In a cohort of patients with atrial fibrillation, many had large noncortical or cortical infarcts or other brain lesions, which were mostly clinically silent but often associated with reduced cognitive function, researchers reported.
The researchers analyzed 1,737 patients with AF (mean age, 73 years; 28% women; 90% taking oral anticoagulants) who underwent a brain MRI and cognitive testing.
“Recent evidence suggests that patients with AF also face an increased risk of cognitive dysfunction and dementia,” David Conen, MD, MPH, from the cardiology division, department of medicine, University Hospital Basel, Switzerland, and colleagues wrote. “The aim of the current study was to assess the relationships of clinically known and unknown (silent) vascular brain lesions detected on brain MRI with cognitive function in a large sample of patients with AF.”
The researchers found that 22% of patients had large noncortical or cortical infarcts, 21% had small noncortical infarcts, 22% had microbleeds and 99% had white matter lesions.
Among the 1,390 patients with no history of stroke or transient ischemic attack, 15% had clinically silent large noncortical or cortical infarcts and 18% had clinically silent small noncortical infarcts, Conen and colleagues wrote.
The Montreal Cognitive Assessment Score was higher in patients without large noncortical or cortical infarcts than in patients with them (25.8 vs. 24.7; P < .001), and the results did not change when only clinically silent large noncortical or cortical infarcts were included (25.8 vs. 24.9; P < .001).
When the researchers conducted a multivariable model, they found the strongest predictor of reduced cognitive function according to the Montreal Cognitive Assessment Score was volume of large noncortical or cortical infarcts (beta = –0.26; 95% CI, –0.4 to –0.13). Microbleeds were not a predictor.
“Our analyses show that the presence of overt or silent [large noncortical or cortical infarcts] on MRI have a similar impact on cognitive function as overt strokes, a finding suggesting that these lesions may explain at least part of the increased risk of cognitive dysfunction in these patients,” Conen and colleagues wrote.
Fertile area of investigation
In a related editorial, Cardiology Today Editorial Board Member Jagat Narula, MD, PhD, MACC, associate dean for global health at Icahn School of Mount Sinai and professor of medicine and Philip J. and Harriet L. Goodhart Chair in Cardiology and director of the Cardiovascular Imaging Program in Mount Sinai’s Zena and Michael A. Wiener Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Center for Cardiovascular Health, and colleagues wrote that “the current study highlighted that the end organs bear the brunt of damage associated with cardiovascular diseases.”
Although these findings invoked the necessity of more extensive imaging workup for the patients with cardiovascular disease, the cost-effectiveness of such a presumption would need to be established,” Narula and colleagues wrote. “This field of heart-to-head interaction and thrombotic or embolic processes should be one of the most fertile areas of investigation so that inferences drawn from the association studies would not need extrapolation.” – by Erik Swain
Disclosures: Conen reports he has received consultant fees from Servier Canada. Please see the study for all other authors’ relevant financial disclosures. The editorial authors report no relevant financial disclosures.