Retrospective cohort study shows much lower rates of intracranial hemorrhage due to minor head injury in patients on new oral anticoagulants
Minor head injury (MHI) represents one of the most common causes of presentation to emergency rooms in Italy and abroad, and it makes up about 88% of all cases of presenting head trauma. It’s universally recognized that patients under chronic anticoagulant therapy have a roughly doubled risk of developing an intracranial hemorrhage (ICH) following an MHI, and have a worse long-term outcome in case they develop MHI. Recent studies report a lower incidence of ICH in patients treated with new oral anticoagulants (NOAC) compared to traditional vitamin K antagonists (VKA), such as warfarin. Despite this, the body of evidence is still too small and heterogeneous to definitively quantify any actual differences between the safety profiles of these two classes of drug in the setting of MHI.
In this retrospective cohort study, we analyze all admissions for head trauma in 2016 and 2017 at the Emergency Department of Hospital S. Matteo in Pavia, Italy, to assess whether patients in therapy with NOACs have a different rate of ICH compared with patients treated with VKAs, antiplatelet drugs, or no relevant therapy. The main purpose of our work is to provide evidential guidance for a subsequent prospective cohort study comparing VKAs with NOACs. The primary outcome is death or the need of neurosurgical intervention due to complications of the trauma, with a secondary outcome being the presence of ICH on CT head. Other clinical and anamnestic parameters are also collected with the purpose of running internal performance analyses and orientating sub-group analyses.
We searched our department’s database for all patients diagnosed with cranial trauma, face/head/neck trauma, and intracranial hemorrhage. We excluded patients with Glasgow Coma Scale <14, patients without a traumatic history (i.e. spontaneous hemorrhages), patients with injuries and mechanisms only involving the face, those being re-admitted for an already registered trauma, and those with incomplete data.
We performed a preliminary analysis of the first 950 patients included (53% women, average age 62), of which 20.4% (194) were on antiplatelet drugs, 6.5% (62) were on VKAs, and 3.3% (31) on NOACs. A few of these patients (8) were excluded from the preliminary analyses due to being on therapy with multiple classes of drugs or with subcutaneous anticoagulants.
9.3% (88) of the analyzed patients had a clinical significant bleeding on a CT head performed during the first presentation or in a re-entry within 30 days. No ICH has been recorded in patients on NOACs, compared to 23.7% in patients on VKAs, 13.2% for antiplatelet drugs, and 7.3% for controls.
Data collection regarding the primary endpoint (neurosurgical intervention or death) is still undergoing.
These preliminary results suggest that NOACs have a better safety profile than VKAs in the setting of MHI. While no definitive conclusions can be drawn yet, this work highlights the value of further investigating the performance of the different classes of anticoagulants after minor head trauma in a prospective observational study.
