New research presented on the EHRA 2025, a scientific congress of the European Society of Cardiology, shows that the presence of atrial fibrillation (AF) increases the risk of future dementia by 21% in patients with the 70 and the risk of early dementia (diagnosed) by 36%. The association was stronger with younger adults and was lost in older adults aged 70 and older.
“This is the largest European population screening that evaluates the association between AF and dementia“Say the authors who include Dr. Julián Rodriguez García from the Electrophysiology and Arithm’s department of Bellvitge University Hospital, Barcelona, Spain.”The association between AF and dementia was stronger in patients younger than 70 and was a maximum of dementia with early start. ”
Atrial fibrillation causes an irregular heartbeat and is relatively common and affects 2-3% of the general population, where prevalence rises with age.
Some studies have suggested an independent association between AF and dementia, while others have not confirmed this relationship. The strength of this association, as well as the interaction with a stroke, remains controversial. “Identify subgroups with the strongest association can help understand the factors of this association and to inform targeted preventive interventions“Explain the authors.
In this new study, the researchers assessed the independent association between AF and incident dementia in Catalonia, Spain. The population -based observational research included persons who were at least 45 years old in 2007 and had no prior diagnosis of dementia. The population came from the system for the development of research in primary care, which provides anonymous data over more than 80% of the Catalan population.
Incident dementia cases were defined using a validated approach based on international classification of disease 10 (ICD10) codes and prescription data for dementia-related medicines. Early start dementia (EOD) was defined as a diagnosis for 65 years. The follow-up period lasted for 15 years, from 2007 to 2021.
The study included 2,520,839 people with an average follow-up of 13 years. At the start, 79,820 patients (3.25%) had a registered diagnosis. In multivarial analyzes, adjusting potential confounders was generally a statistically significant but weak predictor of dementia, linked to a 4% increased risk of dementia.
However, the age turned out to be considerably influenced by the association between AF and dementia. In specified analyzes specified by age, the strength of the association gradually weakened with increasing age: in patients aged 45-50 years, patients with 3.3 times more likely to develop dementia than without finishing. But no association was found in patients older than 70 years.
Further analysis shows that the association lost statistical significance of 70 years. In patients with the diagnosis before the age of 70, on the other hand, the condition independently increased the risk of dementia by 21%, and an even stronger effect was observed for dementia with early start, with the risk of 36%increased.
Thinking about the possible causes of the association, the authors say: “Dementia is often a multifactorial condition with mixed neuropathological findings instead of a single pathophysiological process. This can explain why AF has a greater impact in younger patients, where it could be one of the primary pathogenic factors. Conversely, older persons reduces additional contributors to cognitive decline as age-related neurodegeneration can of the relative impact.”
Sensitivity analyzes that removed cases of earlier stroke during follow-up yielded similar results: AF was associated with a modest increase (6%) in the risk of dementia in the total population, a stronger association (23% increased risk) in those who had the greatest effect in the Midlife) (at the age of 70) risk). That is why patients with AF without an earlier stroke still have a higher risk of dementia, with the greatest risk observed in dementia with early start.
The authors say: “Atrial fibrillation is a risk factor for a stroke and stroke is a risk factor for dementia. However, the observation that the connection between AF and dementia remains unchanged after the exclusion of patients with previous stroke indicates that other mechanisms must be involved in the increased risk of dementia in AF patients. These mechanisms can include silent strokes – which means that those who did not show clinical symptoms and can only be diagnosed with CT scan or MRI – and also micro -infarctions and micro bleeding. ”
Regarding extra potential mechanisms that connect and dementia, the authors say: “Hemodynamic changes, which cause changes in current and blood pressure in the body, caused by AF, and autonomous disruption, which refers to an imbalance in how the body controls automatic functions, such as heart rate, breathing or blood pressure, can also play a role in the disease of small blood vessels in the brain associated with dementia. In addition, systemic inflammation associated with atrial fibrillation can enhance these effects, creating a synergistic path that increases the risk of dementier. ”
In general, they conclude: “The study shows a significant and strong association in younger patients between two pathologies – atrial fibrillation and dementia – that belong to one of the most important health challenges of the 21st century. We must now investigate whether early detection strategies and aggressive management of atrial fibrillation in younger patients can help reduce the risk of dementia and change the natural course of the disease.”
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