CLINICAL SPOTLIGHT: Review of Pollak and Povitz’s Editorial

April Dr Collaboration

Review of Pollak and Povitz’s Editorial on Obstructive Sleep Apnea and Cardiovascular Disease1

In an editorial in the Candian Journal of Cardiology, Drs. Timothy Pollack and Marcus Povitz ask if cardiologists are failing to recognize obstructive sleep apnea in patients with atrial fibrillation and heart failure. In 2018, the Canadian Cardiovasular Society updated their guidelines on the management of atrial fibrillation to specifically recommend the aggressive treatment of cardiovascular risk conditions such as sleep apnea, as they have been shown to reduce the burden of atrial fibrillation and improve quality of life.2

And while there are a number of clinical symptom-based questionnaires that have been proposed (e.g., Epworth Sleepiness Scale) to identify patients with sleep apnea, Drs. Pollack and Povitz ask if enough is being done in cardiac patients given the impact that sleep disordered breathing (SBD) can potentially have on a patient’s cardiac condition. 

The Connection between Atrial Fibrillation and Sleep-Disordered Breathing

Atrial Fibrillation (AF) is the most common arrhythmia diagnosed in clinical practice, and AF may be an unrecognized consequence of SDB / obstructive sleep apnea (OSA). Many patients that are referred to AF clinics have had unsuccessful attempts at managing their condition at primary clinics. It is not uncommon for practitioners at these AF clinics to discover that these patients have either been diagnosed with OSA or have risk factors that suggest they have OSA. 

The authors suggest that much like a stroke triggers screening for AF, that AF should trigger screening for the presence of OSA / SBD. 

Neurocirculatory Consequences of Sleep-Disordered Breathing

SDB not only can affect the cardiovascular system but also the nervous and circulatory systems as well. SDB caused by OSA can lead to repeated nocturnal hypoxia, which can contribute to many ailments, such as cognitive dysfunction, hypertension, and stroke. It can also lead to a distortion of the heart’s electrophysiologic environment, which can lead to arrhythmia. With studies showing that OSA treatment can help prevent such neurocirculatory conditions, treating SDB is essential.

Detecting a Patient’s Risk for SDB: The Importance of Sleep Screening 

While questionnaires like the Epworth Sleep Scale and SNOOZE AF have been developed as an assessment tool to help predict the probability of SDB in patients, many of the available questionnaires are not effective. As a result, Drs. Pollack and Povitz suggest that the best strategy for screening might be to screen all AF and heart failure patients with an at-home sleep apnea test. They note that home sleep apnea testing is relatively inexpensive and sensitive and specific enough to screen this high-risk patient group. 

Recommendations for the Future

Should SDB be considered a cardiovascular risk factor? What benefit does a sleep apnea diagnosis provide to a cardiac patient? The authors recognize that they – and many of their peers – are seeing an increase in patients with AF and heart failure – both diagnoses that are associated with SDB.  But cardiologists can’t do it alone – and neither can respirologists.

The review goes on to make recommendations that cardiologists and sleep medicine specialists work together to better serve their combined patient population. They raise the point that the inconsistent application of tools like the clinical questionniares mentioned above will likely not solve the issues around the rising prevalence of SBD-associated cardiac disease. Rather, they suggest that we need to raise awareness of the implications of SBD-associated cardiac disease and that cardiologists should push for easier access to home sleep apnea testing to help overcome some of the barriers to traditional sleep-laboratory polysomnography. 

Bridging the Gap Between Cardiology and Sleep

What review articles like this tell us is that the linkage between cardiovascular health and sleep cannot be ignored. Cardiologists need to ensure that sleep screening solutions are offered at their practice as common sleep disorders like OSA can attribute to a patient’s heart condition. In doing so, cardiologists will be better equipped to diagnose and treat their patients effectively. 

References:

  1. Pollak PT, Povitz M. Asleep at the Switch? Are We Failing to Recognize Obstructive Sleep Apnea in Patients with Atrial Fibrillation and Heart Failure?. Can J Cardiol. 2019;35(11):1426-1429. doi:10.1016/j.cjca.2019.09.005
  2. Andrade JG, Verma A, Mitchell LB, et al. 2018 focused update of the Canadian Cardiovascular Society guidelines for the management of atrial fibrillation. Can J Cardiol Can J Cardiol 2018;34:1371-92.

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