Should we screen for atrial fibrillation?

Yes—Mark Lown

Atrial fibrillation (AF) is detected in around a third of all patients with ischaemic stroke, Data from stroke registries show that in these patients unknown, untreated, or undertreated AF is responsible for most of the strokes, which are often fatal or debilitating.1 AF screening has been the subject of much recent debate by international collaborations of experts and in the UK parliament because of the increasing prevalence of AF (the number of patients in the UK is predicted to rise from 700 000 in 2010 to between 1.3 and 1.8 million by 20602) and the potential to prevent AF related strokes with appropriate anticoagulation.

Although data from randomised controlled trials are lacking, cohort studies indicate that screen detected AF is not a benign condition and, in the presence of additional risk factors, warrants consideration of anticoagulation. In a cohort study of 5555 asymptomatic patients with incidentally detected AF, anticoagulation therapy (n=2492) compared with no antithrombotic therapy (n=1460) was associated with significantly reduced adjusted risk of stroke from 4% to 1%, and risk of death from 7% to 4% in just 1.5 years.3 This suggests that screen detected AF responds to treatment similarly to that detected during routine care.

An effective and economical screening programme could minimise the potential for harm in terms of inappropriate treatment (anticoagulation leading to an increased risk of major bleeding) and unnecessary investigations; maximising the diagnostic yield of AF that carries significant risk; and maximising the uptake of appropriate anticoagulation treatment in people with newly detected cases.