According to a new study, Atrial fibrillation (Afib) the most common arrhythmia, caused by irregular atrial contractions leading to an irregular heartbeat is associated with silent stroke, as indicated by lesions found in the brain. The study found that those individuals with Afib were at a 7.2-fold increased risk of having a silent stroke a loss of brain tissue on MRI scan but without symptoms or signs of a stroke.
The study, conducted by researchers at the University of Turin, Italy, included 270 individuals being seen at a cardiology or cardiovascular prevention clinic. Ninety of those patients presented with paroxysmal Afib (episodic or intermittent Afib), 90 had persistent Afib, and 90 had regular heart rhythms. All subjects underwent MRIs, which indicated that 89 percent of patients with paroxysmal Afib, 92 percent of patients with persistent Afib and 46 percent of the controls had lesions corresponding with silent stroke. These differences were significant for those patients with either type of Afib as compared to the normal-rhythm control group.
Researchers also report that the cognitive performance of those individuals with Afib was diminished, as compared to normal controls, as deduced from scores on the Repeatable Battery for the Assessment of Neuropsychological Status. Because of the potential for these individuals with silent strokes to have more adverse vascular events with more dire outcomes, researchers believe future studies should look into the use of antithrombotic treatments those which reduce the formation of blood clots as these types of treatments have been shown to be effective in reducing incidence of clinical stroke.
ACSH s Dr. Gilbert Ross observed, This is an important study. Although it is well known that the common arrhythmia atrial fibrillation is a cause of embolic strokes from clots formed in the atrial blood pool, the incidence of silent brain episodes has not been recognized, as far as I know. Of course, it makes perfect sense that the spectrum of cerebral arterial blockage would run from massive stroke down to clinically unnoticed, and this study may provoke some clinicians to do screening MRIs on more patients with Afib. That might not be such a good idea, though, because almost all patients with Afib should be on anticoagulants anyway, so an MRI finding may not change therapy. It s a tough call.