New findings presented at ACNAP 2023, a scientific congress of the European Society of Cardiology (ESC) and published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, reveal that women with atrial fibrillation experience a faster progression towards cognitive impairment and dementia compared to their male counterparts with the same heart rhythm condition.
According to Dr. Kathryn Wood, a researcher from Emory University in Atlanta, USA, symptoms of atrial fibrillation in women are frequently overlooked by healthcare providers or attributed to stress or anxiety. As a result, women may go undiagnosed for extended periods of time, while men are more likely to receive prompt diagnosis and treatment. The consequence of remaining undiagnosed is the lack of oral anticoagulant medication, which is essential in preventing blood clots and strokes associated with atrial fibrillation. Consequently, women may experience the formation of clots that travel to small blood vessels in their brains, leading to gradual loss of brain function and the development of cognitive impairment.
Dr. Kathryn Wood further explained that the ESC Guidelines for the care of patients with atrial fibrillation emphasize the importance of oral anticoagulants for both women and men. However, there is a discrepancy in the administration of these medications, with women being less likely to receive them compared to men. This disparity contributes to the occurrence of unrecognized small silent strokes in women, which can lead to the gradual deterioration of brain tissue and subsequent cognitive impairment.
This pioneering longitudinal study utilized multicenter data to investigate the disparities between sexes in the prevalence of cognitive disorders and the trajectory towards dementia among patients with atrial fibrillation. The study encompassed 43,630 participants from the National Alzheimer's Coordinating Center (NACC) cohort, which has been collecting data on adults from the general population in the United States since 1984. Among the participants, 4,593 individuals (11%) had atrial fibrillation at the beginning of the study, while 39,037 (89%) did not. The average age of the participants was 78.5 years, and 46% of them were women. Inclusion in the study necessitated having at least three annual clinic visits where participants underwent neuropsychological tests and were categorized as having normal cognition, mild cognitive impairment (MCI), or dementia.
The researchers conducted a comprehensive analysis to investigate two key associations: 1) the relationship between atrial fibrillation and the initial cognitive diagnosis; and 2) the impact of atrial fibrillation on the progression of cognitive diagnosis over time. The analyses were meticulously adjusted to account for various factors that could potentially influence these relationships. These factors included age, sex, race, education, body mass index, smoking habits, depression, hypertension, diabetes, high cholesterol, heart failure, stroke, and sleep apnea. By comparing men and women with atrial fibrillation to those without the condition, the researchers also sought to identify any significant differences based on gender.
In comparison to women without atrial fibrillation, women diagnosed with the condition had a significantly higher likelihood of having mild cognitive impairment (MCI) and dementia at the beginning of the study. The odds ratios for MCI and dementia in women were 3.43 and 3.00, respectively, indicating that women with atrial fibrillation were approximately three times more likely to experience these cognitive conditions. On the other hand, the odds ratios for men were 1.73 and 1.60 for MCI and dementia, respectively. However, these associations did not reach statistical significance in men, suggesting that the relationship between atrial fibrillation and cognitive impairment was not as pronounced in males as it was in females.
Over a median follow-up period of four years, approximately 30% of the participants experienced a worsening of cognitive impairment, and 21% developed dementia. Among women, those with atrial fibrillation had a higher risk of progressing to a more severe stage of cognitive impairment compared to women without the condition, as indicated by a hazard ratio (HR) of 1.21. Furthermore, when examining the progression from one stage to another, women with atrial fibrillation were more likely to transition from normal cognition to mild cognitive impairment (HR 1.17) and from mild cognitive impairment to vascular dementia (HR 2.57) compared to women without atrial fibrillation. However, in men, the associations between atrial fibrillation and a more rapid decline in cognitive function did not reach statistical significance.
