Chronic anticoagulation with warfarin is associated with decreased functional outcome and increased length of stay following craniotomy for acute subdural hematoma

Introduction With the continued rise of the aging population, the incidence of acute subdural hematoma (ASDH) in the setting of chronic oral anticoagulation with warfarin is expected to increase. No study has directly addressed the risks of poorer outcomes in chronically anticoagulated patients after ASDH evacuation. Methods We reviewed retrospectively 94 consecutive cases of ASDH at a single institution with fresh frozen plasma and craniotomy. The outcomes of patients with ASDH in the setting of chronic oral anticoagulation were compared to those of patients with ASDH not taking oral anticoagulation. Results There were 22 patients receiving chronic anticoagulation (11 male, 11 female, mean age 63.7 ± 4 years) with ASDH requiring craniotomy for evacuation. These patients had significantly lower mean discharge Glasgow Outcome Scores (GOS) when compared to control subjects (2.3 ± 0.3 versus 3.0 ± 0.2). Despite presentation with higher Glasgow Coma Scores (GCS), ASDH size tended to be larger in anticoagulated patients, although not significant. Overall mortality was nearly double, that is 55% in anticoagulated patients compared to 29% in those without anticoagulation. Of previously anticoagulated patients alive at discharge, hospital length of stay was longer compared to controls (31.9 ± 8.5 days versus 21.1 ± 2.4 days). Conclusions These data suggest that ASDH evacuation in chronically anticoagulated patients is associated with higher mortality rates, decreased likelihood of independent function, and increased length of hospital stay. Further research is needed to determine if the effect of chronic anticoagulation on outcome is independent of cofounders, such as age and medical comorbidities. These data may help practitioners and families create treatment plans and furthermore serve as the gold standard for the future evaluation of novel anticoagulation reversal agents such as factor VIIa.