Diagnosis Of Pulmonary Arterial Hypertension Research Articles

Circulating Biomarkers in Pulmonary Arterial Hypertension: An Update

Pulmonary arterial hypertension (PAH) is a rare subtype of group 1 pulmonary hypertension (PH) diseases, characterized by high pulmonary artery pressure leading to right ventricular dysfunction and potential life-threatening consequences. PAH involves complex mechanisms: vasoconstriction, vascular remodeling, endothelial dysfunction, inflammation, oxidative stress, fibrosis, RV remodeling, cellular hypoxia, metabolic imbalance, and thrombosis. These mechanisms are mediated by several pathways, involving molecules like nitric oxide and prostacyclin. PAH diagnosis requires clinical evaluation and right heart catheterization, confirming a value of mPAP ≥ 20 mmHg at rest and often elevated pulmonary vascular resistance (PVR). Even if an early and accurate diagnosis is crucial, PAH still lacks effective biomarkers to assist in its diagnosis and prognosis. Biomarkers could contribute to arousing clinical suspicion and serve for prognosis prediction, risk stratification, and dynamic monitoring in patients with PAH. The aim of the present review is to report the main novelties on new possible biomarkers for the diagnosis, prognosis, and treatment monitoring of PAH.

Survival in systemic sclerosis associated pulmonary arterial hypertension in the current treatment era-results from a nationwide study.

Pulmonary arterial hypertension (PAH) is a leading cause of mortality in systemic sclerosis (SSc). This nationwide study aims to describe real world treatment characteristics and assess survival rates of patients with SSc-PAH. In this retrospective cohort study, patients with SSc-PAH were identified from Turkish Ministry of Health National Electronic Database (from January 2016 to September 2022), using ICD-10 codes. Data on demographics, treatment characteristics, and death was collected. Kaplan-Meier curves were used to calculate cumulative probabilities of survival at 1, 3, and 5years. Five hundred forty-seven patients (90.7% female) with SSc-PAH were identified. Median age at PAH diagnosis was 59.9 (50.0-67.4) years. During a median follow-up duration of 3.2 (1.5-4.8) years, 199 (36.4%) deaths occurred. Estimated survival rates at 1, 3, and 5years were 90.2%, 73.2%, and 56.6%, respectively. Survival was similar among patients with and without interstitial lung disease (p = 0.20). Patients who used immunosuppressives had better survival than those who did not (p < 0.001). No difference was observed in survival rates according to initial PAH-specific treatment regimen (monotherapy or combination) (p = 0.49). Compared to most of historical cohorts, higher survival rates for SSc-PAH were observed in this study. Early diagnosis of PAH may have contributed to these findings. The impact of immunosuppressive therapy on prognosis of SSc-PAH needs to be further investigated in prospective studies. Key Points • Early diagnosis is pivotal for better outcomes in SSc-PAH. • Implementation of PAH treatment guidelines in routine clinical practice is still poor and should be improved. • Effect of immunosuppressive therapies on disease course has to be defined in SSc-PAH.

Switching from Beraprost to Selexipag in the Treatment of Pulmonary Arterial Hypertension: Insights from a Phase IV Study of the Japanese Registry (The EXCEL Study: EXChange from bEraprost to seLexipag Study)

Pulmonary arterial hypertension (PAH) remains a significant challenge in cardiology, necessitating advancements in treatment strategies. This study explores the safety and efficacy of transitioning patients from beraprost to selexipag, a novel selective prostacyclin receptor agonist, within a Japanese cohort. Employing a multicenter, open-label, prospective design, 25 PAH patients inadequately managed on beraprost were switched to selexipag. Key inclusion criteria included ongoing beraprost therapy for ≥3 months, a diagnosis of PAH confirmed by mean pulmonary artery pressure (mPAP) ≥ 25 mmHg, and current treatment with endothelin receptor antagonists and/or phosphodiesterase type 5 inhibitors. Outcomes assessed were changes in hemodynamic parameters (mPAP, cardiac index, pulmonary vascular resistance) and the 6 min walk distance (6-MWD) over 3–6 months. The study found no statistically significant changes in these parameters post-switch. However, a subset of patients, defined as responders, demonstrated improvements in all measured hemodynamic parameters, suggesting a potential benefit in carefully selected patients. The transition was generally well-tolerated with no serious adverse events reported. This investigation underscores the importance of personalized treatment strategies in PAH, highlighting that certain patients may benefit from switching to selexipag, particularly those previously on higher doses of beraprost. Further research is needed to elucidate the predictors of positive response to selexipag and optimize treatment regimens for this complex condition.

