Efficacy and Safety of Direct Oral Anticoagulants in Older Adults with Atrial Fibrillation: a Prospective Single-centre Cohort Study

Introduction: Direct oral anticoagulants (DOACs) are underused in the elderly, regardless the evidence in their favour in this population.

Methods: We prospectively enrolled anticoagulant-naïve patients aged ≥ 75 years who started treatment with DOACs for atrial fibrillation (AF) and stratified them in older adults (aged 75-84 years) and extremely older adults (≥ 85 years). Thrombotic and hemorrhagic events were evaluated for 12 months follow-up.

Results: We enrolled 518 consecutive patients. They were mostly aged 75-84 years (299 patients; 57.7%) vs. ≥ 85 years (219 patients; 42.3%). Extremely older adults showed higher incidence of all the endpoints (systemic cardioembolism [HR 3.25 (95% CI 1.71-6.18)], major bleeding [HR 2.75 (95% CI 1.77-4.27)], and clinically relevant non-major bleeding [HR 2.13 (95% CI 1.17-3.92)]) vs. older adults during the first year after starting anticoagulation. In patients aged ≥ 85 years, no difference in the aforementioned endpoints was found between those receiving on-label vs. off-label DOACs. In the extremely older adults, chronic kidney disease, polypharmacy, use of antipsychotics, and DOAC discontinuation correlated with higher rates of thrombotic events, whereas a history of bleeding, Charlson Index ≥ 6, use of reduced DOAC dose, absence of a caregiver, use of non-steroidal anti-inflammatory drugs (NSAIDs), and HAS-BLED score ≥ 3 were associated with major bleedings.

Conclusions: Naïve patients aged ≥ 85 who started a DOAC for AF are at higher risk of thrombotic and bleeding events compared to those aged 75-84 years in the first year of therapy. History of bleeding, HAS-BLED score ≥ 3 and use of NSAIDs are associated with higher rates of major bleeding.