Achilles tendon thickness normalized to body surface area as a marker of asymptomatic peripheral arterial disease

The normalisation of Achilles tendon thickness (ATT) to anthropometric parameters may increase the diagnostic efficiency of the assessment of ATT. The aim of this study was to compare the diagnostic value of AT dimensions depending on their normalization to body surface area (BSA) in patients with asymptomatic peripheral arterial disease (PAD).

All patients underwent duplex scanning of the carotid arteries and the lower limb arteries. Asymptomatic PAD was defined as the presence of ≥50% stenosis in the carotid and/or lower limb arteries. ATT was measured using a longitudinal scan, width (ATW) and cross-sectional area (AT CSA), which was determined during a cross-sectional scan.

The study included 369 patients, among whom asymptomatic PAD was detected in 18 (4.88%) patients. Only the ATT demonstrated diagnostic value for asymptomatic PAD. After normalizing the size of the AT to the BSA, the diagnostic performance of ATT, ATW and AT CSA became statistically significant. Among the studied parameters, only an increase in ATT/BSA >0.29 cm/m² was associated with a significant increase in the odds ratio (OR) of asymptomatic PAD by 4.11 times (95% CI 1.08-15.7; p = .038) after adjustments.

An increase in ATT/BSA >0.29 cm/m² predicted the presence of asymptomatic PAD with a sensitivity of 61.1% and a specificity of 77.9%. ATT/BSA values of less than 0.29 cm/m² made it possible to exclude asymptomatic PAD with a probability of 97.5%. An increase in ATT/BSA >0.29 cm/m² was associated with a 4.11-fold increase in the OR of asymptomatic PAD (95% CI 1.08-15.7).