Assessment of pleural pressure during sleep in Marfan syndrome

Study Objectives: Patients with Marfan syndrome (MFS) have a high risk for aortic aneurysms. They are also susceptible to sleep-disordered breathing that may expose them to highly negative intrathoracic pressures known to increase aortic transmural pressure, which may accelerate aortic dilatation. Our objective was to quantify overnight intrathoracic pressure changes during sleep in snoring patients with MFS and the therapeutic effect of continuous positive airway pressure (CPAP). Methods: We used a questionnaire to identify self-reported snoring patients with MFS. In these patients, we monitored intrathoracic pressure using esophageal pressure (Pes) during overnight baseline and CPAP sleep studies. We defined a peak-inspiratory Pes (Pes_peak-insp) < 2 5 cm H₂O as greater than normal and examined the distribution of Pes_peak-insp during baseline and CPAP studies. Results: In our sample of 23 snorers with MFS, we found that 70% of sleep breaths exhibited Pes_peak-insp < 25 cm H₂O, with apnea/hypopneass accounting for only 12%, suggesting prevalent stable flow-limited breathing and snoring. In a subset (n = 12) with Pes monitoring during a CPAP night, CPAP lowered the mean proportion of breaths with Pes_peak-insp < 25 cm H₂O from 83.7% ± 14.9% to 3.6% ± 3.0% (P < .001). In addition, contemporaneous aortic root diameter was associated with the mean Pes_peak-insp during inspiratory flow–limited breathing and apneas/hypopneas (b = 20.05, r = .675, P = .033). Conclusions: The sleep state in MFS revealed prolonged exposure to exaggerated negative inspiratory Pes, which was reversible with CPAP. Since negative intrathoracic pressure can contribute to thoracic aortic stress and aortic dilatation, snoring may be a reversible risk factor for progression of aortic pathology in MFS.