Effect of atrial fibrillation on progression of cognitive impairment in patients with and without prior stroke.

BACKGROUND

Atrial fibrillation (AF) increases risk of stroke and cognitive impairment.

OBJECTIVE

This study aimed to identify the unique AF contributions to cognitive impairment progression in patients with or without a stroke history.

METHODS

Associations among AF, stroke history, and cognitive impairment (ie, advancing from normal to mild cognitive impairment or dementia) were evaluated using Cox proportional hazards regression with the National Alzheimer's Coordinating Center clinical case series.

RESULTS

Of 19,533 participants, 16,727 had no AF/no stroke; 548 had no AF + stroke; 2121 had AF + no stroke, and 137 had AF + stroke. Cognitive decrease was common no AF + no stroke: 4482 [27%], no AF + stroke: 222 [41%], AF + no stroke: 662 [31%], and AF + stroke: 59 [43%] P < .0001]) despite few new covert strokes. Women with AF experienced more cognitive decrease over time than did those without AF among subjects without a stroke history (hazard ratio [HR] 1.18, 95% confidence interval [CI] 1.00‒1.40), but AF was not associated with cognitive decrease in men. Stroke history was associated with cognitive decrease in men with AF (HR 2.33, CI [1.31-4.12) and without AF (HR 1.65, CI 1.09-2.50) and women without AF (HR 1.84, CI 1.43-2.38).

CONCLUSION

Important sex-specific differences were observed. AF was associated with cognitive decrease primarily in female patients without prior stroke, whereas prior stroke was a predictor of decrease in male patients regardless of AF status. In women, the association between stroke and cognitive decrease was evident primarily in those without AF. Findings underscore the complex interplay among AF, stroke, and sex in shaping cognitive trajectories and highlight the need for sex-specific risk stratification in patients with AF.