Key Points

The association was stronger in younger adults and was lost in older adults aged 70 years and over, according to new research presented at the 'EHRA 2025', a scientific congress of the European Society of Cardiology, in Austria.

"This is the largest European population-based study evaluating the association between AF and dementia," said the authors that included Dr Julian Rodriguez García of the Electrophysiology and Arrhythmia department of the Bellvitge University Hospital, Barcelona, Spain.

"The association between AF and dementia was stronger in patients under 70 and was maximal for early-onset dementia," García noted.

Atrial fibrillation causes an irregular heartbeat and is relatively common, affecting 2-3 per cernt of the general population, with the prevalence rising with age.

In this new study, the researchers assessed the independent association between AF and incident dementia in Catalonia, Spain.

The study included 2,520,839 individuals with an average follow-up of 13 years. At baseline, 79,820 patients (3.25%) had a recorded diagnosis of AF. In multivariable analyses adjusting for potential confounders, AF was, overall, a statistically significant but weak predictor of dementia, linked with a 4% increased risk of dementia.

However, age was found to significantly affect the association between AF and dementia.

In pre-specified analyses stratified by age, the strength of the association progressively weakened with increasing age: in patients aged 45-50, those with AF were 3.3 times more likely to develop dementia than those without AF. But in patients aged over 70 years, no association was found.

Further analysis showed the association lost statistical significance from 70 years. By contrast, in patients diagnosed with AF before the age of 70, the condition independently increased the risk of dementia by 21 per cent, and an even stronger effect was observed for early-onset dementia, with AF increasing the risk by 36 per cent.

"The study demonstrates a significant and strong association in younger patients between two pathologies - atrial fibrillation and dementia - that are among the major health challenges of the 21st century," said the authors.

- IANS