title: Arterial pressure: agreement between a brachial cuff-based device and radial tonometry.
abstract: OBJECTIVE
  Aortic (central) blood pressure (BP) differs from brachial BP and may be a superior predictor of cardiovascular events. However, its measurement is currently restricted to research settings, owing to a moderate level of operator dependency. We tested a new noninvasive device in a large UK cohort. The device estimates central BP using measurements obtained with an upper arm cuff inflated to suprasystolic pressure. We compared these estimates with those obtained using radial tonometry as well as with invasively acquired measurements of aortic BP in a limited number of individuals.
  
  
  METHODS
  Consecutive cuff-based and tonometry-based estimates of the pressure waveform and the central BP were obtained from 1107 individuals (70 ± 6 years). Short-term and long-term reproducibility studies were performed on 28 individuals. Simultaneous cuff-based and invasively measured pressure traces were acquired and compared in an additional six individuals (65 ± 20 years).
  
  
  RESULTS
  Central systolic BP, as estimated by the cuff-based device, was found to be highly reproducible (coefficient of variation 4 and 8% for short and long-term reproducibility, respectively) and was comparable to that estimated by tonometry (average difference 3 ± 6  mmHg, intraclass correlation coefficient = 0.91). The cuff-based pressure waveforms were similar to those acquired invasively (cross-correlation coefficient 0.93), and the difference in the estimated central systolic BP was -5 ± 8  mmHg (P = 0.2).
  
  
  CONCLUSIONS
  Cuff-based devices show promise to simplify the measurement of central BP, whilst maintaining a similar fidelity to tonometry. This could lead to improved adoption of estimates of central BP in clinical practice.
authors.affiliation: aInternational Centre for Circulatory Health, Imperial College London & Imperial College Healthcare NHS Trust bDepartment of Bioengineering, Imperial College London, London, UK.
authors.forename: Chloe M
authors.initials: CM
authors.lastname: Park
authors.forename: Olga
authors.initials: O
authors.lastname: Korolkova
authors.forename: Justin E
authors.initials: JE
authors.lastname: Davies
authors.forename: Kim H
authors.initials: KH
authors.lastname: Parker
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Siggers
authors.forename: Katherine
authors.initials: K
authors.lastname: March
authors.forename: Therese
authors.initials: T
authors.lastname: Tillin
authors.forename: Nish
authors.initials: N
authors.lastname: Chaturvedi
authors.forename: Alun D
authors.initials: AD
authors.lastname: Hughes
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D001795:Blood Pressure Determination / Q000295:instrumentation*; D002138:Calibration; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000295:instrumentation* / Q000379:methods; D008875:Middle Aged; D015203:Reproducibility of Results; D006113:United Kingdom