Risk Assessment for Cardiovascular Events using Achilles Tendon Thickness and Softness and Intima-Media Thickness in Familial Hypercholesterolemia

Aims: This was a retrospective cohort study that aimed to determine cutoff values for major adverse cardiovascular events (MACEs) in patients with heterozygous FH (HeFH) for Achilles tendon (AT) thickness (ATT) measured by ultrasonography (US-ATT) and radiography (Xp-ATT), AT softness, and intima-media thickness of carotid artery (C-IMT), and to examine the effectiveness of these values as well as AT calcification as indexes in assessing risk for MACEs. Methods: The subjects were 391 clinically diagnosed HeFH patients. Kaplan-Meier curves were drawn based on the threshold values for the individual indexes calculated from ROC curves, and multivariate analysis was used to examine whether they were predictors of the development of MACEs. Results: The median observation period was 1,239 days (700-1,827 days). Twenty-one subjects (5%) had MACEs during the observation period. The cutoff values for MACEs for US-ATT were 9.9 mm in males and 7.1 mm in females, and those for C-IMT were 1.6 mm in males and 1.5 mm in females. Subjects were classified into two groups according to whether they were above or below the cutoff values and presence of calcification, and we compared MACE rates between them. MACE rates were significantly increased in groups with AT thickening determined by ultrasonography (P<0.001), AT softening (P<0.001), presence of calcification in AT (P=0.016) and greater C-IMT (P<0.001). However, classification according to Xp-ATT revealed no significant difference in MACE rate (P=0.112). Conclusions: These thresholds and examination for AT calcification will help in risk assessment for patients in Japanese FH practice and encourage stricter and more comprehensive management for patients who exceed the thresholds.