Tanaka Shinichiro, Kawasaki Masanori, Noda Toshiyuki, Segawa Tomonori, Iwama Makoto, Yagasaki Hiroto, Ueno Takahiro, Yoshizane Takashi, Kato Takashi, Fuseya Takahiro, Watanabe Sachiro, Minagawa Taro, Minatoguchi Shinya, Okura Hiroyuki
The Department of Cardiology, Asahi University Hospital, 3-23 Hashimoto-cho, Gifu, 500-8523, Japan.
Gifu Heart Center, Gifu, Japan.
Heart Vessels. 2023 Jan;38(1):18-31. doi: 10.1007/s00380-022-02129-5. Epub 2022 Jul 10.
High-risk coronary plaques have certain morphological characteristics. Thus, comprehensive assessment is needed for the risk stratification of plaques in patients with coronary artery disease. Integrated backscatter intravascular ultrasound (IB-IVUS) has been used successfully used to evaluate the tissue characteristics of coronary plaques; however, the mechanical properties of plaques have been rarely assessed. Therefore, we developed Speckle-tracking IVUS (ST-IVUS) to evaluate the mechanical properties of coronary plaque. This study aimed to evaluate the relation between the tissue characteristics of coronary plaques using IB-IVUS and their mechanical properties using ST-IVUS. We evaluated 95 non-targeted plaques in 95 patients undergoing elective percutaneous coronary intervention to the left anterior descending artery. We set regions of interest (ROIs) in the cross-sectional images of coronary plaques where we divided 120 degree plaques into four quadrants (every 30 degrees), with the center at the area of maximum atheroma thickness. We measured relative calcification area (%CA, relative fibrous area (%FI) and relative lipid pool area (%LP) in a total of 380 ROIs. In ST-IVUS analysis, we measured strain in the circumferential direction of the lumen area (LA strain: %), the external elastic membrane area strain (EEM strain: %), and strain in the radial direction (radial strain: %). On global cross-sectional area IB-IVUS analysis, the %CA was 1.2 ± 1.2%; the %FI was 49.0 ± 15.9%, and the %LP was 49.7 ± 16.5%. In ST-IVUS analysis, the LA strain was 0.67 ± 0.43%; the EEM strain was 0.49 ± 0.33%, and the radial strain was 2.02 ± 1.66%. On regional analysis, the %LP was not associated with the LA strain (r = - 0.002 p = 0.97), the EEM strain (r = - 0.05 p = 0.35), or with the radial strain (r = - 0.04 p = 0.45). These trends were seen between the %FI and the LA strain (r = 0.02 p = 0.74), the %FI and the EEM strain (r = 0.05 p = 0.35), and the %FI and the radial strain (r = 0.04 p = 0.50). A significant correlation was only observed between the %CA and the LA strain (r = - 0.15 p = 0.0038). Our findings indicate that the associations between mechanical properties and tissue characteristics lacked statistical significance, more often than not, and that it is necessary to evaluate the mechanical properties as well as plaque characteristics for risk stratification of coronary plaques.
高危冠状动脉斑块具有一定的形态学特征。因此，对于冠心病患者的斑块风险分层需要进行综合评估。集成背向散射血管内超声（IB-IVUS）已成功用于评估冠状动脉斑块的组织特征；然而，斑块的力学特性很少被评估。因此，我们开发了斑点追踪IVUS（ST-IVUS）来评估冠状动脉斑块的力学特性。本研究旨在评估使用IB-IVUS评估的冠状动脉斑块组织特征与其使用ST-IVUS评估的力学特性之间的关系。我们评估了95例接受选择性经皮冠状动脉介入治疗左前降支的患者中的95个非靶向斑块。我们在冠状动脉斑块的横截面图像中设置感兴趣区域（ROI），将120度的斑块分为四个象限（每30度一个），中心位于最大动脉粥样硬化厚度区域。我们在总共380个ROI中测量了相对钙化面积（%CA）、相对纤维面积（%FI）和相对脂质池面积（%LP）。在ST-IVUS分析中，我们测量了管腔面积圆周方向的应变（LA应变：%）、外弹力膜面积应变（EEM应变：%）和径向应变（径向应变：%）。在整体横截面面积IB-IVUS分析中，%CA为1.2±1.2%；%FI为49.0±15.9%，%LP为49.7±16.5%。在ST-IVUS分析中，LA应变为0.67±0.43%；EEM应变为0.49±0.33%，径向应变为2.02±1.66%。在区域分析中，%LP与LA应变（r = -0.002，p = 0.97）、EEM应变（r = -0.05，p = 0.35）或径向应变（r = -0.04，p = 0.45）均无相关性。在%FI与LA应变（r = 0.02，p = 0.74）、%FI与EEM应变（r = 0.05，p = 0.35）以及%FI与径向应变（r = 0.04，p = 0.50）之间也观察到了这些趋势。仅在%CA与LA应变之间观察到显著相关性（r = -0.15，p = 0.0038）。我们的研究结果表明，力学特性与组织特征之间的关联大多缺乏统计学意义，并且有必要同时评估力学特性和斑块特征以进行冠状动脉斑块的风险分层。
