Decrease in incidence of oral anticoagulant-related intracerebral hemorrhage over the past decade in the Netherlands

Background Data on oral anticoagulant-related (OAC) intracerebral hemorrhage (ICH) incidence are scarce. Most studies on incidence time trends were performed before the introduction of Direct Oral Anticoagulants (DOACs). Between 2008 and 2018, the number of OAC-users in the Netherlands increased by 63%, with the number of DOAC-users almost equaling that of Vitamin K Antagonists (VKA)-users. We aimed to determine the recent total and OAC-related ICH incidence and assess changes over the last decade, including the effect of DOAC introduction. Methods All adult non-traumatic ICH patients presenting in any of three hospitals in the enclosed region of South-Limburg, the Netherlands, were retrospectively included, during two 3-year time periods: 2007-2009 and 2017-2019. OAC-related ICH was defined as ICH in patients using VKAs or DOACs. We calculated the incidence rate ratio (IRR) between the two study periods. Results In the 2007-2009 period, we registered 652 ICHs of whom 168 (25.8%) were OAC-related (all VKA). In the 2017-2019 period, we registered 522 ICHs, 121 (23.2%) were OAC-related (70 VKA and 51 DOAC). In 2007-2009, the annual incidence of total ICH and OAC-related ICH was 40.9 and 10.5 per 100,000 person-years, respectively, which decreased to 32.4 and 7.5 per 100,000 person-years in 2017-2019. The IRR for total ICH and OAC-related ICH was 0.67 (95%-CI: 0.60-0.75) and 0.58 (0.46-0.73), respectively. Conclusion Both total ICH and OAC-related ICH incidence decreased over the past decade in South-Limburg, the Netherlands, despite the aging population and increasing number of OAC-users. The introduction of DOACs, and possibly an improved cardiovascular risk management and change in OAC prescription pattern, could explain these findings.