Risks for silent cerebral infarctions (SCIs) were two times greater in patients with atrial fibrillation, according to a meta-analysis published Nov. 4 in Annals of Internal Medicine. Researchers noted that this increased risk remained regardless of whether the atrial fibrillation was paroxysmal or persistent.

Boston researchers reviewed studies through May 2014 to determine if any association could be made between atrial fibrillation and the prevalence of SCI. Searches of MEDLINE, PsycINFO, Cochrane Library, CINAHL, and EMBASE gave Shadi Kalantarian, MD, MPH, from the Institute for Heart Vascular and Stroke Care and the Massachusetts General Hospital in Boston, and colleagues 17 studies to calculate SCI prevalence. They were able to derive risk using data from 11 of those studies.

They found among the patients in these reports, magnetic resonance imaging revealed 40 percent had SCI lesions. In studies using computed tomography, 22 percent of patients were found to have SCIs.

Between computed tomography and magnetic resonance imaging data, odds for SCI when the patient had atrial fibrillation but no history of symptomatic stroke were around 2.62.

They noted that reports associated SCI with increased risks for stroke and dementia.

Kalantarian et al expressed some concern that many of the studies available, particularly autopsy-based ones, were insufficiently sensitive or powered or did not collect enough data to get better readings on SCI risk and prevalence among atrial fibrillation patients. Nor were they able to determine whether anticoagulation had an effect on preventing SCI in atrial fibrillation patients.

The research team recommended more studies explore SCIs in atrial fibrillation patients. Future research, they wrote, should explore appropriate preventative and treatment strategies to reduce risk for developing future stroke, dementia or death.