title: Double product reflects the predictive power of systolic pressure in the general population: evidence from 9,937 participants.
abstract: BACKGROUND
  The double product (DP), consisting of the systolic blood pressure (SBP) multiplied by the pulse rate (PR), is an index of myocardial oxygen consumption, but its prognostic value in the general population remains unknown.
  
  
  METHODS
  We recorded health outcomes in 9,937 subjects (median age, 53.2 years; 47.3% women) randomly recruited from 11 populations and enrolled in the International Database on Ambulatory blood pressure in relation to Cardiovascular Outcomes (IDACO) study. We obtained the SBP, PR, and DP for these subjects as determined through 24-hour ambulatory monitoring.
  
  
  RESULTS
  Over a median period of 11.0 years, 1,388 of the 9,937 study subjects died, of whom 536 and 794, respectively, died of cardiovascular (CV) and non-CV causes, and a further 1,161, 658, 494, and 465 subjects, respectively, experienced a CV, cardiac, coronary, or cerebrovascular event. In multivariate-adjusted Cox models, not including SBP and PR, DP predicted total, CV, and non-CV mortality (standardized hazard ratio [HR], ≥ 1.10; P ≤ 0.02), and all CV, cardiac, coronary, and stroke events (HR, ≥ 1.21; P < 0.0001). For CV mortality (HR, 1.34 vs. 1.30; P = 0.71) and coronary events (1.28 vs. 1.21; P = 0.26), SBP and the DP were equally predictive. As compared with DP, SBP was a stronger predictor of all CV events (1.39 vs. 1.27; P = 0.002) and stroke (1.61 vs. 1.36; P < 0.0001), and a slightly stronger predictor of cardiac events (1.32 vs. 1.22; P = 0.06). In fully adjusted models, including both SBP and PR, the predictive value of DP disappeared for fatal endpoints (P ≥ 0.07), coronary events (P = 0.06), and stroke (P = 0.12), or DP was even inversely associated with the risk of all CV and cardiac events (both P ≤ 0.01).
  
  
  CONCLUSIONS
  In the general population, we did not observe DP to add to risk stratification over and beyond SBP and PR.
authors: Department of Cardiovascular Sciences, Studies Coordinating Centre, Division of Hypertension and Cardiovascular Rehabilitation, University of Leuven, Leuven, Belgium.
authors: Rudolph
authors: R
authors: Schutte
authors: Lutgarde
authors: L
authors: Thijs
authors: Kei
authors: K
authors: Asayama
authors: José
authors: J
authors: Boggia
authors: Yan
authors: Y
authors: Li
authors: Tine W
authors: TW
authors: Hansen
authors: Yan-Ping
authors: YP
authors: Liu
authors: Masahiro
authors: M
authors: Kikuya
authors: Kristina
authors: K
authors: Björklund-Bodegård
authors: Takayoshi
authors: T
authors: Ohkubo
authors: Jørgen
authors: J
authors: Jeppesen
authors: Christian
authors: C
authors: Torp-Pedersen
authors: Eamon
authors: E
authors: Dolan
authors: Tatiana
authors: T
authors: Kuznetsova
authors: Katarzyna
authors: K
authors: Stolarz-Skrzypek
authors: Valérie
authors: V
authors: Tikhonoff
authors: Sofia
authors: S
authors: Malyutina
authors: Edoardo
authors: E
authors: Casiglia
authors: Yuri
authors: Y
authors: Nikitin
authors: Lars
authors: L
authors: Lind
authors: Edgardo
authors: E
authors: Sandoya
authors: Kalina
authors: K
authors: Kawecka-Jaszcz
authors: Jan
authors: J
authors: Filipovsky
authors: Yutaka
authors: Y
authors: Imai
authors: Jiguang
authors: J
authors: Wang
authors: Hans
authors: H
authors: Ibsen
authors: Eoin
authors: E
authors: O'Brien
authors: Jan A
authors: JA
authors: Staessen
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000401:mortality*; D003971:Diastole / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D015996:Survival Rate; D013599:Systole / Q000502:physiology*
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