Brain Lesions and Cognitive Function After Ablation for Atrial Fibrillation

Researchers led by Karl Georg Haeusler investigated the incidence of ischemic brain lesions via magnetic resonance imaging (MRI) and assessed their associations with cognitive functioning three months after first-time ablation in patients with paroxysmal atrial fibrillation (AF). Their article in Circulation reported that “chronic white matter damage as well as acute ischemic lesions detected by brain MRI were found frequently after first-time ablation for paroxysmal AF using uninterrupted oral anticoagulation.”

Their conclusions were based on analysis of the AXAFA-AFNET 5 randomized clinical trial, which administered uninterrupted apixaban or vitamin K antagonist to 674 randomized patients with AF undergoing first-time ablation therapy. MRI was performed within three to 48 hours after ablation in eligible patients from 25 European and United States centers. The Montreal Cognitive Assessment (MoCA) tool was used to perform cognitive assessments three to six weeks prior to ablation and again after three months.

The investigators reported that at least one acute brain lesion was detected in 84 of 321 (26.1%) patients with analyzable imaging, 44 (27.2%) of which were treated with apixaban and 40 (24.8%) of which were treated with vitamin K antagonist (p = 0.675). Reportedly, the median MoCA score was similar between patients with or without acute brain lesions at the three month timepoint (p = 0.948). Using fluid-attenuated inversion recovery, the investigators observed cerebral chronic white matter damage in 130 (40.5%) patients and identified an association between this damage and lower median MoCA scores both before and after ablation. However, “this association was no longer significant when adjusted for age and sex,” the authors noted, although, age itself “was associated with lower MoCA scores before ablation (relative risk = 1.02 per 10 years; 95% confidence interval [CI], 1.01–1.03]) and three months after ablation (relative risk = 1.02 per 10 years; 95% CI, 1.01–1.03).”

Primarily, the authors concluded that acute ischemic brain lesions were not correlated with cognitive function after first-time ablation with oral anticoagulants in patients with AF. They noted that “lower MoCA scores before and after ablation were associated only with older age, highlighting the safety of AF ablation on uninterrupted oral anticoagulation.”