Incidence of Previously Undiagnosed Atrial Fibrillation in High-Risk Patients
Understanding Atrial Fibrillation
Atrial fibrillation (AF) is a medical condition characterized by the asynchronous contraction of the atria and ventricles, leading to a rapid and irregular heart rhythm. This irregularity increases the risk of stroke as it can facilitate the formation of blood clots that may travel to the brain, obstructing its blood supply.
Research Study Overview
A study led by James A. Reiffel, M.D., aimed to evaluate the incidence of previously undiagnosed atrial fibrillation among high-risk patients using insertable cardiac monitors (ICM). The findings from the REVEAL AF Study were recently published in the Journal of the American Medical Association (JAMA).
Study Methodology
From November 2012 to January 2017, researchers enrolled 446 patients identified as having a substantial risk for developing AF. The risk assessment was conducted using the CHADS2 scoring system, where patients with a score of 3 or a score of 2 combined with at least one of the following conditions were considered high risk:
– Coronary artery disease
– Renal impairment
– Sleep apnea
– Chronic obstructive pulmonary disease (COPD)
Patients were monitored until they completed their 30-month visit or their last 18-month visit, with in-office evaluations occurring every six months. The study focused on detecting atrial fibrillation lasting at least six minutes at the 18-month mark.
Study Results
Of the 446 patients enrolled, 385 received insertable cardiac monitors and were observed for an average of 22.5 months. The study revealed that atrial fibrillation lasting at least six minutes was detected in 29.3% of patients by the 18-month follow-up. Notably, the incidence rates of atrial fibrillation were consistent across patients with CHADS2 scores of 2, 3, and 4 or greater.
Conclusion and Future Research
The findings indicate that insertable cardiac monitors can effectively identify previously undiagnosed atrial fibrillation in patients at risk. The study highlights the significant incidence of undetected AF in high-risk patients, suggesting that further research is necessary to explore the implications of identifying subclinical or asymptomatic atrial fibrillation, particularly for those with an elevated risk of stroke.
Reference
Reiffel, J.A., et al. (2017). Incidence of previously undiagnosed atrial fibrillation using insertable cardiac monitors in a high-risk population: The REVEAL AF study. JAMA Cardiology. doi:10.1001/jamacardio.2017.3180