Atrial Fibrillation and Obstructive Sleep Apnea: Do Mortality Trends Reflect Disease Burden or Diagnostic Gaps?

The authors demonstrated a striking and consistent rise in atrial fibrillation (AF)–related mortality involving obstructive sleep apnea (OSA), particularly among elderly, female, rural, and minority populations [1]. This important analysis highlights the growing public health burden of AF–OSA overlap. However, several issues merit further clarification and discussion.

The authors report a steep increase in AF-related mortality involving OSA over the past two decades [1]. However, as AF prevalence and mortality have also generally increased in the U.S. population [2], it is unclear whether the observed trend is specific to patients with comorbid OSA or merely reflects overall AF epidemiology. A comparative analysis of mortality trends in AF patients without OSA would be helpful to determine the additive risk associated with OSA.

During the study period (1999–2020), catheter ablation became increasingly adopted for rhythm control in AF [3]. Recent studies suggest that AF ablation is associated with improved long-term outcomes, particularly in younger male patients [4]. Yet, despite these advances, AF-related mortality in patients with OSA continued to rise. How do the authors interpret this apparent contradiction? Were these procedures less commonly used or less effective in the OSA subgroup?

The study identifies AF (ICD-10 I48.x) as the “underlying” cause of death and OSA (G47.33) as a “contributing” condition [1]. However, the clinical circumstances in which AF is recorded as the primary cause of death—distinct from its role as a comorbidity in stroke, heart failure, or sudden death—are not well defined. It would be informative to clarify how “AF-related mortality” was operationalized in this study and whether misclassification or variation in coding practices may have influenced the observed trends.

The authors correctly point out the rising burden of AF-related mortality in the presence of OSA [1]. Yet over the same period, mortality from stroke and heart failure—two major downstream complications of AF—has generally declined, partly due to improvements in anticoagulation and HF management [5]. This discrepancy raises the question of whether the increase in AF-related deaths reflects actual clinical deterioration or improved documentation of AF on death certificates.

While the use of CDC WONDER provides valuable national-level insights [1], the reliance on death certificate data introduces several limitations. OSA is often underdiagnosed, particularly among women, minorities, and older adults—groups in whom mortality increases were most pronounced. Additionally, data on OSA severity, AF subtype, comorbidities (e.g., heart failure, chronic kidney disease), and continuous positive airway pressure adherence were not available. These unmeasured variables may have played an important role in shaping the observed trends.

The authors declare no conflicts of interest.