ABSTRACT: Current evidence on the effects of continuous positive airway pressure (CPAP) on cardiac mechanics in patients with obstructive sleep apnea (OSA) is based on a few single studies. The authors investigated this topic through a meta-analysis of speckle tracking echocardiography (STE) studies that provided data on left ventricular (LV) and right ventricular (RV) mechanics as assessed by global longitudinal strain (GLS). The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search English-language review papers published from inception to January 31, 2022. Studies were identified by crossing the following terms: "obstructive sleep apnea", "sleep quality", "sleep disordered breathing", "continuous positive airway pressure therapy", "noninvasive ventilation", "left ventricular hypertrophy", "systolic dysfunction", "global longitudinal strain", "left ventricular mechanics", "right ventricular mechanics", "echocardiography" and "STE echocardiography". The meta-analysis, including a total of 337 patients with OSA from nine studies (follow-up 2-24 months) showed a significant GLS improvement in both LV and RV after CPAP, standard mean difference (SMD) being 0.51±0.08, CI:0.36-0.66, p = .0001 and 0.28±0.07, CI:0.15-0.42, p = .0001), respectively. Corresponding SMD values for LV ejection fraction (LVEF) and tricuspid annular plane systolic excursion (TAPSE) were 0.20±0.06, CI:0.08-0.33, p = .001 and 0.08±0.06, CI: -0.04/0.20, p = .21. Our meta-analysis suggests that: I) CPAP treatment exerts beneficial effects on biventricular function in patients with OSA; II) the assessment of cardiac mechanics by STE should be routinely recommended for monitoring cardiac function in this setting, due to limitations of conventional echocardiography in evaluating biventricular performance.
