Underuse of Anticoagulation in Older Patients with Atrial Fibrillation and CHADS2 Score ≥ 2: Are We Doing Better Since the Marketing of Direct Oral Anticoagulants?

OBJECTIVE: Our objectives were to (1) describe the evolution of the underuse of anticoagulants in older people with atrial fibrillation (AF) and a CHADS2 score ≥ 2 since direct oral anticoagulants (DOACs) were introduced to the market and (2) describe factors associated with this underuse.
METHODS: We conducted a retrospective cross-sectional study including geriatric patients admitted during the pre-DOAC (2008-2011) and post-DOAC (2013-2015) periods in an academic hospital in Belgium. Five inclusion criteria were met: age ≥ 75 years, diagnosis of AF, indication for anticoagulation (CHADS2 score ≥ 2), risk of functional decline (Identification of Seniors At Risk [ISAR] score ≥ 2), and comprehensive geriatric assessment. The use of anticoagulants and antiplatelets at home before admission was recorded. Risks of stroke and bleeding were calculated using CHADS2 and HEMORR2HAGES scores, respectively. Three different logistic regression models were performed to describe the evolution of and factors associated with the underuse of anticoagulants after DOAC marketing.
RESULTS: Anticoagulant underuse, present in 209 of 614 (34%) geriatric patients with AF, was lower in patients with a history of stroke (28.5%) or congestive heart failure (26.9%) but higher in those receiving antiplatelets (56.2%) and in older individuals. Anticoagulant underuse decreased significantly from the pre-DOAC (37.3%) to the post-DOAC (29.7%) era, as shown by two analyses using propensity scores.
CONCLUSION: In older patients with AF, anticoagulant underuse was mainly associated with antiplatelet use. Anticoagulant underuse and antiplatelet use have both decreased since DOAC marketing. Underuse of anticoagulants was still a concern for three in ten geriatric patients with AF at high risk of stroke (CHADS2 score ≥ 2).