An ABI greater than 1.3 suggests?

• A. Normal ABI range is 0.9 to 1.3
• B. ABI greater than 1.3 indicates incompressible vessels due to calcified arteries, typically associated with diabetes
• C. Abnormal ABI due to venous disease
• D. ABI cannot be determined in a resting patient

Answer: (B)

ABI measures the ratio of ankle to brachial systolic pressures to assess arterial perfusion. A normal range is about 0.9 to 1.3. When the ABI is greater than 1.3, it points to noncompressible arteries from calcification in the vessel walls (medial calcific sclerosis). This makes the arteries stiff, so the cuff cannot compress them properly and the ankle pressure ends up reading falsely high. This situation is common in diabetes and related conditions. Because the vessels are noncompressible, the ABI can’t reliably reflect blood flow, so clinicians often turn to alternative tests like the toe-brachial index or imaging to evaluate for peripheral arterial disease.