Pulmonary Artery Distensibility is Worsened in Obstructive Sleep Apnea Syndrome.

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) leads to right ventricular (RV) dysfunction and pulmonary hypertension (PH) in the later stages. Early determination of these conditions is very important.

OBJECTIVES

We aimed to evaluate the correlations of pulmonary artery distensibility, right pulmonary artery fractional shortening (RPA-FS), and pulmonary artery stiffness (PAS) with PH among newly diagnosed OSAS patients.

METHODS

We prospectively evaluated 34 newly diagnosed OSAS patients and 28 controls. The study subgroups were determined according to the apnea-hypopnea index (AHI). All patients underwent a transthoracic echocardiographic examination. Conventional RV parameters, PAS, and RPA-FS parameters were measured.

RESULTS

RPA-FS was significantly lower in the OSAS group (p < 0.001) and positively correlated with tricuspid annular systolic excursion (TAPSE) (p = 0.047) and pulmonary acceleration time (PAT) (p = 0.006), and inversely correlated with systolic pulmonary artery pressure (sPAP) (p = 0.013), and PAS (p < 0.001). Consistent with this result, PAS was significantly worse in the patients with OSAS compared to the controls (27.1 ± 3.5 to 15.8 ± 2.7, p < 0.001), and inversely correlated with RPA-FS (p < 0.001), PAT (p = 0.001), and TAPSE (p = 0.035). PAS was positively correlated with sPAP (p = 0.001). There were statistically significant differences for both PAS and RPA-FS among the OSAS subgroups with regards to the severity of disease (p < 0.001). The correlation analyses showed a significantly positive correlation between RPA-FS and mean O2 saturation. RPA-FS was also inversely correlated with AHI. Similarly, PAS was positively correlated with AHI and arousal index.

CONCLUSIONS

PAS and RPA-FS are worsened in patients with OSAS, and are correlated with PH and severity of OSAS.