Wave reflections and systemic vascular resistance are stronger determinants of pulse pressure amplification than aortic stiffness in drug-naïve hypertensives

Abstract

Background: Aortic-to-brachial pulse pressure (PP) amplification is a novel biomarker that prognosticates the cardiovascular risk above and beyond central aortic and brachial blood pressure. This phenomenon is modulated by left ventricular contractility and chronotrophy, large-artery stiffness and reflecting properties of microcirculation. However, the relative importance of these parameters as hemodynamic determinant of PP amplification remains elusive. Methods: A total of 88 consecutive drug-naïve hypertensives underwent a non-invasive assessment of central and peripheral hemodynamics via impedance cardiography and pulse wave analysis. Participants were classified into tertiles according to the magnitude of PP amplification. Hemodynamic determinants of low PP amplification were explored in univariate and multivariate regression analysis. Results: Compared with the high tertile, patients within the low PP amplification tertile were older and more commonly female and had lower height, weight and heart rate. Augmentation index (AIx) and systemic vascular resistance index (SVRI) were higher among patients within the low PP amplification tertile, whereas aortic pulse wave velocity (PWV) did not differ among groups. In multivariate analysis, higher AIx (OR: 1.27; 95% CI: 1.09–1.48) and higher SVRI were independently associated with higher odds for low PP amplification, whereas higher heart rate was the only parameter related to lower odds for low PP amplification (OR: 0.84; 95% CI: 0.71–0.99). Conclusion: This study shows that among newly-diagnosed drug-naïve hypertensives, elevated wave reflections and systemic vascular resistance are stronger determinants of PP amplification than aortic stiffness.

Keywords

• augmentation index
• pulse pressure amplification
• pulse wave velocity
• systemic vascular resistance
• hypertension