Lifestyle factors and their modifications have long been established as critical elements for the successful prevention and treatment of cardiometabolic disease. In addition to dietary habits and physical activity levels, sleep patterns are also a key behavior to consider in interventions. Sleep-disordered breathing, insomnia, obstructive sleep apnea, and other sleep disorders are known risk factors for a variety of cardiometabolic conditions ranging from obesity and hypertension to stroke, coronary heart disease, and heart failure. As they affect the quality, timing, and duration of sleep, sleep disorders significantly increase both physical and mental health risks and therefore require the recognition of their substantial impact on patient wellbeing.
Atrial Fibrillation and Sleep-Disordered Breathing
Linked to excessive daytime sleepiness, sleep-disordered breathing (SDB) is one of many sleep disorders that can threaten cardiometabolic health and in particular, the risk of adverse outcomes in patients with atrial fibrillation (AF). This sleep disorder includes both obstructive sleep apnea as well as central sleep apnea which are also associated with atrial fibrillation.
In the case of obstructive sleep apnea, patients experience repetitive upper-airway obstruction during sleep accompanied by intermittent hypoxia, rises in carbon dioxide, autonomic nervous system fluctuations as well as intrathoracic pressure alterations. On the other hand, central sleep apnea, can be neurally mediated and in the presence of cardiovascular disease is characterized by alterations in chemo-sensitivity and chemo-responsiveness. Current data implicate the potential for obstructive sleep apnea to trigger atrial arrhythmogenesis while emerging research supports the association between central sleep apnea, Cheyne-Stokes respiration, and incident atrial fibrillation.
Sleep-disordered breathing affects as many as 74% of all patients with AF and has been identified as an independent predictor of stroke, per the most recent data. Research has also indicated that patients with AF who are treated for sleep-disordered breathing experience an increase in arrhythmia-free survival following pharmacologic treatment or catheter ablation. As such, the European Society of Cardiology and Heart Rhythm Society recommend screening atrial fibrillation patients for SDB and other sleep disorders as well as initiating treatment to reduce potential compounding risks for poor health outcomes.
Effect of Sleep Apnea on AF Management
The presence of sleep apnea has also been connected to decreased efficacy of rhythm-control strategies for atrial fibrillation. Patients suffering from obstructive sleep apnea experience a higher risk for recurrent atrial fibrillation after cardioversion and up to a 25% greater risk of recurrence following catheter ablation when compared with individuals without the sleep disorder.
Furthermore, observational studies have shown higher rates of atrial fibrillation following pulmonary vein isolation in obstructive sleep apnea patients who did not use continuous positive airway pressure (CPAP) than in those who did. This treatment may have beneficial effects on cardiac structural remodeling as cardiac magnetic resonance imaging has shown improvements in patients with sleep apnea; those who received less than four hours of CPAP per night exhibited larger left atrial dimensions and increased left ventricular mass compared with those who received over four hours of CPAP per night. However, the need remains for large, high-quality randomized controlled trials to eliminate the potential for unmeasured biases caused by differences between CPAP users and nonusers, including general adherence to medical therapy and additional healthcare interventions.
Further Study and Clinical Implications
As current literature suggests, patients with AF should be evaluated for symptoms of sleep apnea, nonetheless, further investigation is needed to confirm the benefits of sleep apnea treatment as well as the need for and cost-effectiveness of routine sleep apnea screening and treatment. Emerging findings and further research will likely inform the development of updated clinical guidelines and inform future screening protocols.
Due to the high prevalence of sleep apnea in patients with atrial fibrillation, its general adverse effects, the influence of sleep disorders on AF, and the cardiometabolic benefits of effective treatment, AF patients must be assessed for sleep disorders routinely. Based on the available data, experts argue that both screening and management of sleep apnea should be organized in a more multidisciplinary and integrated manner that involves a primary care physician, cardiologist, and sleep specialist to guarantee optimal patient outcomes.
To help facilitate improvements in AF care, clinicians are invited to attend our upcoming CMHC Masterclass: The Intersection of Cardiometabolic Health and Sleep Disorders on May 22, 2021 which will delve into the multidisciplinary methods for addressing sleep disorders to improve cardiometabolic health as part of comprehensive lifestyle modifications.