Cerebral microbleeds and asymptomatic cerebral infarctions in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is a cardiac arrhythmia that does not infrequently induce ischemic strokes; however, little research has been reported on focal cerebral microangiopathic lesions in patients with AF. Recently cerebral microbleeds (CMBs) have been noticed for their potential implication in cerebral small vessel disease. Therefore, we had 2 goals in the present study: (1) to compare the prevalence of CMBs in patients with AF with that in patients without AF, and (2) to prove that CMBs could be a clinical predictive factor for the development of future cerebral microangiopathy in patients with AF without a history of symptomatic cerebral infarction in a prospective manner.

METHODS: We performed yearly brain magnetic resonance imaging (MRI) assessments for a maximum of 5 years in 131 patients with AF and 112 control patients. Seventy-seven patients with AF underwent more than 3 yearly MRI scans.

RESULTS: The Kaplan-Meier curve showed that the development of an asymptomatic cerebral infarction (ACI) was associated with the baseline presence of a CMB (P=.004). A multivariate Cox regression analysis revealed that the CMBs at baseline were significantly associated with an increment in not only the occurrence of ACIs (hazard ratio [HR], 5.414; 95% confidence interval [CI], 1.03-28.43; P=.046) but also in the consecutive development of CMBs (HR, 6.274; 95% CI, 1.43-27.56; P=.015).

CONCLUSIONS: Patients with AF had a significantly higher prevalence of CMBs. The presence of CMBs in the baseline MRI may predict the consequent onset of an ACI and increase in CMBs in patients with AF.