CMR may help predict stroke risk in patients with AF

Based on cardiac magnetic resonance (CMR) measurements in patients with atrial fibrillation, there was an association between left atrial reservoir dysfunction and a prior history of stroke or transient ischemic attack, according to a retrospective study.

Lead researcher Hiroshi Ashikaga, MD, PhD, of the Johns Hopkins University School of Medicine in Baltimore, Maryland, and colleagues published their findings online in the Journal of the American Heart Association on April 27.

In the U.S., approximately six million people have atrial fibrillation, which is the most common arrhythmia and is associated with an increased risk of stroke.

Between June 2010 and August 2013, researchers examined 525 consecutive patients who were referred to the Johns Hopkins Hospital for catheter ablation of atrial fibrillation, including 300 who underwent a routine pre-ablation CMR.

They then evaluated 169 patients who had a history of atrial fibrillation in sinus rhythm at the time of pre-ablation CMR. Eighteen patients had a history of stroke. The mean age was 59 years, and 74 percent of patients were male.

Researchers found that greater left atrial volumes, lower left atrial emptying fractions, lower left atrial maximum and pre-atrial strains and lower peak strain rate were associated with a prior history of stroke or transient ischemic attack.

“Our research suggests that certain features of the heart’s upper left chamber that are easily seen on heart MRI could be the smoking gun we need to tell apart low-risk from high-risk patients,” Ashikaga said in a release.

Limitations of the study included its single-center, retrospective design, which could lead to selection bias such as not including patients who died of stroke. Researchers also noted that they did not perform CMR at the time of the stroke or transient ischemic attack. In addition, they could not determine the time from stroke to CMR.

The researchers are planning on evaluating the predictive value of CMR in assessing stroke risk in patients with and without atrial fibrillation.