Frantz, Robert P.

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 Introduction Sex-based differences in morbidity and mortality for pulmonary hypertension (PH) are insufficiently addressed in current research. However, recognizing these differences is crucial for optimal clinical management and improving outcomes. This study assesses the effect of sex on survival among PH patients, while accounting for disease severity, comorbidities, treatment, and race. Methods We analyzed data from the PVRI GoDeep meta-registry, including all incident patients with complete hemodynamic profiles. Survival was evaluated using Kaplan-Meier and Cox proportional hazards models, adjusted for various confounders. Analyses included both PAH and non-PAH groups and risk assessment by the ESC/ERS 2022, REVEAL lite 2, and COMPERA 4-strata scores. All analyses were performed using R (The R Foundation). Results A total of 19,663 incident PH patients were included in the analysis, with 5,581 patients (28%) diagnosed with Group 1 PH and a median age of 64 years [IQR: 52-73]. Among these, male patients (8,704, 44%) had a significantly higher mortality risk than female patients across the entire cohort and within all PH subtypes. The adjusted hazard ratio for mortality in male versus female patients was 1.391 [95% CI: 1.260-1.536] in the overall population and 1.404 [95% CI: 1.264-1.561] for those with PAH. This survival difference was consistent across various severity levels, age groups, and in the presence of comorbidities such as obesity and cardiovascular diseases, as well as among those receiving PAH-specific therapies as well as patients who remained without treatment during the observation period. Notably, male disadvantage in survival was observed in low, intermediate, and high-risk categories for ESC/ERS 2022, REVEAL lite 2, and COMPERA scores but not within REVEAL 2.0, which includes male sex as a non-modifiable risk factor. Racial analysis revealed a greater mortality risk for males among White patients, with no significant differences noted in Black or Asian populations. Conclusion Our PVRI GoDeep meta-registry analysis demonstrates that male PH patients face higher mortality risk across both PAH and non-PAH groups, independent of disease etiology, age, severity, comorbidities, and treatment factors, with this risk amplified in White patients. These findings suggest that male sex should be further considered as a risk factor to refine predictive models for survival in PH.

Abstract INTRODUCTION: Pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis (PVOD/PCH) is a rare subgroup of pulmonary arterial hypertension (PAH). Unfortunately, there is significant overlap between PVOD and PAH, making differentiation difficult. Thus, a constellation of investigations is necessary to suggest such a diagnosis. CASE PRESENTATION: A 65-year-old female with a history of smoking was diagnosed with idiopathic PAH following 2 months of worsening dyspnea. Right heart catheterization (RHC) revealed a mean PA pressure (mPAP) 58mmHg, pulmonary artery wedge pressure (PAWP) 14mmHg, cardiac output/index (CO/CI) 5.5/2.6, and pulmonary vascular resistance (PVR) 8 Wood units. Further workup excluded other causes of pulmonary hypertension (Table 1). Tadalafil was initially started followed by macitentan, which were associated with worsening hypoxemia and dyspnea. Computed tomography (CT) scan of the chest revealed mediastinal lymphadenopathy and small bilateral pleural effusions. This development in relation to the initiation of PAH-directed therapies raised concern for possible PVOD. Medical therapy was downtitrated, but worsening hypoxemia in the setting of worsening edema led to the cessation of all therapies. Due to clinical concern, the patient was admitted for a repeat RHC and close supervision during a trial of epoprostenol. RHC revealed a mPAP of 57mmHg, PAWP 5mmHg, CO/CI 3.4/1.6 and PVR 15 Wood units. She had been on metoprolol for hypertension which was discontinued. Low-dose epoprostenol was started at 1ng/kg/min. Her oxygen requirements increased slightly which improved with diuresis. Epoprostenol was slowly titrated with improvements in CI. Repeat chest CT showed mild diffuse centrilobular nodular opacities more prominent compared to prior scans, and adenopathy. After a steady dose of epoprostenol (4ng/kg/min), the patient improved with lower oxygen requirements. She was discharged with plans to continue low dose outpatient epoprostenol and start sotatercept. Lung transplant evaluation is on hold pending response to this approach. Genetic testing is pending. DISCUSSION: Despite challenges of definitive diagnosis where lung biopsy is risky, a diagnosis of PVOD can be supported from a spectrum of strongly suggestive clinical, hemodynamic and radiographic features. Though genetic testing for the EIF2AK4 mutation may confirm the presence of heritable PVOD, its absence does not exclude its possibility as most cases do not have an identifiable genetic cause. Management is challenging given ineffective or potentially harmful responses to PAH-directed therapies, though some do respond to a variable extent. As suggested here, close supervision during epoprostenol infusion adds to the limited body of evidence supporting such endeavors when initiating vasodilatory therapies in patients with suspected PVOD.

