As the prevalence of atrial fibrillation (AF) increases, a greater understanding of the costs associated with AF care is required. While individuals with greater arrhythmic burden may interact with the health system more frequently, the relationship between AF burden and costs remains undefined.

In a longitudinal patient cohort with paroxysmal AF and newly implanted cardiovascular implantable electronic devices (CIED) (2010-2016), we linked CIED remote-monitoring data with Medicare claims to assess the association between the 30-day averaged device-detected daily percentage of time in AF (“AF burden”) and healthcare costs.

Among 39,345 patients, the mean age was 77.1 ± 8.7 years, 60.7% were male, and the mean CHA₂DS_2-VASc score was 4.9 ± 1.3. The mean total 1-year costs were $18,668 ± 29,173, driven by hospitalization costs where two-thirds of admissions were due to heart failure. Increasing AF burden was associated with increasing costs: $17,860 ± 28,525 for 0% daily AF burden; $18,840 ± 29,104 for 0-5% daily AF burden; and $20,968 ± 31,228 for 5-98% daily AF burden. There was a linear relationship between AF burden expressed as a continuous variable and 1-year costs (adjusted cost rate ratio 1.031 per 10% daily duration in AF, 95% confidence interval 1.023-1.038; P < .001).

Among older patients with paroxysmal AF and CIEDs, increasing AF burden is associated with higher healthcare costs. As the observational study design is unable to determine causal relationships, prospective study is required to explore the intriguing hypothesis that targeted AF strategies, including comorbidity management, that reduce AF burden may also reduce the high annual costs associated with AF.