Pulse volume recordings to identify falsely elevated ankle brachial index

Area of Science:

• Vascular Medicine
• Diagnostic Imaging
• Diabetology

Background:

• Ankle-brachial index (ABI) can be falsely elevated due to medial arterial calcification, limiting its use, particularly in diabetic patients.
• Peripheral arterial disease (PAD) diagnosis relies on accurate ABI measurements, but calcification poses a significant challenge.

Purpose of the Study:

• To evaluate the utility of pulse volume recording (PVR) in detecting falsely elevated ABI.
• To assess if PVR parameters can improve the accuracy of PAD diagnosis in at-risk populations.

Main Methods:

• Retrospective analysis of PVR in 171 patients (342 limbs), with 43% diagnosed with diabetes.
• Automatic calculation of pulse waveform parameters: upstroke time and percentage mean artery pressure.
• Comparison of ABI with toe-brachial index (TBI) to identify discrepancies.

Main Results:

• Diabetes, low ABI (≤0.90), prolonged upstroke time (≥180 ms), and high percentage mean artery pressure (≥45%) were associated with a low TBI (<0.60).
• In patients with ABI > 0.90, percentage mean artery pressure ≥45% differentiated diabetic patients from controls (0.45 ± 0.17 vs. 0.35 ± 0.16, p=0.03).
• Upstroke time did not significantly discriminate falsely elevated ABI.

Conclusions:

• While ABI is the gold standard for PAD diagnosis, percentage mean artery pressure offers a valuable adjunct.
• Percentage mean artery pressure, derived during ABI measurement, can help identify falsely elevated ABI, especially in diabetic individuals.
• PVR parameters, particularly percentage mean artery pressure, enhance the diagnostic capability of ABI in complex cases.