Outcome of older hip fracture patients on anticoagulation: a comparison of vitamin K-antagonists and Factor Xa inhibitors.

Introduction: Older hip fracture patients are still challenging in daily clinical practice. Due to the high prevalence of osteoporosis and atrial fibrillation in this age group, the number of fragility fracture patients under oral anticoagulation (OAC) increases. The outcome is still disappointing, short- and long-term mortality and morbidity is high. The impact of pre-existing OAC is not yet clear, especially regarding new OAC drugs like Factor Xa inhibitors (FXa). The purpose of our study was to compare the short-term outcome of older hip fracture patients, without OAC (controls), on Vitamin K antagonists (VKA) and on FXa.
Materials and Methods: The study is a retrospective case-control study including patients older than 70 years who sustained hip fractures caused by an inadequate trauma and treated at a level 1 trauma center from February 2017 to June 2018. Patient's information was taken from patient's charts. 102 cases were analysed, 61 controls, 41 on OAC (15 on VKA and 26 on FXa). As outcome parameter we defined mortality, perioperative complications, bleeding, need of blood supplements, delay of surgery, length of stay, and a combined outcome parameter (mortality, myocardial infarction, stroke, thromboembolic events, blood preservations, re-vision surgery, major bleeding and decline of hemoglobin).
Results: Eight patients died during hospital stay, in-hospital mortality was 7.8%. The highest mortality rate was found in patients on VKA (20%), compared to patients on FXa (3.8%) and controls (6.6%). However, mortality rate did not differ significantly within the groups. The combined endpoint was significantly more frequently seen in patients on OAC compared to controls (p = 0.006). No difference was observed between patients on VKA or FXa. Mean time to surgery and LOS was significantly longer in patients on OAC compared to controls. No significant differences were seen between VKA and FXa.
Conclusions: In our study OAC was significantly associated with worse outcome compared to controls. Marginal differences were observed between patients on FXa or VKA. Further studies involving a higher number of patients are necessary to confirm our results. At that time, some our results have to interpreted carefully and need confirmation.