Iwama Makoto, Tanaka Shinichiro, Yagasaki Hiroto, Ueno Takahiro, Yoshizane Takashi, Kato Takashi, Morishita Kentaro, Arai Masazumi, Noda Toshiyuki
Department of Cardiology, Gifu Prefectural General Medical Center, Gifu, Japan.
Department of Internal Medicine, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, 501-0296, Japan.
Heart Vessels. 2025 Jun 3. doi: 10.1007/s00380-025-02563-1.
Excimer laser coronary angioplasty (ELCA) plays an important role in modifying plaque composition, yet its impact on neointimal tissue (NIT) in in-stent restenosis lesions has remained unclear. While integrated backscatter intravascular ultrasound (IB-IVUS) can characterize plaque composition in de novo lesions, its ability to reflect tissue characteristics in NIT is limited due to the distinct structural and acoustic properties of neointimal tissue. This study aimed to investigate the effects of ELCA on NIT using IB-IVUS. We examined 49 in-stent lesions in 49 patients. IB-IVUS analysis focused on a 10 mm segment centered on the minimum lumen area (MLA), with data collected every 1 mm. Color maps were generated based on IB-IVUS backscatter values and included the following classifications: Red (typically calcification in de novo lesions), Yellow (dense fibrosis), Green (fibrosis), Blue (lipid pool), and Purple (lipid pool with attenuation). These classifications are based on tissue characteristics as defined in de novo settings and may differ in in-stent neointimal tissue. We compared Color-Ave (average color-coded area across 11 cross-sections, mm) and %Color-Ave (relative to neointimal tissue area), before and after ELCA. IB-related values, including mean (Ave-IB) and variance (Variance-IB), were automatically obtained. Following ELCA, Purple-Ave and %Purple-Ave significantly decreased (from 0.95±1.28 mm to 0.77±1.13 mm, and from 13.5±12.8% to 11.2±11.1%, both p=0.002). %Green-Ave increased significantly (from 53.6±14.1% to 55.5±12.7%, p=0.016), although Green-Ave remained unchanged. No significant changes were observed in Red-, Yellow-, and Blue-code areas. Similar trends were observed in MLA- and volume-based analyses. Ave-IB increased (p=0.028), while Variance-IB decreased (p=0.005). Changes in IB-related values were associated with their pre-ELCA levels. ELCA appears to ablate tissue with high IB-related values, leading to reduced tissue heterogeneity, even in NIT where tissue characterization by IB-IVUS is inherently limited.
准分子激光冠状动脉成形术（ELCA）在改变斑块成分方面发挥着重要作用，但其对支架内再狭窄病变中新生内膜组织（NIT）的影响仍不明确。虽然集成背向散射血管内超声（IB-IVUS）能够对初发病变中的斑块成分进行表征，但由于新生内膜组织独特的结构和声特性，其反映NIT中组织特征的能力有限。本研究旨在使用IB-IVUS研究ELCA对NIT的影响。我们检查了49例患者的49个支架内病变。IB-IVUS分析聚焦于以最小管腔面积（MLA）为中心的10毫米节段，每1毫米收集一次数据。基于IB-IVUS背向散射值生成彩色图，包括以下分类：红色（通常为初发病变中的钙化）、黄色（致密纤维化）、绿色（纤维化）、蓝色（脂质池）和紫色（伴有衰减的脂质池）。这些分类基于初发情况下定义的组织特征，在支架内新生内膜组织中可能有所不同。我们比较了ELCA前后的颜色平均值（Color-Ave，11个横截面的平均颜色编码面积，单位为毫米）和颜色平均值百分比（%Color-Ave，相对于新生内膜组织面积）。自动获取与IB相关的值，包括平均值（Ave-IB）和方差（Variance-IB）。ELCA术后，紫色平均值和紫色平均值百分比显著降低（从0.95±1.28毫米降至0.77±1.13毫米，从13.5±12.8%降至11.2±11.1%，p均=0.002）。绿色平均值百分比显著增加（从53.6±14.1%增至55.5±12.7%，p=0.016），尽管绿色平均值保持不变。红色、黄色和蓝色编码区域未观察到显著变化。在基于MLA和体积的分析中也观察到类似趋势。Ave-IB增加（p=0.028），而Variance-IB降低（p=0.005）。与IB相关的值的变化与其ELCA术前水平相关。即使在通过IB-IVUS进行组织表征本质上受限的NIT中，ELCA似乎也能消融具有高IB相关值的组织，从而降低组织异质性。