Differential expression and analysis of extrachromosomal circular DNAs as serum biomarkers in pulmonary arterial hypertension

BackgroundExtrachromosomal circular DNAs (eccDNAs) have been reported to play a key role in the occurrence and development of various diseases. However, the characterization and role of eccDNAs in pulmonary arterial hypertension (PAH) remain unclear.MethodsIn the discovery cohort, we first explored eccDNA expression profiles by Circle-sequencing analysis. The candidate eccDNAs were validated by routine polymerase chain reaction (PCR), TOPO-TA cloning and Sanger sequencing. In the validation cohort, 30 patients with PAH and 10 healthy controls were recruited for qPCR amplification to detect the candidate eccDNAs. Datas at the baseline were collected, including clinical background, biochemical variables, echocardiography and hemodynamic factors. Receiver operating characteristic curve was used to investigate the diagnostic effect of the eccDNA.ResultsWe identified a total of 21,741 eccDNAs in plasma samples of 3 IPAH patients and 3 individuals in good health, and the expression frequency, GC content, length distribution, and genome distribution of the eccDNAs were thoroughly characterized and analyzed. In the validation cohort, 687 eccDNAs were differentially expressed in patients with IPAH compared with healthy controls (screening threshold: |FC|≥2 and P < 0.05). Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the specific eccDNAs in IPAH were significantly enriched in calcium channel activity, the mitogen-activated protein kinase pathway, and the wnt signaling pathway. Verification queue found that the expression of eccDNA-chr2:131208878–131,424,362 in PAH was considerably higher than that in healthy controls and exhibited a high level of accuracy in predicting PAH with a sensitivity of 86.67% and a specificity of 90%. Furthermore, correlation analysis disclosed a significant association between serum eccDNA-chr2:131208878–131,424,362 and mean pulmonary artery pressure (mPAP) (r = 0.396, P = 0.03), 6 min walking distance (6MWD) (r = -0.399, P = 0.029), N-terminal pro-B-type natriuretic peptide (NT-proBNP) (r = 0.685, P < 0.001) and cardiac index (CI) (r = − 0.419, P = 0.021).ConclusionsThis is the first study to identify and characterize eccDNAs in patients with PAH. We revealed that serum eccDNA-chr2:131208878–131,424,362 is significantly overexpressed and can be used in the diagnosis of PAH, indicating its potential as a novel non-invasive biomarker.

Aberrant Long-Chain Fatty Acid Metabolism Associated with Evolving Systemic Sclerosis-Associated Pulmonary Arterial Hypertension.

We sought to investigate differential metabolism in patients with systemic sclerosis (SSc) who develop pulmonary arterial hypertension (PAH) versus those who do not, as a method of identifying potential disease biomarkers. In a nested case-control design, serum metabolites were assayed in SSc subjects who developed right heart catheterization-confirmed PAH (n=22) while under surveillance in a longitudinal cohort from Johns Hopkins, then compared to metabolites assayed in matched SSc patients who did not develop PAH (n=22). Serum samples were collected at "proximate" (within 12 months) and "distant" (within 1-5 years) time points relative to PAH diagnosis. Metabolites were identified using liquid chromatography-mass spectroscopy (LC-MS). An LC-MS dataset from SSc subjects with either mildly elevated pulmonary pressures or overt PAH from the University of Michigan was compared. Differentially abundant metabolites were tested as predictors of PAH in two additional validation SSc cohorts. Long-chain fatty acid metabolism (LCFA) consistently differed in SSc-PAH versus SSc without PH. LCFA metabolites discriminated SSc-PAH patients with mildly elevated pressures in the Michigan cohort and predicted SSc-PAH up to two years prior to clinical diagnosis in the Hopkins cohort. Acylcholines containing LCFA residues and linoleic acid metabolites were most important for discriminating SSc-PAH. Combinations of acylcholines and linoleic acid metabolites provided good discrimination of SSc-PAH across cohorts. Aberrant lipid metabolism is observed throughout the evolution of PAH in SSc. Lipidomic signatures of abnormal LCFA metabolism distinguish SSc-PAH patients from those without PH, including prior to clinical diagnosis and in mild disease.

