Central blood pressure augmentation and central-to-peripheral blood pressure amplification in relation to cardiovascular end points.

Abstract

Background: Central hemodynamic indices might provide additional prognostic information for cardiovascular risk beyond blood pressure (BP) and other conventional risk factors. The aim of the study is to investigate whether indices of central BP augmentation and central-to-peripheral BP amplification were associated with cardiovascular end points. Methods: In a population-based cohort study of 5,608 adults recruited in Europe, Asia and South America, baseline measurements included cardiovascular risk factors, central hemodynamic measurements derived from the radial pulse wave analysis by the tonometric method with the SphygmoCor device (Atcor, Australia). The primary outcome was a composite cardiovascular end point. Secondary end points included total mortality, fatal and nonfatal coronary events and fatal and nonfatal stroke. The multivariable-adjusted hazard ratios (HR) were expressed as the risk per 1-SD increment in central hemodynamic indices. Results: Among 5,608 participants (54.1% women; mean age, 54.2 years), median follow-up was 4.1 years. Central augmentation index, augmentation pressure, systolic BP (SBP) amplification (brachial SBP minus central SBP), pulse pressure (PP) amplification (brachial PP minus central PP) and PP amplification ratio (brachial PP/central PP*100%) averaged 26.8%, 12.7 mmHg, 10.3 mmHg, 11.4 mmHg and 130.9%, respectively. The primary composite cardiovascular end point occurred in 255 participants (4.5%). Central augmentation index (HR, 1.21; 95%CI, 1.00-1.47; P=0.048) and augmentation pressure (HR, 1.17; 95%CI, 1.01-1.36; P=0.033), but not amplification indices (P>=0.18), were significantly associated with the primary outcome. For secondary end points, central augmentation index (HR, 1.56; 95%CI, 1.17-2.09; P=0.003), augmentation pressure (HR, 1.36; 95%CI, 1.06-1.75; P=0.017) and PP amplification ratio (HR, 0.63; 95%CI, 0.44-0.91; P=0.015) were significantly associated with coronary end points, while there was no significant association with total mortality and stroke. Conclusions: In adult populations, central BP augmentation indices were associated with cardiovascular outcomes independent of conventional cardiovascular risk factors.