title: Crucial Effect of Calibration Methods on the Association Between Central Pulsatile Indices and Coronary Atherosclerosis.
abstract: BACKGROUND
  Several studies have reported that central systolic blood pressure (SBP) estimation is affected by calibration methods. However, whether central pulsatile indices, namely pulse pressure (PP) and fractional PP (FPP) (defined as PP/mean arterial pressure (MAP)), also depend on calibration methods remains uninvestigated. This study assessed the accuracy and discriminatory ability of these indices for coronary atherosclerosis using 2 calibration methods.
  
  
  METHODS
  Post-hoc analysis of a previous cross-sectional study (n = 139) that investigated the association between central pulsatile indices and coronary atherosclerosis. A validated-oscillometric device provided PP and FPP at the brachial artery (bPP and bFPP) and central artery using 2 calibration methods: brachial SBP/diastolic BP (DBP) (cPPsd and cFPPsd) and MAP/DBP (cPPmd and cFPPmd). Accuracy was assessed against invasive measurements (cPPinv and cFPPinv). Multivariate logistic and linear regression analyses were performed to assess the association between pulsatile indices and the presence of coronary artery disease (CAD) and SYNTAX score, respectively.
  
  
  RESULTS
  cPPmd and cFPPmd were closer to invasive values than cPPsd (cPPsd: 39.6±12.6; cPPmd: 60.2±20.1; cPPinv: 71.4±22.9). cFPP exhibited similar results (cFPPsd: 0.35±0.09; cFPPmd: 0.55±0.14; cFPPinv: 0.70±0.19). In patients ≥70 years, only cFPPmd was significantly associated with CAD risk (odds ratio: 1.66 (95% confidence interval: 1.05-2.64)). SYNTAX score was significantly correlated with cPPmd, cFPPmd, and bFPP (standardized β: cPPmd 0.39, cFPPmd 0.50, bFPP 0.42, all P < 0.01). No significant association was observed in patients aged <70 years.
  
  
  CONCLUSIONS
  Central pulsatile indices calibrated with brachial MAP/DBP were more accurate and discriminatory for coronary atherosclerosis than SBP/DBP calibration.
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakagomi
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan. shookada-circ@umin.ac.jp.
authors.forename: Sho
authors.initials: S
authors.lastname: Okada
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Shoji
authors.affiliation: Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods*; D002138:Calibration; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow
keywords: blood pressure; calibration methods; central blood pressure; central pulse pressure; coronary atherosclerosis; hypertension; pulse wave analysis.