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Background: Pulmonary hypertension (PH) is a life-threatening disease affecting up to 1% of the global population. Diagnosis can be challenging and is often delayed due to the need for advanced imaging and invasive procedures. The use of artificial intelligence applied to ECGs (ECG-AI) has been shown to detect subtle patterns in voltage-time data and may be a valuable tool for the early detection of PH. Hypothesis and Purpose: To evaluate the performance of a previously trained, ECG-AI algorithm to detect PH (ECG-AI PH) using real-world data (RWD) collected in a multicenter, validation study. A joint primary hypothesis required sensitivity (Sn), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) to exceed the null values of 76%, 70%, 10% and 90%. Study Design and Methods: This retrospective validation study was conducted at 5 geographically diverse U.S. health systems. Adult subjects were eligible for inclusion if they had a 12-lead ECG paired with an echocardiogram (Echo) in which tricuspid regurgitation velocity (TRV) was recorded, following presentation with dyspnea. Patients were classified according to echocardiographic criteria as either PH (PH+, TRV >3.4 m/s) or controls (PH-, TRV ≤2.8 m/s) to simulate the real-world use of ECG-AI, where a positive result could lead to a follow-up Echo. The study database was locked before processing the digital ECGs with ECG-AI PH. Performance was also estimated in a subset of subjects that later had a right heart catheterization using mPAP ≥ 20mmHg as the definition of PH. Results: A total of 14281 subjects (53% female, 63% aged 50+ years) met the inclusion criteria, including 3019 PH+ cases and 11262 PH- controls (Figure). Sn and Sp were 84.0% (95% CI: 82.6%, 85.3%) and 71.7% (95% CI: 70.9%, 72.6%), respectively. The positive and negative predictive values were 18.9% (95% CI: 18.4%, 19.4%) and 98.3% (95% CI: 98.1%, 98.4%), respectively, at 7.3% prevalence. Each endpoint met pre-defined performance criteria. In the subset of 1683 subjects with a follow up RHC, performance remained robust (Sn 85% (1155/1358); Sp 46% (151/325)). Conclusion: While ECG-AI PH was first developed as an investigational tool to detect PH, continued development as software as a medical device for clinical use demonstrated that the algorithm retained strong performance to detect PH in diverse, non-overlapping clinical settings and patient populations.

Introduction: PH increases RV afterload, often leading to RV systolic and diastolic failure. The metabolic mechanisms underlying RV dysfunction remain poorly understood and are largely unexplored across non-PAH forms of PH. Aims: We aimed to identify which metabolites and metabolic pathways associated with imaging measures of RV systolic function. Methods: We analyzed data from the multi-center PVDOMICS cohort, which includes echo, CMR, invasive hemodynamics, clinical phenotyping, and untargeted plasma metabolomics (via Metabolon). RV systolic function metrics selected as the outcome measures for this study were fractional area change (echo), global longitudinal strain (echo), and RVEF (CMR). Associations between non-xenobiotic, named metabolites and RV function measures were assessed using linear regression adjusted for age, sex, BMI, and PH group, with significance defined by FDR <0.05. Metabolite set enrichment analysis (MSEA) was performed to identify significantly enriched pathways (FDR <0.20). To complement MSEA, we conducted mean-aggregation analysis: we averaged metabolite concentrations within each pathway and tested associations with RV function using the same covariate adjustments (FDR <0.05). Results: We identified 979 participants with plasma metabolomics and at least one available outcome measure (317 Group 1 PH; 106 Group 2 PH; 140 Group 3 PH; 51 Group 4 PH; 26 Group 5 PH; 81 Healthy Controls; 258 Disease Comparators). Linear regression identified 170 metabolites from the 647 named metabolites significantly associated with all 3 RV metrics (Top 10 by average ranked p-value displayed in Image 1 ). MSEA revealed seven enriched pathways across all RV metrics: Androgenic Steroids, Pregnenolone Steroids, Progestin Steroids, Fatty Acid Metabolism (Acyl Choline), Histidine metabolism, Vitamin A metabolism, Gamma-glutamyl Amino Acid ( Image 2) . Mean aggregation analysis showed that higher concentrations of Androgenic/Pregnenolone Steroids and Vitamin A metabolites strongly associated with improved RV function, while higher levels of Fatty Acid Metabolism (Acyl Carnitine) and Acetylated Peptides associated with worse function ( Image 3 ). Conclusions: Using data from the multi-institutional PVDOMICS cohort, we provide a blueprint of metabolites and metabolic pathways associated with RV systolic function across the spectrum of PH. Steroid hormones as well as Vitamin A and fatty acid metabolites emerged as central to RV systolic function.

