Hassoun, Paul M.

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dilation on computed tomography (CT) has been associated with moderate-to-severe ­pulmonary hypertension (PH) using outdated diagnostic criteria.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 >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 <.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 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.