A study published in the International Journal of Cardiology demonstrated that there is a high rate of sleep disordered breathing (SDB) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). In addition, the investigators found that precapillary pulmonary hypertension and obstructive sleep apnea (OSA) may be causative factors for central sleep apnea (CSA) and PH, respectively.
A total of 50 patients scheduled for elective pulmonary endarterectomy (PEA) were included in this prospective cohort study. Investigators recorded unattended cardiorespiratory fitness the night prior and 1 month following the intervention. The American Academy of Sleep Medicine guidelines were used to score each recording, with scores provided for CSA, OSA, and hypopneas. Patients either had no SDB (n=18), dominant OSA (n=22), or dominant CSA (n=10).
On the night prior to the elective PEA procedure, the prevalence rate of SDB (obstructive or central apnea-hypopnea index [AHI] ≥5/h) was approximately 64%. The mean AHI in patients with SDB was 22.7±18.7 events/h, with a significantly higher score noted in patients with dominant CSA vs patients with dominant OSA (37.1±25.2 vs 16.2±10.0 events/h, respectively; P <.0001). No significant differences were observed between patients with regard to risk factors for OSA or CSA.
According to the mean right atrial pressures (mRAPs) and mean pulmonary artery pressures (mPAP), there were significantly greater compromised profiles from no SDB to dominant OSA and dominant CSA (mRAP: 5.5±3.9 vs 7.0±4.5 vs 9.7±4.3 mm Hg [P =.054] and mPAP: 39±12 vs 48±11 vs 51±16 mm Hg [P =.0.47]). Patients with dominant CSA who transitioned to dominant OSA or no SDB had greater post-PEA cardiac output improvements compared with other patients, despite no statistically significant difference between groups (+0.97±0.44 vs +0.59±0.43 vs +0.49±0.35 L/min).
A limitation of this study included the use of preoperative nocturnal polygraphy prior to the PEA procedure, which may have resulted in the loss of sleep in some patients.
Findings from this analysis suggested that “CSA was likely induced by CTEPH starting from a condition of no SDB and that the surgical intervention led to a restoration of the original normal breathing pattern.”
La Rovere MT, Fanfulla F, Taurino AE, et al. Chronic thromboembolic pulmonary hypertension: Reversal of pulmonary hypertension but not sleep disordered breathing following pulmonary endarterectomy. Int J Cardiol. 2018;264:147-152.