Abstract Rationale Pulmonary artery (PA) dilation on computed tomography (CT) has been associated with moderate-to-severe ­pulmonary hypertension (PH) using outdated diagnostic criteria. The association between PA size and mean PA pressure (mPAP) in mild PH and the prognostic implications of PA dilation remain unclear. Objectives To investigate associations between PA size, mPAP, and survival in subjects without significant lung disease aside from PH. Methods PA size on CT was measured for individuals with group 1 or 2 PH and matched controls in the Pulmonary Vascular Disease Phenomics cohort. Outcomes included mPAP on right heart catheterization (RHC) and time to heart and/or lung ­transplantation or death. Measurements and Main Results A total of 691 subjects were included, with 595 undergoing RHC. PA diameter and PA:aorta ratio demonstrated significant association with mPAP (ρ = 0.557 and 0.564, respectively). Size increased incrementally from no PH to mild PH to moderate-severe PH for PA diameter (27.64 [95% CI, 17.64-37.64] mm to 30.65 [95% CI, 18.99-42.31] mm to 36.00 [95% CI, 22.46-49.54] mm) and PA:aorta (0.89 [95% CI, 0.53-1.24] to 0.99 [95% CI, 0.63-1.35] to 1.19 [95% CI, 0.60-1.78]). PA diameter and PA:aorta demonstrated good discrimination of mPAP &gt;20 mm Hg (area under the curve: 0.834 and 0.816, respectively). Transplant-free survival decreased across the continuum of PA diameter and PA:aorta (P &lt;.001). Adjusted hazard ratio of third versus first quartile values was 2.36 (95% CI, 1.58-3.54) for PA diameter and 2.24 (95% CI, 1.52-3.30) for PA:aorta. Conclusions In subjects without significant lung disease outside of PH, PA size on CT was associated with increased mPAP and decreased transplant-free survival across the spectrum of PH severity and demonstrated modest diagnostic discriminatory ability using updated hemodynamic criteria.

Abstract Rationale Pulmonary hypertension (PH) is associated with significant morbidity and mortality. Ground-glass opacities (GGOs) are common in Group 1 PH, but their clinical significance is unclear. Objectives We sought to characterize the clinical features and outcomes of patients with Group 1 PH with and without GGOs in the PVDOMICS study, a prospective multicenter cohort study aimed at deep phenotyping PH. Methods Patients with incident and prevalent PH were enrolled across seven U.S. centers. We included patients with Group 1 PH and excluded those with parenchymal lung disease or without chest imaging, resulting in a cohort of 242 patients. Results GGOs were common among patients with Group 1 PH (43% prevalence), associated with female sex, younger age, prostanoid use, and longer disease duration. GGOs were more common among patients with familial pulmonary arterial hypertension and pulmonary veno-occlusive disease. GGOs were associated with established markers of disease severity, including echocardiographic (right ventricular systolic pressure and tricuspid annular plane systolic excursion), biomarkers (N-terminal pro B-type natriuretic peptide), and worse hemodynamics (higher mean pulmonary artery pressure, pulmonary vascular resistance, and pulmonary artery wedge pressure). GGOs were associated with worse transplant-free survival (hazard ratio, 2.49; 95% confidence interval = 1.43–4.32; P = 0.001) and had independent prognostic value for predicting transplant-free survival after adjusting for European Society of Cardiology and European Respiratory Society risk stratification (hazard ratio, 2.19; 95% confidence interval = 1.20–3.99; P = 0.01). Conclusions Overall, GGOs were associated with specific clinical characteristics and disease phenotypes, as well as worse hemodynamics, longer disease duration, prostanoid use, and worse survival. Future studies evaluating the pathophysiology and “omic” correlates of GGOs are warranted. Clinical trial registered with www.clinicaltrials.gov (NCT02980887).

