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Published on: June 18, 2021
Non-Traumatic Subdural Hemorrhage and Risk of Arterial Ischemic Events
Santosh B Murthy1, Xian Wu2, Ivan Diaz2
1From the Clinical and Translational Neuroscience Unit, Department of Neurology, Feil Family Brain and Mind Research Institute (S.B.M., M.P., N.S.P., C.I., A.E.M., J.C., B.B.N., H.K.), Weill Cornell Medicine, New York, NY.
Insights
Patients with nontraumatic subdural hemorrhage (SDH) face a significantly increased risk of arterial ischemic events, particularly ischemic stroke, within four weeks post-discharge. This heightened risk may be linked to the interruption of antithrombotic therapies.
Area of Science:
- Neurology
- Cardiology
- Epidemiology
Background:
- The risk of arterial ischemic events following subdural hemorrhage (SDH) is not well-established.
- Understanding this risk is crucial for patient management and preventative strategies.
Purpose of the Study:
- To evaluate the risk of acute ischemic stroke and myocardial infarction in patients with and without nontraumatic SDH.
- To identify the temporal relationship between SDH and arterial ischemic events.
Main Methods:
- Retrospective cohort study using Medicare claims data (2008-2014).
- Identified patients with nontraumatic SDH and assessed arterial ischemic events (ischemic stroke, myocardial infarction) using ICD-9-CM codes.
- Employed Cox regression to calculate hazard ratios adjusted for demographics and comorbidities, focusing on 4-week intervals post-discharge.
Main Results:
- Among 1.7 million beneficiaries, 2939 had SDH.
- A substantially increased risk of arterial ischemic events (HR, 3.6) was observed within 4 weeks after SDH, driven by ischemic stroke (HR, 4.2).
- No increased risk was found beyond 4 weeks; myocardial infarction risk was not significantly associated with SDH.
Conclusions:
- Nontraumatic SDH is associated with a heightened risk of arterial ischemic events, primarily ischemic stroke, in the 4 weeks following diagnosis.
- The interruption of antithrombotic therapy may contribute to this increased risk.
- Risk stratification based on indications for antithrombotic therapy is important for understanding event occurrence.
Abstract:
Background and Purpose- The risk of arterial ischemic events after subdural hemorrhage (SDH) is poorly understood. This study aimed to evaluate the risk of acute ischemic stroke and myocardial infarction among patients with and without nontraumatic SDH. Methods- We performed a retrospective cohort study using claims data from 2008 through 2014 from a nationally representative sample of Medicare beneficiaries. The exposure was nontraumatic SDH. Our primary outcome was an arterial ischemic event, a composite of acute ischemic stroke and acute myocardial infarction. Secondary outcomes were ischemic stroke alone and myocardial infarction alone. We used validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes to identify our predictor and outcomes. Using Cox regression and corresponding survival probabilities, adjusted for demographics and vascular comorbidities, we computed the hazard ratio in 4-week intervals after SDH discharge. We performed secondary analyses stratified by strong indications for antithrombotic therapy (composite of atrial fibrillation, peripheral vascular disease, valvular heart disease, and venous thromboembolism). Results- Among 1.7 million Medicare beneficiaries, 2939 were diagnosed with SDH. In the 4 weeks after SDH, patients' risk of an arterial ischemic event was substantially increased (hazard ratio, 3.6 [95% CI, 1.9-5.5]). There was no association between SDH diagnosis and arterial ischemic events beyond 4 weeks. In secondary analysis, during the 4 weeks after SDH, patients' risk of ischemic stroke was increased (hazard ratio, 4.2 [95% CI, 2.1-7.3]) but their risk of myocardial infarction was not (hazard ratio, 0.8 [95% CI, 0.2-1.7]). Patients with strong indications for antithrombotic therapy had increased risks for arterial ischemic events similar to patients in the primary analysis, but those without such indications did not demonstrate an increased risk for arterial ischemic events. Conclusions- Among Medicare beneficiaries, we found a heightened risk of arterial ischemic events driven by an increased risk of ischemic stroke, in the 4 weeks after nontraumatic SDH. This increased risk may be due to interruption of antithrombotic therapy after SDH diagnosis.
