Evaluation of different metrics as an index for the assessment of arterial stiffness

Abstract

Elevated intravascular pressure is a contributing factor to increased arterial stiffness, and is a risk factor for cardiovascular morbidity and mortality. Assessment of arterial stiffness is of importance in evaluating cardiovascular risk. Pulse wave velocity (PWV) has been broadly used in the assessment of arterial stiffness. We compared three different metrics of arterial stiffness to PWV. Hemodynamic recordings were carried out in anesthetized hypertensive and normotensive rats (n = 25; 13–14 weeks old). Four parameters were calculated (PWV, elastic modulus (Einc), stiffness index (β), and pressure-strain modulus (Ep)) as metrics of arterial stiffness. Hypertensive in comparison to normotensive rats had significantly higher systolic and diastolic blood pressures. Metric for arterial stiffness were significantly (p < 0.002) higher in hypertensive animals: PWV (8.46 ± 2.01 vs. 6.39 ± 1.28 m/s), Ep (0.246 ± 0.019 vs. 0.137 ± 0.010 dyn/cm2 × 10–6), Einc (17.5 ± 1.8 vs. 10.1 ± 0.9 dyn/cm2 × 10–6), and β (2.43 ± 0.11 vs. 1.98 ± 0.08) (mean±SE). Bland-Altman analysis revealed β as the only metric aligned with PWV in hypertensive state. We find in state of reduced arterial compliance associated with high systemic pressure, β but not Einc or Ep is an index of arterial stiffness showing agreement with PWV.

Keywords

• arterial stiffness
• elastic modulus
• high intravascular pressure
• pressure strain modulus
• pulse wave velocity
• stiffness index