Abstract Rationale A subset of patients with group 1 pulmonary hypertension (PH) have superimposed left heart abnormalities with unclear metabolic implications. Objectives To compare serum/transpulmonary metabolome between group 1 PH stratified by heart failure with preserved ejection fraction (HFpEF) probability. Methods Patients with group 1 PH were stratified into low (&lt;25%) and high (⩾75%) HFpEF-ABA (age, body mass index, and atrial fibrillation) probability, with healthy control subjects and subjects with clinical HFpEF used for comparison of venous and transpulmonary metabolomics. Measurements and Main Results Group 1 PH + high HFpEF probability (n = 131) was associated with a significant increase in 207 metabolites (false discovery rate [FDR] P &lt; 0.05 and fold change &gt;1) (n = 193, t test) and a significant decrease in 231 metabolites (FDR P &lt; 0.05 and fold change &lt;1) (n = 193, t test) compared with group 1 PH + low HFpEF probability (n = 62). Group 1 PH + high HFpEF probability was associated with enhanced tryptophan metabolism with higher downstream kynurenine metabolite concentrations and lower serotonin concentrations (FDR P &lt; 0.002 for all, n = 193, t test). Linoleate (precursor to arachidonic acid and prostaglandins) and arginine and homoarginine (precursors to nitric oxide) were all lower in group 1 PH + high HFpEF probability (FDR P &lt; 0.03 for all, n = 193, t test). Metabolome changes in group 1 PH + high HFpEF probability overlapped with clinical HFpEF (n = 240) but were abnormal relative to control subjects (n = 85) (P &lt; 0.0001 for all, n = 456, t test). There was no evidence of differential transpulmonary uptake/release of most metabolites, suggesting probable nonpulmonary origin (except for serotonin, interaction P = 0.04; and kynurenine, interaction P = 0.03; n = 433, mixed model). Conclusions Patients with group 1 PH + high HFpEF probability have a unique metabolome characterized by enhanced tryptophan-kynurenine pathway breakdown, deficiency of amino acids (such as glycine and serine), lower serotonin, and decreased prostaglandin and nitric oxide precursors. Despite fulfilling clinical criteria for group 1 PH, these metabolome changes were comparable with clinical HFpEF, supporting biological overlap between these two forms of PH.

BACKGROUND: Patients with lung disease, sleep apnea, and chronic thromboemboli can develop pulmonary hypertension, currently classified as group 3 or 4. Many of these patients also have risk factors for heart failure with preserved ejection fraction (HFpEF), but the optimal approach to identify the disease overlap remains unclear. METHODS: Pretest probability for HFpEF was determined using the HFpEF-ABA (age, body mass index, atrial fibrillation) algorithm among adjudicated group 3 or 4 patients at risk for pulmonary hypertension in the PVDOMICS study (Redefining Pulmonary Hypertension Through Pulmonary Vascular Disease Phenomics). Patients were stratified by current resting right heart catheterization criteria, and in a separate analysis, stratified only by HFpEF-ABA probability into low (<25%), intermediate, and high (≥75%) HFpEF probability groups. RESULTS: Among 598 patients with group 3 disease, 27% (n=161) had elevated pulmonary capillary wedge pressure (PCWP) with postcapillary pulmonary hypertension even at rest, which was associated with the highest exercise PCWP. However, regardless of this resting PCWP-based classification, a larger subset had intermediate-to-high HFpEF-ABA probabilities (32% [n=197] high and 57% [n=358] intermediate HFpEF probability). High HFpEF probability in group 3 disease was associated with higher resting and dynamic PCWP response to NO, fluid, and exercise ( P <0.0001 for all). These changes were comparable with more traditionally defined HFpEF without pulmonary vascular disease (n=61) but less severe than those with combined precapillary and postcapillary pulmonary hypertension HFpEF (n=31; interaction P =0.006). Increasing HFpEF probability in group 3 disease was associated with worse left heart remodeling, quality of life, 6-minute walk distance, and peak VO 2 ( P <0.0001 for all). Findings were replicated in group 4 disease (n=102). CONCLUSIONS: Quantifying pretest probability for HFpEF in patients with sleep apnea, lung disease, or chronic thromboemboli identifies a progressive gradient for dynamic PCWP abnormalities with worse functional status and quality of life. These subclinical left heart abnormalities are not universally detectable by resting right heart catheterization alone and call for further study of whether strategies to prevent or treat HFpEF might improve functional status in these patients with high risk of occult HFpEF.

