Stroke risk doubled in permanent AF vs. paroxysmal AF among nonanticoagulated patients

BARCELONA, Spain — Among patients with atrial fibrillation who are taking aspirin but not an anticoagulant, those with permanent atrial fibrillation were twice as likely to have a stroke compared with those with paroxysmal atrial fibrillation, according to data pooled from two trials.

Researchers analyzed 6,563 aspirin-treated patients with AF from the ACTIVE-A and AVERROES trials. Results were presented at ESC Congress 2014.

Thomas Vanassche, MD, PhD, and colleagues stratified patients by whether they had permanent, persistent or paroxysmal AF and whether they had a stroke or systemic embolism during the study period.

Compared with those with paroxysmal AF, those with permanent AF were twice as likely to have a stroke or systemic embolism (4.2% vs. 2.1%; unadjusted HR=2.04; 95% CI, 1.6-2.61; adjusted HR=1.83), Vanassche, of McMaster University in Hamilton, Ontario, Canada, and colleagues found.

Those with persistent AF were also more likely to have a stroke or systemic embolism compared with patients with paroxysmal AF, although to a lesser degree (3% vs. 2.1%; unadjusted HR=1.43; 95% CI, 1.04-1.96; adjusted HR=1.44), they found.

In a multivariate analysis, the researchers determined that type of AF was the second-greatest independent predictor of stroke or systemic embolism, behind only previous stroke or transient ischemic attack. Age and sex were also independent predictors.

“Although it may seem intuitive that the continuous presence of AF carries a higher stroke risk than short, intermittent episodes, this has been an area of controversy,” Vanassche said in a press release. “Current guidelines recommend that the pattern of AF should not be taken into account when assessing the stroke risk in patients with AF, suggesting that, when it comes to stroke risk, ‘any AF is AF.’

“All patients with AF should be assessed for risk, and if the risk is sufficiently high, they should be treated with anticoagulants,” Vanassche added. “Thus, our results strengthen the existing recommendations.”

For more information:

Vanassche T. Abstract 4182. Presented at: the European Society of Cardiology Congress; Aug. 30-Sept. 3, 2014; Barcelona, Spain.

Disclosure: The ACTIVE-A trial was sponsored by Sanofi Aventis and Bristol-Myers Squibb. The AVERROES trial was sponsored by Bristol-Myers Squibb and Pfizer. Vanassche reports no relevant financial disclosures.