Abstract 11007: Utility of Cardio-ankle Vascular Index and Flow-mediated Dilatation for Non-invasive Detection of Vascular Dysfunction in Sleep Disordered Breathing

Abstract

Backgrounds: Since association of sleep disordered breathing (SDB) with cardiovascular diseases has been reported, non-invasive detection of arterial sclerosis in the early stage is clinically important in patients with SDB. Flow-mediated dilatation (%FMD) and Cardio-ankle vascular index (CAVI) are novel indices for endothelial function and arterial sclerosis, respectively. However, it is not clear whether these are clinically useful to assess vascular function in SDB patients.

Methods: In this study, 344 patients with SDB were enrolled. %FMD, CAVI, and echocardiographic parameters (left ventricular ejection fraction, left ventricular end diastolic volume index, left ventricular end systolic volume index, left ventricular mass index and left atrial volume index) were determined. Apnea-hypopnea index (AHI) was measured by polysomnography, and patients were divided into two groups: group A (mild SDB; AHI < 15 times/hr, n =107) and group B (moderate-severe SDB; AHI ≥ 15 times/hr, n =237).

Results: There were no significant differences in any echocardiographic parameters between two groups. Importantly, %FMD was significantly lower and CAVI was significantly higher in group B than in group A (4.0 ± 2.4% vs. 6.2 ± 3.6%, P<0.01 and 8.6 ± 1.9 vs. 7.7 ± 2.0, P<0.01). There were negative correlations between AHI and %FMD (R=-0.40, P<0.01) and between %FMD and CAVI (R=-0.35, P<0.01).

Conclusions: Although cardiac function was not different, vascular dysfunction was evident in patients with moderate-severe SDB compared to mild SDB. %FMD and CAVI are useful tools to identify vascular dysfunction non-invasively in SDB patients.