Fast assessment of left ventricular systolic function in obstructive sleep apnea patients with automated function imaging: Comparison with mitral annular plane systolic excursion.

Background: Early detection of left ventricular (LV) subclinical dysfunction is clinically relevant before developing irreversible impairment in obstructive sleep apnea (OSA) patients. Mitral annulus plane systolic excursion (MAPSE) is a fast tool for OSA due to high prevalent obesity; another quick but more comprehensive tool is LV global longitudinal stain (GLS) based on automated function imaging (AFI). We therefore aimed to compare the feasibility and reproducibility of AFI to MAPSE in OSA patients, as a good model in whom obesity is common.

Methods: A comprehensive echocardiographic examination was done in 186 consecutive patients having polysomnography for suspected OSA. MAPSE was measured by using M-mode to calculate excursion of mitral annulus. GLS was derived by offline analysis of three long-axis views that semi-automatically detects LV endocardial boundary, which is adjusted manually as necessary with AFI measurement. Variability of AFI and MAPSE were compared among the different subgroups.

Results: Despite a relatively high obesity rate (42.9%), the feasibility of AFI was 94% (175/186) and that of 100% in MAPSE. AFI showed excellent correlation (r = .882) superior to MAPSE (r = .819) between the Expert and Beginner. Intra- and inter- observer variability of AFI and MAPSE in Bland-Altman analysis were 5.5% and 6.5%; 6.2% and 8.8%, respectively. In repeated measurements, AFI showed higher intra-class correlation (ICC = .95) than MAPSE (ICC = .87) (p < 0.05). Furthermore, analysis showed that AFI was feasible even in more obese patients (BMI≥28 kg/m ).

Conclusions: Even in obese patients with OSA, AFI-GLS is feasible and more reliable for less expert operators than MAPSE in detecting LV longitudinal dysfunction.