November 3rd, 2014
AF Patients at Increased Risk for Silent Strokes
The increased risk of stroke in people with atrial fibrillation (AF) is well known, and this stroke risk is, of course, linked to an increased risk of cognitive impairment and dementia. Less well known is that people with AF have an increased risk for cognitive impairment independent of their stroke risk. Now a new study published in Annals of Internal Medicine offers evidence that this increased risk may be linked to a higher rate of silent strokes in AF patients.
Researchers at the Massachusetts General Hospital in Boston performed a systematic review and meta-analysis of observational studies utilizing CT or MRI that examined the prevalence of silent cerebral infarctions (SCIs) in 505 people with AF and 3,902 in people without AF. (Earlier studies using autopsies were discarded because of their low quality.) Patients with AF had more than a two-fold increase in risk. SCIs were found in 45.4% of people with AF compared with 15.63% of people without AF (OR, 2.62; CI, 1.81 – 3.80).
The study was unable to evaluate whether anticoagulants, which are the cornerstone of stroke prevention in AF patients, reduced the risk of SCI. The authors concluded that randomized trials need to be performed to assess whether SCI should be incorporated in the standard AF risk evaluation score to evaluate eligibility for anticoagulation therapy.