Small and large artery elasticity indices in peripheral arterial occlusive disease (PAOD)

In peripheral arterial occlusive disease (PAOD), arterial compliance of the central arteries has been reported to be reduced. It is, however, not clear whether, in PAOD, decreased arterial compliance is also accompanied by similar changes in the peripheral arteries. Therefore the aim of the study was to determine the large (C1) and small (C2) artery elasticity indices in PAOD and their relations to its well-accepted characteristics (ankle-brachial index, ABI; pulse pressure, PP; absolute claudication distance, ACD). A total of 43 patients with PAOD (mean age 68 ± 9 years; ABI of the limiting leg 0.65 ± 0.14; SBP (systolic blood pressure) 149 ± 20 mmHg, and ACD 488 ± 187 m) were enrolled as well as 16 control subjects of comparable age (69 ± 4 years) and blood pressure (SBP 147 ± 27 mmHg). All subjects underwent non-invasive pulse wave analysis in order to determine arterial compliance of the aorta and major side branches (C1) and of the distal circulation (C2), using a modified Windkessel model. In PAOD, both C1 (1.41 ± 0.56 ml/mmHg) and C2 (0.023 ± 0.012 ml/mmHg) were comparable to values in an age and blood pressure-matched control group (C1, 1.25 ± 0.66 ml/mmHg; C2, 0.027 ± 0.008 ml/mmHg). C1 was significantly correlated with ACD (r = 0.36, p = 0.02), PP (r = -0.33, p < 0.02) and only borderline with ABI (r = 0.28, p = 0.07). C2 was correlated with PP (r = -0.38, p < 0.01), ABI (r = 0.36, p < 0.02) but not with ACD. Large (C1) and small (C2) artery elasticity indices in PAOD were decreased but comparable to values in an elderly group with isolated systolic hypertension. Moreover, C1 and C2 correlated with markers (ABI and PP) of severity of vascular disease.