Pulmonary hypertension (PH) can be caused by various factors, including hypoxia at high altitudes and alveolar hypoxia due to lung disease. Sleep-disordered breathing (SDB) is another common cause of PH, but little research has been done on its prevalence and effects on non-Group 3 PH. The Pulmonary Vascular Disease Phenomics Program (PVDOMICS) is the first study to incorporate home sleep apnea testing across all PH groups, including control and comparator groups. The study has revealed several interesting findings, including significant variability in the severity of SDB across all PH groups, with Group 2, 4, and 5 PH having the highest mean apnea hypopnea index (AHI). Surprisingly, Group 3 PH did not show the greatest burden of SDB. Sleep-related hypoxia, which can cause hypoxic pulmonary vasoconstriction, was found to vary across PH groups, with Group 1 PH patients having a median of 37% of sleep time below the oxygen saturation threshold of 90%. This finding has not been observed before and is currently unexplained. Sleep-related hypoxia was more common in PH than in comparators in Groups 3 and 4 PH, and it was associated with right ventricular dysfunction and worse 5-year survival outcomes. The study highlights the need for further research on the epidemiology of SDB and PH, the impact of sleep metrics on all PH groups, the role of alveolar hypoxia in promoting pulmonary vascular disease, the longitudinal associations of nocturnal oxygen desaturation and SDB on right ventricular structure and function, and the mechanistic underpinnings of physiologic contributions of SDB and associated intermittent hypoxia and autonomic fluctuations and pathways of inflammation on the pathophysiology of PH.
During the workshop, we will explore several questions related to PVD and SDB. These include:
- Does nocturnal desaturation worsen PVD in all PH groups, or could it actually promote improvement?
- What are the defining characteristics of SDB in PVD patients, and how do they contribute to the development of PVD? This information could help us create personalized interventions.
- Is it possible to reverse or improve PVD associated with SDB or nocturnal desaturation?
- Can interventions targeting nocturnal alveolar hypoxia improve outcomes for all PH patients?
- Are there specific phenotypes of PVD that are more closely linked to SDB and/or nocturnal desaturation?
- Can we identify molecular signatures of SDB in PVD patients that could help us diagnose its presence, track response to therapy, and identify patients most likely to benefit from sleep interventions?
The purpose of this discussion is to examine the current understanding of sleep health and dysfunction in the five established groups of pulmonary hypertension (PH). We will identify areas where knowledge is lacking and critical needs regarding the impact of sleep-disordered breathing (SDB), nocturnal hypoxemia, and other sleep disruptions (such as insomnia, abnormal sleep duration, and sleep fragmentation) on pulmonary vascular disease, including mild pulmonary hypertension. Additionally, we will discuss new interventions, trial designs, and endpoints to evaluate the potential effectiveness of sleep interventions in treating pulmonary vascular disease (PVD). Our goals are to discuss the state of knowledge of sleep health and dysfunction, identify areas where further research is needed, and explore new interventions to address pulmonary vascular disease.
- Discuss the current understanding of sleep health and dysfunction in the five established pulmonary hypertension (PH) groups.
- Identify gaps in knowledge and critical needs regarding the impact of sleep disordered breathing (SDB), nocturnal hypoxemia, and other sleep disruptions (such as insomnia, abnormal sleep duration, and sleep fragmentation) on pulmonary vascular disease, including mild pulmonary hypertension.
- Explore new interventions, trial designs, and endpoints to evaluate the potential effectiveness of sleep interventions in treating pulmonary vascular disease (PVD).
- Address disparities related to race/ethnicity, geography, or other social determinants of health.