Changes in Incidence of and Treatment for Atrial Fibrillation in Younger Patients

Atrial fibrillation (AF) incidence rates increased from 2000 through 2018 in patients aged younger than 65 years. Following a first AF diagnosis, cumulative incidence rates increased in oral anticoagulant therapy (OAC), electrical cardioversion, and catheter ablation in the first year, according to study findings published in the International Journal of Cardiology.

Investigators sought to explore changes over time in incidence rates of AF, treatment approaches, and AF hospital readmission (primary or secondary diagnosis for in-patient or emergency room visit following primary AF visit) rates in patients aged younger than 65 years.

They conducted a retrospective cohort study using Danish nationwide registries and data from 2000 through 2018 to identify 60,917 patients aged between 18 and 65 years with a first AF diagnosis. Patients were categorized according to the following calendar periods:

• 2000 to 2002; n=8150 (13.4%)
• 2003 to 2006; n=11,898 (19.5%)
• 2007 to 2010; n=13,560 (22.3%)
• 2011 to 2014; n=14,167 (23.3%)
• 2015 to 2018; n=13,142 (21.5%)

There was similar burden of comorbidities, age, and sex distribution in all 5 calendar periods.  Across calendar periods, 73.2% of patients were admitted with AF as primary diagnosis and 26.8% of patients were admitted with AF as a secondary diagnosis.

Patients with previous AF diagnosis; those that had filled prescriptions of OAC in the 6 months prior to AF diagnosis; those that had prescriptions of dronedarone, amiodarone, digoxin, or flecainide prior to the AF diagnosis; those with prior catheter ablation for AF; and those with congenital heart disease or mitral valve stenosis were excluded.

There was a stepwise increase in the crude incidence rate of AF across the following calendar periods:

• 2000 to 2002 (78.7 per 100,000 person years; 95% CI, 77.0-80.4)
• 2003 to 2006 (86.3 per 100,000 person years; 95% CI, 84.7-87.8)
• 2007 to 2010 (97.9 per 100,000 person years; 95% CI, 96.3-99.6)
• 2011 to 2014 (102.3 per 100,000 person years; 95% CI, 100.7-104.0)

The increase was not observed in 2015 to 2018 (93.6 per 100,000 person years; 95% CI, 92.0-95.2).

There was a stepwise increase in cumulative incidence of OAC treatment within 3 months after AF diagnosis from 2000 to 2002 (28.5%) through 2015 to 2018 (47.8%; P_{for trend} ≤.0001). Among patients treated with OAC, 44.8% had a CHA2DS2-VASc score of 0, 20.2% had a score of 1, and 35.0% had a score of more than 1.

Incidence of OAC treatment within 3 months before and after ablation increased from 2000 to 2002 (54.3%) through 2015 to 2018 (95.5%; P_{for trend}≤.0001).

There was a stepwise increase in cumulative incidence of electrical cardioversion from 2000 to 2002 (2.0%) through 2015 to 2018 (8.7%; P <.0001). There was also a stepwise increase in cumulative incidence of catheter ablation within 1 year of AF diagnosis from 2000 to 2002 (1.2%) through 2015 to 2018 (7.6%; P <.0001). Among all patients receiving catheter ablation (n=2562), 15.1% had a heart failure (HF) diagnosis within 2 years prior to catheter ablation. Incidence of 1-year AF readmission showed no differences across time.

Study limitations include a lack of data on critical clinical factors and AF type and duration.

“In a nationwide cohort from 2000 to 2018 examining patients under 65 years of age, we found an increment in the incidence of AF over calendar time,” the study authors wrote. “The use of catheter ablation, electrical cardioversion, and OAC treatment increased throughout the study period.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.