title: Success and predictors of blood pressure control in diverse North American settings: the antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT).
abstract: BACKGROUND
  Blood pressure control (<140/90 mm Hg) rates for hypertension fall far short of the US national goal of 50% or more. Achievable control rates in varied practice settings and geographic regions and factors that predict improved blood pressure control are not well identified.
  
  
  OBJECTIVE
  To determine the success and predictors of blood pressure control in a large hypertension trial involving a multiethnic population in diverse practice settings.
  
  
  METHODS
  The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial is a randomized, double-blind, active-controlled clinical trial with a mean follow-up of 4.9 years. Participant enrollment began in February 1994 and follow-up was completed in March 2002.
  
  
  METHODS
  A total of 623 centers in the United States, Canada, and the Caribbean.
  
  
  METHODS
  A total of 33,357 participants (aged > or =55 years) with hypertension and at least one other coronary heart disease risk factor.
  
  
  METHODS
  Participants were randomly assigned to receive (double-blind) chlorthalidone, 12.5-25 mg/d (n=15,255), amlodipine 2.5-10 mg/d (n=9048), or lisinopril 10-40 mg/d (n=9054) after other medication was discontinued. Doses were increased within these ranges and additional drugs from other classes were added as needed to achieve blood pressure control (<140/90 mm Hg).
  
  
  METHODS
  The outcome measures for this report are systolic and diastolic blood pressure, the proportion of participants achieving blood pressure control (<140/90 mm Hg), and the number of drugs required to achieve control in all three groups combined.
  
  
  RESULTS
  Mean age was 67 years, 47% were women, 35% black, 36% diabetic; 90% were on antihypertensive drug treatment at entry. At the first of two pre-randomization visits, blood pressure was <140/90 mm Hg in only 27.4% of participants. After 5 years of follow-up, the percent controlled improved to 66%. Systolic blood pressure was <140 mm Hg in 67% of participants, diastolic blood pressure was <90 mm Hg in 92%, the mean number of drugs prescribed was 2.0+/-1.0, and the percent on > or =2 drugs was 63%. Blood pressure control varied by geographic regions, practice settings, and demographic and clinical characteristics of participants.
  
  
  CONCLUSIONS
  These data demonstrate that blood pressure may be controlled in two thirds of a multiethnic hypertensive population in diverse practice settings. Systolic blood pressure is more difficult to control than diastolic blood pressure, and at least two antihypertensive medications are required for most patients to achieve blood pressure control. It is likely that the majority of people with hypertension could achieve a blood pressure <140/90 mm Hg with the antihypertensive medications available today.
authors.forename: William C
authors.initials: WC
authors.lastname: Cushman
authors.forename: Charles E
authors.initials: CE
authors.lastname: Ford
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Cutler
authors.forename: Karen L
authors.initials: KL
authors.lastname: Margolis
authors.forename: Barry R
authors.initials: BR
authors.lastname: Davis
authors.forename: Richard H
authors.initials: RH
authors.lastname: Grimm
authors.forename: Henry R
authors.initials: HR
authors.lastname: Black
authors.forename: Bruce P
authors.initials: BP
authors.lastname: Hamilton
authors.forename: Joanne
authors.initials: J
authors.lastname: Holland
authors.forename: Chuke
authors.initials: C
authors.lastname: Nwachuku
authors.forename: Vasilios
authors.initials: V
authors.lastname: Papademetriou
authors.forename: Jeffery
authors.initials: J
authors.lastname: Probstfield
authors.forename: Jackson T
authors.initials: JT
authors.lastname: Wright
authors.forename: Michael H
authors.initials: MH
authors.lastname: Alderman
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Weiss
authors.forename: Linda
authors.initials: L
authors.lastname: Piller
authors.forename: Judy
authors.initials: J
authors.lastname: Bettencourt
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Walsh
mesh_terms: D000368:Aged; D017311:Amlodipine / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D002170:Canada; D002752:Chlorthalidone / Q000627:therapeutic use; D004311:Double-Blind Method; D017292:Doxazosin / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy* / Q000208:ethnology; D017706:Lisinopril / Q000627:therapeutic use; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000208:ethnology / Q000517:prevention & control*; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States; D014900:West Indies
chemical_list: D000959:Antihypertensive Agents; D017311:Amlodipine; D017706:Lisinopril; D017292:Doxazosin; D002752:Chlorthalidone