Extent of lipid core plaque in patients with Achilles tendon xanthoma undergoing percutaneous coronary intervention for coronary artery disease

Background: It has been reported that Achilles tendon xanthoma (ATX), being one of the important diagnostic criteria for familial hypercholesterolemia, is independently associated with the severity of coronary artery disease (CAD). The aim of this study was to investigate plaque vulnerability in CAD patients with ATX.

Methods: Patients with CAD who underwent percutaneous coronary intervention (PCI) with near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) guidance were enrolled. Soft X-ray radiography of the Achilles tendon was performed, and a maximum thickness of 9 mm or more was regarded as ATX. Using NIRS-IVUS, the degree of lipid core plaque (LCP) was evaluated by calculating the maximum value of lipid core burden index (LCBI) for any of the 4-mm segments (maxLCBI_4mm) in the target lesion and non-target vessel.

Results: In a total of 156 patients, 14 patients (9.0%) had ATX. MaxLCBI_4mm in the ATX group was significantly greater in the target lesion (p<0.001) and in the non-target vessel (p=0.032) compared to the non-ATX group. When patients were divided into tertiles according to Achilles tendon thickness, maxLCBI_4mm was progressively increased in favor of thickness, although there was only a tendency in the target lesion (p=0.062), and no statistical significance in the non-target vessel (p=0.189). Multiple linear regression analysis determined ATX as an independent predictor for maxLCBI_4mm in the target lesion and non-target vessel.

Conclusions: ATX was associated with the degree of LCP in CAD patients requiring PCI. High-risk patients with lipid-rich vulnerable plaque can possibly be detected by evaluating Achilles tendon thickness.