Is Antithrombotic Drug Use Tied to the Rising Incidence of Subdural Hematoma?

Antithrombotic medications, especially vitamin K antagonists (VKAs), are associated with increased risk of subdural hematoma, according to the results of a recent study.

Recent reports have indicated that the incidence of subdural hematoma have been increasing, but the extent to which this is related to the use of antithrombotic drugs is not well understood.
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To explore this relationship, researchers conducted a case-control study of 10,010 Danish participants aged 20 to 89 years with first subdural hematoma principal discharge diagnosis from 2000 to 2015. These participants were matched by age, sex, and calendar year to 400,380 individuals from the general population. Incidence of subdural hematoma and antithrombotic drug use was calculated using population-based regional data and national data from Denmark.

Overall, 47.3% of patients with subdural hematoma were taking antithrombotic medications. Current use of low-dose aspirin, clopidogrel, a direct oral anticoagulant, and VKA were associated with higher risk of subdural hematoma. The risk was highest in patients who were taking VKA concurrently with an antiplatelet drug.

The researchers noted that the prevalence of antithrombotic drug use increased from 31.0 per 1000 in the general population in 2000 to 76.9 per 1000 in 2015, while the incidence of subdural hematoma increased from 10.9 per 100,000 person-years in 2000 to 19.0 per 100,000 person-years in 2015.

“In Denmark, antithrombotic drug use was associated with higher risk of subdural hematoma; and the highest odds of subdural hematoma was associated with combined use of a VKA and an antiplatelet drug,” the researchers concluded. “The increased incidence of subdural hematoma from 2000 to 2015 appears to be associated with the increased use of antithrombotic drugs, particularly use of a VKA among older patients.”

—Michael Potts

Reference:

Gaist D, Rodriguez LAG, Hellfritzsch M, et al. Association of antithrombotic drug use with subdural hematoma risk. JAMA. 2017;317(8):836-846.