title: Impact of initial blood pressure on antihypertensive response in patients with acute hypertension.
abstract: BACKGROUND
  The effect profile of differing antihypertensive agents is well studied, but minimal data regarding the interaction between hemodynamic response and presenting blood pressure (BP) exist.
  
  
  OBJECTIVE
  Achievement of target BP is less likely in patients with higher initial BPs.
  
  
  METHODS
  This is a substudy of the multicenter safety and efficacy Evaluation of intravenous Cardene (nicardipine) and Labetalol Use in the Emergency department (CLUE) trial that randomized patients to Food and Drug Administration-recommended intravenous dosing of nicardipine or labetalol to reach a physician predefined systolic BP (SBP) and target range (TR) of ±20 mm Hg within 30 minutes. The proportion achieving TR was assessed as a function of initial SBP, and dichotomized comparisons were made using median SBP. Likelihood of a final BP within TR was modeled using logistic regression with forced inclusion of initial BP as a categorical variable.
  
  
  RESULTS
  A total 223 patients were enrolled; 115 (51.6%) had an initial SBP greater than the median 202 mm Hg. The median SBP (interquartile range) of the high BP group was 218 (210-228) mm Hg vs the low BP group 190 (182-197) mm Hg (P < 0.0001). No groupwise differences existed except that the high group had higher mean (SD) serum creatinine level at baseline (3.1 [3.9] vs 1.9 [2.3], P = .008). The proportion of patients achieving SBP within TR at 30 minutes did not differ (85.2% [98 of 115] vs 88.9% [96 of 108], P = .42). Randomization to nicardipine (odds ratio = 2.85; 95% confidence interval, 1.16-7.01), but not initial SBP (odds ratio = 0.60; 95% confidence interval, 0.25-1.44), was associated with achievement of target SBP at 30 minutes.
  
  
  CONCLUSIONS
  Initial SBP is not a predictor of the ability to achieve a prespecified target range SBP within 30 minutes.
authors.affiliation: Emergency Medicine, Baylor College of Medicine, Houston, TX. Electronic address: sfarias33@gmail.com.
authors.forename: Serafin
authors.initials: S
authors.lastname: Farias
authors.affiliation: Emergency Medicine, Baylor College of Medicine, Houston, TX.
authors.forename: W Frank
authors.initials: WF
authors.lastname: Peacock
authors.affiliation: Emergency Medicine, Baylor College of Medicine, Houston, TX.
authors.forename: Michael
authors.initials: M
authors.lastname: Gonzalez
authors.affiliation: Wayne State University Department of Emergency Medicine, Detroit, MI.
authors.forename: Phillip D
authors.initials: PD
authors.lastname: Levy
mesh_terms: D000208:Acute Disease; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D003404:Creatinine / Q000097:blood; D004636:Emergency Service, Hospital; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D007262:Infusions, Intravenous; D007741:Labetalol / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000008:administration & dosage / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; D003404:Creatinine; D009529:Nicardipine; D007741:Labetalol