Positive Vasoreactivity Testing in Pulmonary Arterial Hypertension: Therapeutic Consequences, Treatment Patterns, and Outcomes in the Modern Management Era.

Among patients with pulmonary arterial hypertension (PAH), acute vasoreactivity testing during right heart catheterization may identify acute vasoresponders, for whom treatment with high-dose calcium channel blockers (CCBs) is recommended. However, long-term outcomes in the current era remain largely unknown. We sought to evaluate the implications of acute vasoreactivity response for long-term response to CCBs and other outcomes. Patients diagnosed with PAH between January 1999 and December 2018 at 15 pulmonary hypertension centers were included and analyzed retrospectively. In accordance with current guidelines, acute vasoreactivity response was defined by a decrease of mean pulmonary artery pressure by ≥10 mm Hg to reach <40 mm Hg, without a decrease in cardiac output. Long-term response to CCBs was defined as alive with unchanged initial CCB therapy with or without other initial PAH therapy and World Health Organization functional classification I/II or low European Society of Cardiology/European Respiratory Society risk status at 12 months after initiation of CCBs. Patients were followed for up to 5 years; clinical measures, outcome, and subsequent treatment patterns were captured. Of 3702 patients undergoing right heart catheterization for PAH diagnosis, 2051 had idiopathic, hereditary, or drug-induced PAH, of whom 1904 (92.8%) underwent acute vasoreactivity testing. A total of 162 patients fulfilled acute vasoreactivity response criteria and received an initial CCB alone (n=123) or in combination with another PAH therapy (n=39). The median follow-up time was 60.0 months (interquartile range, 30.8-60.0), during which overall survival was 86.7%. At 12 months, 53.2% remained on CCB monotherapy, 14.7% on initial CCB plus another initial PAH therapy, and the remaining patients had the CCB withdrawn or PAH therapy added. CCB long-term response was found in 54.3% of patients. Five-year survival was 98.5% in long-term responders versus 73.0% in nonresponders. In addition to established vasodilator responder criteria, pulmonary artery compliance at acute vasoreactivity testing, low risk status and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels at early follow-up correlated with long-term response and predicted survival. Our data display heterogeneity within the group of vasoresponders, with a large subset failing to show a sustained satisfactory clinical response to CCBs. This highlights the necessity for comprehensive reassessment during early follow-up. The use of pulmonary artery compliance in addition to current measures may better identify those likely to have a good long-term response.

(647) - Journey from Symptoms to Diagnosis in Pulmonary Arterial Hypertension: Results from a Cross-Sectional Survey of Real-World Patients in Latin America

(647) - Journey from Symptoms to Diagnosis in Pulmonary Arterial Hypertension: Results from a Cross-Sectional Survey of Real-World Patients in Latin America

Recent progress in the roles of microRNAs in pulmonary arterial hypertension associated with congenital heart disease

Research on noncoding RNA, particularly microRNAs (miRNAs), is growing rapidly. Advances in genomic technologies have revealed the complex roles of miRNAs in pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD). It has been demonstrated that the progression of PAH associated with CHD is characterized by particular dysregulation of miRNAs and is related to cardiovascular remodeling, cell death, and right ventricle dysfunction. This review provides a comprehensive overview of the current state of knowledge regarding the involvement of miRNAs in the pathogenesis and progression of PAH associated with CHD. We commence by explaining the process of miRNA synthesis and its mode of action, as well as the role of miRNA in PAH associated with CHD. Moreover, the article delves into current breakthroughs in research, potential clinical implications, and prospects for future investigations. The review provides the insight into novel approaches for diagnosis, prognosis, and therapy of PAH associated with CHD.

[Once in a blue moon: coronavirus disease complicates pregnancy in a patient with unknown pulmonary hypertension and subsequent left ventricular dysfunction].

During COVID-19 pandemic, several clinical manifestations have been described beyond respiratory compromise that characterizes the viral disease. Cardiovascular manifestations are one of the main complications. In this case, we report an unusual association between the novo diagnosis of pulmonary arterial hypertension in a pregnant patient with SARS Cov-2, with subsquent development of left ventricular dysfunction.

