Screening a silent killer cuts risk of stroke and death: JAMA opinion

Atrial fibrillation is a very common abnormal heart rhythm that poses the risk of blood clots forming inside the heart. When clots break off they usually travel to the brain, causing severe strokes.

Research reveals that previously undetected asymptomatic AF carries a doubling of the risk of stroke and a doubling of premature death compared to age and gender matched people without AF.

There is also good evidence that treating asymptomatic AF with the oral anticoagulant drug warfarin or the newer oral anticoagulants can almost completely reverse the increased risk of stroke, and partially reverse the increased risk of associated death.

“Widespread screening for asymptomatic atrial fibrillation could cost-effectively reduce strokes and their associated disability, and help save lives,” says University of Sydney and Heart Research Institute Cardiology Professor, Ben Freedman, a co-author of the viewpoint in today’s JAMA. “But this is not yet widely recommended in guidelines.”

AF is a common and serious heart arrhythmia accounting for 1 in every 3 strokes. In 27 per cent of AF-related strokes this heart arrhythmia hasn’t been detected prior to stroke as it is often asymptomatic. Incidentally detected AF isn’t usually associated with palpitations or elevated heart rate, which may explain why stroke can be an unexpected and serious first sign of AF.

Professor Freedman and colleagues have published evidence revealing that AF can be detected easily and accurately via an inexpensive ECG using a novel hand-held device attached to an iPhone. The iPhone-based ECG device can diagnose AF in 30 seconds.

“Given such easy ways to detect AF, and our demonstration of the poor outcomes that can be substantially modified by treatment, we believe there is a reasonable, cost-effective case to screen for this abnormal heart rhythm in the population, as well as in the clinic,” Professor Freedman says.

Fast Facts on Atrial fibrillation, screening and treatment

• Atrial fibrillation (AF) is responsible for one third of all strokes.
• 27 per cent of AF-related strokes aren’t detected prior to stroke because AF is often asymptomatic (no apparent symptoms and unrecognised by the person with AF)
• AF-related strokes are more severe and cause greater disability than non-AF strokes
• Widespread screening for asymptomatic AF among people aged 65 years and over would be a potent way to prevent strokes and the burden of stroke-related harm because AF-related strokes are largely preventable by treatment with oral anticoagulant drugs.
• It is time to re-evaluate our guidelines on AF to include screening.

Study: Freedman B, Lowres, N, Asymptomatic atrial fibrillation: the case for screening to prevent stroke, JAMA V314, 18, November 10, 2015