Cardio Sleep Review

Dedicated to the Nexus of Cardiology and Sleep Apnea Management

Issue 4,

COVID-19 Clinical Challenges and Opportunities

by Dr. Jennifer Cook
Global Medical Director

Jennifer Cook, MD, is Global Medical Director at Itamar® Medical, and also serves as Professor of Medicine, Advanced Heart Failure Cardiologist at the University of Cincinnati. In this Q&A, Cardio Sleep Review (CSR) speaks with Dr. Cook about managing sleep-disordered breathing in afib patients when healthcare resources around the country are battling COVID-19.

CSR: These are unprecedented and uncertain times we find ourselves in. Healthcare and healthcare professionals are on the frontline battling this pandemic. How has the COVID-19 health crisis impacted your specialty of Cardiology, your Cardiologist colleagues and the patients you treat?

Dr. Cook: Across the country, hospitals are either battling an influx of COVID-19 patients or bracing themselves to handle the crisis. In most centers, elective surgeries and procedures have been canceled in order to keep healthy patients out of the hospital and keep beds open for patients with acute respiratory illness. Some cardiologists are being called into critical care positions to serve acutely ill COVID-19 patients, many have seen a significant decline in their outpatient and cath lab volumes. So many of us are asking the question what can we do? Especially when our clinics are suspended, and procedures postponed an indefinite period of time. If we focus on patients with atrial fibrillation, there are many who are symptomatic and identified for ablation but may have that therapy delayed for a prolonged period of time.

CSR: There is a well-established connection between atrial fibrillation and sleep-disordered breathing, yet the diagnosis is not often made. Do you suspect these patients are affected by sleep-disordered breathing?

Dr. Cook: Absolutely so. We know that sleep apnea is a relevant co-morbidity in cardiovascular patients, the precise prevalence among patients presenting to EP clinics is not known. We recently initiated a study in Phoenix, AZ, at Arizona Heart Rhythm Center. Dr. Vijay Swarup has a busy practice where he performs a high volume of afib ablations. He sought to implement screening among his patients and in one year performed almost 200 home diagnostic sleep studies where 48% were positive and referred for PAP therapy. So these data inform what disease burden exists in private practice, and the numbers are consistent with clinical trials. A study by Dr. Elad Anter describing the presence of altered atrial substrate in untreated sleep apnea was published in 2017, again showing 50% of patients referred for ablation have OSA.1

CSR: So given the high prevalence of sleep apnea in the cardiovascular patient, what should the EP do to ensure sleep-disordered breathing doesn’t impact their patient’s outcomes?

Dr. Cook: Did you see the scientific statement published in the March 9 2020 issue of Circulation? It was titled Lifestyle and Risk Factor Modification for Reduction of Atrial Fibrillation and emphasizes three main points

  • There is a high prevalence of sleep-disordered breathing among patients with atrial fibrillation
  • There is a dose-dependent relationship between sleep-disordered breathing and afib burden
  • And CPAP therapy improves afib ablation outcomes, therefore, all patients should be screened

Overall the authors recommend an integrated care approach and provides an ideal operational framework for an EP clinic.1

CSR: Ok. that makes sense. How would you describe this integrated care approach?

Dr. Cook: A group at the University of North Carolina Chapel Hill published a description of their integrated care model in JACC: Clinical Electrophysiology in January of this year. Among patients seen in the emergency department who had a diagnosis of atrial fibrillation, they developed two cohorts. The first cohort received standard practice and the second cohort was enrolled in a NP-guided, cardiologist-supervised disease-specific clinic. They achieved the outcomes presented in this figure: where screening and treatment for sleep apnea improved from around 10% to nearly 100%.

CSR: That is a rather wide gap. Is this gap in screening typical in the cardiology practices you have seen?

Dr. Cook: Absolutely. And I get it. As a cardiologist in a busy heart failure practice, I have the same challenges. There is pressure to see more patients in fewer minutes and the support staff is often maxed out. That is why I have been part of this effort at Itamar® Medical to come alongside cardiologists and provide solutions to complement their practices. The evidence is so strong that there is a dose-dependent relationship between sleep-disordered breathing and afib burden. I believe that occult sleep apnea is negatively affecting afib ablation success rates for the majority of EPs. Take a look at this figure that I adapted from a meta-analysis published by Ashish Shukala in 2015 in JACC: Clinical Electrophysiology. Seven studies compared afib recurrence post pulmonary vein isolation among OSA patients receiving CPAP compared to untreated. In every publication the comparison was striking.

Although treated sleep apnea had a recurrence rate around 30%, untreated sleep apnea patients had more than 50% chance of failed ablation. In the meta-analysis, the relative risk reduction was found to be 44%.3 I think if EPs understood that they could improve their procedural outcomes by recognizing and treating occult sleep apnea they would see clear benefit in their practice.

CSR: Ok, this all makes sense. There is a high prevalence of sleep-disordered breathing among patients with atrial fibrillation. There is a dose dependent relationship between sleep-disordered breathing and afib burden. And CPAP therapy improves afib ablation outcomes therefore all patients should be screened. So how do we ensure these patients receive the necessary screening, diagnostic testing and treatment to ensure optimal outcomes?

Dr. Cook: We are all trying to sort out the new normal amid the COVID-19 crisis. We want to support our patients and our practice while we weather the storm. For those who have not included screening for sleep apnea among their patients presenting for ablation, my suggestion is that you do so now.

Although your clinic visits and cath lab schedules are currently curtailed, it is possible to take this hiatus as an opportunity to lay the framework for diagnostic screening for obstructive sleep apnea. When back to regular schedule you may then reap the benefits of improved ablation outcomes. By recognizing and treating occult sleep apnea they would see a clear benefit in their practice.


  1. Anter E, Di Biase L, Contreras-Valdes FM, et al. Atrial Substrate and AF Triggers in Sleep Apnea. Circ Arrhythm Electrophysiol. 2017;10:e005407. DOI: 10.1161/CIRCEP.117.005407
  2. Chung MK, Eckhardt LL, Chen LY, et al. Lifestyle and Risk Factor Modification for Reduction of Atrial Fibrillation: A Scientific Statement From the American Heart Association. Circulation. 2020; 9 Mar;141:e750–e772.
  3. Shukla A, Aizer A, Holmes D, et al. Effect of Obstructive Sleep Apnea Treatment on Atrial Fibrillation Recurrence: A Meta-Analysis. J Am Coll Cardiol EP. 2015 Mar, 1 (1-2) 41-51.

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Cardio Sleep Review
Publisher: Itamar Medical
Editor: Melih Alvo

The Cardio Sleep Review editorial team thanks all those who contributed to this publication.

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