Left ventricular remodeling and dysfunction in obstructive sleep apnea Systematic review and meta-analysis

Background Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular mortality and morbidity. Several studies have reported that it affects the left ventricle; however, large randomized controlled trials are lacking. The current study aimed to summarize the association between OSAS and left ventricular (LV) structure and function. Methods Electronic databases (PubMed, Embase, and Cochrane) and references were searched for articles published until March 2018. A systematic review and meta-analysis were performed to assess LV structure and function in OSAS patients based on echocardiography. Results In total, 17 studies with 747 OSAS patients and 426 control participants were included. Patients with OSAS showed an increase in LV diastolic diameter (weighted mean difference [WMD], 95% CI: 1.24 [0.68, 1.80]; p < 0.001), LV systolic diameter (WMD, 95% CI: 1.14 [0.47, 1.81]; p = 0.001), and LV mass (WMD, 95% CI: 35.34 [20.67, 50.00]; p < 0.001). In addition, left ventricular ejection fraction (LVEF) significantly decreased in the OSAS group compared with the controls (WMD, 95% CIs: -1.82 [-2.76, -0.87]; p < 0.001), and the reduction in LVEF was consistent with the severity of OSAS. The OSAS group also showed an increase in left atrial diameter (WMD, 95% CI: 2.13 [1.48, 2.77]; p < 0.001) and left atrial diameter volume index (WMD, 95% CIs: 3.96 [3.32, 4.61]; p < 0.001). Conclusion Obstructive sleep apnea syndrome leads to atrial dilatation, left ventricular hypertrophy, enlargement, mass increase and reduction of systolic function. Treatments for OSAS might be beneficial for the preservation of left cardiac structure and function.