Which finding is most diagnostic for peripheral arterial occlusive disease?

Which finding is most diagnostic for peripheral arterial occlusive disease?

• A. Ankle-brachial index (ABI) less than 0.90
• B. History of smoking
• C. Age over 55
• D. Prolonged capillary refill time greater than 2 seconds

Answer: (A)

Measuring the ankle-brachial index directly assesses arterial blood flow to the legs. An ABI under 0.90 is diagnostic for peripheral arterial occlusive disease because it reveals reduced perfusion from arterial narrowing. This noninvasive test provides a quantitative, objective indicator of lower-extremity arterial obstruction, and lower values correlate with greater disease. While smoking is a strong risk factor for PAD and age over 55 increases likelihood, neither alone confirms the disease. Prolonged capillary refill time suggests poor perfusion but is not specific to PAD and can occur in many conditions. Therefore, the ABI threshold is the most diagnostic finding for PAD, guiding further confirmation with imaging as needed.

Measuring the ankle-brachial index directly assesses arterial blood flow to the legs. An ABI under 0.90 is diagnostic for peripheral arterial occlusive disease because it reveals reduced perfusion from arterial narrowing. This noninvasive test provides a quantitative, objective indicator of lower-extremity arterial obstruction, and lower values correlate with greater disease.

While smoking is a strong risk factor for PAD and age over 55 increases likelihood, neither alone confirms the disease. Prolonged capillary refill time suggests poor perfusion but is not specific to PAD and can occur in many conditions. Therefore, the ABI threshold is the most diagnostic finding for PAD, guiding further confirmation with imaging as needed.