Risk of thromboembolic complications after intracerebral hemorrhage according to ethnicity

Introduction: Incidence of thromboembolic (TE) disease varies with race and ethnicity yet little is known about whether these differences also apply to the poststroke period. We review the literature and compare published data with observations from two recent global trials on intracerebral hemorrhage (ICH). Methods: A systematic review of the literature in EMBASE/Medline identified relevant articles. Published data were compared to the TE events-myocardial infarction (MI), cerebral infarction (CI), deep venous thrombosis (DVT), and pulmonary embolism (PE)-observed among placebo patients in two trials investigating the efficacy and safety of recombinant factor VIIa (rFVIIa) (Novo Nordisk A/S, Denmark) in the treatment of spontaneous ICH. The relative risk of TE complications after ICH was estimated for blacks/African Americans and Asians after adjustment for relevant risk factors. Results: Only four relevant studies on TE disease after stroke were identified with data limited to poststroke MI and CI in a mixture of ischemic stroke and ICH patient populations. In the literature, blacks/African Americans appear to have a lower incidence rate of cardiac and cerebro-vascular complications after stroke, and Asians have a higher incidence rate of recurrent strokes, compared with Caucasians. In the two global trials, the overall poststroke incidence rates of MI, CI, DVT, and PE at 3 months after ICH onset were 2.3%, 2.0%, 3.7%, and 1.1%, respectively. After adjustment for differences in baseline risk factors, blacks/African Americans had a significantly higher risk of developing DVT compared with Caucasians (OR=5.64, P=0.0334), while Asians had a strong trend toward a higher risk of DVT (odds ratio=3.22, P=0.0932). The adjusted relative risk of PE, CI, and MI was not significantly different across ethnicities. Conclusion: This is the first study to specifically examine the risk of TE complications in the post-ICH period according to ethnicity. In a limited ICH population, we observed a significantly higher risk of DVT in blacks/African Americans compared with Caucasians after adjustment for differences in risk factors. We observed nonsignificant trends toward differences in the relative risk of MI, CI, or PE across ethnicities.