Minimum National Prevalence of Diagnosed Atrial Fibrillation Inferred From California Acute Care Facilities

When I began practicing medicine and specializing in cardiology, clinical electrophysiology was in its infancy. Cardiac arrhythmias were routinely managed by internists, and atrial fibrillation (AF) was viewed as almost as innocuous as the common cold. In the years since then, we have witnessed the growth and maturation of cardiac electrophysiology, leading to the transfer of virtually all patients with cardiac arrhythmias to the care of clinical electrophysiologists. The last arrhythmias still routinely treated by internists are likely simple premature atrial and ventricular complexes as well as AF. However, AF care has increasingly moved to electrophysiology experts, given recent knowledge of its effects on morbidity and mortality and the development of ablation techniques that can effectively treat this common tachyarrhythmia.

The paper by Noubiap et al¹ provides an updated analysis on the prevalence of AF using California's statewide healthcare database. Their findings indicate that the proportion of patients with diagnosed AF has increased, likely owing to the aging population, increasing number of risk factors, improved overall survival rates, and enhanced AF detection methods. They found that patients with AF were relatively younger, less likely to be female or White, and more likely to have hypertension and diabetes. They estimate that the current prevalence of diagnosed AF in the US is at least 10.55 million, representing almost 4.5% of the adult population, thus increasing the burden on healthcare workers, particularly electrophysiologists. These trends are likely to be mirrored globally, highlighting important considerations for public health planning. As always, prevention is preferable to treatment, and addressing risk factors such as obesity, hypertension, and diabetes may help reduce AF burden.

Stroke risk, one of the most feared complications of AF, has been thought to increase with increasing time spent in AF. As many as one-third of patients with AF may experience asymptomatic episodes. Among such patients, stroke risk increased to greater than 3% per year among those with subclinical AF episodes lasting longer than 24 hours. A recent retrospective cohort study by McIntyre et al² analyzed whether the frequency or duration of device-detected subclinical AF lasting less than 24 hours was associated with the risk of stroke or systemic embolism. They found that the frequency of subclinical AF and duration of its longest episode under 24 hours were not associated with the risk of stroke or systemic embolism. This critically important finding, if substantiated by other trials, would provide reassurance to patients and healthcare workers that short episodes of subclinical AF lasting less than 24 hours may not significantly increase stroke risk.

Reference

1. Noubiap JJ, Tang JJ, Teraoka JT, Dewland TA, Marcus GM. Minimum National Prevalence of Diagnosed Atrial Fibrillation Inferred From California Acute Care Facilities. J Am Coll Cardiol. 2024 Aug 19. doi: 10.1016/j.jacc.2024.07.014. Online ahead of print. https://www.sciencedirect.com/science/article/abs/pii/S0735109724079038?via%3Dihub

2. McIntyre WF, Benz AP, Healey JS, et al. Risk of Stroke or Systemic Embolism According to Baseline Frequency and Duration of Subclinical Atrial Fibrillation: Insights From the ARTESiA Trial. Circulation. 2024 Sep 4. doi: 10.1161/CIRCULATIONAHA.124.069903. Online ahead of print. https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.124.069903