Effect of antiplatelet/anticoagulant agents in elderly patients of chronic subdural hematoma: a case control study from a tertiary care centre

Background: Bleedings are well known risks of both antiplatelet and anticoagulant therapy and both therapies have historically been considered as risk factors for CSDH. The aim of the study was to evaluate the association between exposure to anticoagulant/antiplatelet therapy and chronic subdural haematoma (CSDH).Methods: Single institution case-control study was conducted in patients older than 60 years who visited our academic tertiary care Emergency Department from January 2012 to December 2016. Patients with CSDH were identified by review of case and controls were selected with a 1:3 ratio for gender, age (60 years), year of admission and recent trauma.Results: There were 124 cases and 372 controls included in the study. Both anticoagulant and antiplatelet agents were associated with an increased risk of CSDH with an OR of 1.22 (CI 95% 0.66-1.54) and 1.12 (CI 95% 0.68-1.54), respectively. While OR was 1.11 (CI 95% 0.54-2.32), 1.21 (CI 95% 0.61-2.45), and 0.53 (CI 95% 0.33-0.78) for patients receiving oral anticoagulants, ADP-antagonists, and Cox-inhibitors, respectively. History of recent trauma was an effective modifier of the association between anticoagulants and CSDH. OR of 1.69 (CI 95% 0.99-2.96) was found for patients with history of trauma and OR of 4.27 (CI 95% 2.23-8.32) for patients without history of trauma.Conclusions: Anticoagulant and antiplatelet therapy have a significant association with an increased risk of CSDH. This association appears even stronger in those patients under anticoagulant therapy, who develop a CSDH in the absence of a recent trauma.