Pathophysiology of the right ventricle and of the pulmonary circulation in pulmonary hypertension: an update

Proteomic- and metabolomic-based mechanisms of androgen-mediated right ventricular maladaptive remodeling under pressure overload

BACKGROUND

Right ventricular (RV) maladaptive remodeling has been demonstrated to be more severe in males than in females under similar afterload, with androgen potentially involved. However, the mechanism remains unknown.

METHODS

We performed RV proteomics and metabolomics in male and castrated rats with pulmonary artery banding (PAB) or sham surgery. The core pathway was tested in other sets of male, castrated male, and testosterone-replaced rats with and without pathway inhibitors administration and in RV remodeling patients. Metabolite verification was carried out by matching secondary spectra.

RESULTS

With the same extent of increases in RV afterload, male PAB rats exhibited more pronounced RV hypertrophy and fibrosis than castrated PAB rats (p < 0.05). The omics analysis indicated that pathways and functions related to oxidative stress were exhibited in the male group, with the platelet-derived growth factor (PDGF) pathway being among them. More proteins and metabolites associated with fatty acid metabolism were downregulated in males. Correlation analysis showed that PDGF receptor beta (PDGFRB) and signal transducer and activator of transcription 3 (STAT3) were negatively correlated with carnitine and reactive oxygen species scavenging metabolites only in male rats. The activation of the PDGF pathway was verified in testosterone-replaced PAB rats and male patients with RV remodeling. Treatments with PDGFRB inhibitor and STAT3 inhibitor could reverse RV maladaptive remodeling in male and testosterone-replaced PAB rats but not in castrated ones.

CONCLUSIONS

Androgen might exacerbate RV maladaptive remodeling via intensified oxidative stress and insufficient energy supply, with activating the PDGFRB-STAT3 signaling being one of the possible pathways.

Ca2+ Cycling Alteration in a Porcine Model of Right Ventricular Dysfunction

BACKGROUND

Pulmonary hypertension is a severe disease with high mortality rates due to right ventricular (RV) failure. The molecular and cellular processes involved in RV remodeling, including Ca2+ handling, remain elusive due to the lack of relevant animal models. In this study, we aim to understand better the pathophysiological mechanisms involved in RV failure.

METHODS

We used the chronic thromboembolic pulmonary hypertension (CTEPH) pig model, which leads to progressive RV hypertrophy and dysfunction. Cellular, molecular unbiased global transcriptional profiling and biochemical analyses were performed on RV cardiomyocytes from CTEPH and Sham-operated pigs.

RESULTS

CTEPH pigs replicated the hemodynamics and histological changes of human CTEPH features. Transcriptome analysis in Sham and CTEPH pigs revealed molecular RV remodeling close to human patients with pulmonary arterial hypertension with decompensated RV function and notably identified changes in genes involved in Ca2+ signaling. At the cellular level, CTEPH myocytes presented reduced L-type Ca2+ current in association with reduced mRNA of CACNA1C. Furthermore, CTEPH myocytes showed lower [Ca2+]i transients, decreased sarcoplasmic reticulum Ca2+ content, and decreased cell shortening, related to reduced SERCA2a (Sarco/endoplasmic reticulum Ca2+-ATPase isoform 2a) protein expression. Moreover, CTEPH cardiomyocytes exhibited reduced Ca2+ spark occurrence, which relied on smaller RyR2 (ryanodine receptor 2) clusters and T-tubule disorganization. Finally, these alterations in Ca2+ homeostasis were also associated with an increased store-operated Ca2+ entry and the de novo expression of the Ca2+ sensor protein STIM1L in CTEPH myocytes as well as in RV from human patients with pulmonary arterial hypertension.

CONCLUSIONS

Our data reveal cellular Ca2+ cycling remodeling that participates in the pathogenesis of RV dysfunction and may constitute therapeutic targets to limit the development of RV dysfunction.

Clinical outcomes of pregnancy in patients with pulmonary hypertension: A single center observational study

BACKGROUND

Pulmonary hypertension (PH) is associated with right ventricular failure in pregnant women and increases maternal morbidity and mortality during parturition and postpartum periods. According to current guidelines, pregnancy is contraindicated in women with PH. However, in recent decades, favorable outcomes have been observed in cases where the disease is well controlled. However, several questions remain unanswered regarding this issue.

OBJECTIVE

This study aimed to investigate the medium-term outcomes of pregnancy in women with PH and to identify predictors for poor pregnancy outcomes in this population.

METHODS

A retrospective review of the medical records at our hospital was conducted to identify pregnant women with PH between July 2017 and December 2021. We collected data on maternal age, gravidity, parity, PH category, New York Heart Association Function class, N-terminal-pro Brain natriuretic peptide (NT-ProBNP) levels, mode of delivery, type of anesthesia, use of advanced therapy, and fetal outcomes. Based on the severity of PH, patients were categorized into three groups: group A systolic pulmonary arterial pressure (SPAP) 40-50 mmHg, group B 50-70 mmHg, and group C SPAP ≥ 70 mmHg.

RESULTS

The study included 78 individuals in group A, 22 in group B, and 18 in group C. Of the 118 individuals, 80 were classified as having pulmonary arterial hypertension (PAH), including congenital heart disease-associated PAH, idiopathic PAH, and other PAH subtypes, while 38 were classified as having PH associated with left heart disease (PH-LHD). The mortality rate was higher in the PAH category (6.3%, 5/80) than in the PH-LHD category (2.6%, 1/38). The NT-proBNP value was highest in group C (1723.5 ± 738.0pg/ml), compared with group B (196.6 ± 79.6 pg/ml) and group A (128.7 ± 54.3 pg/ml). Overall maternal mortality was 5.1% (6/118), with significantly higher mortality rates observed in group C (27.8%, 5/18) compared to group B (4.6%, 1/22), and no deaths in group A. Compared to groups A and B, gestational duration was shorter (median 26 weeks), and abortion rates were higher (38.9%, 7/18) in group C. Cesarean section rates were high across all three groups. The overall maternal mortality rate was 5.1% (6/118). Of them, five individuals were in group C, only one woman had moderate PH with perinatal cardiomyopathy and a lower LVEF of 15%. There was no maternal mortality in Group A with mild PH. All maternal deaths occurred postpartum. Excluding 17 cases of miscarriage (gestation less than 28 weeks), the overall offspring mortality rate was 4.0% (4/101), with one fetal mortality in group B, three fetal deaths in group C, and no fetal mortality observed in group A.

CONCLUSION

Severe PH and high NT-proBNP levels are strongly correlated with increased maternal mortality rates in pregnant women. Conception should be contraindicated in cases of severe PAH with elevated NT-proBNP levels. In situations where unplanned pregnancy occurs in severe PAH patients with decompensated heart function, early pregnancy termination and multidisciplinary management are crucial to ensure maternal safety. However, pregnancy should be considered individually in women with moderate and mild PH and preserved right heart function.

Genetic screening in cohort of Egyptian patients with pulmonary arterial hypertension disease

BACKGROUND

Variants in the bone morphogenetic protein 2 receptor gene (BMPR2) are the most frequent genetic cause of pulmonary arterial hypertension (PAH). However, correlation of BMPR2 variants and PAH clinical phenotype remains to be elucidated.

METHODS AND RESULTS

The goal of the present study is to investigate variants of the causative gene (BMPR2) in 25 Egyptian patients clinically pre-diagnosed with PAH symptoms and 10 healthy candidates using Sanger sequencing technique. Three pathogenic heterozygous missense variants have been illustrated in BMPR2 gene, two novel variants (V387E, E481K) in exon 9 and 11 respectively and one previously reported missense variant (C496G) in exon 11. The remaining 22 patients as well as the 10 healthy individuals showed no pathogenic variants.

CONCLUSION

Further studies on larger number of participants, using advanced NGS technique, should be performed to enrich information about genotype/phenotype correlations and incidence of PAH disease among Egyptian population; thus, it would provide families of PAH patients with accurate genetic counseling in order to prevent disease recurrence.

Survival rates at one and five years for patients with group 1 pulmonary arterial hypertension at high altitude: A retrospective cohort study

ObjectivesGroup 1 pulmonary arterial hypertension (PAH) causes increased vascular resistance, right heart failure, and reduced survival. High-altitude PAH survival data are limited despite chronic hypoxia's potential impact on disease progression and risk stratification. The objective was to evaluate survival stratified by the European Society of Cardiology/European Respiratory Society (ESC/ERS) baseline risk score, REVEAL risk score 2.0, and etiologies in patients with PAH at high altitudes.MethodsA retrospective cohort study was conducted to evaluate functional and hemodynamic variables and risk stratification using the ESC/ERS baseline risk score and REVEAL risk score 2.0. One-year and five-year survival rates were determined from admission to the pulmonary hypertension program until death or the end of follow-up.ResultsA total of 188 patients were included. The overall survival rate at one year was 95.8%, and at five years it was 86.8%. Precisely, 50% (95 out of 188) had congenital heart disease, 34% (63 out of 188) had idiopathic, and 13% (24 out of 188) had connective tissue disease. Risk stratification using REVEAL risk score 2.0 classified 58% (109 out of 188) of patients as low risk, 26% as intermediate risk, and 16% (30 out of 188) as high risk. Using the ESC/ERS baseline risk score, Stratification indicated 78% (146 out of 188) low risk, 21% (40 out of 188) intermediate risk, and 1% (2 out of 188) high risk. High risk according to ESC/ERS baseline risk score (p < 0.001) and REVEAL risk score 2.0 (p < 0.001) was associated with lower survival. Idiopathic etiology was associated with a lower survival rate (p = 0.011).ConclusionThe survival of patients with PAH at a high-altitude expert center was 95.8% at one year and 86.8% at five years. Risk stratification using the REVEAL risk score 2.0 and the ESC/ERS baseline risk score was associated with higher mortality in patients classified as high risk.

