Pre-morbid antiplatalet use is associated with larger haematoma volume and worse outcome after intracerebral haemorrhage: population-based study

Background: Premorbid oral anticoagulation is a risk factor for poor outcome following intracerebral haemorrhage (ICH). In a recent study of hospitalised patients with ICH, premorbid aspirin use also increased early mortality, possibly via early haematoma growth. We aimed to determine whether this association could be reproduced in a population-based stroke incidence study.

Methods: Consecutive patients with ICH were prospectively ascertained from the Oxford Vascular Study. Data were collected on vascular risk factors and pre-morbid medication use. Patients on anticoagulation prior to the ICH were excluded. The outcomes were haematoma volume, location and 30 day mortality.

Results: Over a period of 52 months, 60 patients had ICH [53% male; mean age 76yrs], of whom 24 (40%) had been on antiplatelet agents (aspirin monotherapy 17, dual therapy 5, clopidogrel monotherapy 2). Antiplatelet use was the only pre-morbid factor significantly associated with 30-day mortality (age adjusted OR 3,4, 95% CI 1,1–10,1, p=0,03). Pre-morbid antiplatelet use was also independently predictive of haematoma volumes ≥30ml (age adjusted OR 3.3, 1.1–10.4, p=0.04), which along with haemorrhage into the basal ganglia or thalamus were the only other factors predictive of 30-day mortality.

Conclusion: Pre-morbid aspirin use is associated with increased 30-day mortality following ICH in a population-based study. If causal, the association is likely to be due to increased haematoma volume in antiplatelet users, suggesting that haemostatic therapy might be most effective in this group. Differences in severity of stroke in relation to premorbid medication should also be taken into account in analysis of outcomes in randomized controlled trials of antiplatelet drugs.