Risk of Stroke Following Hypertensive Encephalopathy (P1.082)

OBJECTIVE: To evaluate the risk of stroke after a diagnosis of hypertensive encephalopathy (HE). BACKGROUND: Although asymptomatic hypertension is a well-established risk factor for stroke, little is known about stroke risk after HE, when neurologic sequelae of hypertension have become evident. DESIGN/METHODS: We identified all patients discharged from California, New York, and Florida emergency departments and acute care hospitals between 2005 and 2012 with a primary International Classification of Diseases, 9th Edition, Clinical Modification discharge diagnosis of HE (437.2). Patients discharged with a primary diagnosis of seizure (345.x) served as negative controls since seizures represent transient, non-vascular neurological disease, and patients with a primary diagnosis of transient ischemic attack (TIA; 435.x) served as positive controls with known, increased stroke risk. Our primary outcome was the composite of subsequent ischemic stroke or intracerebral hemorrhage (ICH). In secondary analyses, we considered ischemic stroke and ICH separately. Kaplan-Meier survival statistics were used to calculate cumulative outcome rates, and Cox proportional hazard analysis was used to examine the association between exposures and outcomes while adjusting for vascular risk factors. RESULTS: We identified 8,233 patients with HE, 191,091 with seizure, and 308,680 with TIA. The 1-year rate of our primary outcome after HE was 4.90[percnt] (95[percnt] confidence interval [CI], 4.45-5.40), as compared to 0.92[percnt] (95[percnt] CI, 0.88-0.97) following seizure and 4.49[percnt] (95[percnt] CI, 4.42-4.57) following TIA. Ischemic stroke risk was elevated in patients with HE (hazard ratio [HR], 1.9; 95[percnt] CI, 1.7-2.0) and TIA (HR, 2.2; 95[percnt] CI, 2.1-2.3) compared to those with seizures. The risk of ICH was significantly elevated only in those with HE (HR, 2.0; 95[percnt] CI, 1.7-2.5), but not TIA (HR, 1.0; 95[percnt] CI, 0.9-1.1). CONCLUSIONS: Patients with HE face a high risk of future cerebrovascular events, particularly ICH. Disclosure: Dr. Lerario has nothing to disclose. Dr. Merkler has nothing to disclose. Dr. Gialdini has nothing to disclose. Dr. Parikh has nothing to disclose. Dr. Navi has nothing to disclose. Dr. Kamel has received personal compensation for activities with Genentech as a scientific advisory board member and/or speaker. Dr. Kamel has received personal compensation in an editorial capacity for Journal Watch Neurology.