Postoperative Atrial Fibrillation and Risk of Development of Dementia

Postoperative atrial fibrillation (POAF) is a common postsurgical complication with increased risk of mortality and morbidity, but its association with incident dementia is unknown.

The purpose of this study was to determine if POAF is associated with increased risk of incident dementia.

This is a retrospective cohort study of Medicare beneficiaries, based on a 5% sample of claims from January 1, 2008, to December 31, 2018. We included adults aged at least 66 years with continuous coverage in Medicare who were hospitalized for surgery. Patients with prior diagnoses of dementia or stroke were excluded. Our primary exposure was AF status stratified as POAF, no AF, or previously diagnosed AF. Our primary outcome was a new diagnosis of dementia after the index hospitalization.

In our study of 670,745 patients, POAF occurred in 22.7% among those undergoing cardiac surgery and 2.2% among those undergoing noncardiac surgery. Among those undergoing cardiac surgery, the incidence of dementia was similar in those with POAF (4.4%) compared to those with no AF (4.6%); among those undergoing noncardiac surgery, the incidence of dementia was higher in those with POAF (12.5%) compared to those with no AF (9.3%). In an adjusted Cox model, there was an association between POAF and incident dementia only among those undergoing noncardiac surgery (HR: 1.20; 95% CI: 1.11-1.29).

POAF is associated with incident dementia among older adults undergoing noncardiac surgery. Increased attention and further study are needed to best guide future treatment to prevent dementia in high-risk populations such as those with POAF.