AHEAD Study: an observational study of the management of anticoagulated patients who suffer head injury

Abstract

ObjectivesManagement of anticoagulated patients after head injury is unclear due to lack of robust evidence. This study aimed to determine the adverse outcome rate in these patients and identify risk factors associated with poor outcome.DesignMulticentre, observational study using routine patient records.Setting33 emergency departments in England and Scotland.Participants3566 adults (aged ≥16 years) who had suffered blunt head injury and were currently taking warfarin.Main outcome measuresPrimary outcome measure was rate of adverse outcome defined as death or neurosurgery following initial injury, clinically significant CT scan finding or reattendance with related complication within 10 weeks of initial hospital attendance. Secondary objectives included identifying risk factors for adverse outcome using univariable and multivariable analyses.ResultsClinical data available for 3534/3566 patients (99.1%), median age 79 years; mean initial international normalised ratio (INR) 2.67 (SD 1.34); 81.2% Glasgow Coma Scale (GCS) 15: 59.8% received a CT scan with significant head injury-related finding in 5.4% (n=208); 0.5% underwent neurosurgery; 1.2% patients suffered a head injury-related death. Overall adverse outcome rate was 5.9% (95% CI 5.2% to 6.7%). Patients with GCS=15 and no associated symptoms had lowest risk of adverse outcome (risk 2.7%; 95% CI 2.1 to 3.6). Patients with GCS=15 multivariable analysis (using imputation) found risk of adverse outcome to increase when reporting at least one associated symptom: vomiting (relative risk (RR) 1.8; 95% CI 1.0 to 3.4), amnesia (RR 3.5; 95% CI 2.1 to 5.7), headache (RR 1.3; 95% CI 0.8 to 2.2), loss of consciousness (RR 1.75; 95% CI 1.0 to 3.0). INR measurement did not predict adverse outcome in patients with GCS=15 (RR 1.1; 95% CI 1.0 to 1.2).ConclusionsIn alert warfarinised patients following head injury, the presence of symptoms is associated with greater risk of adverse outcome. Those with GCS=15 and no symptoms are a substantial group and have a low risk of adverse outcome.Trial registration numberNCT02461498.

Incidence of intracranial bleeding in anticoagulated patients with minor head injury: a systematic review and meta‐analysis of prospective studies

“…A total of five studies (4080 GCS 15, anticoagulated patients) were included in the final meta‐analysis (Smits et al , ; Menditto et al , ; Nishijima et al , ; Mason et al , ; Versmée et al , ) from the Netherlands, France, Italy, USA and UK (Table ). All authors supplied data for GCS 15 patients.…”

Understanding the management of patients with head injury taking warfarin: who should we scan and when? Lessons from the AHEAD study

“…It has sufficient power to describe outcomes for these patients and clearly demonstrates a reduced risk of adverse outcome in patients on warfarin with a mild head injury and GCS 15 with no other neurological symptoms 20. This evidence illustrates how there is significant variation between patients with head injury and that general guidelines are not always applicable to the specific patient in front of you.…”

“…With GCS 15 and no other neurological symptoms, patient A is at reduced risk for adverse outcome 20. The AHEAD study suggests that you may be able to make a time-saving and cost-saving decision by giving her good verbal and written head injury advice and discharging her.…”

“…You may consider it good practice to check her INR too, as there has been shown to be a higher prevalence of non-therapeutic INRs in patients presenting to the ED than in the community 45. However, the AHEAD study found no association between INR and outcomes in patients with GCS 15,20 so in this case the value will not affect her risk of intracranial injury. Based on the AHEAD data, there is no justification to admit and/or observe this patient in case of a delayed bleed 32…”

“…New evidence from the AHEAD study shows that patients taking warfarin who present to the ED with a minor head injury (ie, GCS 15) and no other symptoms have a reduced risk of adverse outcome (risk 2.7%; 95% CI 2.1 to 3.6) 20. This suggests that routine scanning of these patients may be unnecessary.…”