Premorbid oral antithrombotic therapy and risk for reaccumulation, reoperation, and mortality in acute subdural hematomas.

OBJECT: Acute subdural hematomas (SDHs) impart serious morbidity and mortality on the elderly population, with only 5% of those older than 65 years of age attaining functional independence. Despite its widespread use, oral antithrombotic therapy (OAT) in the context of acute SDH has not been extensively studied. The authors sought to evaluate the impact of premorbid OAT on recurrence of SDH, radiographic outcome, and mortality in patients undergoing surgical evacuation of an acute SDH.

METHODS: The authors conducted a retrospective comparative cohort study reviewing all surgically treated cases of acute SDH at their institution between September 2005 and December 2008. They assessed baseline demographics, coagulation parameters, surgical management, and clinical course. Study end points included additional craniotomy for SDH reaccumulation, follow-up Rotterdam score, recurrent SDH volumetric analysis, Glasgow Outcome Score, and death.

RESULTS: A total of 300 patients with acute SDH treated by craniotomy were assessed. Of these patients, 49% (148 patients) were receiving OAT. Of those who were on a regimen of OAT, 49% were taking warfarin (mean international normalized ratio 3.1 ± 1.8), 31% were receiving antiplatelet therapy, and 20% were on a regimen of a combination of agents. On presentation, 72% of those using OAT received reversal agents. Recurrence of SDH necessitating additional evacuation was not significantly different with respect to premorbid OAT status (13% vs 14%). Patients with a history of OAT did not demonstrate a significant difference in Rotterdam score (2 vs 2), recurrent SDH volume (24.1 vs 19.6 cm(3)), GOS score (4 vs 3), or mortality (21% vs 24%). These findings remained stable after controlling for age, injury mechanism, and injury severity.

CONCLUSIONS: Premorbid OAT was not a significant risk factor for recurrence of SDH necessitating additional evacuation following acute SDH. Additionally, postoperative Rotterdam score, volume of SDH reaccumulation, and overall mortality were not predicted by antithrombotic history. While premorbid use may predispose the patient to an SDH, OAT does not increase the risk of morbidity or mortality following surgical intervention.