Prevention of Dementia in Patients with Atrial Fibrillation

Abstract

Atrial fibrillation (AF) is the most common form of arrhythmia in the elderly population and increases stroke risk by a factor of 4- to 5-fold. There is increasing evidence to suggest that incident AF may contribute to the development of dementia, independent of overt stroke. In particular, relatively younger patients with AF are more prone to dementia development than older patients with AF. Evidence is accumulating regarding the possible treatment strategies for preventing dementia in patients with AF. Oral anticoagulation may be effective for reducing the risk of dementia, even in patients with low stroke risks. Among oral anticoagulants, the use of non-vitamin K antagonists have been associated with a considerably decreased risk of dementia than warfarin. Moreover, successful catheter ablation for AF has also been associated with decreased dementia risk compared to medical therapy, suggesting that restoration of sinus rhythm, and not the ablation procedure itself, as the important mechanism in the prevention of AF-associated dementia. Among midlife patients with AF, there appeared to be a U-shaped association of blood pressure (BP) and a linear association of hypertension with dementia risk. A BP of 120 to 129/80 to 84 mmHg has been identified as the optimal range. Finally, integrated management of AF was associated with a reduced risk of dementia in AF patients.

Keywords: Anticoagulants; Atrial fibrillation; Catheter ablation; Dementia; Risk factors.

Figure 1. Risk of dementia according to atrial fibrillation in the study population (left). Effects of OAC on the risk of dementia in patients with atrial fibrillation (right). Figure courtesy of Kim et al.

AD = Alzheimer's disease, AF = atrial fibrillation; CI = confidence interval; HR = hazard ratio; OAC = oral anticoagulant, VaD = vascular dementia.

Figure 2. HRs for dementia per decade of age in the presence of AF. (A) Including stroke during the follow-up. (B) Excluding stroke during the follow-up. The horizontal line (at HR 1) indicates no difference in HRs between the AF and non-AF groups. Figure courtesy of Kim et al.

AF = atrial fibrillation; HR = hazard ratio.

Figure 3. Risk of dementia according to oral anticoagulant regimens from Asian, European, and North American populations. Incidences were presented as rates per 100 person-years. Figure courtesy by Kim et al.

Incidences were presented as rates per 100 person-years. CI = confidence interval; HR = hazard ratio; IPW = inverse probability of treatment weighting; NHIS = National Health Insurance Service; NOAC = non-vitamin K antagonist oral anticoagulant; PSM = propensity score matching. ^*Incidences and HRs were propensity-weighted; ^†Incidences were not presented in the article; ^‡CHA₂DS₂-VASc ≤1 (no points for female sex).

Figure 4. Cumulative incidence curves of overall dementia in propensity-matched patients undergoing ablation or medical therapy (left). Risk of dementia in propensity score-matched patients undergoing ablation or medical therapy (right). Figure courtesy of Kim et al.

AD = Alzheimer's disease, AF = atrial fibrillation; Tx = treatment; VaD = vascular dementia.

Figure 5. Association of (A) systolic and (B) diastolic BP at baseline with dementia risk. Figure courtesy of Kim et al.

BP = blood pressure; CI = confidence interval; HR = hazard ratio. ^*HRs were calculated with a systolic or diastolic BP of 120 or 80 mmHg as reference.

Figure 6. Association of hypertension burden during follow-up with dementia risk. Figure courtesy of Kim et al.

CI = confidence interval; FU = follow-up; HR = hazard ratio; HTN = hypertension. ^*HRs were calculated with the burden under 40% as reference.