Impact of continuous positive airway pressure treatment on myocardial performance in patients with obstructive sleep apnea. A conventional and tissue Doppler echocardiographic study.

INTRODUCTION: Obstructive sleep apnea (OSA) is a highly prevalent condition related to several cardiovascular complications. We assessed the effects of continuous positive airway pressure (CPAP) treatment on myocardial performance and various somatometric parameters in patients with severe OSA receiving CPAP.
MATERIALS AND METHODS: This is a prospective longitudinal study of 44 patients aged 55.8 ± 10.6 years (79.5 % men), with newly diagnosed moderate and severe OSA (apnea-hypopnea index ≥15 with polysomnographic evaluation). All patients enrolled received CPAP therapy. The study protocol included a complete conventional and tissue Doppler echocardiographic study at baseline and 12 months after CPAP treatment.
RESULTS: Among patients enrolled, 31 completed the prespecified study protocol. After CPAP therapy, a decrease in pulmonary artery systolic pressure (p < 0.001), right ventricular (RV) diameter (p = 0.012), inferior vena cava diameter (p = 0.005), and RV wall thickness (p = 0.006) was observed. In addition, tricuspid annular plane systolic excursion values (p = 0.048) and tissue E/A ratio at the tricuspid annulus (p = 0.01) were significantly increased. Moreover, a reduction in left ventricular (LV) mass was observed (p < 0.001). With respect to somatometric parameters, body mass index and waist diameter (p < 0.001 for both) were reduced. Importantly, the improvement in apnea-hypopnea index was associated with the improvement in pulmonary artery systolic pressure, independently from confounders such as age, gender, and the reduction in body mass index. DISCUSSION: CPAP therapy in OSA patients was found to improve right heart chambers remodeling and performance as well as somatometric characteristics. The impact of CPAP on LV performance seems less pronounced.