Arterial stiffness and 5-year mortality in patients with peripheral arterial disease.

Among patients with peripheral arterial disease (PAD) the risk of mortality remains extremely high. We investigated whether arterial stiffness evaluated by aortic Pulse Wave Velocity (aPWV) and Augmentation index normalized for a standard heart rate of 75 bpm (Aix@75), predict cardiovascular disease (CVD) and total mortality in PAD and No-PAD patients. In 231 PAD patients (ankle-brachial index-ABI ≤ 0.9) and 167 No-PAD (ABI ≥ 0.91 < 1.3) the aPWV and Aix @75HR were evaluated using arterial tonometry and ABI values were obtained using an 8-MHz Doppler probe. The CVD and total mortality rates in relation to aPWV and Aix@75HR were analyzed using Cox regression model. During a mean follow-up of 5.4 ± 2 years 39 (16.9%) deaths occurred in PAD patients and 8 (4.8%) in No-PAD. In the population study, the age was a predictor of CVD mortality (HR = 0.143, 95% CI, 0.06-0.23; p = 0.0004) while the aPWV, was a predictor of total mortality (HR = 1.18, 95% CI, 1.07-1.30; p = 0.0008). In the PAD group, the aPWV remained associated with an increased risk for total mortality (HR = 1.14, 95% CI, 1.03-1.27; p = 0.010). An increase of aPWV may be an indicator of total mortality in PAD patients.

Arterial stiffness and subendocardial viability ratio in patients with peripheral arterial disease.

Arterial stiffening is a hallmark of the aging process and atherosclerosis, including peripheral arterial disease (PAD). We investigated the associations between carotid-femoral pulse wave velocity (c-fPWV), augmentation index corrected for heart rate (Aix@HR75), ankle brachial index (ABI), and subendocardial viability ratio (SEVR), an indicator of cardiac perfusion. The c-fPWV, Aix@HR75, and SEVR was estimated using applanation tonometry. The ankle systolic pressure measurements for the calculation of the ABI were obtained using an 8-mHz Doppler probe. The study group included 555 subjects, mean age 63 ± 11 years (248 PAD (ABI < 1.0), and 307 non-PAD (ABI ≥ 1.0 ≤ 1.3). After the stepwise selection process in both PAD and non-PAD patients SEVR was not related to c-fPWV and ABI (P = .154; P = .156) and (P = .101; P = .402), respectively. In PAD patients, SEVR was negatively related to Aix@HR75 (P < .0001) and aortic PP (P = .0005). In conclusion, arterial stiffness is associated with non-invasive indices of myocardial perfusion in PAD patients, suggesting a potential pathophysiological link for increased cardiovascular events.

Aortic augmentation index in patients with peripheral arterial disease.

Aortic augmentation index (AIx) is used to investigate arterial stiffness. The authors tested the hypothesis that patients with peripheral arterial disease (PAD) demonstrate a higher AIx and also evaluated several related factors. In 97 patients with PAD, identified by ankle-brachial pressure index (ABPI ≤ 0.9), and 97 controls (ABPI ≥ 0.91< 1.4), AIx (%) was determined using tonometry of the radial artery. There was no significant difference between patients and controls in characteristics of age, sex, height, diastolic blood pressure, mean blood pressure, and heart rate. AIx was higher in patients with PAD (32 ± 9 vs 28 ± 9; P = .001). In multivariate regression analysis, AIx was independently associated with heart rate (ß = -0.40, P = .0005). This study showed that AIx increased in patients with PAD and that heart rate is a determinant of AIx. Further studies are necessary to assess the pathophysiological and clinical importance of AIx in patients with PAD.

Increased aortic stiffness and related factors in patients with peripheral arterial disease.

A number of conditions have been associated with functional changes of large arteries. The aim of this study was to evaluate the factors associated with aortic stiffness in patients with peripheral arterial disease (PAD). The authors studied 86 patients with PAD (ankle-brachial pressure index [ABPI] ≤0.9) and 86 controls. Aortic stiffness was determined by pulse wave velocity (aPWV) using applanation tonometry. In PAD patients, aPWV was higher compared with controls (11 ± 3 vs 9.8 ± 1.8; P=.002). In multiple regression analysis, aPWV was independently associated with pulse pressure (ß=0.05, P=.01) in the PAD patients and with age in the control group (ß=0.08, P=.0005). The results of this study confirm an aPWV increase in patients with PAD and emphasize the association between blood pressure and aPWV. Further studies are necessary to assess whether higher aortic stiffening adds prognostic value to ABPI, which is the most powerful prognostic indicator in PAD.

Energetics of walking in patients with peripheral arterial disease: a proposed functional evaluation protocol.

The energy cost of walking (at 3.2 km x h(-1)) per unit distance (J x kg(-1) x m(-1)) at gradients of 0%, +7%, and +12% and during a progressive test (2% increase in gradient every 2 min), as well as the overall (aerobic plus anaerobic) net cumulative energy consumption and the corresponding maximal exercise duration were assessed in 19 patients with peripheral arterial disease (PAD) and in 13 moderately active control subjects. With a 0% gradient, the energy cost of walking was approximately 40% greater in patients with PAD than in controls (2.93+/-0.52 and 2.13+/-0.33 J x kg(-1) x m(-1) respectively; P <0.01). In contrast, at gradients of +7% and +12%, the energy cost of walking was similar in the two groups (+7%: PAD, 4.15+/-0.74 J x kg(-1) x m(-1); controls, 4.18+/-0.54 J x kg(-1) x m(-1); +12%: PAD, 5.59+/-1.03 J x kg(-1) x m(-1); controls, 5.64+/-0.75 J x kg(-1) x m(-1)). In patients with PAD, maximal exercise duration with gradients of 0%, +7% and +12% was 449+/-254, 322+/-200 and 229+/-150 s respectively, whereas the net cumulative energy consumption at fatigue was almost constant at approximately 1100 J x kg(-1) for all gradients. The greater energy cost of walking in PAD patients compared with controls in level, but not uphill, walking is interpreted as being mainly the consequence of an altered mechanical locomotory pattern, and not of lower metabolic efficiency. For a wide range of loads, net cumulative energy consumption appears to be independent of maximal exercise duration, a finding that provides a practical criterion for assessing the degree of functional impairment of patients with PAD on metabolic grounds.