- Atrial fibrillation is a common arrhythmia, and experts are interested in the relationship between atrial fibrillation and other conditions like dementia.
- Recent study results suggest that atrial fibrillation increases the risk of dementia and that the risk association is stronger for younger individuals.
- The results suggest the importance of treating atrial fibrillation as soon as possible and emphasizing possible preventative measures.
Atrial fibrillation (AFib) affects
Recent study findings regarding AFib and dementia risk were presented at the European Heart Rhythm Association (EHRA) 2025.
The research — called “Association between atrial fibrillation and dementia, with a particular focus on early-onset dementia: A longitudinal population-based study in Catalonia, Spain” — from medical institutions in Spain, involved over 2.5 million participants, and researchers found that having AFib was a weak predictor of dementia.
When looking at risk in various age groups, participants with AFib were at a 21% greater risk for dementia if they were below 70 years old.
The risk was greatest for dementia diagnosis before age 65. In contrast, the associated risk for dementia was no longer statistically significant for participants over seventy.
This study results have not yet been published in a peer-reviewed journal.
The authors of this study noted that there are mixed results when it comes to AFib affecting dementia risk, and that there is a lack of data focusing on the Mediterranean population.
They also noted that gaining more data about which subpopulations have the greatest associations between AFib and dementia can help experts understand why and help with finding specific, preventative strategies. Thus, they sought to “assess the independent association between [atrial fibrillation] and incident dementia.”
This study was a population-based observational study among participants in Catalonia, Spain. Researchers used data from the System for the Development of Research in Primary Care. This system allowed researchers to look at vast anonymized data.
Researchers used demographic records, ICD-10 codes, laboratory data, and drug prescription data in their analyses. The ICD-10 codes and drug prescription data were used to identify the cases of dementia.
All participants were at least 45 years old. After excluding people who had previous cognitive impairment or dementia, the overall analysis included 2,458,905 individuals.
The researchers also conducted a separate analysis that further excluded participants who had prevalent or incident stroke, ultimately including 2,377,638 participants in this analysis.
The average follow-up time with participants was 13 years. Of the study population, 3.25% had AFib. Throughout the follow-up, researchers found a greater crude incidence of dementia among participants who had AFib, and the univariate analysis showed AFib was a strong predictor of someone developing dementia.
However, after they adjusted for potential confounders, AFib was only a weak predictor of someone developing dementia.
When looking at participants based on age, the risk for dementia in participants with AFib decreased with increased age.
Of note, once participants were older than 70, the risk for dementia associated with AFib was no longer at a level that was statistically significant.
In participants under 70, AFib “independently increased the risk of dementia by 21%.” Participants with AFib under seventy were also at a 36% increased risk for early-onset dementia. For this study, that meant getting a diagnosis of dementia before age 65.
Researchers observed similar findings when excluding participants with baseline stroke or those who experienced a stroke during the follow-up. In this group, AFib appeared to increase the risk for early onset dementia by 52%.
Study author Julian Rodriguez-Garcia, MD, from the Bellvitge University Hospital, Hospitalet de Llobregat, Barcelona, Spain, highlighted the following components of the findings to Medical News Today:
“Our study highlights that [atrial fibrillation] is an independent predictor of dementia, with a stronger association in individuals under 70 years of age, especially for early-onset dementia. Notably, the association between [atrial fibrillation] and dementia weakened in individuals over 70, suggesting that the impact of [atrial fibrillation] may diminish as other factors contributing to cognitive decline become more dominant in older age groups.”
Since the full study has not been published, this makes it challenging to examine the full limitations of the work. Complete publication of the work will allow for a more in-depth view of the findings.
However, the study focused on individuals in Spain, so greater diversity in future studies could be helpful, as well as focusing on other populations.
While researchers were able to adjust for potential confounders, residual confounding is likely still possible. They used codes and prescription data to confirm dementia cases, but it is possible that they missed some cases of dementia or that some participants received an incorrect diagnosis.
Additionally, it is important to note that the research only describes an increased risk for dementia, not that AFib causes dementia.
Paul Drury, MD, a board-certified cardiologist and associate medical director of electrophysiology at MemorialCare Saddleback Medical Center in Laguna Hills, CA, who was not involved in the study, noted to MNT that “[t]here are interesting findings [in this study]; however, it is retrospective and does not tease out which specific treatments patients received or other comorbidities.”
“There does however [appear to] be a much stronger association with dementia the earlier a person is diagnosed with AFib, which implies that AFib has potential mechanisms that can lead to dementia. Larger studies that involve more diverse patient populations and are able to control for specific treatments such as anticoagulation use, rate vs rhythm control or ablation will be needed to confirm the causality of dementia from AFib,” Drury advised.
Rodriguez-Garcia further noted that:
“Future research should focus on understanding the underlying mechanisms by which [atrial fibrillation] contributes to dementia, particularly in younger individuals. Exploring how [atrial fibrillation] leads to changes in brain structure, such as brain atrophy or microinfarcts, could offer new insights. Additionally, longitudinal studies that assess the impact of early intervention for [atrial fibrillation], including rhythm control and management of cardiovascular risk factors, are needed to determine whether these strategies can reduce dementia risk in the long term.”
These study results add to the understanding of the relationship between dementia and AFib and drew on data from a very large study population.
Drury noted that:
“Multiple prior studies have shown an increased risk of dementia in patients with AFib. Some small trials have shown the ability to decrease the risk of dementia with more aggressive treatment such as cardiac ablation or chronic anticoagulation therapy. This study supplements these prior findings, however discovering a way to alter the risk of dementia in a young patient diagnosed with AFib is still necessary.”
Overall, these study results highlight how AFib may particularly increase the risk for dementia in younger individuals.
“From a clinical perspective,”, Rodriguez-Garcia, added, “our findings emphasize the importance of actively managing [atrial fibrillation], particularly in younger individuals.”
“While the increased risk of dementia in those with [atrial fibrillation] is well-established, preventing the onset of [atrial fibrillation] through cardiovascular Health management could significantly reduce the likelihood of cognitive decline later in life,” he advised.
“Furthermore, the association of [atrial fibrillation] with dementia in patients under 70 suggests that proactive monitoring for cognitive impairment in these individuals could allow for early intervention. The findings also call for a deeper exploration of how rhythm control strategies and other [atrial fibrillation] treatments might potentially mitigate cognitive decline in affected patients,” said Rodriguez-Garcia.
