Larive, Brett

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<0.001; PHAR r=0.33 p<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 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.

Abstract Aims Patients with pulmonary hypertension (PH) are grouped based upon clinical and haemodynamic characteristics. Groups 2 (G2, left heart disease [LHD]) and 3 (G3, lung disease or hypoxaemia) are most common. Many patients display overlapping characteristics of heart and lung disease (G2–3), but this group is not well-characterized. Methods and results Patients with PH enrolled in the prospective, NHLBI-sponsored PVDOMICS network underwent intensive clinical, biomarker, imaging, gas exchange and exercise phenotyping. Patients with pure G2, pure G3, or overlapping G2–3 PH were compared across multiple phenotypic domains. Of all patients with predominant G2 (n = 136), 66 (49%) were deemed to have secondary lung disease/hypoxaemia contributors (G2/3), and of all patients categorized as predominant G3 (n = 172), 41 (24%) were judged to have a component of secondary LHD (G3/2), such that 107 had G2–3 (combined G2/3 and G3/2). As compared with G3, patients with G2 and G2–3 were more obese and had greater prevalence of hypertension, atrial fibrillation, and coronary disease. Patients with G2 and G2–3 were more anaemic, with poorer kidney function, more cardiac dysfunction, and higher N-terminal pro-B-type natriuretic peptide than G3. Lung diffusion was more impaired in G3 and G2–3, but commonly abnormal even in G2. Exercise capacity was severely and similarly impaired across all groups, with no differences in 6-min walk distance or peak oxygen consumption, and pulmonary vasoreactivity to nitric oxide did not differ. In a multivariable Cox regression model, patients with G2 had lower risk of death or transplant compared with G3 (hazard ratio [HR] 0.51, 95% confidence interval [CI] 0.30–0.86), and patients with G2–3 also displayed lower risk compared with G3 (HR 0.57, 95% CI 0.38–0.86). Conclusions Overlap is common in patients with a pulmonary or cardiac basis for PH. While lung structure/function is clearly more impaired in G3 and G2–3 than G2, pulmonary abnormalities are common in G2, even when clinically judged as isolated LHD. Further study is required to identify optimal systematic evaluations to guide therapeutic innovation for PH associated with combined heart and lung disease. Clinical Trial Registration: ClinicalTrials.gov NCT02980887.

Abstract Aims Iron deficiency is common in pulmonary hypertension, but its clinical significance and optimal definition remain unclear. Methods and results Phenotypic data for 1028 patients enrolled in the Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics study were analyzed. Iron deficiency was defined using the conventional heart failure definition and also based upon optimal cut-points associated with impaired peak oxygen consumption (peakVO2), 6-min walk test distance, and 36-Item Short Form Survey (SF-36) scores. The relationships between iron deficiency and cardiac and pulmonary vascular function and structure and outcomes were assessed. The heart failure definition of iron deficiency endorsed by pulmonary hypertension guidelines did not identify patients with reduced peakVO2, 6-min walk test, and SF-36 (P &gt; 0.208 for all), but defining iron deficiency as transferrin saturation (TSAT) &lt;21% did. Compared to those with TSAT ≥21%, patients with TSAT &lt;21% demonstrated lower peakVO2 [absolute difference: −1.89 (−2.73 to −1.04) mL/kg/min], 6-min walk test distance [absolute difference: −34 (−51 to −17) m], and SF-36 physical component score [absolute difference: −2.5 (−1.3 to −3.8)] after adjusting for age, sex, and hemoglobin (all P &lt; 0.001). Patients with a TSAT &lt;21% had more right ventricular remodeling on cardiac magnetic resonance but similar pulmonary vascular resistance on catheterization. Transferrin saturation &lt;21% was also associated with increased mortality risk (hazard ratio 1.63, 95% confidence interval 1.13–2.34; P = 0.009) after adjusting for sex, age, hemoglobin, and N-terminal pro-B-type natriuretic peptide. Conclusion The definition of iron deficiency in the 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) pulmonary hypertension guidelines does not identify patients with lower exercise capacity or functional status, while a definition of TSAT &lt;21% identifies patients with lower exercise capacity, worse functional status, right heart remodeling, and adverse clinical outcomes.

