Simple mouthpiece could ease heart strain in sleep apnea patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age of at least 40 years old with the capacity to provide signed, written informed consent * Ischemic or non-ischemic cardiomyopathy with a left ventricular ejection fraction of 20% to 40% in the previous 6 months * Stable chronic HF with NYHA functional class I-III symptoms on maximally tolerated background therapy for at least 4 weeks * NT-proBNP \>600 pg/mL (for participants in sinus rhythm) or \>900 pg/mL (for participants in atrial fibrillation) in the previous 6 months (same as leading HF trials) * Agree to follow the study protocol * Able and willing to undergo a hospital-based overnight polysomnography Exclusion Criteria: * Known OSA and already on regular treatment * Moderate or severe valvular stenosis or regurgitation * Severe hypoxemia on polysomnography ODI \>60 or min SpO2 \<60% * Specific HF etiologies, including hypertrophic cardiomyopathy with left ventricular outflow tract obstruction; pericardial disease; infiltrative or inflammatory myocardial disease; valvular heart disease with severe aortic or primary mitral regurgitation, moderate or severe aortic stenosis, any mitral stenosis requiring surgical repair, or active endocarditis * Contraindications to MAD: less than six teeth in each arch; inability to advance the mandible and open the jaw widely. * Pre-existing temporomandibular joint problems, severe bruxism, and advanced periodontal disease (with mobility affecting MAD stability). * Patients who are planning to have restorations, dental prostheses or implants done in the next 12 months * Limited life expectancy (\< one year) * Cardiac or cerebrovascular events in the past 6 months, including myocardial infarction, unstable angina leading to hospitalization, uncontrolled cardiac arrhythmia, carotid surgery or stenting, stroke, transient ischemic attack, carotid revascularization, endovascular procedure, or surgical intervention for peripheral vascular disease * Current or planned mechanical circulatory support or heart transplantation Current or planned (within the next 6 months) hemodialysis or peritoneal dialysis