A systematic review and meta‐analysis to determine the effect of oral anticoagulants on incidence of dementia in patients with atrial fibrillation

Abstract

Aims:To assess the effect of oral anticoagulant (OAC) administration on incidence of dementia in patients with atrial fibrillation (AF) with Systematic review and meta-analysis. Methods:We systematically searched the electronic databases including Pubmed, Embase, Cochrane library and ClinicalTrails.gov for relevant articles. The primary outcome was the incidence of dementia. The adjusted risk ratio (RR), odds ratio or hazard ratio were extracted and pooled by the random-effects models. Subgroup analysis was performed according to the setting observational window. Risk of bias was assessed using the Newcastle-Ottawa Scale, while publication bias was assessed by the Begg's and Egger's tests.Results: Nine studies were included in this review (2 prospective and 7 retrospective observational studies, including 613,920 patients). The results presented the significant association between OAC therapy and the reduced risk of dementia compared with no treatment (RR [95% CI] = 0.72 [0.60, 0.86], I 2 = 97.2%; P = .000). In the subgroup analysis with an observational window, the pooled RR became statistically non-significant (including four studies, RR [95% CI] = 0.75 [0.51, 1.10], I 2 = 98.8%; P = .000). There is no significant risk of bias and publication bias. Conclusions:This study indicated the protective effect of OAC therapy for dementia in patients with AF. However, the results are limited because of high heterogeneity, inconsistent direction of effect in subgroup analysis with an observational window.Further prospective well-designed study is needed with longer follow-up duration in younger patients. Review criteria• The inclusion criteria were as follows: (a) patients with AF who were ≥18 years; (b) investigating the effects of OACs on the incidence of dementia; (c) reporting the outcomes as HR, RR or OR, with 95% CIs; (d) RCTs or observational studies. • The exclusion criteria were as follows: (a) patients with the history of dementia or moderateto-severe cognitive dysfunction; (b) only crude or unadjusted HR, RR or OR; (c) crosssectional studies; (d) following types of articles: conference abstracts, editorials, letters, expert opinions, case reports, case series or reviews.

Heart Disease and Stroke Statistics—2023 Update: A Report From the American Heart Association

“…56 In a meta-analysis of 9 studies including 613 920 patients with AF, anticoagulant treatment was associated with 28% lower (14%–40% lower) risk of dementia compared with no treatment, albeit with high heterogeneity of study-specific findings ( I 2 =97%). 58 In a study of 407 871 older adults enrolled in the US Veterans Health Administration, AF was associated with increased risk of dementia (OR, 1.14 [95% CI, 1.07–1.22]); anticoagulant use among those with AF also was associated with increased risk of dementia (OR, 1.44 [95% CI, 1.27–1.63]). 57…”

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

“…66 In a meta-analysis of 9 studies including 613 920 patients with AF, anticoagulant treatment was associated with 28% lower (14%–40% lower) risk of dementia compared with no treatment, albeit with high heterogeneity of study-specific findings ( I 2 =97%). 68 However, in a study of 407 871 older adults enrolled in the US Veterans Health Administration, AF was associated with increased risk of dementia (OR, 1.14 [95% CI, 1.07–1.22]); anticoagulant use among those with AF also was associated with increased risk of dementia (OR, 1.44 [95% CI, 1.27–1.63]). 67…”

A comparison of the effects of NOAC and VKA therapy on the incidence of dementia in patients with atrial fibrillation: A systematic review and meta‐analysis

“…Furthermore, our subgroup analysis showed that NOAC had a stronger protective effect than VKA regardless of whether a blank period was included, which was different from the findings of a previous meta-analysis. 18 Indeed, dementia cases were more likely to appear within the initial year of monitoring, suggesting that the participants were already in the prodromal stage of dementia development before they were enrolled. 40 Thus, the blank period may help to minimize the overestimation of pharmacological protective effects.…”

“…Therefore, dementia diagnosed at the beginning of follow‐up, known as the “blank period,” should be excluded. Unfortunately, the pooled risk ratio of studies with an observational blank period was not statistically significant 18 . Moreover, varying definitions of anticoagulation were used when grouping in a number of cohort studies, which may directly affect the statistical results of the study.…”

“…Unfortunately, the pooled risk ratio of studies with an observational blank period was not statistically significant. 18 Moreover, varying definitions of anticoagulation were used when grouping in a number of cohort studies, which may directly affect the statistical results of the study. Regretfully, there was no comprehensive study being conducted to examine this matter.…”