Longitudinal trends demonstrate an increase in the prevalence of cardiovascular (CV) risk factors in the general population; however, the burden of CV risk factors or established disease in patients across WSPH groups remains unknown. Accordingly, we examined the prevalence of CV risk factors and established disease in the PVDOMICS (Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics) cohort. PVDOMICS enrolled 1,097 subjects with pulmonary hypertension (PH) (mPA ≥ 25 mmHg) and at-risk disease comparators (mPa < 25 mmHg) from six US centers. Compared to participants with PH attributable to left heart disease (LHD-PH; WSPH Group 2, n=145) who are expected to have a high burden of CV risk factors and disease, patients with WSPH Groups 1,3,4,and 5 (non-LHD-PH)(n=618) were younger (56.2 ± 14.5 vs 67.7 ± 11.7 yrs, p<0.02) with no difference in %female or race. Non-LHD-PH had a lower prevalence of the CV disease risk factors hypertension (38.6% vs. 66.7%, p<0.02), diabetes mellitus (21.4 vs. 41.0%, p<0.02), and metabolic syndrome (30.8 vs. 48.4%, p<0.02) compared to LHD-PH, while smoking, hypercholesterolemia, and family history of CV disease were similar between groups. The prevalence of established CV disease, including myocardial infarction, CABG or stent, stroke, arrhythmia, or peripheral arterial disease was significantly lower in non-LHD-PH than in LHD-PH. At right heart catheterization, although mPA pressures were similar between the groups, PVR (5.5[3.3, 8.7] vs. 3.7[7.2, 5.7] WU, p<0.02), and cardiac output were higher (5.4 ± 1.9 vs. 4.9 ± 1.6 L/min, p<0.02) in non-LHD-PH compared to LHD-PH. This corresponded to a higher left ventricular ejection fraction by echo (62.2 ± 8.2 vs. 54.0 ± 14.0 %, p<0.02) and greater 6-minute walk distance (361.8 ± 134.7 vs. 294.7 ± 118.7 m, p<0.02). Non-LHD-PH also had better cardiovascular health compared to LHD-PH with higher modified American Heart Association Life’s Simple 7 scores (6.7 ± 1.6 vs. 5.8 ± 1.5, P<0.02). Taken together, these data demonstrate that CV disease risk factors and CV disease are frequent comorbidities that occur in patients with non-LHD-PH, although CV health is not as impaired as in patients with LHD-PH. How this affects PH-related outcomes remains to be determined.

Left atrial (LA) size and function is recognized as a cumulative index of pulmonary capillary wedge pressure (PCWP) and an index of left heart disease (LHD). While anticipated that LA features contribute to LHD-associated pulmonary hypertension (PH), we hypothesized that LA abnormalities (LAA) may exist in other WSPH groups. Therefore, we examined LA structure and function in the PVDOMICS cohorts. PVDOMICS enrolled 1097 total subjects with PH (mPA > 25 mmHg) and at-risk disease comparators (mPA<25 mmHg) for each of the WSPH groups. Patients with WSPH Groups 1, 3, 4, and 5 [non-Group 2] (n=618) were younger (56.2 ± 14.5 vs 60.1 ± 12.7 yrs, p<.02) and had less hypertension (38.6% vs 51.5 %, p<.02) than their non-Group 2 comparators (n=204). They also had less hypertension, diabetes, and a lower BMI than WSPH Group 2 (n=145), whereas WSPH Group 2 and its comparator Group 2 (n=130) were similar. LA area by echo was greater in WSPH Group 2 compared to non-Group 2 (22.8 ± 6.6 vs 16.9 ± 5.0 cm 2 , p<.02), in the comparator Group 2 vs. non-Group 2 comparators (22.7 ± 7.9 vs 16.4 ± 4.7 cm 2 , p<.02) but similar between WSPH group 2 and its comparator. MRI LA ejection fraction was lowest in Group 2 (33.2 ± 17.7%) and comparator Group 2 (38.9 ±16.7%, p=ns), significantly lower than WSPH non-Group 2 (45.9 ±14.7%, p<.02) which was lower than comparator non-Group 2 (50.9 14.6%, p<.02) which was lower than normal controls (n=96) (58.4 ±1.7%, p<.02). At right heart catheterization, whereas mPA pressures were similar between WSPH non-Group 2 and Group 2, resting PCW (11.1± 5.3 vs 20.3 5.6 mm Hg, p<0.02) was lower in WSPH non-Group 2 , PVR was higher (5.5[3.3, 8.7] vs. 3.7[7.2, 5.7] WU, p<0.02), and cardiac output was higher (5.4 ± 1.9 vs. 4.9 ± 1.6 L/min, p<0.02). Following a fluid challenge, PCW remained lower (14.9 ± 5.8 vs 20.7 ± 4.5 mm Hg, p<0.02) and PVR higher (5.2[3.1, 7.8] vs. 3.2[2.3, 5.5] WU, p<0.02). PCW and PVR at rest were lower in the comparator non-Group 2 vs WSPH non-Group 2 (8.9 ± 4.1 vs 11.1± 5.3 mm Hg, p<.02) and 1.7[1.2, 2.3] vs 5.5[3.3, 8.7] WU, p<.02. Thus, while LAA are most notable in WSPH and comparator Group 2’s, LAA differ between WSPH non-Group 2 and its non-Group 2 comparators. The role of LAA as predictors of PH outcomes remains to be determined.