Comparative effects of CPAP and Mandibular Advancement Device Treatment on Cardiac Structure and Function in OSA: A Cardiovascular Magnetic Resonance Randomised Controlled Study

AimsAdverse cardiac remodelling is observed in obstructive sleep apnoea (OSA). However, the impact of OSA treatment on cardiac remodelling remains poorly defined. The Cardiosleep Research Program on Obstructive Sleep Apnoea, Blood Pressure Control and Maladaptive Myocardial Remodeling--Non-inferiority Trial (CRESCENT) showed that treatment with a mandibular advancement device (MAD) was non-inferior to continuous positive airway pressure (CPAP) for reducing 24-hour mean arterial BP in patients with hypertension and moderate-to-severe OSA. This cardiovascular magnetic resonance (CMR) substudy aimed to evaluate the comparative effects of MAD and CPAP on myocardial structure and function in patients with OSA. Methods and Results85 patients with hypertension, increased cardiovascular risk and newly-diagnosed moderate-to-severe OSA (Apnoea-Hypopnoea Index [AHI] [≥]15 events/hour), underwent contrast-enhanced CMR at baseline and following 12 months of treatment with CPAP (n=49) or MAD (n=36). LV mass, volumes, function and markers of diffuse myocardial fibrosis, including the extracellular volume (ECV) fraction and interstitial volume, were measured. Across the cohort, a small reduction in the ECV fraction was observed (25.0{+/-}2.0 vs 24.3{+/-}2.0%; p=0.002), accompanied by a reduction in the interstitial volume over a 12-month period of OSA treatment (24.0[21.3-27.7] vs 23.3[20.4-27.4]mL; p=0.044). The reduction in ECV fraction was similar between the CPAP and MAD groups (p=0.94). Conclusion12 months treatment of OSA with either CPAP or MAD in patients with hypertension is associated with a small reduction in myocardial ECV fraction, a surrogate marker of diffuse myocardial fibrosis. Further confirmation of these findings in larger cohorts is warranted. (Cardiosleep Research Program on Obstructive Sleep Apnea, Blood Pressure Control and Maladaptive Myocardial Remodeling--Non-inferiority Trial [CRESCENT]; NCT04119999).