New Estimates Suggest Atrial Fibrillation 3 Times More Common Than Thought

New prevalence estimates of atrial fibrillation (AF) found that approximately 10.5 million US adults, or 5% of the population, have the condition.¹ The findings, published in the Journal of the American College of Cardiology, suggest AF is 3 times more common than previously thought.²

An aging population in tandem with increasing hypertension, diabetes, and obesity rates in the US have led to increased AF prevalence in recent years. While past research estimated that 3.3 million adults in the US would have AF in 2020, this estimate was based on data from 1996 to 1997 and has not been revisited since.¹ The new study estimated the number of adults in the US diagnosed with AF and the age-, sex-, and race-standardized prevalence of the condition.

"Atrial fibrillation doubles the risk of mortality, is one of the most common causes of stroke, increases risks of heart failure, myocardial infarction, chronic kidney disease and dementia, and results in lower quality of life," first author Jean Jacques Noubiap, MD, PhD, a postdoctoral scholar at the University of California San Francisco (UCSF) with a specialty in global cardiovascular health, said in a statement. "Fortunately, atrial fibrillation is preventable, and early detection and appropriate treatment can substantially reduce its adverse outcomes.”

Noubiap and colleagues used statewide health care databases in California to create a cohort of patients who received hospital-based care between 2005 and 2019, using International Classification of Diseases codes to identify patients with AF and comorbidities. Data from the US Census were used to calculate the prevalence of diagnosed AF.¹

Out of a total of 29,250,310 patients, AF was diagnosed in 2,003,867 for a prevalence of 6.8%. In 2005 to 2009, 4.49% of patients were diagnosed, with the proportion of affected individuals increasing to 6.82% in 2015 to 2019. The patient population shifted younger, and patients with AF were less likely to be female or White over time. People diagnosed with AF were also more likely to have hypertension and diabetes as time went on.

The authors’ overall estimate of the current national prevalence of AF is at least 10.55 million individuals (95% CI, 10.48-10.62 million). This translates to 4.48% of adults in the US (95% CI, 4.47%-4.49%). These estimates put the prevalence of AF 3 times higher than what was projected in the study using 1996 to 1997 data.

"Physicians recognize that atrial fibrillation is often encountered in essentially every field of practice," senior and corresponding author Gregory M. Marcus, MD, MAS, a cardiologist and electrophysiologist at UCSF Health, said.² "These data provide objective evidence to demonstrate that prior projections severely underestimated how common it truly is."

While the new analysis provides estimates, Marcus noted that the actual prevalence of AF is likely higher, and the advent of wearable technology might soon illuminate the true prevalence of the condition in the US population.

"With the growing use of consumer wearables designed to detect atrial fibrillation combined with safer and more effective means to treat it, this current prevalence of atrial fibrillation in health care settings may soon be dwarfed by future health care utilization that will occur due to the disease," Marcus said.

References

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 Amer College of Cardiol. Published online September 11, 2024. doi:10.1016/j.jacc.2024.07.014

2. How many people have A-Fib? three times more than we thought. News release. University of California – San Francisco. September 11, 2024. Accessed September 12, 2024. https://www.sciencedaily.com/releases/2024/09/240911142132.htm