Bradycardias in Patients with Pulmonary Hypertension-Prevalence, Pathophysiology and Clinical Relevance

INTRODUCTION

Arrhythmias are a frequent complication of pulmonary hypertension (PH). Supraventricular tachycardias (SVT) are predominantly reported and are associated with clinical deterioration and an increased mortality. In contrast, the prevalence and clinical relevance of bradycardias is largely unclear. Therefore, the aim of the present study was to determine a prevalence of bradycardias in PH patients and to outline their clinical relevance.

MATERIAL AND METHODS

Between January 2000 and June 2013, consecutive PH patients were pro- and retrospectively enrolled in two cohorts. Patients received either a 24 h or 72 h Holter ECG.

RESULTS

A total of 314 patients (58% female, mean age: 63 years) from PH groups 1-5 (39%, 11%, 19%, 28%, 3%) were included. Basic heart rhythm was sinus rhythm in 87% of patients (9% atrial fibrillation, 2% atrial flutter and 2% paced rhythm). Further arrhythmias were detected in 34% of patients (SVT: 12%, non-sustained ventricular tachycardia: 16%) with a 6% prevalence of relevant bradycardias. Atrioventricular block was revealed in 5% of patients (seven first-degree, one and three second-degree Wenckebach and Mobitz type, respectively, four third-degree), and 1% revealed sinoatrial block (one second-degree, third-degree and unspecified each).

CONCLUSIONS

The prevalence of bradycardias appears to be about 5-10% in PH patients. Most of them are short and self-limiting. However, some patients experience syncope or clinical deterioration and, therefore, need specific treatment. To find these patients, long-term ECG monitoring combined with ECG-symptom correlation may be useful. Bradycardic medication should be excluded as a cause.

Central Venous Pressure as a Predictor of Acute Kidney Injury in Cardiac Surgery: A Systematic Review of Observational Studies

Background/Objectives: Acute kidney injury (AKI) is a syndrome characterized by impaired kidney function, which is associated with reduced survival and increased morbidity. Central venous pressure (CVP) is a widely used hemodynamic parameter for assessing the volume status of patients and evaluating their response to fluid resuscitation. This systematic review aims to analyze various prospective and retrospective observational and controlled trials to determine the association between CVP and the risk of developing AKI in patients undergoing cardiac surgery. Additionally, it examines whether elevated CVP serves as an accurate predictor of AKI in this patient population. Methods: A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, using PubMed as the primary database. The search focused on studies published after 2014 that included adult patients undergoing cardiac surgery with reported measurements of CVP and kidney function assessment. Studies conducted on animals, pediatric populations, those published before 2014, or in languages other than English were excluded from the review. Results: Through the analysis of 21 studies, a clear association between higher CVP and increased AKI risk emerged. The most critical CVP thresholds identified were 10 mmHg, 12 mmHg, 14 mmHg, and 20 mmHg, with risk increasing progressively beyond these values. CVP ≥ 10 mmHg was the most commonly reported cutoff for elevated AKI risk, showing 1.42 to 4.53 times increased odds. CVP ≥ 12 mmHg further amplified the risk, while CVP ≥ 14 mmHg was consistently associated with severe AKI and the need for RRT. The highest threshold (CVP ≥ 20 mmHg) showed the greatest risk escalation, linked to fluid overload, right heart failure, and mortality. Studies also suggest an optimal CVP range of 6-8 mmHg to minimize AKI incidence. Conclusions: Elevated CVP is an independent risk factor for the development of AKI in patients undergoing cardiac surgery. These findings suggest that CVP monitoring can play a significant role in predicting AKI and guiding perioperative management strategies.

PTN secreted by cardiac fibroblasts promotes myocardial fibrosis and inflammation of pressure overload-induced hypertrophic cardiomyopathy through the PTN-SDC4 pathway

AIMS

Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left ventricular hypertrophy (LVH) with key pathologic processes including myocardial necrosis, fibrosis, inflammation, and hypertrophy, which are involved in heart failure (HF), stroke, and even sudden death. Our aim was to explore the communication network among various cells in the heart of transverse aortic constriction (TAC) surgery induced HCM mice.

MATERIALS AND METHODS

Single-cell RNA-seq data of GSE137167 was downloaded from the Gene Expression Omnibus (GEO) database. Seurat was used to perform the standard workflow. CellChat was utilized to compute the cell-cell interaction network and analyze the ligand-receptor pairs. Weighted gene co-expression network analysis (WGCNA) was conducted to identify gene co-expression modules. In vitro and in vivo studies were performed to verify bioinformatic analysis findings through real-time quantitative PCR (RT-qPCR), Edu staining, transwell assay, western blot, immunofluorescence assay, CCK-8, hematoxylin and eosin (H&E) staining, and echocardiography based on TAC mouse model.

KEY FINDINGS

Our results showed that after TAC surgery, the interaction between cardiac fibroblasts and macrophages was very common, and the increasing pleiotrophin (PTN) ligand secreted by cardiac fibroblasts could promote the self-proliferation or invasion for myocardial fibrosis as well as stimulate the inflammatory response of macrophages to contribute TAC surgery induced HCM through acting on Syndecan 4 (SDC4) receptor.

SIGNIFICANCE

Our study demonstrates that PTN derived from cardiac fibroblasts may play potential role in pressure overload-induced HCM through activating the PTN-SDC4 pathway in cardiac fibroblasts and macrophages, which may be a potential therapeutic target for pressure overload-induced HCM patients.

Test-retest Assessment of Biventricular Myocardial Oxidative Metabolism and Perfusion in Pulmonary Hypertension Patients Using 11C-acetate PET Imaging: A Pilot Study

PURPOSE

11C-acetate PET is used to measure biventricular oxygen myocardial consumption rate (MVO2) and myocardial blood flow (MBF) changes associated with right ventricular (RV) remodelling. We studied PET reproducibility and repeatability for such RV assessments.

PROCEDURES

10 pulmonary hypertension (PH) patients underwent 11C-acetate PET. Five of these patients also had a repeat scan after 26 ± 2 weeks. A one-tissue compartment model was used to measure the myocardial tissue-activity washout rate (k2 [1/min] for MVO2 estimation) and the blood-to-tissue activity flux (K1 [1/min] for MBF calculation). Values were measured by 2 blinded observers and analyzed by ANOVA and Bland-Altman tests. The interquartile ranges (IQR), within-subject coefficients of variation (wCV), and intraclass correlation coefficients (ICC) were reported.

RESULTS

All patients had stable PH with the clinical assessments showed comparable biventricular function and size between baseline and follow-up. The k2-derived MVO2 and K1-derived MBF values were consistently higher in the LV than RV. The high inter- and intra-observer reproducibility (for biventricular MVO2 and MBF) was indicated by low IQR (≤ 7.6%) and wCV (≤ 8%) as well as high ICC (≥ 95%). The test-retest (baseline to follow-up) repeatability showed larger IQR (≤ 35.4%) and wCV (≤ 29%) but consistently high ICC (= 95%).

CONCLUSIONS

MVO2 and MBF values measured in the RV of patients with PH were highly reproducible and repeatable. This can help inform the design of clinical research studies using serial 11C-acetate PET imaging to evaluate RV metabolism.

The role of the TAPSE/sPAP ratio as a predictor of mortality in Pulmonary Arterial Hypertension: Its value for patient risk stratification

Background

The tricuspid annular plane systolic excursion and systolic pulmonary artery pressure (TAPSE/sPAP) ratio has been proposed as an indicator of ventriculo-arterial coupling, predicting right ventricular failure (RVF) and mortality in patients with pulmonary arterial hypertension (PAH).

Objective

To evaluate the usefulness of the TAPSE/sPAP ratio in predicting outcomes and improving risk stratification in patients with PAH.

Methods

156 patients with PAH were included. Clinical, functional, echocardiographic, and haemodynamic variables, along with the TAPSE/sPAP ratio, were analysed based on etiological PAH subgroups and outcomes. Additional statistical measures, such as the area under the curve (AUC), net reclassification index (NRI), and integrated discrimination improvement, assessed the predictive ability of TAPSE/sPAP in combination with the ESC/ERS risk score, and other risk assessment strategies (COMPERA and Reveal Lite 2).

