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 = 1.21; 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). CONCLUSION In the general population, we did not observe DP to add to risk stratification over and beyond SBP and PR.