Adherence to oral anticoagulation in ischemic stroke patients with atrial fibrillation

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOAC) have superior safety and comparable efficacy profile compared to vitamin-K antagonists (VKAs), with more convenient dosing schemes. However, issues with adherence to the NOACs remain unsolved. AIMS: We sought to investigate the adherence to oral anticoagulation (OAC) and baseline factors associated with poor adherence after ischaemic stroke in patients with atrial fibrillation (AF). METHODS: We recruited hospitalised patients (2013–2019) from two prospective stroke registries in Larissa and Helsinki University Hospitals and invited survived patients to participate in a telephone interview. We assessed adherence with the Adherence to Refills and Medications Scale (ARMS) and defined poor adherence as a score of over 17. In addition to demographics, individual comorbidities, and stroke features, we assessed the association of CHA(2)DS(2)-VASc and SAMe-TT(2)R(2) scores with poor adherence. RESULTS: Among 396 patients (median age 75.0 years, interquartile range [IQR] 70–80; 57% men; median time from ischaemic stroke to interview 21 months [IQR 12–33]; median ARMS score 17 [IQR 17–19]), 56% of warfarin users and 44% of NOAC users reported poor adherence. In the multivariable regression model adjusted for site, sex, and age, poor adherence was independently associated with tertiary education, absence of heart failure, smoking history, use of VKA prior to index stroke, and prior ischaemic stroke. CHA(2)DS(2)-VASc and SAMe-TT(2)R(2) scores were not associated with poor adherence. CONCLUSIONS: Adherence was poor in half of AF patients who survived an ischaemic stroke. Independent patient-related factors, rather than composite scores, were associated with poor adherence in these patients. KEY MESSAGES: Adherence was poor in half of the atrial fibrillation patients who survived an ischaemic stroke. Independent patient-related factors rather than composite scores were associated with poor adherence. The findings support the importance of recognising adherence support as a crucial part of holistic patient care recommended by recent AF guideline.