ABSTRACT
OBJECTIVE: Evaluation of diagnostic accuracy of an oscillometry-based device (VascAssist) combining fully automated ankle-brachial index (ABI) and pulse-wave velocity (PWV) assessment for detection of peripheral arterial disease (PAD). SUBJECTS AND METHODS: 110 consecutive subjects including symptomatic PAD patients (n = 41) and healthy PAD-free participants (n = 69) were recruited. All subjects underwent standard manual Doppler-based ABI (sABI) and oscillometry-based automated ABI (aABI) measurements (VascAssist). Oscillometry by the VascAssist included central and peripheral PWV assessment. Additionally, arterial stiffness (AS) was evaluated by flow-mediated vasodilation (FMD) of the brachial artery in all patients. All symptomatic PAD patients underwent catheter angiography for endovascular intervention and post-interventional acquisition of sABI, aABI, PWV and FMD. RESULTS: Sensitivity, specificity, PPV and NPV of aABI for detecting PAD was 73%, 100%, 100%, and 86% as compared to 80%, 96%, 92%, and 89% for sABI. Pearson-correlation for diabetics was r = 0.81; (P < .001) and for non-diabetics r = 0.77; (P < .001). Bland-Altman-analysis revealed a difference (95% CI) for diabetics of 0.09 (-0.22-0.4] and non-diabetics 0.022 [-0.25-0.295]. Weak correlation exists for FMD/AS analysis (pre-interventional R = 0.386, P = .043; post-interventional R = -0.06; P = .76) and significant increase of pre-/post-interventional PWV analysis (P < .001). CONCLUSION: Combined automatic ABI and PWV acquisition with the VascAssist device showed excellent diagnostic accuracy for detection of PAD. Compared to FMD, AS analysis may serve as an investigator-independent (screening) tool for determination of functional vascular damage in atherosclerosis.
Subject(s)
Atherosclerosis/diagnosis , Blood Pressure Determination/methods , Blood Pressure/physiology , Brachial Artery/physiopathology , Oscillometry , Pulse Wave Analysis/methods , Vascular Stiffness/physiology , Adult , Aged , Aged, 80 and over , Atherosclerosis/physiopathology , Brachial Artery/diagnostic imaging , Female , Humans , Male , Middle Aged , Reproducibility of Results , Severity of Illness Index , Ultrasonography, Doppler , Young AdultABSTRACT
This study aims to investigate whether a Web-based tool will facilitate the adoption of feedback control over calorie balance in overweight individuals, thereby promoting an increase of physical activity and a reduction of body weight and cardiovascular risk factors. This is a prospective exercise intervention study, commencing with a minimum weekly 3 × 20-min requirement of high-intensity interval training and requirement for Web-based self-monitoring and self-reporting of exercise and body weight. Subjects of this study include 83 overweight, sedentary, otherwise healthy adults aged 26-68 years. Anthropometric parameters, body fat, peak oxygen consumption, self-reported physical activity, frequency of use of the Web-based tool are among the characters measured in this study. This 24-week intervention substantially increased time spent for exercise (mean and median of 135 and 170 min/week, respectively) among the 72 % of participants who had adopted cognitive feedback control vs. no increase in the remaining participants of nonadopters. Adopters witnessed significantly improved peak oxygen consumption of >1 metabolic equivalent vs. no improvement among nonadopters. Adopters also reduced body mass index, body weight, and body fat by 1.6 kg/m(2), 4.8 kg, and 3.6 kg, respectively vs. 0.4 kg/m(2), 1.4 kg, and 1.1 kg in the control group. The increase in physical activity came at virtually no intervention effort of the investigators. This study demonstrates for the first time that adoption of cognitive feedback control over energy balance is possible with the help of a simple Web-based tool and that overweight adopters self-regulate exercise volume to significantly reduce body weight and improve biomarkers of fitness and cardiovascular risk.
