Evaluation of nontarget lesions in femoropopliteal disease using near-infrared spectroscopy intravascular ultrasound imaging.

Background: In coronary artery disease (CAD), lipid-core-containing plaque (LCP) in nontarget lesions detected using near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) was related to increased major adverse cardiovascular events in patients with CAD. In the endovascular therapy field, few previous studies using NIRS-IVUS revealed the presence of LCPs in severe stenotic lesions of femoropopliteal disease.

Aim: This study aimed to assess the plaque morphology of nontarget lesions, especially LCPs, and compare it with that of target lesions using NIRS-IVUS in patients with femoropopliteal disease.

Methods: This single-center prospective observational study included 14 patients who underwent endovascular therapy for FP disease. NIRS-IVUS assessment was performed on the entire FP arterial segment. Forty-one LCP lesions with a maximum lipid-core burden index in any 4-mm region (max LCBI) > 100 were detected using NIRS-IVUS. We evaluated the patient and lesion characteristics. LCP lesions were divided into the target (n = 18) and nontarget (n = 23) lesion groups for comparison.

Results: Patient characteristics were notable for advanced age (76.8 ± 6.6 years); high proportion of males (78.7%); and high incidence of hypertension (100%), dyslipidemia (78.6%), diabetes (64.3%). Regarding NIRS findings, the target lesion group exhibited a significantly smaller proportion of LCPs concerning the lesion length (25.9 ± 15.7% vs. 50.6 ± 29.2%, p = 0.002) than the nontarget lesion group. Conversely, there were no significant differences in the value of max LCBI (284.4 ± 153.4 vs. 289.5 ± 113.1, p = 0.90), length of LCP lesion (9.8 ± 9.7 mm vs. 10.7 ± 6.9 mm, p = 0.74), and distribution of LCPs (p = 0.08) between the groups. In addition, the number of LCPs in the target FP artery positively correlated with max LCBI in the target FP artery (r = 0.671, p = 0.008).

Conclusions: NIRS-IVUS findings demonstrated the presence of LCPs in nontarget lesions in patients with FP disease. Moreover, the abundance of LCPs in nontarget lesions was similar to that in target lesions in FP disease.