Impact of atrial fibrillation burden on cognitive function after left atrial ablation - Results of the MACPAF study

Atrial fibrillation (AF) is associated with cognitive decline and dementia irrespective of AF-related ischemic stroke. We investigated whether AF burden after ablation in patients with symptomatic paroxysmal AF has an impact on cognitive function. After enrolment to the prospective MACPAF study, study patients received an insertable loop recorder (ILR) and underwent serial neurological/cognitive assessment. To compare cognitive function, the delta of baseline and six months test results (Δ_pre/post) and a score to assess overall cognitive performance were computed. Thirty patients (median age 65 years (IQR 57-69), 40% female) were divided into groups according to median AF burden (<0.5% vs. ≥0.5%) after ablation. Overall cognitive performance did not differ in patients with an AF burden < 0.5% (median 120% [IQR 100-150]) vs. ≥0.5% (median 120% [IQR 100-160]) within six months after ablation (p = 0.74). Comparing Δ_pre/post, patients with an AF burden ≥ 0.5% showed significantly better results in the digit-span backwards test (median + 1 [IQR 0 - +2 points]) compared to patients with an AF burden < 0.5% (median 0 [IQR -1-+1]) six months after ablation (p = 0.03). In patients with an AF burden < 0.5%, there was a statistical trend towards better results in the RAVLT test (median + 3 [IQR 0-+4]; p = 0.08) and the ROC test (median + 3 [IQR -1-+5; p = 0.07) compared to patients with an AF burden ≥ 0.5% (median -1 [IQR -3-+2] words and median -1 [IQR -5-+2] points, respectively). Therefore, AF burden had no significant impact on cognitive performance within six months after ablation. Clinical Trial Registration: clinicaltrials.gov NCT01061931.