Results

Most patients were female (86.5%), with a median age of 45.5 (IQR: 29-58) years. The TAPSE/sPAP ratio for the whole group was 0.26 (IQR: 0.190-0.347) mm/mmHg, which was similar among different aetiologies, but different between deceased and surviving patients (0.14 vs. 0.27 mm/mmHg, respectively, P < 0.001). A TAPSE/sPAP ratio <0.18 mm/mmHg independently predicted mortality (AUC: 0.859, 95% CI: 0.766- 0.952; P < 0.001). Integration with the ESC/ERS risk score improved predicted mortality (AUC: 0.87 vs. 0.75, p = 0.002) and risk stratification, reclassifying 14.28% of events and 36.92% of non-events, with an NRI of 39.4% (P < 0.001). Likewise, integration with other scores improved predicted ability of COMPERA and REVEA Lite2; COMPERA+TAPSE/sPAP (AUC: 0.837 vs 0.742; p = 0.005) and REVEAL Lite 2 +TAPSE/sPAP (AUC: 0.840 vs. 0.713; p < 0.001).

Conclusions

A TAPSE/sPAP ratio <0.18 mm/mmHg predicts mortality in PAH. The combination of the TAPSE/sPAP ratio with the ESC/ERS risk score improved risk stratification, and reclassification emphasizing the potential of ESC/ERS+TAPSE/sPAP as a valuable tool for risk assessment and clinical decision-making in PAH patients. Integration of TAPSE/sPAP ratio with other scores (COMPERA and (REVEAL Lite 2) also improved the risk stratification and reclassification of these risk scores.

Mechanisms and treatment of pulmonary arterial hypertension

Substantial progress has been made in the management of pulmonary arterial hypertension (PAH) in the past 25 years, but the disease remains life-limiting. Established therapies for PAH are mostly limited to symptomatic relief by correcting the imbalance of vasoactive factors. The tyrosine kinase inhibitor imatinib, the first predominantly non-vasodilatory drug to be tested in patients with PAH, improved exercise capacity and pulmonary haemodynamics compared with placebo but at the expense of adverse events such as subdural haematoma. Given that administration by inhalation might reduce the risk of systemic adverse effects, inhaled formulations of tyrosine kinase inhibitors are currently in clinical development. Other novel therapeutic approaches for PAH include suppression of activin receptor type IIA signalling with sotatercept, which has shown substantial efficacy in clinical trials and was approved for use in the USA in 2024, but the long-term safety of the drug remains unclear. Future advances in the management of PAH will focus on right ventricular function and involve deep phenotyping and the development of a personalized medicine approach. In this Review, we summarize the mechanisms underlying PAH, provide an overview of available PAH therapies and their limitations, describe the development of newer, predominantly non-vasodilatory drugs that are currently being tested in phase II or III clinical trials, and discuss future directions for PAH research.

Echocardiographic Parameters of the Right Ventricle in Patients With Pulmonary Hypertension: A Review

To diagnose pulmonary hypertension (PH) and assess its severity, accurate measurement of pulmonary artery (PA) pressure is crucial. However, there can be significant discrepancies between echocardiography (Echo) and invasive catheterization. The right ventricle (RV) has a complex structure, and its remodeling in PH is diverse, making it challenging to evaluate RV physiology with a single imaging modality. While right heart catheterization is the gold standard, its practicality in clinical settings is limited. Cardiac magnetic resonance imaging (MRI) is valuable for RV evaluation, with 4-dimensional flow MRI showing promise, yet accessibility remains a concern. Thus, in PH patient management, Echo plays a central role as a practical decision-making tool. This review aims to elucidate Echo parameters in PH patients, highlighting differences in PA systolic pressure measurements, RV-PA coupling, RV remodeling patterns crucial for understanding PH progression, and clinical evidence regarding RV strain. Additionally, it aims to introduce new Echo parameters that help understand RV in PH.

Exercise Pulmonary Hypertension and Beyond: Insights in Exercise Pathophysiology in Pulmonary Arterial Hypertension (PAH) from Invasive Cardiopulmonary Exercise Testing

Pulmonary arterial hypertension (PAH) is a rare, progressive disease of the pulmonary vasculature that is associated with pulmonary vascular remodeling and right heart failure. While there have been recent advances both in understanding pathobiology and in diagnosis and therapeutic options, PAH remains a disease with significant delays in diagnosis and high morbidity and mortality. Information from invasive cardiopulmonary exercise testing (iCPET) presents an important opportunity to evaluate the dynamic interactions within and between the right heart circulatory system and the skeletal muscle during different loading conditions to enhance early diagnosis, phenotype disease subtypes, and personalize treatment in PAH given the shortcomings of contemporary diagnostic and therapeutic approaches. The purpose of this review is to present the current applications of iCPET in PAH and to discuss future applications of the testing methodology.

Pathophysiology of Group 3 Pulmonary Hypertension Associated with Lung Diseases and/or Hypoxia

Pulmonary hypertension associated with lung diseases and/or hypoxia is classified as group 3 in the clinical classification of pulmonary hypertension. The efficacy of existing selective pulmonary vasodilators for group 3 pulmonary hypertension is still unknown, and it is currently associated with a poor prognosis. The mechanisms by which pulmonary hypertension occurs include hypoxic pulmonary vasoconstriction, pulmonary vascular remodeling, a decrease in pulmonary vascular beds, endothelial dysfunction, endothelial-to-mesenchymal transition, mitochondrial dysfunction, oxidative stress, hypoxia-inducible factors (HIFs), inflammation, microRNA, and genetic predisposition. Among these, hypoxic pulmonary vasoconstriction and subsequent pulmonary vascular remodeling are characteristic factors involving the pulmonary vasculature and are the focus of this review. Several factors have been reported to mediate vascular remodeling induced by hypoxic pulmonary vasoconstriction, such as HIF-1α and mechanosensors, including TRP channels. New therapies that target novel molecules, such as mechanoreceptors, to inhibit vascular remodeling are awaited.

Evolving perspectives on aortic stenosis: the increasing importance of evaluating the right ventricle before aortic valve intervention

Aortic stenosis (AS) was historically considered a disease of the left side of the heart, with the main pathophysiological impact being predominantly on the left ventricle (LV). However, progressive pressure overload in AS can initiate a cascade of extra-valvular myocardial remodeling that could also precipitate maladaptive alterations in the structure and function of the right ventricle (RV). The haemodynamic and clinical importance of these changes in patients with AS have been largely underappreciated in the past. Contemporary data indicates that RV dilatation or impairment identifies the AS patients who are at increased risk of adverse clinical outcomes after aortic valve replacement (AVR). It is now increasingly recognised that effective quantitative assessment of the RV plays a key role in delineating the late clinical stage of AS, which could improve patient risk stratification. Despite the increasing emphasis on the pathological significance of RV changes in AS, it remains to be established if earlier detection of these changes can improve the timing for intervention. This review will summarise the features of normal RV physiology and the mechanisms responsible for RV impairment in AS. In addition, we will discuss the multimodality approach to the comprehensive assessment of RV size, function and mechanics in AS patients. Finally, we will review the emerging evidence reinforcing the negative impact of RV dysfunction on clinical outcomes in AS patients treated with AVR.

Right ventricular myocardial work: proof-of-concept for the assessment of pressure-strain loops of patients with pre-capillary pulmonary hypertension

BACKGROUND

Right ventricular myocardial work (RVMW) assessed by transthoracic echocardiography allows to study the right ventricular (RV) function using RV pressure-strain loops. The assessment of these novel indexes of RVMW has not yet been exten sively studied, namely in pre-capillary pulmonary hypertension (PH) population.

OBJECTIVES

to evaluate the relationship between RVMW and invasive indices of right heart catheterization (RHC) in a cohort of patients with group I and group IV PH and to compare with a control group without PH.

METHODS

A prospective registry of pre-capillary PH patients was used and compared with a control group without PH. In both groups, patients underwent same day RHC and echocardiographic assessment. Dedicated software for left ventricle myocardial work was used for the RV. RV global work index (RVGWI) was calculated as the area of the RV pressure-strain loops. From RVGWI, RV global constructive work (RVGCW), RV global wasted work (RVGWW), and RV global work efficiency (RVGWE) were estimated.

RESULTS

25 pts were included: 17 pts with PH were compared with 8 pts without PH. RVGWI, RVGCW and RVGWW were significantly higher in PH patients than in controls (p < 0,05), while RVGWE was significantly lower (p < 0,05). Significant correlations were found between mean pulmonary artery pressure, cardiac index, venous oxygen saturation, NT-proBNP and RVGCW, RVGWW and RVGWE; between pulmonary vascular resistance, cardiac output, right ventricular stroke work and RVGWI, RVGCW, RVGWW and RVGWE; between stroke volume and RVGWW and RVGWE; between pulmonary artery pulsatility index and RVGWI, RVGCW and RVGWW; between RA pressure and RVGWE.

CONCLUSIONS

Patients with pre-capillary PH present significantly higher RVGWI, RVGCW and RVGWW and lower RVGWE than patients without PH. Echocardiographic RVMW-derived indexes show significant correlation with invasive measurements and NT-proBNP. Larger studies are needed to assess the prognostic value of these novel indexes.

Management of Critically Ill Patients With Pulmonary Arterial Hypertension in Transport: A Narrative Review

Pulmonary arterial hypertension (PAH) is a unique disease process with a highly complex physiology. Patients with PAH are often on specialized medications that exert specific hemodynamic effects. Furthermore, when they become critically ill, the management strategy can be counterintuitive. Commonly accepted, evidence-based management for the general population, such as fluid boluses in the setting of sepsis, can be harmful to this patient cohort. Often, these patients require highly specialized care at tertiary and quaternary centers, which necessitates critical care transport. Therefore, it is important that critical care transport crews understand the distinctive pathophysiology and management of critically ill patients with PAH.

