Irregular Heartbeat May Speed Cognitive Decline
(HealthDay News) – In the absence of stroke, older adults who develop atrial fibrillation are at increased likelihood of experiencing a more rapid cognitive decline compared to similarly aged people without atrial fibrillation, according to a study published online June 5 in Neurology.
Evan L. Thacker, PhD, from the University of Alabama at Birmingham, and colleagues analyzed longitudinal data from 5,150 men and women (aged ≥65 years) participating in the Cardiovascular Health Study. Participants were enrolled in 1989/1990 or 1992/1993 and did not have atrial fibrillation or a history of stroke at baseline. If participants experienced incident clinical stroke, they were censored. Hospital discharge diagnosis codes and annual study electrocardiograms identified incident atrial fibrillation. Rate of cognitive decline was assessed with mean scores on the 100-point Modified Mini-Mental State Examination (3MSE), administered annually up to nine times.
The researchers found that 552 participants (10.7%) developed incident atrial fibrillation over a mean follow-up of seven years. There was a faster decline in mean 3MSE scores after incident atrial fibrillation compared with no prior atrial fibrillation. For participants without a history of atrial fibrillation from age 80–85 years, the predicted five-year decline in mean 3MSE score was 6.4 points. However, for participants experiencing incident atrial fibrillation at age 80, the decline was 10.3 points.
"In the absence of clinical stroke, people with incident atrial fibrillation are likely to reach thresholds of cognitive impairment or dementia at earlier ages than people with no history of atrial fibrillation," the authors write.
Two authors disclosed financial ties to Medtronic and Merck.