Association of Central Arterial Stiffening with Myocardial Oxygen Supply-Demand Indices in Healthy Adults

Central arterial stiffening may increase systolic aortic impedance and reduce diastolic perfusion pressure, thereby impairing myocardial oxygen supply-demand balance. We tested the hypothesis that longitudinal changes in proximal aortic stiffness are more closely associated with changes in subendocardial viability ratio (SEVR) and its constituent systolic and diastolic pressure-time indices than changes in overall aortic stiffness. We investigated 10-year longitudinal changes in central arterial stiffness in 64 adults spanning a wide age range (19-73 years at pre-measurement). Carotid-femoral pulse wave velocity (cfPWV) was measured as the reference standard for aortic stiffness, whereas heart-brachial PWV (hbPWV) was used as an index of aortic stiffness for more proximal segment. Aortic pressure waveform was derived from carotid arterial pressure, and SEVR was calculated as the ratio of diastolic to systolic aortic pressure-time integrals. cfPWV and hbPWV increased, whereas SEVR decreased over the follow-up period in all age groups (p<0.01). Although changes in hbPWV were positively associated with changes in both systolic and diastolic pressure-time indices (r=0.41 and r=0.55, respectively; both p<0.01), they were not associated with changes in SEVR (r=0.02, p=0.87). Changes in cfPWV were not significantly associated with changes in either pressure-time index or SEVR. These results suggest that longitudinal changes in proximal aortic stiffness are associated with changes in the individual pressure-time indices of myocardial oxygen demand and supply, but not with changes in their balance as assessed by SEVR.