Persistence of oral anticoagulation therapy in atrial fibrillation: A retrospective cohort study in primary care in Italy

Background: Although oral anticoagulants (OAC) prevent stroke in patients with atrial fibrillation (AF), poor compliance and discontinuation are a concern. Objectives: To determine the duration of, and the pattern of persistence with, OAC therapy in patients with AF, using the definitions: persisters, those who received continuous OAC for 1 year; interrupters, those who stopped therapy (no prescription for >2 months) and then restarted within 1 year; and discontinuers, those who stopped initial therapy and did not restart. Methods: Data used were derived from a central database informed by Italian general practitioners. Patients diagnosed after January 2001 were classified as persisters, interrupters, or discontinuers. Duration of OAC was determined from the date of first prescription. Results: Persistence patterns were assessed in 1707 and 1236 patients receiving OAC with 1 or 2 years’ follow-up from first prescription, respectively. Persisters and interrupters comprised 42.5% and 32.8% of patients at 1 year, and 24.3% and 49.1% at 2 years’ follow-up, respectively. The proportion of persisters and interrupters was similar after 1 and 2 years at 75% and 73%, respectively. Kaplan–Meier analysis showed a decrease in persisters to <25% at 2 years, suggesting that OAC interruption is still common even after longer periods of therapy. Discontinuers comprised 25% of patients at 1 year (mean duration of therapy: 176 days) and 27% at year 2. Averaged across all three groups, mean duration of OAC therapy was 257 and 374 days at 1 and 2 years’ follow-up, respectively. Conclusions: With current OAC therapy, discontinuation and interruption are common at any time, even after sustained periods of persistent use. These findings highlight the need for new stroke prevention strategies in AF that may also reduce discontinuation and improve persistence with OAC.