Background
We investigated population-wide changes in prescriptions of oral anticoagulants (OAC) (vitamin K antagonists [VKA]) compared to direct oral anticoagulants (DOAC) and whether these translated into a decline in incidences of OAC-related intracerebral hemorrhages (ICH).
Methods
This observational study analyzed OAC use in Southern Finland during 2005-2009 (pre-DOAC era) and 2015-2019 (transition-to-DOAC era) based on national registries. From medical records, we identified all non-traumatic ICH patients admitted to our tertiary hospital, the only one admitting neurological emergencies within the region. We compared the impact of DOACs versus VKAs on annual ICH incidence using an adjusted generalized additive model (GAM).
Results
The total population increased from 1.4 to 1.7 million between 2005 and 2019. The use of OACs increased from 1.65% of the population in 2005-2009 (100% VKA) to 2.97% in 2015-2019 (64% VKA, 36% DOAC), resulting in 368,055 person-years of OAC use. In 2019, DOAC use exceeded VKA use. The annual incidence of ICH was 12/100,000 person-years in both periods. During 2005-2009, 115 (13%) of 917 ICHs were OAC-related (100% VKA) compared to 178 (18%) of 1002 ICHs in 2015-2019 (73% VKA, 27% DOAC). In the GAM, the rate of ICH among patients on DOACs was 53% lower than among patients on VKA (p < 0.001).
Conclusions
ICH incidence remained stable despite near-doubled OAC use. The lower ICH rates with DOACs compared to VKAs support their safety advantage.