An Unsupervised Approach to Derive Right Ventricular Pressure-Volume Loop Phenotypes in Pulmonary Hypertension

Although right ventricle (RV) dysfunction drives clinical worsening in pulmonary hypertension (PH), information about RV function has not been well integrated in PH risk assessment. The gold standard for assessing RV function and ventriculo-arterial coupling is the construction of multi-beat pressure-volume (PV) loops. PV loops are technically challenging to acquire and not feasible for routine clinical use. Therefore, we aimed to map standard clinically available measurements to emergent PV loop phenotypes. One hundred and one patients with suspected PH underwent right heart catheterization (RHC) with exercise, multi-beat PV loop measurement, and same-day cardiac magnetic resonance imaging (CMR). We applied unsupervised k-means clustering on 10 PV loop metrics to obtain three patient groups with unique RV functional phenotypes and times to clinical worsening. We integrated RHC and CMR measurements to train a random forest classifier that predicts the PV loop patient group with high discrimination (AUC = 0.93). The most informative variable for PV loop phenotype prediction was exercise mean pulmonary arterial pressure (mPAP). Distinct and clinically meaningful PV loop phenotypes exist that can be predicted using clinically accessible hemodynamic and RV-centric measurements. Exercise mPAP may inform RV pressure-volume relationships.

Cardiopulmonary Exercise Testing in Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease that has a high impact on patients' quality of life, morbidity and mortality. PAH is characterized by extensive pulmonary vascular remodeling that results in an increase in pulmonary vascular resistance and right ventricular afterload, and can lead to right heart failure. Patients with PAH exhibit inefficient ventilation, high dead space ventilation, dynamic hyperinflation, and ventricular-arterial uncoupling, which can contribute to high dyspnea and low exercise tolerance. Cardiopulmonary exercise testing can help to diagnose PAH, define prognosis and treatment response in PAH, as well as discriminate between different pulmonary vascular diseases.

Echocardiography of the right heart in pulmonary arterial hypertension: insights from the ULTRA RIGHT VALUE study

Aims

Outcome in pulmonary arterial hypertension (PAH) is determined by right ventricular (RV) function adaptation to increased afterload. Echocardiography is easily available to assist bedside evaluation of the RV. However, no agreement exists about the feasibility and most relevant measurements. We therefore examined the feasibility, quality, and clinical correlations of standard echocardiographic variables in the evaluation of PAH.

Methods and results

The present multicentric study collected echocardiographic examinations with centralized reading in 401 patients with prevalent PAH. Clinical variables, as World Health Organization (WHO) functional class (FC), 6 min walk distance (6MWD), brain natriuretic peptide (BNP)/NT-proBNP, invasive haemodynamics, the European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines-derived four-strata score, and the United States Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) 2.0 score, were also collected. Echocardiographic measurements showed variable degrees of dilation of the right heart as assessed by right atrial and RV areas, altered indices of systolic function such as tricuspid annular plane systolic excursion (TAPSE), fractional area change, or 2D strain, and derived estimates of RV to pulmonary artery (PA) coupling by referring these measurements to systolic PA pressure (sPAP). All these measurements were feasible. All measurements of right heart dimensions and function, particularly TAPSE/sPAP, were correlated with WHO-FC, 6MWD, BNP/NT-proBNP, invasive haemodynamics, and ESC/ERS and REVEAL 2.0 scores.

Conclusion

The present quality-controlled data from a network of PAH referral centres offer the background needed for further evaluation of the added value of echocardiography to currently recommended risk assessments in PAH.

The Diagnostic Accuracy of an Electrocardiogram in Pulmonary Hypertension and the Role of "R V1, V2 + S I, aVL - S V1"

Background: Pulmonary hypertension (PH) can cause characteristic electrocardiographic (ECG) changes due to right ventricular hypertrophy and/or strain. The aims of the present study were to explore the diagnostic accuracy of ECG parameters for the diagnosis of PH, applying the recently adjusted mean pulmonary artery pressure (mPAP) threshold of >20 mmHg, and to determine the role of "R V1, V2 + S I, aVL - S V1". Methods: Between July 2012 and November 2023, 100 patients without PH, with pulmonary arterial hypertension, or with chronic thromboembolic pulmonary hypertension were retrospectively enrolled. Results: The sensitivity and specificity of the ECG parameters for the diagnosis of PH varied from 3 to 98% and from 3 to 100% (means: 39% and 87%). After optimising the parameters' cut-offs, the mean sensitivity (39% to 66%) increased significantly but the mean specificity (87% to 74%) slightly decreased. "R V1, V2 + S I, aVL - S V1" was able to predict an mPAP >20 mmHg (OR: 34.33; p < 0.001) and a pulmonary vascular resistance >5 WU (OR: 17.14, p < 0.001) but could not predict all-cause mortality. Conclusions: Even with improved cut-offs, ECG parameters alone are not able to reliably diagnose or exclude PH because of their low sensitivity. However, they still might be helpful to reveal a suspicion of PH, especially in early diagnostic stages, e.g., in primary care with general practitioners or non-specialised cardiologists and pulmonologists. "R V1, V2 + S I, aVL - S V1" was able to predict the diagnosis of (severe) PH but could not predict all-cause mortality. Nevertheless, it can still be useful in risk stratification.

Intraoperative right ventricular end-systolic pressure-volume loop analysis in patients undergoing cardiac surgery: A proof-of-concept methodology

Background

Perioperative right ventricular (RV) dysfunction is associated with increased morbidity and mortality in cardiac surgery patients. This study aimed to demonstrate proof of concept in generating intraoperative RV pressure-volume (PV) loops and conducting an end-systolic PV relationship (ESPVR) analysis using data obtained from routinely used intraoperative monitors.

Methods

Adult patients undergoing cardiac surgery with the placement of a pulmonary artery catheter (PAC) between May 2023 and March 2024 were included prospectively. The PV loops were generated using 3-dimensional echocardiographic RV volume data and continuous RV pressure data obtained from a PAC. The volume-time and pressure-time curves were digitized using the semiautomatic WebPlotDigitizer program and synchronized to reconstruct an RV PV loop and analyze ESPVR using the previously validated single-beat method.

Results

Intraoperative RV PV loops were generated for 25 patients, including 17 patients with preserved RV systolic function (group 1) and 8 patients with reduced systolic function (group 2). Mean Ees, Ea, and Ees/Ea ratio were 0.63 ± 0.25 mm Hg/mL, 0.60 ± 0.23 mm Hg/mL, and 1.0 8 ± 0.31 mm Hg/mL, respectively, by the Pmax method and 0.56 ± 0.32 mm Hg/mL, 0.60 ± 0.23 mm Hg/mL, and 0.91 ± 0.21 mm Hg/mL, respectively, by the V0 method. Group 1 had a significantly higher Ees compared to group 2 regardless of the calculation method and a larger Ees/Ea ratio calculated by the V0 method.

Conclusions

It is clinically feasible to derive RV PV loops from routine hemodynamic and echocardiographic data. With further validation and technological support, this can be a potential real-time intraoperative RV function monitoring tool.

SGLT2 inhibitors as a potential therapeutic option for pulmonary hypertension: mechanisms and clinical perspectives

Pulmonary arterial hypertension (PAH), one subtype of pulmonary hypertension (PH), is a life-threatening condition characterized by pulmonary arterial remodeling, elevated pulmonary vascular resistance, and blood pressure in the pulmonary arteries, leading to right heart failure and increased mortality. The disease is marked by endothelial dysfunction, vasoconstriction, and vascular remodeling. The role of Sodium-Glucose Co-Transporter-2 (SGLT2) inhibitors, a class of medications originally developed for diabetes management, is increasingly being explored in the context of cardiovascular diseases, including PAH, due to their potential to modulate these pathophysiological processes. In this review, we systematically examine the burgeoning evidence from both basic and clinical studies that describe the effects of SGLT2 inhibitors on cardiovascular health, with a special emphasis on PAH. By delving into the complex interactions between these drugs and the potential pathobiology that underpins PH, this study seeks to uncover the mechanistic underpinnings that could justify the use of SGLT2 inhibitors as a novel therapeutic approach for PAH. We collate findings that illustrate how SGLT2 inhibitors may influence the normal function of pulmonary arteries, possibly alleviating the pathological hallmarks of PAH such as inflammation, oxidative stress, aberrant cellular proliferation, and so on. Our review thereby outlines a potential paradigm shift in PAH management, suggesting that these inhibitors could play a crucial role in modulating the disease's progression by targeting the potential dysfunctions that drive it. This comprehensive synthesis of existing research underscores the imperative need for further clinical trials to validate the efficacy of SGLT2 inhibitors in PAH and to integrate them into the therapeutic agents used against this challenging disease.