Prognostic and diagnostic utility of interleukin-6 in pediatric pulmonary arterial hypertension — a case-control study

Pulmonary arterial hypertension (PAH) in pediatrics is a progressive disease with significant vascular remodeling, right sided heart failure, and death if left untreated. Elevated interleukin-6 (IL-6) level in PAH patients is taken as an independent predictor of adverse outcome including mortality. The aim of this study was to investigate and compare serum levels of IL-6 in children with PAH and healthy matched controls, and correlate between IL-6 and degree of PAH, as well as mortality. IL-6 was measured by ELISA in serum samples in 40 children with PAH (age 1–12 years) and 40 age and sex-matched healthy controls. There was a statistically significant increase in IL-6 level among PAH cases compared with the controls (1.85 ng/L vs 1.30 ng/L, p-value = 0.004). IL-6 at cut off point 1.45 ng/L significantly predict pulmonary hypertension in children (AUC = 0.685, 75% sensitivity, and 65% specificity with p = 0.002). There was no statistically significant association between IL-6 level and degree of PAH (p = 0.218). There was no statistically significant association between IL-6 level and mortality (p = 0.662).    Conclusion: IL-6 significantly predict PAH in pediatrics but there is no association between IL-6 level and degree of PAH or mortality. IL-6 may provide a less costly and less invasive method for disease detection.What is Known:• Definitive diagnosis of PAH is made by right heart catheterization, while echocardiography is the gold standard for tracking the course of the disease.What is New:• It was assumed that children with a diagnosis of PAH would have higher serum IL-6 levels than controls. Furthermore, an adverse relationship between the blood IL-6 level and PPAH was predicted.

Hierarchical Hybrid Networks for Automatic Pulmonary Blood Vessel Segmentation in Computed Tomography Images.

Pulmonary arterial hypertension (PAH) is considered the third most common cardiovascular disease after coronary heart disease and hypertension. The diagnosis of PAH is mainly based on the comprehensive judgment of computed tomography and other medical image examinations. Medical image processing based on deep learning has achieved significant success. However, the data belongs to the patient's privacy; therefore, the medical institutions as data custodians have the responsibility to protect the security of their data privacy. This situation makes medical institutions face a dilemma when building data-driven deep learning-assisted medical diagnosis methods. On the one hand, they need to pursue more high-quality data based on Big Data architecture for deep learning; on the other hand, they need to protect patient privacy to avoid data leakage. In response to the above challenges, we propose a hierarchical hybrid automatic segmentation model for pulmonary blood vessels based on local learning and federated learning approaches for segmenting the pulmonary blood vessels. The experiments prove the proposal could automatically segment the vessels from the original CT. It also indicates that the model based on a federated learning approach can achieve impressive performance under the premise of protecting data privacy for Big Data.

The diagnostic journey of pulmonary arterial hypertension patients: results from a multinational real-world survey.

Pulmonary arterial hypertension (PAH) is a life-threatening, progressive disease often diagnosed late in its course. To present patient-reported data that were captured within a large, multinational, point-in-time survey of PAH-treating physicians and their patients to better understand the diagnostic journey. Cross-sectional survey conducted in five European countries (EU5), Japan and the USA. PAH-treating pulmonologists, cardiologists, rheumatologists or internists (USA only) completed a patient record form (PRF) for the next four consecutive adult PAH patients they saw; these patients filled in a patient self-completion (PSC) form on an anonymous, voluntary basis. Our report focuses on patient data; data are from PSC forms unless stated otherwise. Physician-reported PRFs and self-completed PSC forms were obtained for 1152 and 572 patients, respectively. Patients' mean (SD) age was 59.1 (14.0) years, 55.6% were female, and 57.3% had idiopathic PAH. Patient-reported data showed an average delay of 17.0 months between symptom onset and PAH diagnosis. This is longer than physicians estimated (13.8 months): this disparity may be partly due to the time taken by patients to consult a physician about their symptoms [9.6 months overall, longest in the USA (15.3 months)]. Most patients (71.6%) initially consulted primary care physicians about their symptoms and 76.4% of patients were referred to a specialist. Misdiagnoses occurred in 40.9% of patients [most frequent in the USA (51.3%), least common in Japan (27.6%)] and they saw an average of 2.9 physicians overall (3.5 in EU5 versus 2.0 in Japan/USA) before being diagnosed. Diagnosis was most often made by cardiologists (50.4%) or pulmonologists (49.3%). Our data suggest that diagnostic delay in PAH results from patient- and physician-related factors, which differ across regions and include lack of awareness of PAH on both sides. Development of better screening strategies may help address this barrier to timely PAH diagnosis.