ABSTRACTThere is a need for objective, continuous and remote assessment of exercise capacity in patients with pulmonary arterial hypertension (PAH). Using data from the TRACE study, in which 108 adult patients with PAH were continuously monitored with a wrist‐worn accelerometer, we evaluated whether actigraphy can facilitate continuous monitoring of exercise capacity. Distributions of step rate, distance and duration of patient's walking bouts were estimated at baseline, Week 16 and Week 24 using 2‐week periods of actigraphy data. Twenty‐one metrics per walking bout characteristic were described (mean, standard deviation, 19 percentiles [5th–95th]). The relationships between these metrics and the 6‐min walk distance (6MWD), Borg dyspnea index (BDI), and the PAH Symptoms and Impact questionnaire (PAH‐SYMPACT) Physical Impact domain score were assessed at the three timepoints. Test‐retest reliability, and discriminant and known‐group validity of each metric were also evaluated. All metrics of step rate and bout distance were significantly correlated with 6MWD (Pearson's correlation coefficients: 0.34–0.67; p < 0.005) and the PAH‐SYMPACT Physical Impact domain score (Pearson's correlation coefficients: −0.51 to −0.32; p < 0.05) at all timepoints. Negative correlations were also observed with the BDI and the actigraphy‐derived metrics, with the majority reaching significance. Strong test‐retest reliability was demonstrated (intra‐class correlation coefficient ≥ 0.70). The metrics differentiated well between patients with varying disease severity levels. In conclusion, actigraphy‐derived metrics of patients' walking bouts correlate significantly with 6MWD, BDI and physical impacts of PAH, indicating the utility of actigraphy in facilitating continuous monitoring of exercise capacity in adult patients with PAH.Trial RegistrationClinicalTrials.gov: NCT03078907; URL: clinicaltrials.gov.

Background Right ventricular (RV) maladaptation to elevated pulmonary afterload is the primary determinant of outcomes in pulmonary artery (PA) hypertension; however, the pathobiological mechanisms underlying RV decompensation remain poorly understood. Methods We performed global untargeted metabolomics on plasma from 55 patients who underwent gold‐standard RV‐PA coupling measurements using multibeat pressure volume loop assessment in a single‐center cohort and from 1027 patients with coupling surrogate measurements in a larger multicenter cohort, the PVDOMICS (Pulmonary Vascular Disease Phenomics) study. Age and sex‐adjusted linear regression was performed to identify associations between metabolites and coupling metrics. Additionally, we performed a metabolic flux analysis using gene expression data from RV tissue in an independent cohort of 32 patients. Partial least squares–discriminant analysis was used to identify metabolites and reactions characteristic of the decompensated RV. Results RV‐PA coupling was negatively associated with tricarboxylic acid (TCA) cycle intermediate levels. Specifically, plasma α‐ketoglutarate and fumarate were significantly associated with all coupling metrics in both cohorts. Metabolic flux analysis indicated that decompensated RVs exhibited aberrant TCA cycle activity, including reduced acetyl coenzyme A entry and increased lactate elimination, suggesting a shift from the TCA cycle toward glycolysis at the RV tissue level. Conclusions We identify an association between circulating TCA cycle intermediate levels and RV‐PA uncoupling in 2 independent cohorts, and dysregulated TCA cycle metabolism in decompensated PA hypertension RVs, suggesting that aberrant TCA cycle metabolism could represent a hallmark of RV maladaptation in PA hypertension. Further study of this pathway is warranted to develop novel biomarkers of RV function or RV‐targeted therapies.

