Objective: The objective of this study was to clarify whether or not pulse volume recoding (PVR) parameters have screening capability equivalent to ankle-brachial pressure index after walking (Ex-ABI) for patients with 0.91 or higher ABI.
Patients and Methods:The subjects were 87 patients (147 limbs) with symptoms of lower extremities with 0.91 or higher ABI. In all patients, upstroke time (UT), percentage of mean artery pressure (%MAP) of PVR and Ex-ABI were measured, and computed tomographic angiography (CTA) was concomitantly performed. Results: Area under the curve (AUC) of receiver operating characteristics (ROC) curves of Ex-ABI, %MAP, and UT were 0.90, 0.70, and 0.81, respectively. A significant difference was noted in AUC between Ex-ABI and %MAP (p <0.001). When the cut-off values were set at %MAP ≥45% and UT ≥180 msec, the accuracies of %MAP and UT were markedly lower than that of Ex-ABI. When the cut-off values were corrected to the values determined from the ROC curves (%MAP ≥41, UT ≥164 msec), the diagnostic accuracy of UT increased markedly. Conclusion: In patients with 0.91 or higher ABI, screening capability of PVR parameters was markedly lower than that of Ex-ABI, but UT has screening capability close to that of Ex-ABI when the cut-off value is corrected downward.Keywords: peripheral arterial disease, ankle-brachial pressure index, pulse volume recording
IntroductionThe standard value of ankle-brachial pressure index (ABI) to detect peripheral artery disease (PAD) is 0.9 or lower, 1) but sticking to this value increases the probability of overlooking PAD showing boundary (0.91-1.0) and normal (1.1 or higher) values. 2) To prevent this overlooking, measurement of ABI immediately after walking (Ex-ABI) is recommended for patients with 0.91 or higher ABI. 3) However, although Ex-ABI is a superior method to detect the above PAD, it is not readily introduced into busy clinical sites because it requires an expensive exercise device, multiple manpower, and testing time. Solving these problems was tried by concomitant use of pulse volume recoding (PVR) for measurement of ABI in some studies. [4][5][6] Using oscillometric methods, PVR parameters can be measured simultaneously with ABI, being easy to introduce it into clinical sites. However, it is unclear whether or not these PVR parameters have screening capability equivalent to Ex-ABI. The objective of this study was to clarify whether or not these PVR parameters have screening capability equivalent to Ex-ABI for patients with 0.91 or higher ABI. The scanning range was planned with a scout view and included the entire vascular tree from the abdominal aorta to ankles. A total of 60-90 mL of contrast media (Proscope 300, Tokyo, Japan) was administered with an automated injector (KCA00226, Nemoto, Tokyo, Japan) at a flow rate of 2-3 mL/sec through a 20-G needle that was placed in a superficial vein. PAD is defined as the presence of stenosis of more than 75% in the case of lesion from an iliac artery to knee on CTA.
Patients and Methods
Patients
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