Effects of mandibular advancement device versus continuous positive airway pressure on cardiac remodeling in obstructive sleep apnea: a randomized CMR substudy

Obstructive sleep apnea (OSA) is associated with adverse cardiac remodeling, including diffuse myocardial fibrosis. Continuous positive airway pressure (CPAP) is the standard treatment for OSA, while mandibular advancement devices (MAD) may represent an alternative. However, their comparative effects on myocardial structure remain incompletely defined. To compare the effects of MAD and CPAP on cardiac remodeling assessed by cardiovascular magnetic resonance (CMR) in patients with OSA. This prespecified CMR substudy of the randomized CRESCENT trial included patients who agreed to participate in both baseline and 12-month CMR examinations (aged 59±8 years, 89% male, with hypertension, elevated cardiovascular risk and moderate-to-severe OSA). The mean body mass index was 28.6±4.6 kg/m2. Participants underwent contrast-enhanced CMR at baseline and after 12 months of treatment with either MAD (n = 36) or CPAP (n = 49). CMR-derived measures included left ventricular (LV) mass, cardiac volumes and function; and extracellular volume (ECV) fraction as a marker of diffuse myocardial fibrosis. At baseline, mean 24-hour systolic blood pressure was 126 ± 11mmHg, ECV fraction was 25.0 ± 2.0% and 27% of participants met CMR criteria of LV hypertrophy. After 12 months, a modest but significant reduction in ECV fraction was observed in patients treated with MAD (24.9 ± 2.3% to 24.0 ± 2.2%; P = 0.047) and CPAP (25.1 ± 1.9% to 24.4 ± 1.6%; P = 0.004). There was no significant difference in ECV fraction reduction between MAD and CPAP (P = 0.576). No significant between-group differences were observed for changes in LV mass, cardiac volumes and function. Both MAD and CPAP were associated with modest reductions in ECV fraction over 12 months, with no detectable between-group difference. No accompanying improvements in LV mass or cardiac function were observed, likely reflecting the predominantly preserved myocardial phenotype at baseline. (Cardiosleep Research Program on Obstructive Sleep Apnea, Blood Pressure Control and Maladaptive Myocardial Remodeling—Non-inferiority Trial [CRESCENT]; NCT04119999).