Garry, Jonah D

BACKGROUND: The metabolic mechanisms underlying right ventricular (RV) dysfunction are poorly understood, particularly outside of group 1 pulmonary hypertension (PH). We aimed to identify metabolites and pathways associated with RV systolic function and explored whether associations differed by pulmonary vascular resistance, PH group 1 status, and sex. METHODS: We analyzed data from the multicenter PVDOMICS (Pulmonary Vascular Disease Phenomics) cohort. RV systolic function metrics included fractional area change (echo), global longitudinal strain (echo), and ejection fraction (cardiac magnetic resonance). We used linear regression adjusted for age, sex, body mass index, and PH group to assess associations between metabolites and RV function. Pathway enrichment analyses were used to identify pathways significantly associated with RV function. Interaction terms were assessed to determine whether metabolite associations were modified by pulmonary vascular resistance, group 1 PH status, or sex. Least absolute shrinkage and selection operator regression was used to develop metabolite-based scores for RV function, and prognostic performance was assessed. RESULTS: There were 979 participants with plasma metabolomics and RV function data. Linear regression identified 170 metabolites that were significantly associated with all 3 RV metrics. Androgenic steroid, gamma-glutamyl amino acid, polyamine, vitamin A, fatty acid, and sterol pathways are most strongly associated with RV systolic function. Two metabolites interacted with group 1 PH status, and 6 interacted with pulmonary vascular resistance. Four androgenic steroids are associated more strongly with RV systolic function in women compared with men. Metabolite-based scores were prognostically equivalent to RV systolic function metrics and less accurate than REVEAL Lite 2 scores. CONCLUSIONS: We provide a blueprint of metabolites and metabolic pathways associated with RV systolic function across the spectrum of PH. Novel links to vitamin A and glutathione metabolites were observed. We detected few metabolites that associated with RV systolic function differentially by group 1 PH status or degree of pulmonary vascular resistance elevation. Androgenic steroids may associate more strongly with RV systolic function in women compared with men.

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.