Antithrombotic treatment should be suspended following acute subdural haematoma (SDH), but uncertainty remains over optimal timing of treatment resumption, experts say.
In new practical guidance, clinicians noted that a lack of data from randomised controlled trials prevents robust recommendations on restarting antithrombotic therapy post-SDH. However, observational studies suggest that resumption within seven to 14 days may be safe in selected patients.
The authors highlighted limited evidence on venous thromboembolism (VTE) chemoprophylaxis after SDH. While mechanical prophylaxis should be initiated on admission, the authors said further research is needed to define the role of pharmacological prophylaxis.
They also noted the growing significance of middle meningeal artery embolisation in SDH management.
“Decision making surrounding antithrombotic medication is often complex, but current advice in the acute setting supports suspending anticoagulants and considering their reversal, depending on the severity of bleeding and thrombosis risk,” wrote the clinicians, including senior author Dr Frances Rickard, a consultant geriatrician at North Bristol NHS Trust.
“It is still uncertain when to restart antithrombotic medication, with observational data favouring early resumption,” they added.
In the paper, published in Practical Neurology [link here], the authors highlighted that conservative management of SDH patients often falls under the responsibility of neurologists, but that management should involve multidisciplinary discussion, particularly with haematology for decisions on antithrombosis.
Although the risk of haematoma expansion generally decreases with time, the data suggest that severe SDH expansion more than 72 hours after injury only occurs in patients over 75 years following low-velocity falls from standing.
This has meant some clinicians are hesitant to restart antithrombotic therapy, which, combined with the lack of standardised guidelines, has led to heterogeneity in practice, the authors said.
While data suggest that stopping antithrombotics for short periods gives a relatively low risk of thrombosis, “rare circumstances such as acute co-existent pulmonary embolism or left ventricular thrombosis may complicate these decisions and require bespoke multidisciplinary decisions,” they authors noted.
The guidance also highlighted that antiplatelet management is complex after percutaneous coronary intervention, due to the increased risk of in-stent thrombosis, and the authors advise consulting with cardiology.
Given that thromboembolic complications carry a higher risk of adverse outcomes than haemorrhage in patients with surgically treated chronic SDH, the guidance advised starting mechanical VTE prophylaxis on admission for acute or chronic SDH.
While strong evidence on the benefits of VTE chemoprophylaxis is lacking, it is generally considered appropriate after 48–72 hours of clinical and radiological stability, the guidance noted.
The risk of chronic SDH recurrence is significantly increased by bilateral haematomas, lack of surgical evacuation and male sex, as well as, to a lesser extent, with pre-existing antithrombotic use and larger haematoma volume.
Middle meningeal artery embolisation has emerged as a promising treatment option, with real-world UK data showing that the procedure more than halved the risk of chronic SDH recurrence and enabled earlier, safer reintroduction of antithrombotic therapy.
Although NICE did not recommend routine use of the procedure in 2023, citing insufficient data, the guidance is due to be reviewed in 2026 following the recent publication of observational and randomised data.
However, the article noted that selection criteria “remain controversial” and conservative European recommendations have since been superseded by subsequent treatment algorithms, with the authors providing the one used at their centre, which splits the decision into symptomatic or asymptomatic chronic SDH.
The authors noted that blood pressure targets are also subject to discussion and there are currently no guidelines on blood pressure management in SDH, while antiseizure medications should only be given to patients with clinical or electroencephalographic evidence of seizure activity, or concurrent subarachnoid or contusional haemorrhage.
Statins after SDH are recommended by US guidelines and while atorvastatin is not routinely used in UK practice, “this may change with further randomised controlled trial evidence,” the authors suggested, with tranexamic acid similarly requiring more robust evidence.
Dexamethasone is not recommended following SDH. However, early mobilisation (within the first two days in clinical trials) is advised.