Pulmonary arterial hypertension: Navigating the pathways of progress in diagnosis, treatment, and patient care

Pulmonary arterial hypertension (PAH) is a form of precapillary pulmonary hypertension caused by a complex process of endothelial dysfunction and vascular remodeling. If left untreated, this progressive disease presents with symptoms of incapacitating fatigue causing marked loss of quality of life, eventually culminating in right ventricular failure and death. Patient management is complex and based on accurate diagnosis, risk stratification, and treatment initiation, with close monitoring of response and disease progression. Understanding the underlying pathophysiology has enabled the development of multiple drugs directed at different targets in the pathological chain. Vasodilator therapy has been the mainstay approach for the last few years, significantly improving quality of life, functional status, and survival. Recent advances in therapies targeting dysfunctional pathways beyond endothelial dysfunction may address the fundamental processes underlying the disease, raising the prospect of increasingly effective options for this high-risk group of patients with a historically poor prognosis.

Long-term swimming exercise attenuates right ventricular hypertrophy via modulating meta-inflammation in monocrotaline-induced pulmonary hypertensive rats

Pulmonary arterial hypertension (PAH) is a complex disease characterized by elevated pulmonary vascular resistance, resulting in right ventricular (RV) hypertrophy and, eventually, failure, which remains the primary cause of mortality in PAH patients. While current PAH therapies primarily target vascular abnormalities, most fail to address RV dysfunction. Therefore, improving RV function is a critical treatment goal. Exercise has emerged as an effective intervention for PAH, but the specific impact of swimming exercise on this disease and its associated pathological changes has been less extensively studied. In this study, we investigated the effects of swimming training (60 min/day, 5 days/week for 4 weeks) on monocrotaline (MCT; 60 mg/kg, i. p.)-induced PAH in rats. Our findings demonstrate that swimming significantly attenuates RV hypertrophy and reduces mean pulmonary arterial pressure (MPAP), mitigating the detrimental effects of PAH. Furthermore, we observed structural remodeling in the right ventricle, including increased myocardial necrosis, collagen deposition, and fibrosis-related protein expression. Swimming exercise training was found to reduce these pathological changes, suggesting a protective effect on the right ventricle. Mechanistically, our study revealed the crucial role of meta-inflammation in PAH and the anti-PAH effects of exercise. Swimming training attenuated macrophage accumulation, reduced serum inflammatory cytokines, and improved systemic and RV insulin sensitivity, highlighting its potential to modulate meta-inflammatory processes. In summary, our study suggests that swimming training exerts a beneficial effect on RV function and hypertrophy in MCT-induced PAH rats by targeting meta-inflammation. These results underscore the potential value of exercise-based rehabilitation as a complementary therapy for PAH patients.

Integrative Multiomics in the Lung Reveals a Protective Role of Asporin in Pulmonary Arterial Hypertension

BACKGROUND

Integrative multiomics can elucidate pulmonary arterial hypertension (PAH) pathobiology, but procuring human PAH lung samples is rare.

METHODS

We leveraged transcriptomic profiling and deep phenotyping of the largest multicenter PAH lung biobank to date (96 disease and 52 control) by integration with clinicopathologic data, genome-wide association studies, Bayesian regulatory networks, single-cell transcriptomics, and pharmacotranscriptomics.

RESULTS

We identified 2 potentially protective gene network modules associated with vascular cells, and we validated ASPN, coding for asporin, as a key hub gene that is upregulated as a compensatory response to counteract PAH. We found that asporin is upregulated in lungs and plasma of multiple independent PAH cohorts and correlates with reduced PAH severity. We show that asporin inhibits proliferation and transforming growth factor-β/phosphorylated SMAD2/3 signaling in pulmonary artery smooth muscle cells from PAH lungs. We demonstrate in Sugen-hypoxia rats that ASPN knockdown exacerbated PAH and recombinant asporin attenuated PAH.

CONCLUSIONS

Our integrative systems biology approach to dissect the PAH lung transcriptome uncovered asporin as a novel protective target with therapeutic potential in PAH.

Pathophysiology of the right ventricle and its pulmonary vascular interaction

The right ventricle and its stress response is perhaps the most important arbiter of survival in patients with pulmonary hypertension of many causes. The physiology of the cardiopulmonary unit and definition of right heart failure proposed in the 2018 World Symposium on Pulmonary Hypertension have proven useful constructs in subsequent years. Here, we review updated knowledge of basic mechanisms that drive right ventricular function in health and disease, and which may be useful for therapeutic intervention in the future. We further contextualise new knowledge on assessment of right ventricular function with a focus on metrics readily available to clinicians and updated understanding of the roles of the right atrium and tricuspid regurgitation. Typical right ventricular phenotypes in relevant forms of pulmonary vascular disease are reviewed and recent studies of pharmacological interventions on chronic right ventricular failure are discussed. Finally, unanswered questions and future directions are proposed.

Right ventricular phenotyping in incident patients with idiopathic pulmonary arterial hypertension

BACKGROUND

Right ventricular (RV) imaging has not a definite role in risk stratification of pulmonary arterial hypertension (PAH) patients. We tested the hypothesis that echocardiography-derived phenotypes, depicting different degrees of RV remodeling and dysfunction, may provide additional prognostic information to current risk stratification tools.

METHODS

Consecutive incident PAH patients aged ≥18 years, diagnosed between January 2005 and December 2021, underwent clinical assessment, right heart catheterization, standard echocardiography. Simple echocardiographic variables were combined in order to define a priori four phenotypes representing different degrees of RV dilatation and RV-pulmonary arterial (PA) coupling: Phenotype 1 with mildy dilated right ventricle and preserved RV-PA coupling (n = 152 patients); phenotype 2 with mildly dilated right ventricle and poor RV-PA coupling (n = 143 patients); phenotype 3 with severely dilated right ventricle and preserved RV-PA coupling (n = 201 patients); phenotype 4 with severely dilated right ventricle and poor RV-PA coupling, with or without severe tricuspid regurgitation (n = 519 patients). Risk stratification was based on the European Society of Cardiology/European Respiratory Society (ESC/ERS) 3-strata model and Registry to Evaluate Early and Long-Term PAH disease Management (REVEAL) 2.0 score.

RESULTS

These phenotypes were present in all risk groups. Notably, regardless of the ESC/ERS risk stratum assigned to the patient, phenotype 4 was associated with a 2-fold increase of the odds of death (HR 2.1, 95% CI 1.6-2.8, p < 0.001), while phenotype 1 was associated with a 71% reduction in the odds of dying (HR 0.29, 95% CI 0.18-0.47, p < 0.001).

CONCLUSIONS

Echocardiography-derived phenotypes describing RV remodeling and dysfunction may provide prognostic information which is independent of and additional to the clinically defined risk in incident PAH patients.

Carotid Baroreceptor Stimulation Ameliorates Pulmonary Arterial Remodeling in Rats With Hypoxia-Induced Pulmonary Hypertension

BACKGROUND

Sympathetic hyperactivity plays an important role in the initiation and maintenance of pulmonary hypertension. Carotid baroreceptor stimulation (CBS) is an effective autonomic neuromodulation therapy. We aim to investigate the effects of CBS on hypoxia-induced pulmonary hypertension and its underlying mechanisms.

METHODS AND RESULTS

Rats were randomly assigned into 4 groups, including a Control-sham group (n=7), a Control-CBS group (n=7), a Hypoxia-sham group (n=10) and a Hypoxia-CBS group (n=10). Echocardiography, ECG, and hemodynamics examination were performed. Samples of blood, lung tissue, pulmonary arteries, and right ventricle were collected for the further analysis. In the in vivo study, CBS reduced wall thickness and muscularization degree in pulmonary arterioles, thereby improving pulmonary hemodynamics. Right ventricle hypertrophy, fibrosis and dysfunction were all improved. CBS rebalanced autonomic tone and reduced the density of sympathetic nerves around pulmonary artery trunks and bifurcations. RNA-seq analysis identified BDNF and periostin (POSTN) as key genes involved in hypoxia-induced pulmonary hypertension, and CBS downregulated the mRNA expression of BDNF and POSTN in rat pulmonary arteries. In the in vitro study, norepinephrine was found to promote pulmonary artery smooth muscle cell proliferation while upregulating BDNF and POSTN expression. The proliferative effect was alleviated by silence BDNF or POSTN.

CONCLUSIONS

Our results showed that CBS could rebalance autonomic tone, inhibit pulmonary arterial remodeling, and improve pulmonary hemodynamics and right ventricle function, thus delaying hypoxia-induced pulmonary hypertension progression. There may be a reciprocal interaction between POSTN and BDNF that is responsible for the underlying mechanism.

Transplantation, bridging, and support technologies in pulmonary hypertension

Despite the progress made in medical therapies for treating pulmonary hypertension (PH), a subset of patients remain susceptible to developing a maladaptive right ventricular phenotype. The effective management of end-stage PH presents substantial challenges, necessitating a multidisciplinary approach and early identification of patients prone to acute decompensation. Identifying potential transplant candidates and assessing the feasibility of such a procedure are pivotal tasks that should be undertaken early in the treatment algorithm. Inclusion on the transplant list is contingent upon a comprehensive risk assessment, also considering the specific type of PH and various factors affecting waiting times, all of which should inform the decision-making process. While bilateral lung transplantation is the preferred option, it demands expert intra- and post-operative management to mitigate the heightened risks of pulmonary oedema and primary graft dysfunction in PH patients. Despite the availability of risk assessment tools, the occurrence of acute PH decompensation episodes can be unpredictable, potentially leading to refractory right ventricular failure even with optimal medical intervention, necessitating the use of rescue therapies. Advancements in right ventricular assist techniques and adjustments to graft allocation protocols for the most critically ill patients have significantly enhanced the survival in intensive care, affording the opportunity to endure while awaiting an urgent transplant. Given the breadth of therapeutic options available, specialised centres capable of delivering comprehensive care have become indispensable for optimising patient outcomes. These centres are instrumental in providing holistic support and management tailored to the complex needs of PH patients, ultimately enhancing their chances of a successful transplant and improved long-term prognosis.

