LARGE ARTERY MECHANICAL
PROPERTIES CORRELATE WITH SEVERITY OF CORONARY ARTERY DISEASE. TK Waddell*, TL Medley, CD Gatzka, JD Cameron, AM Dart, BA
Kingwell. Alfred & Baker Medical Unit, Baker Medical Research
Institute, Prahran, Victoria, Australia. Objectives: Proximal aortic compliance has been shown to
be lower in coronary artery disease (CAD) patients compared with healthy
matched controls. The present
study aimed to characterise large artery mechanical properties in relation to
severity of CAD, as determined by the magnitude of the maximum coronary
stenosis on angiography. Methods: Seventy-two males with CAD (mean ± SD, 57 ± 9 years) and forty age and gender matched healthy controls (54 ± 10 years) were recruited. CAD patients were classified
as having a maximum stenosis of 50-79% (moderate CAD; n = 35) or >=80% (severe CAD; n = 37) of at least one major coronary
artery. Arterial mechanics were assessed by measuring systemic arterial
compliance (SAC), aortic input impedance and pulse wave velocity (PWV). Results: SAC was significantly
lower in the severe CAD group (mean ± SEM, 0.44 ± 0.04 arbitrary compliance units,
ACU) compared to moderate CAD (0.55 ± 0.04 ACU; p = 0.05) and controls (0.62 ± 0.04 ACU; p = 0.001). Furthermore, aortic input
impedance was significantly higher in severe CAD (2.59 ± 0.23 mmHg.s.cm-1) compared to moderate CAD
(2.06 ± 0.17 mmHg.s.cm-1; p =
0.04) and controls (1.75 ± 0.12 mmHg.s.cm-1; p = 0.001). A similar trend was also
evident for carotid-femoral PWV (severe CAD: 11.34 ± 0.71 ms-1 versus moderate CAD: 9.55 ± 0.49 ms-1; p = 0.02; and controls: 9.30 ± 0.29 ms-1; p = 0.005), however there was no
difference in femoral-dorsalis pedis PWV between the three groups. Resting
carotid pulse pressure was significantly greater in the severe CAD group (54 ± 4 mmHg) compared to moderate CAD (45 ± 3 mmHg; p = 0.05) and controls (39 ± 2 mmHg; p = 0.001), but there was no difference in
brachial systolic, diastolic, mean arterial pressure or heart rate between the
three groups. Conclusions: These findings
suggest that there is a correlation between the severity of aortic and coronary
atherosclerosis, and that large artery mechanical properties represent a
surrogate marker of disease severity in CAD patients.
