title: Derivation and validation of diagnostic thresholds for central blood pressure measurements based on long-term cardiovascular risks.
abstract: OBJECTIVE
  This study sought to derive and validate outcome-driven thresholds of central blood pressure (CBP) for diagnosing hypertension.
  
  
  BACKGROUND
  Current guidelines for managing patients with hypertension mainly rely on blood pressure (BP) measured at brachial arteries (cuff BP). However, BP measured at the central aorta (central BP [CBP]) may be a better prognostic factor for predicting future cardiovascular events than cuff BP.
  
  
  METHODS
  In a derivation cohort (1,272 individuals and a median follow-up of 15 years), we determined diagnostic thresholds for CBP by using current guideline-endorsed cutoffs for cuff BP with a bootstrapping (resampling by drawing randomly with replacement) and an approximation method. To evaluate the discriminatory power in predicting cardiovascular outcomes, the derived thresholds were tested in a validation cohort (2,501 individuals with median follow-up of 10 years).
  
  
  RESULTS
  The 2 analyses yielded similar diagnostic thresholds for CBP. After rounding, systolic/diastolic threshold was 110/80 mm Hg for optimal BP and 130/90 mm Hg for hypertension. Compared with optimal BP, the risk of cardiovascular mortality increased significantly in subjects with hypertension (hazard ratio: 3.08, 95% confidence interval: 1.05 to 9.05). Of the multivariate Cox proportional hazards model, incorporation of a dichotomous variable by defining hypertension as CBP ≥ 130/90 mm Hg was associated with the largest contribution to the predictive power.
  
  
  CONCLUSIONS
  CBP of 130/90 mm Hg was determined to be the cutoff limit for normality and was characterized by a greater discriminatory power for long-term events in our validation cohort. This report represents an important step toward the application of the CBP concept in clinical practice.
authors.affiliation: Joanna Briggs Institute, Faculty of Health Sciences, The University of Adelaide, Adelaide, Australia; Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan; Cardiovascular Research Center, National Yang-Ming University, Hospital, Taipei, Taiwan; Department of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hao-Min
authors.initials: HM
authors.lastname: Cheng
authors.forename: Shao-Yuan
authors.initials: SY
authors.lastname: Chuang
authors.forename: Shih-Hsien
authors.initials: SH
authors.lastname: Sung
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Yu
authors.forename: Alan
authors.initials: A
authors.lastname: Pearson
authors.forename: Edward G
authors.initials: EG
authors.lastname: Lakatta
authors.forename: Wen-Harn
authors.initials: WH
authors.lastname: Pan
authors.forename: Chen-Huan
authors.initials: CH
authors.lastname: Chen
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D013624:Taiwan / Q000453:epidemiology
keywords: BP; CBP; CI; DBP; PP; SBP; blood pressure; central blood pressure; confidence interval; cuff BP; diagnostic thresholds; diastolic blood pressure; high blood pressure; hypertension; peripheral blood pressure; pulse pressure; systolic blood pressure