Diagnostic Value of Serum Galectin-3 Binding Protein Level in Patients with Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) still lacks effective biomarkers to assist in its diagnosis and prognosis. Galectin-3 binding protein (Gal-3BP) plays a role in immune and inflammatory diseases. This study aimed to evaluate Gal-3BP as a prognostic and predictive factor in patients with PAH. From January 2017 to December 2019, we enrolled 167 consecutive PAH patients and 58 healthy controls. Right heart catheterization (RHC) was used to diagnose PAH. Serum Gal-3BP levels were measured by high-sensitivity human enzyme-linked immunosorbent assay (ELISA). Serum Gal-3BP levels in the PAH group were significantly higher compared with the control group (4.87±2.09 vs 2.22±0.86 μg/mL, p<0.001). Gal-3BP level was correlated with several hemodynamic parameters obtained from RHC (p<0.001). Multivariate linear regression analysis showed that Gal-3BP was a risk factor for PAH (odds ratio (OR)=2.947, 95% CI: 1.821-4.767, p<0.001). The optimal cut-off value of serum Gal-3BP level for predicting PAH was 2.89 μg/mL (area under the curve (AUC)=0.860, 95 % CI: 0.811-0.910, p<0.001). Kaplan-Meier analysis showed that Gal-3BP levels above the median (4.87 μg/mL) were associated with an increased risk of death in patients with PAH (hazard ratio (HR)=8.868, 95 % CI: 3.631-21.65, p<0.0001). Cox multivariate risk regression analysis showed that Gal-3BP was a risk factor for death in PAH patients (HR=2.779, 95 % CI: 1.823-4.237, p<0.001). Serum Gal-3BP levels were increased in patients with PAH, and levels of Gal-3BP were associated with the severity of PAH. Gal-3BP might have predictive value for the diagnosis and prognosis of PAH.

Possible Hereditary Pulmonary Arterial Hypertension: from Clinical to Genetic Investigation in Precision Medicine Era

Background: Pulmonary Hypertension is a life-threatening disease characterized by a progressive increase of pulmonary vascular resistance that often leads to right ventricular (RV) failure and death. Major discoveries have been obtained within the last decade in the field of hereditary predisposition to pulmonary arterial hypertension (PAH). At least 6% of all PAH cases are familial in origin known as Familial Pulmonary Arterial Hypertension (FPAH) and display autosomal dominant inheritance with incomplete penetrance. While early diagnosis is associated with improved long-term survival, however at present, most patients are diagnosed at a very advanced stage of HPAH indicating that the early screening for HPAH is crucial. In this regard, genetic testing is an effective strategy for the early diagnosis and management of PAH, specifically Hereditary Pulmonary Arterial Hypertension (HPAH). We present two cases of Familial Pulmonary Arterial Hypertension and in-depth analysis of diagnostic cascade to allow an earlier and more reliable diagnosis of possible Hereditary Pulmonary Arterial Hypertension (HPAH). Case Illustration: Familial cases, a 44-years old man and his son a 17-years old boy, came with chief complaint of dyspnea. His daughter or his sister passed away when 4 years old due to PH. Both patients had been subsequently diagnosed with PAH with possible HPAH after the exclusion of primary and secondary heart anomalies using electrocardiography, echocardiography, and cardiac marker test. Both patients subsequently were performed right heart catheterization (RHC). Conclusions: We describe familial cases of pulmonary hypertension with clinically presenting right-sided heart failure. Diagnostic investigation was performed according to recent guideline to rule out and rule in all the possible cause of pulmonary hypertension. However, the final assessment showed unknown cause of pre-capillary pulmonary hypertension. Therefore, genetic investigation should be performed in precision medicine era due to high possibility of hereditary pulmonary arterial hypertension.