Prognostic Role of RVGLS/PASP Ratio, a New Echocardiographic Parameter of the Right Ventricle-Pulmonary Artery Coupling, in Patients With Acute Heart Failure

Background and Objectives

Few studies have addressed the predictive implications of right ventricular (RV) and pulmonary arterial (PA) coupling as assessed by echocardiography in patients with acute heart failure (AHF). This study aimed to ascertain the prognostic importance of RV-PA coupling in AHF cases and discern any divergence in its prognostic efficacy based on different heart failure (HF) phenotypes.

Methods

We evaluated RV-PA coupling by measuring the ratio of right ventricular global longitudinal strain (RVGLS) to pulmonary arterial systolic pressure (PASP), termed the RVGLS/PASP ratio, and assessed its prognostic role using the STrain for Risk Assessment and Therapeutic Strategies in Patients with Acute Heart Failure registry.

Results

From an AHF registry of 4312 patients, we analyzed the RVGLS/PASP ratio in 2,865 patients (1,449 men; age, 71.1±13.5 years). At a median follow-up of 35.0 months, 1,199 (41.8%) patients died. Remarkably, PASP (hazard ratio [HR], 1.012; p<0.001), RVGLS (HR, 1.019; p<0.001), and the RVGLS/PASP ratio (HR, 2.426; p<0.001) were statistically significant predictors of all-cause mortality in the univariate analysis. The RVGLS/PASP ratio was a significant predictor of all-cause mortality in all the HF phenotypes, including HF with reduced ejection fraction (HR, 2.124; p=0.002), HF with mildly reduced ejection fraction (HR, 2.733; p=0.021), and HF with preserved ejection fraction (HR, 2.134; p=0.006). Multivariate analysis after adjusting for clinical and echocardiographic variables revealed that the RVGLS/PASP ratio ≤0.32 was associated with a 36% increase in all-cause mortality (HR, 1.365; p<0.001).

Conclusions

Impaired RV-PA coupling, defined as an RVGLS/PASP ratio (≤0.32) was associated with an increased risk of mortality in patients with AHF across all HF phenotypes.

Trial Registration

ClinicalTrials.gov Identifier: NCT03513653.

Tricuspid annular plane systolic excursion to pulmonary artery systolic pressure ratio in chronic thromboembolic pulmonary hypertension improves with balloon pulmonary angioplasty

Right ventricle (RV)-to-pulmonary artery (PA) coupling measured by the ratio of echocardiography-derived tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) is a meaningful prognostic marker in pulmonary hypertension (PH). It's unclear if balloon pulmonary angioplasty (BPA) treatment of chronic thromboembolic pulmonary hypertension (CTEPH) alters RV-PA coupling measured by TAPSE/PASP. We reviewed CTEPH patients treated with BPA at our institution who had a transthoracic echocardiogram (TTE) before BPA and a follow-up TTE at any point during BPA. TAPSE was obtained from the initial and lattermost TTE; hemodynamics were obtained before each BPA session. Between March 2015 to October 2023, there were 228 patients treated with BPA. After excluding post-PTE patients and those without PH, 67 were included. Initial TAPSE/PASP was 0.39 ± 0.21 mm/mmHg. Using previously defined TAPSE/PASP tertiles in PH (<0.19, 0.19-0.32, >0.32 mm/mmHg), there were 6 patients (9%) in low, 30 (45%) in middle, and 31 (46%) in the high tertiles at baseline. The lower TAPSE/PASP tertiles had more severe baseline hemodynamics (p < 0.001) compared to the high TAPSE/PASP cohort. At follow-up, TAPSE/PASP improved to 0.47 ± 0.20 mm/mmHg (p = 0.023), with 2 (3%), 13 (19%), and 52 (78%) patients in the low, middle, high TAPSE/PASP tertiles, respectively. As patients progress through BPA sessions, the TAPSE/PASP ratio increases, possibly reflecting improved RV mechanics and RV-PA coupling. TAPSE/PASP ratio as a marker of RV-PA coupling can improve with BPA treatment and may be an important measure to follow during treatment of CTEPH.

Cardiac Failure and Cardiogenic Shock: Insights Into Pathophysiology, Classification, and Hemodynamic Assessment

Heart failure is defined as increased intracardiac pressures, either alone or combined with reduced cardiac output. Clinically, it is presented with signs and symptoms of congestion and compensated perfusion. Cardiogenic shock, on the other hand, is the spectrum of hemodynamic disturbances that lead to hypoperfusion or need for circulatory support, due to cardiac disease. Both entities affect millions of people worldwide, have a dismal prognosis, and constitute a severe socioeconomic burden. Heart failure can be the aftermath of ischemic heart disease, hypertension, arrhythmias, or cardiomyopathies. It undergoes multiple classifications, facilitating its investigation and treatment. The pathogenetic mechanisms differ in various types of heart failure, regarding the affected ventricles, the duration of symptoms, and their primary/secondary onset. These mechanisms reflect the complex interactions between cardiopulmonary, vascular, and hepatorenal systems. Acute deterioration of cardiac function can lead to cardiogenic shock. Myocardial infarction accounts for 81% of such cases. Healthy lifestyle and timely management of coronary artery disease are paramount, as they can prevent this life-threatening situation and reduce mortality and the economic burden for healthcare systems. Irrespective of the etiology, cardiogenic shock is interpreted using the pressure-volume loop. This can be modified for each ventricle, the underlying pathophysiology, and the time since symptoms' onset. It therefore provides valuable information about the native circulation and the expected alterations under mechanical or pharmacological support, facilitating the decision-making progress. In 2019, given the phenotypical heterogeneity of cardiogenic shock, the Society for Cardiovascular Angiography and Interventions introduced a classification system. According to this, patients are stratified in five stages proportionally to the severity of their condition. Aside from this classification, various biochemical, imaging, and hemodynamic monitoring indices are used to assess coagulation pathway and cardiac, hepatorenal, and pulmonary function, enabling the heart team to tailor therapy. Additionally, the prognostication progress is facilitated by scores, such as the Observatoire Regional Breton sur l'Infarctus (ORBI) score, the intra-aortic balloon pump (IABP) SHOCK-II score, and the CardShock score, indicating suitable escalation or de-escalation strategies. Despite the current progress, there are several areas of advancement regarding the role of vasoactive drugs in cardiogenic shock, revascularization options, mechanical ventilation patterns, hypothermia treatment, and mechanical circulatory support protocols.

Effects of dopamine β-hydroxylase inhibition in pressure overload-induced right ventricular failure

Activation of the sympathetic nervous system is observed in pulmonary arterial hypertension patients. This study investigates whether inhibiting the conversion of dopamine into noradrenaline by dopamine β-hydroxylase (DβH) inhibition with BIA 21-5337 improved right ventricular (RV) function or remodeling in pressure overload-induced RV failure. RV failure was induced in male Wistar rats by pulmonary trunk banding (PTB). Two weeks after the procedure, PTB rats were randomized to vehicle (n = 8) or BIA 21-5337 (n = 11) treatment. An additional PTB group treated with ivabradine (n = 11) was included to control for the potential heart rate-reducing effects of BIA 21-5337. A sham group (n = 6) received vehicle treatment. After 5 weeks of treatment, RV function was assessed by echocardiography, magnetic resonance imaging, and invasive pressure-volume measurements before rats were euthanized. RV myocardium was analyzed to evaluate RV remodeling. PTB caused a fourfold increase in RV afterload which led to RV dysfunction, remodeling, and failure. Treatment with BIA 21-5337 reduced adrenal gland DβH activity and 24-h urinary noradrenaline levels confirming relevant physiological response to the treatment. At end-of-study, there were no differences in RV function or RV remodeling between BIA 21-5337 and vehicle-treated rats. In conclusion, treatment with BIA 21-5337 did not have any beneficial-nor adverse-effects on the development of RV failure after PTB despite reduced adrenal gland DβH activity.

Post-capillary pulmonary hypertension in heart failure: impact of current definition in the PH-HF multicentre study

BACKGROUND AND AIMS

Based on retrospective studies, the 2022 European guidelines changed the definition of post-capillary pulmonary hypertension (pcPH) in heart failure (HF) by lowering the level of mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR). However, the impact of this definition and its prognostic value has never been evaluated prospectively.

METHODS

Stable left HF patients with the need for right heart catheterization were enrolled from 2010 to 2018 and prospectively followed up in this multicentre study. The impact of the successive pcPH definitions on pcPH prevalence and subgroup [i.e. isolated (IpcPH) vs. combined pcPH (CpcPH)] was evaluated. Multivariable Cox regression analysis was used to assess the prognostic value of mPAP and PVR on all-cause death or hospitalization for HF (primary outcome).

