Estimated prevalence of undiagnosed atrial fibrillation in the United States

Abstract

IntroductionAs atrial fibrillation (AF) is often asymptomatic, it may remain undiagnosed until or even after development of complications, such as stroke. Consequently the observed prevalence of AF may underestimate total disease burden.MethodsTo estimate the prevalence of undiagnosed AF in the United States, we performed a retrospective cohort modeling study in working age (18–64) and elderly (≥65) people using commercial and Medicare administrative claims databases. We identified patients in years 2004–2010 with incident AF following an ischemic stroke. Using a back-calculation methodology, we estimated the prevalence of undiagnosed AF as the ratio of the number of post-stroke AF patients and the CHADS2-specific stroke probability for each patient, adjusting for age and gender composition based on United States census data.ResultsThe estimated prevalence of AF (diagnosed and undiagnosed) was 3,873,900 (95%CI: 3,675,200–4,702,600) elderly and 1,457,100 (95%CI: 1,218,500–1,695,800) working age adults, representing 10.0% and 0.92% of the respective populations. Of these, 698,900 were undiagnosed: 535,400 (95%CI: 331,900–804,400) elderly and 163,500 (95%CI: 17,700–400,000) working age adults, representing 1.3% and 0.09% of the respective populations. Among all undiagnosed cases, 77% had a CHADS2 score ≥1, and 56% had CHADS2 score ≥2.ConclusionsUsing a back-calculation approach, we estimate that the total AF prevalence in 2009 was 5.3 million of which 0.7 million (13.1% of AF cases) were undiagnosed. Over half of the modeled population with undiagnosed AF was at moderate to high risk of stroke.

Utilization of anticoagulants and predictors of treatment among hospitalized patients with atrial fibrillation in the USA

“…Atrial fibrillation (AF) is a common cardiac rhythm disorder estimated to affect 5.3 million adults in the United States in 2009 1 . Most often it is a nonvalvular condition and it has long been recognized as a significant risk factor for disabling or fatal ischemic stroke and systemic embolism (SE) [2][3][4] .…”

Frequency of de novo atrial fibrillation in patients presenting with acute ischemic cerebrovascular stroke

“…Additional to this data, it was shown that more than half of the population with undiagnosed AF was at moderate to high risk for stroke. The data of this study also showed that the targeted screening strategy may provide benefit especially in the high-risk subgroup of older than 65 years and with multiple CHADS2 risk factors [20]. In a meta-analysis that investigated patients presenting with a stroke or TIA, 7.7% of the patient were diagnosed with atrial fibrillation in the emergency department, with an additional 5.1% during the hospital stay [21].…”

Outcome of Cardiac Monitor During Sleep Study for Screening of Subclinical Atrial Fibrillation

“…A study showed that 700,000 people in the United States may have undiagnosed AF, with an estimated cost burden of 3.2 billion dollars [19,20]. It is well known that asymptomatic AF is associated with similar risk of all-cause death, cardiovascular death, and thromboembolism compared to symptomatic AF [21].…”