Delayed use of anticoagulants in AF increases risk for dementia

CHICAGO — In individuals with atrial fibrillation, dementia rates increased when anticoagulant treatment was delayed more than 30 days from diagnosis, according to findings presented at Heart Rhythm Society Annual Scientific Sessions.

T. Jared Bunch, MD, director of heart rhythm research at the Intermountain Medical Center Heart Institute and medical director for heart rhythm services for the Intermountain Healthcare System, Salt Lake City, and colleagues studied individuals with AF and no history of dementia (n = 76,230; mean age, 69 years; 57% men); 26,189 were ultimately treated with an antiplatelet (n = 21,781) or warfarin (n = 4,408).

The participants were categorized by initiation of treatment: immediate (less than 30 days after diagnosis) and delayed (more than one year after diagnosis).

T. Jared Bunch

Antiplatelet (aspirin or clopidogrel) or warfarin therapy was started in less than 30 days in 43.6% of participants, in 31 days to 1 year in 10.6% of participants, in 1 year to 3 years in 13.5% of participants and in more than 3 years in 32.3% of participants.

When anticoagulation therapy was not started within 30 days of AF diagnosis, the risk for dementia significantly increased (adjusted HR = 1.63; P = .05). There was linear relationship between time to treatment and risk for dementia.

After stratification of patients by CHA₂DS₂-VASc scores, the researchers found that the association between a delay in therapy and dementia risk was most pronounced in high-risk participants (HR for CHA₂DS₂-VASc score 0-1 = 1.3; P = .75; HR for CHA₂DS₂-VASc score 2-4 = 1.5; P = .19; HR for CHA₂DS₂-VASc score 5 = 2.36; P = .07).

According to the researchers, delay of initiation of anticoagulation therapy might be attributed to low stroke risk, exploration of other treatment options, older age or multiple comorbidities.

“In this study, the trend was to start the less effective therapy, aspirin, early after [AF] diagnosis likely because of its broad availability and ease of use,” Bunch told Cardiology Today. “The opposite was seen with warfarin: People were often treated much later, with the majority started more than 30 days after their diagnosis. These data highlight that this trend is harmful and we as physicians much recognize [AF] early and start appropriate anticoagulation as soon as possible. No. 2, as we study each time delay, there was an increased dementia risk. This suggests that it is never too late to start. Finally, we are hopeful that newer anticoagulants that are in general as effective and safer than warfarin will be started earlier and minimize dementia risk in atrial fibrillation patients. The study of these newer agents is clearly the next step in our research.” – by Cassie Homer

Reference:

Bunch TJ, et al. Abstract C-AB30-03. Presented at: Heart Rhythm Society Annual Scientific Sessions; May 10-13, 2017; Chicago.

Disclosure: Bunch reports receiving an institutional research grant from Boehringer Ingelheim.