Impact of the COVID-19 Pandemic on Health Care Access and Diagnosis of Pulmonary Arterial Hypertension Among Patients With Systemic Sclerosis.

Regular clinical assessment for complications of systemic sclerosis (SSc) such as pulmonary arterial hypertension (PAH) is essential for early institution of therapy and improved outcomes. The objective of this study was to determine the impact of COVID-19 pandemic-related restrictions on health care access of patients with SSc, including screening for PAH. South Australian and Victorian patients enrolled in the Australian Scleroderma Cohort Study were surveyed about their perceptions of the impact of the pandemic on mental well-being, access to medications, investigations, and management of SSc. Frequency of annual rheumatology assessments, pulmonary function tests (PFT), and transthoracic echocardiography (TTE) to screen for PAH were compared with rates from before the pandemic. A total of 312 of 810 patients with SSc responded (38.5% response); 273 were female (87.5%), the median age was 64.7 years, 77.2% had limited disease, the median illness duration was 15.6 years, 15.7% were immunosuppressed, 32.1% had interstitial lung disease, and 6.4% had PAH. A total of 65.7% of consultations were by telehealth, of which 81.2% were by telephone. Compared with respondents in South Australia (n=109), Victorian respondents (n=203) experiencing prolonged lockdown, reported reduced access to their rheumatologist (49.3% vs 27.9%; P = 0.004), greater use of consultation by video (17.3% vs 2.1%; P = 0.008), greater health care disruption (49.0% vs 23.2%; P < 0.001), and worse mental health (P = 0.002). Respondents reported reduced access to PFT and TTE (31.7% and 22.5%, respectively). Annual visits, PFT, TTE, and new diagnoses of PAH were reduced in 2020 to 2022 compared with 2011 to 2019. The COVID-19 pandemic-related disruption to health care for patients with SSc was associated with worse mental health and reduced screening and diagnosis of PAH, which may impact long-term outcomes.

Autologous MPO Knock-out Hematopoietic Stem and Progenitor Cells for Pulmonary Arterial Hypertension

Pulmonary Arterial Hypertension (PAH) is a progressive condition for which there is no cure. Even with substantial pharmacologic advances in the modern treatment era, existing treatments provide only symptomatic relief and survival remains unacceptably poor. Patients who fail to respond to medications usually have the worst prognosis and patients with persistently elevated pulmonary pressure and right heart failure usually die within 5 years. PAH is a severe complication of Systemic sclerosis (SSc) affecting approximately 8%-12% of patients. SSc affects 13.5-44.3 per 100,000 individuals and is complex and diverse, with limited treatment options. SSc-associated PAH is the second largest group of patients with PAH. Once diagnosed, it becomes the leading cause of mortality among this patient population, with a 50% mortality rate within 3 years of PAH diagnosis. Inflammation and endothelial injury being the main components of the syndrome, investigation regarding the underlying mechanisms of this immune response may lead to the development of a new efficient therapy. There is extensive evidence for a pathogenic role for neutrophil myeloperoxidase (MPO) in PAH disease. PAH patients with higher levels of MPO have a poorer outcome. Studies in murine models of PAH demonstrate significant disease amelioration by elimination of neutrophil MPO by hematopoietic stem cell (HSC) transplantation with HSC lacking MPO from germline MPO gene knock-out. We developed a gene therapy approach to PAH in which autologous HSCs will undergo gene editing using CRISPR/Cas9 to achieve bi-allelic disruption of the MPO gene. These MPO-knock-out HSCs will then be autologous transplanted. That autologous transplantation of HSPC in which the MPO gene is disrupted is expected to prevent progression of PAH due to the essential role of neutrophil MPO activity on disease development. We identified a sgRNA that leads to high frequency disruption of MPO in primary human CD34+ hematopoietic stem and progenitor cells (HSPC), leading to efficient elimination of MPO protein in the resultant neutrophils. That sequence was assessed for genome-wide off-target and showed no detectable locus, validating it as a lead candidate for safe gene editing strategy. We validated in an in vitro neutrophil differentiation model the functional efficiency of the knock-out. MPO KO differentiated cells exhibit reduced neutrophil extracellular traps formation (NETosis) and absence of MPO protein. An optimized gene editing protocol for HSC was optimized and showed consistent allelic disruption over 80%. The edited cells retain hematopoietic potential and showed no skewing in the generated lineages in an in vitro colony forming assay. We developed a surrogate gene editing protocol for murine cells and optimized electroporation to achieve high allelic disruption of the murine MPO gene in lineage negative murine hematopoietic cells. The protocol will be tested in a hypoxia-induced PAH murine model. The presented work can represent a major improvement for PAH patient. The limited therapeutic options and severity of the disease urges to develop new approaches. The gene therapy protocol developed showed promising result in vitro and rely on clinical evidences for the implication of MPO in the disease. Results will be tested in a pre-clinical murine model

