Dementia and mild cognitive impairment (MCI) were found to be less common among patients who were prescribed direct oral anticoagulants (DOACs) to treat atrial fibrillation (AF) as opposed to those who were prescribed vitamin K antagonists (VKAs), according to findings published in BMJ Journals.
Using electronic health records (EHRs), the authors conducted a retrospective cohort study among patients with newly diagnosed nonvalvular AF who were 40 years or older. Patients with a history of dementia, mild cognitive impairment, or oral anticoagulant prescription prior to AF were excluded from the analysis.
The study was comprised of 39,200 patients (44.6% women; median age, 76 years) who were diagnosed with AF from 2012 to 2018. Approximately half of the patients (53%, n=20,687) were prescribed VKAs and the rest DOACs (47%, n=18,513) at baseline, with 11% (n=4477) switching oral anticoagulants (most commonly from VKAs to DOACs) during the course of the study.
Patients who were prescribed VKAs had more comorbidities (heart failure, other vascular disease, and chronic renal disease) compared with those who were prescribed DOACs, the study authors noted. Other between-group differences included lower rates of use of antiplatelet drugs (58.7% vs 68.7%), diuretics (43.5% vs 49.5%), and ACE inhibitors (37.8% vs 42.6%) in the DOACs vs VKAs group. In contrast, patients in the VKAs group were more likely to be prescribed beta-blockers (69.2% vs 66.0%), antidepressants (19.1% vs 17.7%), and proton pump inhibitors (46.7% vs 44.6%) compared with the DOAC cohort, the study authors noted.
DOACs Linked to Fewer Dementia Diagnoses
A total of 1258 patients (3.2%) were diagnosed with incident dementia, equating to an incidence rate of 16.5 per 1000 person-years. Treatment with DOACs was associated with a 16% reduction in dementia diagnosis (adjusted HR, 0.84; 95% CI, 0.73-0.98) and a 26% reduction in MCI (HR 0.74; 95% CI, 0.65-0.84) compared with treatment with VKAs.
Study limitations include possible missed dementia diagnoses in EHRs or among patients entering residential care. The authors also could not account for potential differences in treatment adherence among the two cohorts.
The authors observed that patients with AF taking DOACs are less likely to experience dementia or cognitive decline than those prescribed VKAs. “While further evidence, including from randomized controlled trials, would strengthen this finding, it may be relevant to consider cognitive risk profile when prescribing OACs for AF among older individuals,” the study authors concluded.
Cadogan SL, Powell E, Wing K, et al. Anticoagulant prescribing for atrial fibrillation and risk of incident dementia. Heart. Oct 13;heartjnl-2021-319672. doi:10.1136/heartjnl-2021-319672
The article was updated on November 4, 2021,