Severely Elevated Blood Pressure in the Emergency Department is an Independent Predictor of 6- and 12-month Cardiovascular Events
Vahia AT, Siddiqui M, Stahl V, Brody A, Levy P, and Miller J. Severely elevated blood pressure in the emergency department is an independent predictor of 6 and 12 month cardiovascular events. Acad Emerg Med 2017; 24:S8.
Acad Emerg Med
Background: Severely elevated blood pressure (BP) absent acute target organ damage is common in ED patients but the 6 and 12 month risk for such patients is not well described. Objectives: We tested the hypothesis that severely elevated BP, independent of known cardiovascular risk factors, is associated with 6 and 12 month cardiovascular events. 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 an ED sBP < 110 mmHg. Data extraction included the first recorded ED BP and clinical information with a focus on cardiovascular risk factors. Composite outcomes were obtained from diagnostic coding over a 1-year period following the index visit and included death, myocardial infarction (MI), stroke and acute heart failure (AHF). Logistic and Cox proportional hazards modeling analyzed the association between composite outcomes and increments of HTN above a reference sBP110-140 mmHg. The model adjusted for age, sex, race, a history of HTN, insurance, and 7 core 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 4,379 with a sBP ≥ 200 mmHg. In an unadjusted model, the 6-month odds ratio (OR) for a composite event for patients with sBP 180-200, 200-220, and >220 mmHg compared to normotensive patients was 3.0 (95%CI 2.7-3.2), 4 (95%CI 3.6-4.5), and 4.6 (95%CI 3.9- 5.4). At 12 months, these unadjusted odds ratios were nearly identical. Adjusting for age, sex, race, HTN, insurance and multiple cardiovascular comorbidities, sBP 180 - 200 mmHg remained an independent predictor of cardiovascular events (OR 1.15, 95%CI 1.1-1.2), as did sBP 200-220 mmHg (OR 1.3, 95%CI 1.2- 1.4) and sBP > 220 mmHg (1.7 OR, 95%CI 1.5-2.0). Conclusions: Among patients discharged from the ED, severely elevated BP is an independent predictor of 6 and 12 month cardiovascular events, and the magnitude of association increases with higher BP. Further study is needed to evaluate the clinical effectiveness of population health management focused on better awareness and treatment of chronic HTN among ED patients with severely elevated BP.