A recent study published in the European Heart Journal suggests that atrial fibrillation (AF) may impair the brain's waste-clearance system, and restoring normal heart rhythm through catheter ablation could help improve this process. The research was announced on Mar. 30 and provides new insights into why AF is associated with cognitive decline.
This topic is important because AF is the most common cardiac arrhythmia and has been linked to a higher risk of cerebrovascular disease, cognitive impairment, and dementia—even in patients who have not experienced a stroke. Understanding how AF affects brain health could lead to better prevention or treatment strategies for cognitive decline in these patients.
In the study, researchers enrolled 87 stroke-free AF patients between July 2023 and September 2024, along with 44 healthy controls matched for sex, age, and education. Patients were divided into non-paroxysmal and paroxysmal AF groups. Some underwent catheter ablation to restore sinus rhythm. A range of neuropsychological tests assessed memory, attention, executive function, visual ability, language skills, as well as global cognition using tools such as the Montreal Cognitive Assessment (MoCA) and Rey Auditory Verbal Learning Test (RAVLT). Brain magnetic resonance imaging (MRI), including diffusion tensor image analysis along the perivascular space (DTI-ALPS), was used to indirectly measure glymphatic activity—the brain’s system for clearing waste.
Results showed that AF patients had lower scores on multiple cognitive tests compared to controls. The DTI-ALPS index was significantly lower in AF patients—especially those with non-paroxysmal AF—indicating reduced glymphatic activity. Lower DTI-ALPS values were linked with worse performance in executive function, processing speed, and attention domains among these patients.
Among those who underwent catheter ablation therapy to restore sinus rhythm, short-term improvements were observed in their DTI-ALPS index after treatment. This suggests that maintaining regular cardiac rhythm may be important for supporting both glymphatic function and overall cognitive health.
The authors concluded that decreased glymphatic activity appears more pronounced in non-paroxysmal AF cases but can improve following restoration of sinus rhythm via ablation therapy. However, they noted that while these findings highlight an association between heart rhythm management and brain health outcomes in people with atrial fibrillation, causality or long-term benefits remain unproven.