Economic Burden of Delayed Diagnosis in Patients with Pulmonary Arterial Hypertension (PAH).

The aim of this study was to assess health care resource utilization (HRU) and costs associated with delayed pulmonary arterial hypertension (PAH) diagnosis in the United States. Eligible adults with newly diagnosed PAH from Optum's de-identified Clinformatics® Data Mart Database (2016-2021) were assigned to mutually exclusive cohorts based on time between first PAH-related symptom and first PAH diagnosis (i.e., ≤12 months' delay, >12 to ≤24 months' delay, >24 months' delay). All-cause HRU and health care costs per patient per month (PPPM) were assessed during the first year following diagnosis and compared across cohorts using regression analysis adjusted for baseline covariates. Sensitivity analyses were conducted to assess outcomes during all available follow-up post-diagnosis. Among 538 patients (mean age: 65.6 years; 60.6% female), 60.8% had ≤12 months' delay, 23.4% had a delay of >12 to ≤24 months, and 15.8% had >24 months' delay. Compared with ≤12 months, delays of >12 to ≤24 months and >24 months were associated with increased hospitalizations (incidence rate ratio [95% confidence interval]: 1.40 [1.11-1.71] vs 1.71 [1.29-2.12]) and outpatient visits (1.17[1.06-1.30] vs 1.26 [1.08-1.41]). Longer delays were also associated with more intensive care unit (ICU) stays and 30-day readmissions. Diagnosis delays translated into excess costs PPPM of US$3986 [1439-6436] for >12 to ≤24 months and US$5366 [2107-8524] for >24 months compared with ≤12months' delay; increased hospitalization costs (US$3248 [1108-5135] and US$4048 [1401-6342], respectively) being the driver. Sensitivity analyses yielded similar trends. Delayed PAH diagnosis is associated with significant incremental economic burden post-diagnosis, driven by hospitalizations including ICU stays and 30-day readmissions, highlighting the need for increased awareness and a potential benefit of earlier screening.

Right heart failure as a source of B-lines at lung ultrasound: prevalence and functional correlates

Abstract Background Lung ultrasound is part of the standard transthoracic examination and B-lines provide an index of extravascular lung water allowing to measure pulmonary congestion in left heart failure. However, pulmonary congestion can also appear as a consequence of right heart failure and it has been assumed that depends on the increase in central venous pressure increasing the resistance to lymphatic drainage. Aim of this study was to assess the prevalence of lung B-lines in a clinical model of pure right heart failure due to idiopathic pulmonary arterial hypertension (PAH) and its correlation with haemodynamic parameters. Methods All patients referred for suspicion of pulmonary hypertension in a single tertiary centre from January 2020 to December 2022 underwent a complete diagnostic work-up including echocardiography, lung ultrasound and right heart catheterization. The diagnosis of PAH was made following the current international recommendations. Pulmonary congestion was identified by lung ultrasound B-lines using an 8-site scan. Results The study enrolled 102 patients with PAH. Patients’ characteristics are shown in Table 1. The median lung B-lines were 3 [IQR: 1-5]. Results of univariate and multivariate analysis of B-lines predictors are shown in Table 1. Right atrial pressure (RAP), tricuspid annular plane excursion (TAPSE)/ Systolic pulmonary pressure (sPAP) ratio and pro hormone brain natriuretic peptide (proBNP) were independent predictors of B lines. Conclusion RAP, TAPSE/sPAP and proBNP were independent predictors of B lines in PAH patients according to the pathophysiological hypothesis that B-lines depends on the increase in central venous pressure increasing the resistance to lymphatic drainage.Table 1

Urinary proteomic analysis for biomarker discovery of pulmonary arterial hypertension-induced right ventricular failure

