title: The design and rationale of a multicenter clinical trial comparing two strategies for control of systolic blood pressure: the Systolic Blood Pressure Intervention Trial (SPRINT).
abstract: BACKGROUND
  High blood pressure is an important public health concern because it is highly prevalent and a risk factor for adverse health outcomes, including coronary heart disease, stroke, decompensated heart failure, chronic kidney disease, and decline in cognitive function. Observational studies show a progressive increase in risk associated with blood pressure above 115/75 mm Hg. Prior research has shown that reducing elevated systolic blood pressure lowers the risk of subsequent clinical complications from cardiovascular disease. However, the optimal systolic blood pressure to reduce blood pressure-related adverse outcomes is unclear, and the benefit of treating to a level of systolic blood pressure well below 140 mm Hg has not been proven in a large, definitive clinical trial.
  
  
  OBJECTIVE
  To describe the design considerations of the Systolic Blood Pressure Intervention Trial (SPRINT) and the baseline characteristics of trial participants.
  
  
  METHODS
  The Systolic Blood Pressure Intervention Trial is a multicenter, randomized, controlled trial that compares two strategies for treating systolic blood pressure: one targets the standard target of <140 mm Hg, and the other targets a more intensive target of <120 mm Hg. Enrollment focused on volunteers of age ≥50 years (no upper limit) with an average baseline systolic blood pressure ≥130 mm Hg and evidence of cardiovascular disease, chronic kidney disease, 10-year Framingham cardiovascular disease risk score ≥15%, or age ≥75 years. The Systolic Blood Pressure Intervention Trial recruitment also targeted three pre-specified subgroups: participants with chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m(2)), participants with a history of cardiovascular disease, and participants 75 years of age or older. The primary outcome is first the occurrence of a myocardial infarction (MI), acute coronary syndrome, stroke, heart failure, or cardiovascular disease death. Secondary outcomes include all-cause mortality, decline in kidney function or development of end-stage renal disease, incident dementia, decline in cognitive function, and small-vessel cerebral ischemic disease.
  
  
  RESULTS
  Between 8 November 2010 and 15 March 2013, Systolic Blood Pressure Intervention Trial recruited and randomized 9361 people at 102 clinics, including 3331 women, 2648 with chronic kidney disease, 1877 with a history of cardiovascular disease, 3962 minorities, and 2636 ≥75 years of age.
  
  
  CONCLUSIONS
  Although the overall recruitment target was met, the numbers recruited in the high-risk subgroups were lower than planned.
  
  
  CONCLUSIONS
  The Systolic Blood Pressure Intervention Trial will provide important information on the risks and benefits of intensive blood pressure treatment targets in a diverse sample of high-risk participants, including those with prior cardiovascular disease, chronic kidney disease, and those aged ≥75 years.
authors.affiliation: Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA wambrosi@wakehealth.edu.
authors.forename: Walter T
authors.initials: WT
authors.lastname: Ambrosius
authors.affiliation: Section on Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: Kaycee M
authors.initials: KM
authors.lastname: Sink
authors.affiliation: Department of Social Sciences & Health Policy, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: Capri G
authors.initials: CG
authors.lastname: Foy
authors.affiliation: Center for Healthcare Organization and Implementation Research, Bedford Veterans Affairs Hospital, Bedford, MA, USA.
authors.forename: Dan R
authors.initials: DR
authors.lastname: Berlowitz
authors.affiliation: Department of Internal Medicine, University of Utah and Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, UT, USA.
authors.forename: Alfred K
authors.initials: AK
authors.lastname: Cheung
authors.affiliation: Preventive Medicine Section, Veterans Affairs Medical Center, Memphis, TN, USA.
authors.forename: William C
authors.initials: WC
authors.lastname: Cushman
authors.affiliation: Clinical Applications and Prevention Branch, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, MD, USA.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Fine
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, Aurora, CO, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Goff
authors.affiliation: Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Karen C
authors.initials: KC
authors.lastname: Johnson
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Killeen
authors.affiliation: Division of Preventive Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Cora E
authors.initials: CE
authors.lastname: Lewis
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Oparil
authors.affiliation: Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Reboussin
authors.affiliation: Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Rocco
authors.affiliation: Clinical Applications and Prevention Branch, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, MD, USA.
authors.forename: Joni K
authors.initials: JK
authors.lastname: Snyder
authors.affiliation: Section on Gerontology and Geriatric Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: Jeff D
authors.initials: JD
authors.lastname: Williamson
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Jackson T
authors.initials: JT
authors.lastname: Wright
authors.affiliation: Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, USA.
authors.forename: Paul K
authors.initials: PK
authors.lastname: Whelton
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D057911:Angiotensin Receptor Antagonists / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000150:complications; D002985:Clinical Protocols; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010347:Patient Care Planning; D051436:Renal Insufficiency, Chronic / Q000150:complications; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000627:therapeutic use; D013599:Systole; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D049993:Sodium Chloride Symporter Inhibitors; D049994:Sodium Potassium Chloride Symporter Inhibitors
keywords: Randomized clinical trial; blood pressure targets; brain structure and function; cardiovascular; cognition; geriatrics; hypertension; kidney; major adverse cardiovascular outcomes; stroke