Crossover between direct oral anticoagulants (DOACs) has been underinvestigated, but happens frequently in clinical practice. The purpose of this study was to evaluate causes, rates and outcomes of a DOAC-to-DOAC switch.
Patients receiving their first DOAC prescription at the Anticoagulation Center, Cardiology Dept, Bologna-Bellaria Hospital in 2017–2018 were consecutively included and prospectively followed up. DOAC-to-DOAC switch was the main outcome; causes of switch (cardiovascular events and noncardiovascular drug-related adverse events) had direct biannual assessment before and after the switch.
Among 300 patients enrolled (mean age = 79.3 years, mean follow-up = 1.5 years), with no difference in cardiovascular risk factors depending on index DOAC, 13% underwent DOAC-to-DOAC switch, minor bleeding and noncardiovascular adverse events being the most frequent causes. Dabigatran carried a three-fold increase in risk of switch compared with other DOACs, but the mean age of patients who switched was 83. Factors leading to switch resolved in 87% of cases afterwards. Annual rates of cardiovascular/noncardiovascular V events did not differ before and after the switch.
DOAC-to-DOAC switch happens in 9% of patients using DOAC each year, and seems not to impact rates of cardiovascular events after switch. Dabigatran, in the elderly, might be associated with a higher risk of DOAC-to-DOAC switch. Further studies are needed to confirm the long-term safety and effectiveness of switching paradigm.