Cognitive functions in patients with atrial fibrillation at baseline and at different stages after pacemaker implantation depending on the received anticoagulant therapy

Aim. Comparative assessment of cognitive functions (memory, attention, cognition and neurodynamics) in patients with atrial fibrillation before and at different stages after implantation of permanent pacemaker depending on the received anticoagulant therapy.

Methods. We examined 44 patients (average age 65.5 ± 2.5 years) with ischemic heart disease (IHD) complicated by persistent or paroxysmal atrial fibrillation, which required implantation of a permanent pacemaker (PM). The patients were divided into 2 groups: receiving warfarin (28 patients - 63.6 %, average age 65.5 ± 1.6 years) and those who received oral anticoagulants (OAC) (16 patients - 36.4 %, average age 66.3 ± 1.4 years, p = 0.614). To assess the cognitive functions, psycho-physiological complex «Status PF» was used.

Results. Before PM implantation, the patients of both groups had decreased indices of visual memory. On days 5-7 after PM implantation, each group showed its increase (p = 0.001 and p = 0.013, respectively). On days 30-40, patients receiving warfarin developed a dramatic decrease of visual memory compared to the previous data and they became reliably lower than in the control group (p = 0.001). In the group receiving OAC, visual memory stayed unchanged (p = 0.076). Similar changes in warfarin group occurred at the assessment of auditory memory and attention volume (p = 0.001). Cognition indices (difficult analogues) were worse at baseline in warfarin group than in the group of OAC (7.0 ± 0.5 и 9.6 ± 0.6, р1 = 0.003) and this interrelation persisted on two following examinations (9.5 ± 0.4 and 10.8 ± 0.4, р1 = 0.041; 8.5 ± 0.4 and 9.8 ± 0.4, р1 = 0.048). Before PM implantation, the patients of both groups required more time of average exposure for neurodynamics test than in the control group (р = 0.001 and р = 0.002 respectively). On days 5-7 after PM implantation, the average exposure time decreased in both groups and they had no differences between each other and with the control (р1 = 0.132, р = 0.934 and р = 0.058). At the second testing only warfarin group had increased the mentioned time, and it exceeded the same parameter in the OAC group (p = 0.007).

Conclusion. A comparative assessment of cognitive functions in patients with IHD and atrial fibrillation demonstrated that in the warfarin group and the group receiving OAC patients had cognitive deficit more profound in the patients receiving warfarin. Those differences persisted at different stages after permanent PM implantation.