Warfarin reduces silent cerebral infarction in elderly patients with atrial fibrillation.

BACKGROUND

Atrial fibrillation is reportedly one of the risk factors of silent cerebral infarction. The Shiga Atrial Fibrillation Trial was conducted in five medical centers, to test the hypothesis that warfarin can prevent silent cerebral infarction in patients with atrial fibrillation.

METHODS

Magnetic resonance images (MRI) were taken at the time of the patient's entry to the study and 1 year later in 15 asymptomatic patients (74 +/- 4 years old) with atrial fibrillation who were randomly allocated to two treatment groups to receive or not receive warfarin. The frequency of hyperintensities on T2-weighted axis MRI was rated using a four-point scale in the periventricular and centrum semiovale areas. Total silent cerebral infarction scores were calculated at the sum of the scores on MRI.

RESULTS

Silent cerebral infarction was seen in 14 (93%) of the 15 patients with atrial fibrillation and a total of 109 silent cerebral infarction lesions were detected. The number of hyperintensities in the periventricular and centrum semiovale areas increased over the 1 year of study (P < 0.01). The increase in total score over 1 year was less in the warfarin-treated group (1.6 +/- 0.7 compared with 5.4 +/- 0.9, P < 0.05).

CONCLUSION

Anticoagulation therapy can be useful to prevent silent cerebral infarction in neurologically normal elderly patients with atrial fibrillation.