Inflammation may play a key role in the cognitive decline seen in atrial fibrillation. A study published in the Journal of the American Heart Association found that higher CRP levels were associated with increased mortality and progressive cognitive decline in men with AF.

The analysis included 2,109 adults aged 45 years and older from the REGARDS cohort who had atrial fibrillation but no cognitive impairment at baseline. Over a median nine-year follow-up, 285 developed cognitive impairment and 786 died.

Each doubling of baseline CRP levels was linked to a 13% higher risk of death (hazard ratio 1.13; 95% CI 1.08–1.19). While CRP was not associated with overall incident cognitive impairment, men with higher CRP showed greater odds of progressive decline (odds ratio 1.09; 95% CI 1.01–1.17). The relationship was not significant among women.

The findings highlight inflammation-mediated blood–brain barrier dysfunction as a potential mechanism connecting AF with cognitive decline. Addressing systemic inflammation may therefore be important in reducing cognitive deterioration and mortality risk in AF.