Randomized controlled trial of an oral appliance (SomnoDent) for sleep-disordered breathing and cardiac function in patients with heart failure.

In patients with heart failure (HF), sleep-disordered breathing (SDB) is a common comorbidity and a risk factor for poor clinical outcomes. SDB can be ameliorated by continuous positive airway pressure; however, inadequate adherence remains a major cause of treatment failure. On the other hand, the efficacy of oral appliance (OA) has been proved in orthodontics and otolaryngology, although the efficacy of OA in patients with HF remains to be elucidated. This trial aims to determine the efficacy of OA for SDB in patients with HF. Patients with HF undergoing optimal medical therapy who were diagnosed as having SDB (apnea-hypopnea index [AHI] ≥ 10 and percentage of central AHI per total AHI ≤ 70%) by using polysomnography (PSG) will be enrolled in the present study. Either patients with HF with reduced ejection fraction (left ventricular ejection fraction [LVEF] ≤ 50%) or HF with preserved ejection fraction (history of hospitalization because of acute decompensated HF) or plasma B-type natriuretic peptide (BNP) level ≥ 100 pg/mL will be included. Each patient will be randomly assigned into active OA or sham OA. PSG, laboratory, and echocardiographic data will be obtained after 3 months of intervention. The main outcome measures are AHI, plasma BNP, and E/e' determined with echocardiography. Furthermore, overnight urinary catecholamine, 6-min walk distance, Epworth sleepiness scale, and health-related quality of life will be assessed simultaneously. This trial started on April 1, 2017, and the projected end date is March 31, 2019. This study was registered in the University Hospital Medical Information Network (UMIN000025731).