Silent atrial fibrillation is far from benign

Asymptomatic atrial fibrillation should no longer be considered a benign condition, says a leading Sydney cardiologist, who warns it is associated with a significantly increased risk of ischaemic stroke.

In fact, silent AF has just as bad a prognosis as symptomatic AF, says Professor Ben Freedman from the University of Sydney's Charles Perkins Centre.

Presenting his research at the European Society of Cardiology (ESC) conference in Barcelona this week, Professor Freedman provides a strong case for opportunistic AF screening in all patients over 65.

“What we showed in this study is that the asymptomatic variety that is detected incidentally is at least as bad as symptomatic AF,” Professor Freedman tells 6minutes.

“So it needs to be treated in the same way.”

The idea is to find AF before symptoms appear and treat with oral anticoagulants, he adds.

To address how incidentally detected ambulatory AF patients fared compared with symptomatic presentations, Professor Freedman and colleagues analysed a large database of more than 46,000 people.

Based on source of AF diagnosis and symptoms, patients were allocated to one of four groups:

  1. asymptomatic ambulatory AF (AA-AF) detected incidentally in general practice
  2. symptomatic ambulatory AF (SA-AF)
  3. AF recorded as primary diagnosis and during first hospital episode (PH-AF)
  4. AF recorded as secondary diagnosis or during subsequent hospital episode (non-PH-AF)

These were matched with controls.

The researchers found the cumulative incidence of stroke was greatest in the PH-AF and AA-AF groups.

And silent AF has an almost identical prognosis to those with a secondary diagnosis of AF, who tend to be sicker with higher CHA2DS2-VASc scores and other chronic comorbidities, says Professor Freedman.