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.

Abstract Rationale: Prior studies report association between pulmonary artery (PA) dilation on computed tomography (CT) imaging and pulmonary hypertension (PH). These studies predate expansion of PH hemodynamic diagnostic criteria and do not report patient mortality. As such, little is known about the presence of vascular changes in mild PH or their association with survival. We sought to investigate these relationships in individuals without significant parenchymal lung disease. Methods: We obtained CT images for subjects with group 1 or 2 PH, disease comparators, and healthy controls enrolled in the Pulmonary Vascular Disease Phenomics (PVDOMICS) study. We used Osirix imaging software to measure the main, left, and right PA (MPA, LPA, and RPA) and MPA:aorta (PA:Ao) ratio by diameter and cross-sectional area at locations consistent with prior studies. We evaluated associations with mortality and mean PA pressure (mPAP) using multivariable Cox and linear regression models adjusting for age, sex, and BMI. Descriptive statistics are presented as mean ± SD. Results: We identified 558 subjects (59 controls, 138 comparators, and 361 PH [267 group 1, 94 group 2]). 79 subjects had mPAP &lt; 21 mmHg, 39 had mPAP 21-24 mmHg, and 371 had mPAP ≥ 25 mmHg. Increased MPA, LPA, and RPA diameter and area, PA:Aodia, and PA:Aoarea were associated with decreased survival (all p &lt; 0.001) after multivariable adjustment. First versus third quantiles of all measurements were associated with mortality, with adjusted hazard ratio of 2.99 [95% CI 1.77, 5.05] for MPA diameter (2.84 vs 3.82 cm), 3.74 [2.07, 6.74] for MPA area (7.26 vs 12.74 cm2) and 5.24 [2.58, 10.66] for LPA area (4.55 vs 7.03 cm2). All measures significantly increased alongside PH severity from mPAP &lt; 20 to 21-24 to ≥ 25 mmHg (see figure 1 for MPA diameter). All measures positively correlated with mPAP, including MPA diameter (ρspearman = 0.55) and PA:Aodia (ρ = 0.56). After multivariable adjustment, Q1 to Q3 increments in MPA diameter and PA:Aodia were associated with mPAP increase of 12.5 [10.7, 14.4] and 13.9 [11.9, 15.8] mmHg, respectively. BMI showed no correlation with PA size (ρ = 0.076 for MPA area, -0.051 for PA:Aodia). Conclusions: PA size increases alongside PH severity using updated hemodynamic criteria and is associated with incremental increases in PA pressure and mortality. LPA dilation demonstrates particularly strong association with mortality. PA size does not correlate with BMI. These novel findings enhance our understanding of vascular changes across the PH disease spectrum.

ABSTRACT Reduced functional capacity and poor sleep quality are common in pulmonary arterial hypertension (PAH). Wearable devices are an emerging, user‐friendly tool to capture activity and sleep information. We aimed to determine whether Fitbit‐derived activity and sleep trends provide clinically meaningful information in patients with PAH. Our prospective observational study recruited patients with PAH from across the United States using remote enrollment strategies and in‐person efforts. Participants wore a Fitbit device for 12 weeks at baseline and a subgroup with 1‐year follow‐up. A matched control cohort was generated from the All of Us Research Program and we evaluated changes in patients with PAH compared to matched controls. Among 110 patients with baseline monitoring, average daily steps correlated with 6MWD ( r = 0.61, p < 0.001) and percent rapid eye movement (REM) sleep ( r = 0.28, p = 0.008). In 44 PAH participants who completed baseline and 1‐year monitoring, there was a group‐time interaction for percent light sleep ( p = 0.024) and percent REM sleep ( p = 0.034), which demonstrated that sleep quality worsened in patients with PAH over 1 year compared to matched controls. Average daily steps decreased in patients with PAH from 5200 [IQR 3212–7458] at baseline to 4651 [IQR 2912–6827] at 1 year ( p = 0.008). In conclusion, our study demonstrated the potential clinical value of wearable devices by showing that activity and sleep quality are reduced in PAH compared to matched controls and these measures decline over time. Future studies should investigate if monitoring these health behaviors detects early functional decline and whether targeted interventions may improve outcomes.