Abstract Rationale: The 7th World Symposium on Pulmonary Hypertension highlighted the importance of patient-reported outcomes in clinical assessment of pulmonary arterial hypertension (PAH). Patient-reported outcomes, such as health-related quality of life (HRQOL), have been associated with morbidity and mortality in PAH, but the added value of HRQOL measures to validated risk prediction models remains unknown. Methods: Adults with RHC-proven PAH from the Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics (PVDOMICS) Study, a multi-center observational study, were included in this study. The Pulmonary Hypertension Association Registry (PHAR) was used as a validation cohort. HRQOL was measured using the emPHasis-10 score, where higher scores reflect worse HRQOL. Noninvasive risk assessment was measured by REVEAL Lite 2 risk score, categorized into 3-strata. Cox proportional hazard models were used to model survival evaluating the interaction between risk strata and HRQOL scores, adjusting for age, sex, and incident diagnosis. Harrell's C-statistics were calculated to compare discriminative performance. Results: From the PVDOMICS and PHAR cohorts, 265 and 2671 individuals with PAH and complete emPHasis-10 and REVEAL Lite 2 scores were included. Both cohorts had similar demographics, with an average age of 52±13 and 56±16 years, 75% and 72% female, 81% and 75% White, in the PVDOMICS and PHAR cohorts respectively. Over 87% of PVDOMICS were prevalent cases of PAH, while in the PHAR half were incident. Most individuals (62%) in PVDOMICS were REVEAL Lite 2 low risk, with 16% intermediate and 22% high risk; by contrast, in PHAR 33% were low, 29% intermediate, and 38% high risk. REVEAL Lite 2 scores demonstrated weak to moderate correlation with emPHasis-10 scores in both cohorts (PVDOMICS r=0.48 p&lt;0.001; PHAR r=0.33 p&lt;0.001). Notably, the full range of emPHasis-10 scores were observed in the low-risk individuals across both cohorts. In the PVDOMICS adjusted Cox models, higher emPHasis-10 scores predicted poorer survival (p=0.047) particularly among low-risk individuals (interaction versus high-risk group p=0.08). Similar adjusted models in PHAR demonstrated emPHasis-10 to be a confounder (p=0.001) without significant interaction by risk strata (low vs high-risk interaction p=0.94), but the greatest change in median survival time was observed in the low-risk group (Figure 1). Addition of emPHasis-10 to REVEAL Lite 2 scores improved discrimination in predicting survival (PVDOMICS: C-statistic 0.71 vs 0.73; PHAR: C-statistic 0.67 vs 0.69). Conclusions: Across two multicenter cohorts of incident and prevalent PAH, HRQOL as measured by the emPHasis-10 score improved discrimination for survival, particularly among individuals with lower risk scores.

Abstract Rationale: Although guidelines recommend the use of provocative testing to diagnose pulmonary venous hypertension (PVH) that is unapparent at normal resting right heart catheterization (RHC), the incremental value of provocative testing is unknown. We aim to evaluate the incremental diagnostic capability of inhaled nitric oxide (iNO), fluid challenge (FC) or invasive cardiopulmonary exercise testing (iCPET) to unmask PVH using previously defined hemodynamic cutoffs. Methods: We included subjects from the NHLBI-funded Pulmonary Vascular Disease Phenomics (PVDOMICS) study. Our analysis included patients with World Symposium on Pulmonary Hypertension (WSPH) Group 2 disease (G2PH) and G2PH comparators (WSPH Group 2 phenotype without a diagnosis of PH) as determined by the PI or adjudication panel. We then applied a protocol-driven provocative approach based on the feasibility of modalities available in most catheterization labs. Using a pulmonary capillary wedge pressure (PCWP) cutoff of &gt;15, frequencies were identified for subjects based on resting PCWP and with iNO. Frequencies were also identified for: those who received FC with a PCWP cutoff of ≥18 or those who received iCPET with PCWP cutoff of &gt;20 (upright) or &gt;25 (supine). Results: There were 419 subjects identified with WSPH Group 2 disease (Figure). Roughly half were found to have a PCWP &gt;15 during resting RHC (N = 207). Of the remaining subjects with a resting PCWP ≤15 (N = 150), 42 subjects were found to have a PCWP &gt;15 with iNO administration (40.0%). Of the remaining 63 subjects with PCWP ≤15 following iNO administration, nearly half (N = 26, 48.0%) demonstrated a PCWP ≥18 following FC while 8 subjects (14.8%) demonstrated an elevated PCWP following iCPET. Conclusions: There is a high proportion of G2PH patients (∼35%) who appear hemodynamically similar to precapillary PH at rest. Inhaled nitric oxide vasodilatory challenge unmasks G2PH in many patients. In situations where iNO does not disclose the G2PH phenotype, provocation with FC or iCPET can be useful as a supplementary provocative maneuver. Future directions will focus on agnostically assessing the utility of provocation based on grouping subjects by resting hemodynamics as well as assessing the use of provocation in other forms of PH.