mPAP ≥ 25 mmHg and PVR > 3WU). Besides, the effectiveness of pulmonary arterial hypertension (PAH)-specific therapy was evaluated in mild SLE-PAH patients. RESULTS: Those mild SLE-PAH patients had significantly longer progression-free time than the conventional SLE-PAH patients. Among the mild SLE-PAH patients, 4 did not receive PAH-specific therapy and had a similar prognosis as patients not receiving specific therapy. CONCLUSIONS: This study supports the revised hemodynamic definition of SLE-PAH in the 2022 ESC/ERS guideline. Those mild and unclassified SLE-PH patients had a better prognosis, demonstrating the possibility and significance of early diagnosis and intervention for SLE-PAH. This study also proposed a hypothesis that IIT against SLE might be sufficient for those reclassified SLE-PAH patients.