In patients with paroxysmal atrial fibrillation, researchers sought to determine how common ischemic brain lesions were discovered by magnetic resonance imaging and how they related to cognitive performance three months after the initial ablation using continuous oral anticoagulation (AF). In the randomized AXAFA-AFNET 5 trial (Anticoagulation Using the Direct Factor Xa Inhibitor Apixaban During Atrial Fibrillation Catheter Ablation: Comparison to Vitamin K Antagonist Therapy), 674 patients with atrial fibrillation (1:1) to uninterrupted apixaban or vitamin K antagonist therapy before first-time ablation. All eligible patients participating in 25 study locations in Europe and the United States received brain magnetic resonance imaging employing fluid-attenuated inversion recovery and high-resolution diffusion-weighted imaging between 3 to 48 hours following AF ablation. In addition, the Montreal Cognitive Assessment was used to examine patients 3 to 6 weeks before and three months after ablation (MoCA).

High-resolution diffusion-weighted imaging found at least one acute brain lesion in 84 (26.1%) of 321 patients with analyzable magnetic resonance imaging, including 44 (27.2%) apixaban patients and 40 (24.8%) vitamin K antagonist patients (P=0.675). At 3 months following ablation, the median MoCA score was comparable in individuals with and without acute brain injuries (28 [interquartile range (IQR), 26–29] versus 28 [IQR, 26–29]; P=0.948). Cerebral chronic white matter damage (defined as a Wahlund score of 4 points) was found in 130 (40.5%) patients and was linked to lower median MoCA scores before ablation (27 [IQR, 24–28] versus 27 [IQR, 25–29]; P=0.026) and 3 months after ablation (27 [IQR, 25–29] versus 28 [IQR, 26–29]; P=0.011). When age and gender were taken into account, the link was no longer significant. Before ablation, age was linked to lower MoCA scores (related risk, 1.02 per 10 years [95% CI, 1.01–1.03]) and 3 months after ablation (relative risk, 1.02 per 10 years [95% CI, 1.01–1.03]). After first-time ablation for paroxysmal AF utilizing uninterrupted oral anticoagulation, chronic white matter damage, as well as acute ischemia lesions, were often discovered by brain magnetic resonance imaging.