Study supports apixaban use in AF patients with dementia

Anticoagulation therapy with apixaban yields lower rates of ischaemic stroke and intracranial and extracranial major bleeding compared with other oral anticoagulants (OACs) in patients with atrial fibrillation (AF), with the magnitude of benefit for major bleeding even greater for those who have dementia, according to a study.

Researchers performed a retrospective comparative effectiveness study and used propensity score matching to establish three comparative new-user cohorts among 1,160,462 older patients with AF (mean age 77.4 years, 50.2 percent men, 80.5 percent White, 7.9 percent had dementia). Data were collected from the Optum Clinformatics Data Mart, IBM MarketScan Research Database, and Medicare claims databases.

The composite endpoint was any of ischaemic stroke or major bleeding events over the 6-month period after OAC initiation, pooled across databases using random-effects meta-analyses.

The comparative new-user cohorts were as follows: warfarin vs apixaban (501,990 patients, mean age 78.1 years, 50.2 percent women), dabigatran vs apixaban (126,718 patients, mean age 76.5 years, 52.0 percent men), and rivaroxaban vs apixaban (531,754 patients, mean age 76.9 years, 50.2 percent men).

Among patients with dementia, the composite endpoint occurred more frequently among warfarin vs apixaban users (95.7 vs 64.2 events per 1,000 person-years [PYs]; adjusted hazard ratio [aHR], 1.5, 95 percent confidence interval [CI], 1.3–1.7), dabigatran vs apixaban users (84.5 vs 54.9 events per 1,000 Pys; aHR, 1.5, 95 percent CI, 1.2–2.0), and rivaroxaban vs apixaban users (87.4 vs 68.5 events per 1,000 Pys; aHR, 1.3, 95 percent CI, 1.1–1.5).

In all three comparisons, the degree of the benefits associated with apixaban was similar regardless of dementia diagnosis on the HR scale but differed substantially on the rate difference (RD) scale.

The adjusted RD of the composite outcome for warfarin vs apixaban users was 29.8 events per 1,000 PYs in the dementia group vs 16.0 events per 1,000 PYs in the no-dementia group. The corresponding adjusted RD estimates of the composite outcome were 29.6 events per 1,000 PYs in the dementia group vs 5.8 events per 1,000 PYs in the no-dementia group for dabigatran vs apixaban users, and 20.5 events per 1,000 PYs in patients with dementia vs 15.9 events per 1,000 PYs in the no-dementia group for rivaroxaban vs apixaban users.

The pattern was more evident for major bleeding than for ischaemic stroke.

The present data support the use of apixaban for OAC therapy in people living with dementia and who have AF.