Severely Elevated Blood Pressure in the Emergency Department is Associated with Short-Term Stroke Risk
Siddiqui M, Vahia AT, Stahl V, and Miller J. Severely elevated blood pressure in the emergency department is associated with short-term stroke risk. Acad Emerg Med 2017; 24:S128-S129.
Acad Emerg Med
Background: Although uncontrolled hypertension is strongly associated with long-term stroke risk, the short-term risk of severe elevations in BP among ED patients is not well described. Objective: We tested the hypothesis that severely elevated BP places ED patients at risk for short-term stroke, independent of other known cardiovascular risk factors. Methods: We performed a retrospective cohort study using a registry at 8 affiliated hospitals and free-standing EDs. We included all unique adult encounters with recorded BP. We excluded patients that required hospital admission or had sBP < 110 mmHg. Data extraction included the first recorded ED BP and relevant cardiovascular risk factors. The primary outcome included any ischemic or hemorrhagic stroke over a 6-month period following the index visit. Logistic and Cox proportional hazards modeling analyzed the association between increments of BP elevation and the primary outcome, adjusting for age, sex, race, insurance, history of HTN, and known cardiovascular comorbidities. Results: Analysis included 196,244 unique patients over a one year period. The mean age was 46.5 (±19) years, and 56.9% were female. There were 14,887 patients with ED sBP ≥ 180 mmHg, including 4379 with a sBP ≥ 200 mmHg. In an unadjusted model, patients with sBP > 220 mmHg had a relative risk for stroke within 6-months of the index ED visit of 5.5 (95%CI 4.2-7.2) compared to normotensive patients. In the adjusted Cox model, the hazards ratio for patients with sBP > 220 and 200-220 mmHg was 1.9 (95%CI 1.5-2.3) and 1.4 (95%CI 1.2-1.7) respectively. Conclusions: Among patients discharged from the ED with severely elevated BP, the 6-month risk for hemorrhagic or ischemic stroke increases with the severity of BP elevation, independent of age and multiple stroke risk factors.