A new study shows that atrial fibrillation (AF) increases the risk of dementia in older adults who have not had a stroke and have normal baseline cognitive function. The meta-analysis, published in the November edition of HeartRhythm,the official journal of the Heart Rhythm Society, is the first-of-its-kind to observe a large population of patients over a relatively long follow-up period. The study results support an independent longitudinal relationship between the two conditions, therefore associating the presence of AF with greater risk of developing dementia.
The systematic review included eight studies with 77,668 patients and an average age of 60 or older. All studies had a prospective observational design and included older patients with normal cognitive function at the time they entered the study. The meta-analysis adjusted for baseline covariates (factors) including age, gender, hypertension, diabetes, hyperlipidemia, coronary artery disease (CAD) and previous incident of stroke. After making adjustments for these potential risk factors and observing a mean follow-up of 7.7 ± 9.1 years (range 1.8 to 30 years), AF was associated with increased risk of developing dementia (hazard ratio [HR] 1.42, 95% confidence interval [CI] 1.17 to 1.72,P< 0.001).
As the world population ages, the prevalence of AF is projected to increase. In fact, in the next 30-40 years, the number of people diagnosed with AF in the U.S. is expected to more than double, making it one of the most prominently global epidemiologic trends of the 21st century. Similar to AF, the prevalence of dementia is expected to increase in the coming years.
“Thus far, whether AF increases the risk of dementia in patients with normal cognitive function not suffering an acute stroke was controversial. Our analysis shows an independent longitudinal association in a very large population over time,” stated lead-author Pasquale Santangeli, MD, Texas Cardiac Arrhythmia Institute, St. David’s Medical Center in Austin, Texas. “This correlation demonstrates the critical need for all patients with AF to be periodically screened for dementia in order to reach an early diagnosis and treatment of the condition.”
Overall, the study establishes several clinical implications including the impact of periodically screening AF patients for dementia. Dementia should also be included among the outcomes assessed in ongoing and future AF treatment trials. In addition, future studies are warranted to help establish whether effective treatments of AF could reduce the risk of developing dementia in general.