Role of Ventricular Rate Response on Dementia in Cognitively Impaired Elderly Subjects with Atrial Fibrillation: a 10 year study

Background: The role of ventricular rate response (VRr) on the incidence of dementia in elderly subjects with cognitive impairment and atrial fibrillation (AF) is not known. Thus, we examined the ability of VRr to predict dementia in cognitively impaired elderly subjects with and without AF. Methods: A total of 358 cognitively impaired elderly subjects (MMSE <24) with and without AF were stratified in low/high (<50/>90) and moderate (>50/<90 bpm) VRr. A 10-year follow- up was performed. Results: Cognitively impaired subjects with dementia at the end of the follow-up were 135 (37.7%): 33 in the presence (75.0%) and 102 (32.5%) in the absence of AF (p < 0.001). Multivariate analysis shows that AF is a strong predictor of dementia (hazard ratio, HR = 4.10; 95% confidence interval, CI = 1.80–9.30, p < 0.001). More importantly, low/high VRr (<50/>90 bpm) is predictive of dementia in the presence (HR = 7.70, 95% CI = 1.10–14.20, p = 0.03) but not in the absence (HR = 1.85; 95% CI = 0.78–4.47; p = 0.152) of AF. Conclusions: This study demonstrates that AF predicts dementia in elderly subjects with cognitive impairment. Moreover, VRr seems to play a key role in the incidence of dementia in cognitively impaired elderly subjects with AF.