Abstract
Purpose: A 3-year case control study was conducted to determine the prevalence of hypertensive crisis and its subtypes, hypertensive emergency and hypertensive urgency. The secondary objectives were to identify risk factors for hypertensive emergencies and to determine the odds of developing acute target organ damage among predominantly African American patients with a confirmed diagnosis of hypertension.
Materials and methods: Using emergency department medical records, patients with a confirmed diagnosis of hypertension were identified. From the pool of hypertensive patients, cases and controls were selected and matched 1:1 for age, gender and race. Cases were hypertensive patients with hypertensive crisis, defined as BP >= 200/120 mmHg. Controls had a diagnosis of hypertension and BP < 200/120 mmHg. Cases and controls, as well as cases with hypertensive emergencies and hypertensive urgencies were compared based on important demographic and clinical variables.
Results: Almost 90% of study population were African Americans. The prevalence of hypertensive crisis was 11.4% and hypertensive emergencies was 3.2%. Hypertensive emergencies accounted for 28% of patients with crisis. The predictors for hypertensive emergencies were older age (p = .002), male gender (p < .007), anemia (p < .0001), history of coronary artery disease (p < .001), congestive heart failure (p < .001) and chronic renal insufficiency (p < .001). Having healthcare insurance and access to medical care did not reduce the odds of developing hypertensive emergencies. Race was not a significant risk factor in the progression from hypertensive crisis to hypertensive emergencies (p = .47).
Conclusions: The study highlights the high prevalence of hypertensive crisis and hypertensive emergencies in the predominantly African American urban population, which is 5 times the United States average. However, race is not a predictor of development of hypertensive emergencies and acute target organ damage in patients with already severely elevated blood pressure.