Most cardiologists treating atrial fibrillation are already screening for the usual suspects: hypertension, heart failure, diabetes, coronary artery disease. But a growing body of evidence suggests there is a significant comorbidity that frequently goes undetected — and when it does, it quietly undermines treatment outcomes.
Obstructive sleep apnea (OSA) affects an estimated 32% to 63%* of patients with atrial fibrillation. Yet because its symptoms are variable and screening tools have limited sensitivity in the AFib population, the majority of cases go undiagnosed. A 2024 study published in the Journal of the American Heart Association offers some of the most compelling real-world evidence yet for why that gap matters — and what happens when it is addressed.
*https://doi.org/10.1161/JAHA.123.030679
What the research found
The study, authored by Sterling et al. and published in JAHA in May 2024, analyzed data from 5,867 patients with atrial fibrillation who were newly diagnosed with obstructive sleep apnea and initiated on positive airway pressure (PAP) therapy. Using linked objective PAP device data and nationwide insurance claims data, researchers examined how adherence to PAP treatment affected healthcare resource use over two years.
The findings were substantial.
Patients who were fully adherent to PAP therapy had 44% fewer all-cause hospitalizations than those who were nonadherent during the first year of treatment. They also had 36% fewer emergency department visits. Cardiac-related hospitalizations were significantly lower as well — 0.06 per patient in the adherent group versus 0.10 in the nonadherent group.
The cost differential was equally striking. All-cause inpatient costs averaged $2,200 for adherent patients versus $4,483 for nonadherent patients in year one — a difference of more than $2,200 per patient. Total costs (excluding OSA equipment) were significantly lower for adherent patients across both years of follow-up.
These results held up across multiple sensitivity analyses, including propensity score matching, strengthening confidence in the findings despite the study’s observational design.
Why OSA and AFib interact the way they do
The biological relationship between sleep apnea and atrial fibrillation is well-established in published literature, though it remains underappreciated in clinical practice.
During obstructive respiratory events, negative intrathoracic pressure, hypoxia, and autonomic nervous system activation create conditions that are directly arrhythmogenic. Short-term, individual apneic events can trigger premature atrial contractions. Long-term, repeated exposure promotes atrial fibrosis and structural remodeling — lowering the threshold for AF initiation and progression.
This helps explain why OSA is not merely a comorbidity that coexists with AFib, but one that may actively perpetuate it. It also explains why treating OSA appears to improve AFib-related outcomes: by removing a chronic, recurring physiological stressor on atrial tissue.
The JAHA study adds an important dimension to this picture. Rather than asking whether PAP therapy reduces AF recurrence in a controlled trial setting, it asks what actually happens in real-world clinical practice, across nearly 6,000 patients, over two years. The answer is that consistent treatment of OSA is associated with meaningfully better outcomes — fewer hospitalizations, fewer ER visits, and substantially lower costs.
What this means for how physicians monitor AFib patients
The study’s findings have direct implications for cardiac monitoring practices, beyond the obvious message about OSA screening and treatment.
Comorbidity identification changes monitoring strategy. A patient with AFib and undiagnosed OSA presents differently than one whose OSA is being treated. Their rhythm may be more volatile, their arrhythmia burden potentially higher, and their risk of adverse events elevated. Knowing that OSA is present — and whether it is being managed — is clinically relevant information for interpreting monitoring data.
Continuous monitoring enables earlier insight. The JAHA study tracks outcomes over one and two years, but the arrhythmic consequences of OSA can be episodic and unpredictable. A patient’s most significant rhythm events may occur during sleep, when apneic episodes are most frequent. Monitoring systems that provide near real-time data transmission allow physicians to identify clinically meaningful events as they occur — not weeks after the fact.
The data gap is a clinical risk. In patients with AFib and suspected or confirmed OSA, the period between monitoring and diagnosis represents genuine uncertainty. If a patient is experiencing worsening arrhythmia burden related to OSA — whether untreated or recently initiated on PAP — delays in data availability delay clinical response. Near real-time monitoring closes that gap.
The broader picture for cardiac care
The JAHA study is part of a growing body of evidence that positions OSA as a first-class concern in cardiovascular care, not a secondary finding to be deferred to a sleep specialist. An estimated 32% to 63% of AFib patients have OSA, and the majority are undiagnosed. The study’s authors conclude explicitly that “strategies to detect and treat obstructive sleep apnea in patients with atrial fibrillation are warranted.”
For cardiologists, this means two things in practice. First, OSA screening in AFib patients should be routine, not incidental. Second, when OSA is identified, the monitoring approach for that patient’s cardiac care should reflect the added complexity — including the arrhythmic risk profile associated with untreated or undertreated sleep apnea, and the value of continuous, real-time cardiac data during the period of OSA treatment initiation.
The connection between sleep apnea and atrial fibrillation is not new science. But evidence quantifying its clinical and economic consequences at this scale — across nearly 6,000 real-world patients, with objective adherence data, over two years — is. Physicians who act on it will be better positioned to manage one of the most common and costly comorbidity combinations in cardiovascular medicine.
Monitoring the AFib patient who has everything else going on
AFib patients are rarely simple. They tend to carry multiple comorbidities, complex medication regimens, and elevated overall risk. For those with concurrent OSA — a group that may represent the majority of your AFib population — continuous cardiac monitoring is not a luxury. It is how you stay informed in a patient population where the physiological stakes during sleep are real and the symptoms that would otherwise prompt a call to the office often go unreported.
Rhythm Express provides near real-time cardiac monitoring with reports available within 24–48 hours of data capture, giving physicians actionable data while the study is still in progress — not weeks after it ends. For the AFib patient also navigating a new OSA diagnosis or PAP therapy initiation, that timeliness is not an operational convenience. It is a clinical one.
To learn how Rhythm Express supports cardiologists managing complex cardiac monitoring cases, request a demo.
Source: Sterling KL, Alpert N, Malik AS, Pépin J-L, Benjafield AV, Malhotra A, Piccini JP, Cistulli PA; the medXcloud group. Association Between Sleep Apnea Treatment and Health Care Resource Use in Patients With Atrial Fibrillation. Journal of the American Heart Association. 2024;13(9):e030679. https://doi.org/10.1161/JAHA.123.030679