RESULTS

Included were 662 HF patients were (median age 63 years, 60% male). Lowering mPAP from 25 to 20 mmHg resulted in +10% increase in pcPH prevalence, whereas lowering PVR from 3 to 2 resulted in +60% increase in CpcPH prevalence (with significant net reclassification improvement for the primary outcome). In multivariable analysis, both mPAP and PVR remained associated with the primary outcome [hazard ratio (HR) 1.02, 95% confidence interval (CI) 1.00-1.03, P = .01; HR 1.07, 95% CI 1.00-1.14, P = .03]. The best PVR threshold associated with the primary outcome was around 2.2 WU. Using the 2022 definition, pcPH patients had worse survival compared with HF patients without pcPH (log-rank, P = .02) as well as CpcPH compared with IpcPH (log-rank, P = .003).

CONCLUSIONS

This study is the first emphasizing the impact of the new pcPH definition on CpcPH prevalence and validating the prognostic value of mPAP > 20 mmHg and PVR > 2 WU among HF patients.

Pulmonary Hypertension and Right Ventricle: A Pathophysiological Insight

Background

Pulmonary hypertension (PH) is a pulmonary vascular disease characterized by elevated pulmonary vascular pressure. Long-term PH, irrespective of its etiology, leads to increased right ventricular (RV) pressure, RV hypertrophy, and ultimately, RV failure.

Main body

Research indicates that RV failure secondary to hypertrophy remains the primary cause of mortality in pulmonary arterial hypertension (PAH). However, the impact of PH on RV structure and function under increased overload remains incompletely understood. Several mechanisms have been proposed, including extracellular remodeling, RV hypertrophy, metabolic disturbances, inflammation, apoptosis, autophagy, endothelial-to-mesenchymal transition, neurohormonal dysregulation, capillary rarefaction, and ischemia.

Conclusions

Studies have demonstrated the significant role of oxidative stress in the development of RV failure. Understanding the interplay among these mechanisms is crucial for the prevention and management of RV failure in patients with PH.

Chronic thromboembolic pulmonary hypertension: the diagnostic assessment

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) presents a significant diagnostic challenge due to its complex and often nonspecific clinical manifestations. This review outlines a comprehensive approach to the diagnostic assessment of CTEPH, emphasizing the importance of a high index of suspicion in patients with unexplained dyspnea or persistent symptoms post-acute pulmonary embolism. We discuss the pivotal role of multimodal imaging, including echocardiography, ventilation/perfusion scans, CT pulmonary angiography, and magnetic resonance imaging, in the identification and confirmation of CTEPH. Furthermore, the review highlights the essential function of right heart catheterization in validating the hemodynamic parameters indicative of CTEPH, establishing its definitive diagnosis. Advances in diagnostic technologies and the integration of a multidisciplinary approach are critical for the timely and accurate diagnosis of CTEPH, facilitating early therapeutic intervention and improving patient outcomes. This manuscript aims to equip clinicians with the knowledge and tools necessary for the efficient diagnostic workflow of CTEPH, promoting awareness and understanding of this potentially treatable cause of pulmonary hypertension.

DYZY01 alleviates pulmonary hypertension via inhibiting endothelial cell pyroptosis and rescuing endothelial dysfunction

Pulmonary hypertension (PH) is a malignant pulmonary vascular disease with a poor prognosis. Although the development of targeted drugs for this disease has made some breakthroughs in recent decades, PH remains incurable. Therefore, innovative clinical treatment methods and drugs for PH are still urgently needed. DYZY01 is a new drug whose main ingredient is high-purity cannabidiol, a non-psychoactive constituent of cannabinoids that was demonstrated to have anti-inflammatory and anti-pyroptosis properties. Several recent studies have found cannabidiol could improve experimental PH, whereas the mechanistic effect of it warrants further investigation. Thus, this study aimed to investigate whether DYZY01 can treat PH by inhibiting inflammation and pyroptosis and to reveal its underlying mechanism. We established hypoxia and monocrotaline (MCT)-induced PH rat models in vivo and treated them with either DYZY01 (10,50 mg/kg/d) or Riociguat (10 mg/kg/d) by oral administration. The mean pulmonary arterial pressure (mPAP), right ventricular hypertrophy index (RVHI), and extent of vascular remodeling were measured. Meanwhile, the effect of DYZY01 on human pulmonary arterial endothelial cells (HPAECs) was assessed in vitro. The results indicated that DYZY01 significantly reduced mPAP and RVHI in PH rats and reversed the extent of pulmonary vascular remodeling. This improvement may have been achieved by reducing endothelial cell pyroptosis via inhibiting the NF-κB/NLRP3/Caspase-1 pathway. Furthermore, DYZY01 could improve endothelial vascular function, possibly by regulating the secretion of vasodilator factors and inhibiting the proliferation and migration of pulmonary endothelial cells.

Contemporary Treatment of Pulmonary Arterial Hypertension: A U.S. Perspective

Pulmonary arterial hypertension (PAH) is a complex fatal condition that requires aggressive treatment with close monitoring. Significant progress has been made over the last three decades in the treatment of PAH, but, despite this progress, survival has remained unacceptably low. In the quest to improve survival, therapeutic interventions play a central role. In the last few years, there have been remarkable attempts to identify novel treatments. Finally, we have had a breakthrough with the discovery of the fourth treatment pathway in PAH. Activin signaling inhibition distinguishes itself as a potential antiproliferative intervention as opposed to the traditional therapies, which mediate their effect primarily by vasodilatation. With this novel treatment pathway, we stand at an important milestone with an exciting future ahead and the natural question of when to use an activin signaling inhibitor for the treatment of PAH. In this state-of-the-art review, we focus on the placement of this novel agent in the PAH treatment paradigm, based on the available evidence, with special focus on the U.S. patient population. This review also provides an expert opinion of the current treatment algorithm in important subgroups of patients with comorbidities from the U.S. perspective.

Therapeutic approaches for pulmonary hypertension in patients with chronic kidney disease

PURPOSE OF REVIEW

Pulmonary hypertension is a common comorbidity in patients with chronic kidney disease (CKD), but therapeutic options are limited. We discuss the epidemiology of pulmonary hypertension in patients with CKD and review therapies for pulmonary hypertension with a focus on emerging treatments for pulmonary arterial hypertension (PAH).

RECENT FINDINGS

The definition of pulmonary hypertension has been updated to a lower threshold of mean pulmonary artery pressures of more than 20 mmHg, potentially leading to more patients with CKD to qualify for the diagnosis of pulmonary hypertension. Endothelin receptor antagonists, a class of medications, which demonstrated efficacy in patients with PAH, have been shown to slow progression of CKD, but their efficacy in lowering pulmonary artery pressures and their effects on reducing cardiovascular mortality in this population remains unproven. Sotatercept, a novel activin signaling inhibitor, which was previously studied in dialysis patients has been shown to increase exercise capacity in patients with PAH. These studies may lead to new specific therapies for pulmonary hypertension in patients with CKD.

SUMMARY

Pulmonary hypertension is common in patients with CKD. Although our understanding of factors leading to pulmonary hypertension in this population have evolved, evidence supporting disease-specific therapy in CKD is limited arguing for larger, long-term studies.

The importance of incorporating ventricular-ventricular interaction (VVI) in the study of pulmonary hypertension

Ventricular ventricular interaction (VVI) affects blood volume and pressure in the right and left ventricles of the heart due to the location and balance of forces on the septal wall separating the ventricles. In healthy patients, the pressure of the left ventricle is considerably higher than the right, resulting in a septal wall that bows into the right ventricle. However, in patients with pulmonary hypertension, the pressure in the right ventricle increases significantly to a point where the pressure is similar to or surpasses that of the left ventricle during portions of the cardiac cycle. For these patients, the septal wall deviates towards the left ventricle, impacting its function. It is possible to study this effect using mathematical modeling, but existing models are nonlinear, leading to a system of algebraic differential equations that can be challenging to solve in patient-specific optimizations of clinical data. This study demonstrates that a simplified linearized model is sufficient to account for the effect of VVI and that, as expected, the impact is significantly more pronounced in patients with pulmonary hypertension.

A PrOsPective Cohort Study on Interstitial Lung Disease-Associated Pulmonary Hypertension with a ParticulaR Focus on the Subset with Pulmonary Arterial Hypertension Features (POPLAR Study)

INTRODUCTION

The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.

STUDY OBJECTIVE

This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.

METHODS

The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with "ILD-PH with PAH features" and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.

RESULTS

This is a protocol article and the results will be presented after data collection is completed.

CONCLUSION

The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.

TRIAL REGISTRATION

Japan Registry of Clinical Trials: jRCT1010230018.

Tricuspid annular plane systolic excursion over systolic pulmonary artery pressure prognostic value for in-hospital adverse events in patients hospitalized for acute coronary syndrome

AIMS

Although several studies have shown that the right ventricular to pulmonary artery (RV-PA) coupling, assessed by the ratio between tricuspid annular plane systolic excursion and systolic pulmonary artery pressure (TAPSE/sPAP) using echocardiography, is strongly associated with cardiovascular events, its prognostic value is not established in acute coronary syndrome (ACS). We aimed to assess the in-hospital prognostic value of TAPSE/sPAP among patients hospitalized for ACS in a retrospective analysis from the prospective ADDICT-ICCU study.

