0598 EVALUATION OF THE OVERALL CLINICAL EFFECTIVENESS BASED ON CARDIOVASCULAR EFFECTS OF A MANDIBULAR ADVANCEMENT SPLINT IN THE TREATMENT OF OBSTRUCTIVE SLEEP APNEA

Abstract

Introduction: In this prospective clinical trial we evaluated the cardiovascular effects of oral appliance therapy using a custom-made, titratable mandibular advancement splint (MAS) in patients with obstructive sleep apnea (OSA). Methods: Forty-four patients were included after diagnosis of OSA (apnea/hypopnea index (AHI)>15/h sleep) on polysomnography (PSG) and treated with MAS (SomnoMed Flex, Somnodent, Australia, Crows Nest). At baseline and 6-month follow-up, participants underwent portable sleep monitoring (PSM), 24-hour blood pressure (BP) monitoring, a comprehensive 2D, Doppler and tissue Doppler echocardiography, and objective compliance measurement. Patients and their partner had to fill out a visual analogue scale (VAS) for snoring and the Epworth sleepiness scale (ESS) questionnaires. Results: Up to this date, 17 out of 44 included patients completed the 6-month follow-up (age: 47 ± 9 years; 82% male; baseline AHIPSG: 20 ± 4 events/hour; body mass index (BMI): 27 ± 5 kg/m2; 24-hour systolic blood pressure (SBP): 129 ± 15 mmHg, 24-hour diastolic blood pressure (DBP): 77 ± 8 mmHg). A significant decrease in AHI-PSM (10 ± 8 to 5 ± 4 events/hour; p=0.015), VAS (6 ± 3 to 2 ± 2; p=0.000) and ESS (11 ± 5 to 8 ± 5; p=0.043) was observed after 6 months of MAS therapy as compared to baseline. Objective compliance measurement of MAS use, defined as the usage of the MAS divided by the total sleep time, was high at 92%. Taking into account an efficacy of 57% based on the difference in AHI under MAS and at baseline, the mean disease alleviation (MDA) was about 52%. A statistically significant increase in left ventricular ejection fraction (Simpson method) was observed, from 59 ± 7% to 63 ± 7% (p=0.018). At present no significant decrease in 24-hour blood pressure was noted. Conclusion: The preliminary results of this ongoing clinical trial show a significant reduction in AHI, snoring and daytime sleepiness under MAS treatment for moderate to severe OSA. Although no significant effect on 24-hour blood pressure was noted yet, echocardiography showed a significant increase in left ventricular ejection fraction.