Abstract Background Right ventricular failure (RVF) is one of the independent and strong predictors of mortality in pulmonary arterial hypertension (PAH). Urine is more suitable and sensitive for biomarker discovery with no need for homeostatic control compared to blood. Purpose The purpose of this study is to investigate candidate urinary biomarkers for RV structural and functional monitoring during PAH progression. Methods The urinary proteome of 21 monocrotaline (MCT)-induced PAH rats (8 controls, 8 of compensated RV group, 5 of decompensated RV group) were identified using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). And the differential proteins were verified by parallel reaction monitoring (PRM)-targeted quantitative proteomics. Candidate biomarkers were further validated using ELISA in the urine of PAH patients. Results In total, 1811 urinary proteins were identified with at least 1 unique peptide (FDR≤1%). Compared to the control group of rats, 118 and 184 proteins were altered in the compensated and decompensated groups, respectively, and 62 differential proteins were found between the two stages (2.0-fold change, p&amp;lt; 0.05). The canonical pathways revealed that complement system, glutathione metabolism and iron homeostasis were enriched in the compensated stage, while interferon signaling, fibrosis, Wnt signaling and epithelial-mesenchymal transition were enriched in the failing stage. Four proteins confirmed by PRM, which were also of good discrimination ability of two RV stages were selected for further validation. ELISA results of the urine of PAH patients showed that IL18BP, IFNABR, LGALS3BP and α2-AP were sequentially elevated as disease progressed. Correlation analysis with clinical indicators showed that these proteins were positively correlated with right atrial pressure and right heart dilation, and negatively correlated with cardiac index and tricuspid annular plane systolic excursion. The combination of these four proteins panel could significantly distinguish PAH patients from healthy controls (AUC=0.985, 95%CI 0.955-1) and performs well in distinguishing high-risk PAH patients from low-risk ones (AUC=0.922, 95%CI 0.807-1). Conclusions Novel RVF candidate urinary biomarkers were found through in-depth proteomic analysis of PAH rat model. The panel of these four proteins, which were significantly correlated with RV structural remodeling and systolic function, showed good performance in diagnosis and risk stratification of PAH patients.Figure 1.Study workflowFigure 1.Main results of the study

Abstract 14098: Epidemiology and Clinical Outcomes of Cardiac Arrhythmias in Pulmonary Arterial Hypertension

Background: There is limited evidence regarding the impact of cardiac arrhythmias in patients with pulmonary arterial hypertension (PAH). We aim to comprehensively investigate the epidemiology and clinical outcomes of cardiac arrhythmias in patients with PAH. Methods: In a retrospective cohort study including 512 PAH patients from 2001-2021 at 3 Mayo Clinic sites, PAH patients were identified via echocardiogram, pulmonary function tests, and right heart catheterization. Demographic data at PAH diagnosis and clinical outcomes over a 10-year period were collected. The PAH patients were categorized into three groups based on arrhythmic onset: 1) patients with arrhythmia prior to PAH diagnosis, 2) patients diagnosed with arrhythmia during 10-year PAH follow-up, and 3) patients without arrhythmia during 10-year PAH follow-up. Survival outcomes were analyzed using multivariable Cox proportional hazards regression, adjusted with the REVEAL 2.0 score. Results: Among 512 PAH patients (mean age 56.1 years, 81.8% female), the prevalence of cardiac arrhythmias at PAH diagnosis was 10.5%. The cumulative incidences of new-onset arrhythmias at 1, 5, and 10 years were 6.6%, 18.4%, and 29.2%, respectively. Patients with arrhythmia diagnosed before and after PAH diagnosis showed significantly higher all-cause mortality rates with adjusted HR of 2.06 [95% CI 1.36-3.12] and 1.57 [95% CI 1.17-2.20] respectively (Figure 1). Similarly in both arrhythmic groups, there was a shorter median time to the first all-cause hospitalization (9.5 and 15.9 months vs. 21.2 months) and a higher number of all-cause hospitalizations (0.38 and 0.64 times per year vs. 0.10 times per year) compared to the non-arrhythmic group. Conclusions: Cardiac arrhythmias can develop in nearly one-third of PAH patients within 10 years of PAH diagnosis and independently contribute to increased mortality and hospitalization frequency.