METHODS AND RESULTS

A total of 481 consecutive patients hospitalized in intensive cardiac care unit [mean age 65 ± 13 years, 73% of male, 46% ST-elevation myocardial infarction (STEMI)] for ACS [either STEMI or non-STEMI (NSTEMI)] with TAPSE/sPAP available were included in this prospective French multicentric study (39 centres). The primary outcome was in-hospital major adverse cardiovascular events (MACEs) defined as all-cause death, resuscitated cardiac arrest, or cardiogenic shock and occurred in 33 (7%) patients. Receiver operating characteristic curve analysis identified 0.55 mm/mmHg as the best TAPSE/sPAP cut-off to predict in-hospital MACEs. TAPSE/sPAP <0.55 was associated with in-hospital MACEs, even after adjustment with comorbidities [odds ratio (OR): 19.1, 95% confidence interval (CI) 7.78-54.8], clinical severity including left ventricular ejection fraction (OR: 14.4, 95% CI 5.70-41.7), and propensity-matched population analysis (OR: 22.8, 95% CI 7.83-97.2, all P < 0.001). After adjustment, TAPSE/sPAP <0.55 showed the best improvement in model discrimination and reclassification above traditional prognosticators (C-statistic improvement: 0.16; global χ2 improvement: 52.8; likelihood ratio test P < 0.001) with similar results for both STEMI and NSTEMI subgroups.

CONCLUSION

A low RV-PA coupling defined as TAPSE/sPAP ratio <0.55 was independently associated with in-hospital MACEs and provided incremental prognostic value over traditional prognosticators in patients hospitalized for ACS.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05063097.

Load Dependency of Ventricular Pump Function: Impact on the Non-Invasive Evaluation of the Severity and the Prognostic Relevance of Myocardial Dysfunction

Ventricular pump function, which is determined by myocyte contractility, preload and afterload, and, additionally, also significantly influenced by heart rhythm, synchrony of intraventricular contraction and ventricular interdependence, explains the difficulties in establishing the contribution of myocardial contractile dysfunction to the development and progression of heart failure. Estimating myocardial contractility is one of the most difficult challenges because the most commonly used clinical measurements of cardiac performance cannot differentiate contractility changes from alterations in ventricular loading conditions. Under both physiological and pathological conditions, there is also a permanent complex interaction between myocardial contractility, ventricular anatomy and hemodynamic loading conditions. All this explains why no single parameter can alone reveal the real picture of ventricular dysfunction. Over time there has been increasing recognition that a load-independent contractility parameter cannot truly exist, because loading itself changes the myofilament force-generating capacity. Because the use of a single parameter is inadequate, it is necessary to perform multiparametric evaluations and also apply integrative approaches using parameter combinations which include details about ventricular loading conditions. This is particularly important for evaluating the highly afterload-sensitive right ventricular function. In this regard, the existence of certain reluctance particularly to the implementation of non-invasively obtainable parameter combinations in the routine clinical praxis should be reconsidered in the future. Among the non-invasive approaches used to evaluate ventricular function in connection with its current loading conditions, assessment of the relationship between ventricular contraction (e.g., myocardial displacement or deformation) and pressure overload, or the relationship between ejection volume (or ejection velocity) and pressure overload, as well as the relationship between ventricular dilation and pressure overload, were found useful for therapeutic decision-making. In the future, it will be unavoidable to take the load dependency of ventricular function much more into consideration. A solid basis for achieving this goal will be obtainable by intensifying the clinical research necessary to provide more evidence for the practical importance of this largely unsolved problem.

Ultrasound-assisted catheter-directed thrombolysis versus surgical pulmonary embolectomy for intermediate-high or high-risk pulmonary embolism: a randomized phase II non-inferiority trial

OBJECTIVES

We hypothesized that ultrasound-assisted thrombolysis (USAT) is non-inferior to surgical pulmonary embolectomy (SPE) to improve right ventricular (RV) function in patients with acute pulmonary embolism (PE).

METHODS

In a single-centre, non-inferiority trial, we randomly assigned 27 patients with intermediate-high or high-risk acute PE to undergo either USAT or SPE stratified by PE risk. Primary and secondary outcomes were the baseline-to-72-h difference in right-to-left ventricular (RV/LV) ratio and the Qanadli pulmonary occlusion score, respectively, by contrast-enhanced chest-computed tomography assessed by a blinded CoreLab.

RESULTS

The trial was prematurely terminated due to slow enrolment. Mean age was 62.6 (SD 12.4) years, 26% were women, and 15% had high-risk PE. Mean change in RV/LV ratio was -0.34 (95% CI -0.50 to -0.18) in the USAT and -0.53 (95% CI -0.68 to -0.38) in the SPE group (mean difference: 0.152; 95% CI 0.032-0.271; Pnon-inferiority = 0.80; Psuperiority = 0.013). Mean change in Qanadli pulmonary occlusion score was -7.23 (95% CI -9.58 to -4.88) in the USAT and -11.36 (95% CI -15.27 to -7.44) in the SPE group (mean difference: 5.00; 95% CI 0.44-9.56, P = 0.032). Clinical and functional outcomes were similar between the 2 groups up to 12 months.

CONCLUSIONS

In patients with intermediate-high and high-risk acute PE, USAT was not non-inferior when compared with SPE in reducing RV/LV ratio within the first 72 h. In a post hoc superiority analysis, SPE resulted in greater improvement of RV overload and reduction of thrombus burden.

Biventricular Dysfunction and Ventricular Interdependence in Patients With Pulmonary Hypertension: A 3.0-T Cardiac MRI Feature Tracking Study

BACKGROUND

Pulmonary hypertension (PH) results in right ventricular (RV) dysfunction, subsequently leading to left ventricular (LV) impairment. The mechanism underlying ventricular interdependence is largely uninvestigated.

PURPOSE

To explore the biventricular dysfunction and the ventricular interdependence in PH patients.

STUDY TYPE

Retrospective.

POPULATION

One hundred and seven PH patients (mean pulmonary artery pressure >20 mmHg) and 72 age- and sex-matched controls with cardiac magnetic resonance imaging (MRI) studies.

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession sequence.

ASSESSMENT

LV and RV ejection fractions (EF) and RV and LV radial, circumferential, and longitudinal strains were assessed using commercial software. Strains were compared between controls, PH patients with preserved RVEF (RVEF ≥40%, N = 48), and PH patients with reduced RVEF (RVEF <40%, N = 59).

STATISTICAL TESTS

Chi-squared tests or Fisher's exact test, t tests or Mann-Whitney U test, one-way ANOVA with Bonferroni's post hoc correction or Kruskal-Wallis test, Pearson or Spearman correlation, and multivariable linear regression analysis. A two-tailed P < 0.05 was deemed statistically significant.

RESULTS

RV strain decreased sequentially from controls, through PH with preserved RVEF, to PH with reduced RVEF. PH patients with reduced RVEF had significantly lower LV strain, especially septal strain, and LV peak diastolic strain rate compared with both controls and PH patients with preserved RVEF. Multivariable analyses showed that RVEF was independently correlated with LV strain; furthermore, independent of RVEF, RV strain was significantly correlated with LV strain (LVGRS: β = 0.416; LVGCS: β = -0.371; LVGLS: β = 0.283).

DATA CONCLUSION

Subclinical impairment of RV function was found in PH with preserved RVEF. LV strain was impaired when RV was dysfunctional, which was associated with worsening RV strain. Therefore, while focusing on improving RV function, LV dysfunction in PH patients should also be monitored and treated early in order to slow the progression of the disease.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

An electrocardiogram-based AI algorithm for early detection of pulmonary hypertension

BACKGROUND

Early diagnosis of pulmonary hypertension (PH) is critical for effective treatment and management. We aimed to develop and externally validate an artificial intelligence algorithm that could serve as a PH screening tool, based on analysis of a standard 12-lead ECG.

METHODS

The PH Early Detection Algorithm (PH-EDA) is a convolutional neural network developed using retrospective ECG voltage-time data, with patients classified as "PH-likely" or "PH-unlikely" (controls) based on right heart catheterisation or echocardiography. In total, 39 823 PH-likely patients and 219 404 control patients from Mayo Clinic were randomly split into training (48%), validation (12%) and test (40%) sets. ECGs taken within 1 month of PH diagnosis (diagnostic dataset) were used to train the PH-EDA at Mayo Clinic. Performance was tested on diagnostic ECGs within the test sets from Mayo Clinic (n=16 175/87 998 PH-likely/controls) and Vanderbilt University Medical Center (VUMC; n=6045/24 256 PH-likely/controls). In addition, performance was tested on ECGs taken 6-18 months (pre-emptive dataset), and up to 5 years prior to a PH diagnosis at both sites.

RESULTS

Performance testing yielded an area under the receiver operating characteristic curve (AUC) of 0.92 and 0.88 in the diagnostic test sets at Mayo Clinic and VUMC, respectively, and 0.86 and 0.81, respectively, in the pre-emptive test sets. The AUC remained a minimum of 0.79 at Mayo Clinic and 0.73 at VUMC up to 5 years before diagnosis.

CONCLUSION

The PH-EDA can detect PH at diagnosis and 6-18 months prior, demonstrating the potential to accelerate diagnosis and management of this debilitating disease.