Objectives The purpose of this study was to derive a biomechanical stress metric that was based on the multifactorial assessment of coronary plaque morphology, likely related to the propensity of plaque rupture in patients. Background Plaque rupture, the most frequent cause of coronary thrombosis, occurs at locations of elevated tensile stress in necrotic core fibroatheromas (NCFAs). Finite element modeling (FEM), typically used to calculate tensile stress, is computationally intensive and impractical as a clinical tool for locating rupture-prone plaques. This study derived a multifactorial stress equation (MSE) that accurately computes peak stress in NCFAs by combining the influence of several morphological parameters. Methods Intravascular ultrasound and optical frequency domain imaging were conducted in 30 patients, and plaque morphological parameters were defined in 61 NCFAs. Multivariate regression analysis was applied to derive the MSE and compute a peak stress metric (PSM) that was based on the analysis of plaque morphological parameters. The accuracy of the MSE was determined by comparing PSM with FEM-derived peak stress values. The ability of the PSM in locating plaque rupture sites was tested in 3 additional patients. Results The following parameters were found to be independently associated with peak stress: fibrous cap thickness (p < 0.0001), necrotic core angle (p = 0.024), necrotic core thickness (p < 0.0001), lumen area (p < 0.0001), necrotic core including calcium areas (p = 0.017), and plaque area (p = 0.003). The PSM showed excellent correlation (R = 0.85; p < 0.0001) with FEM-derived peak stress, thus confirming the accuracy of the MSE. In only 56% (n = 34) of plaques, the thinnest fibrous cap thickness was a determining parameter in identifying the cross section with highest PSM. In coronary segments with plaque ruptures, the MSE precisely located the rupture site. Conclusions The MSE shows potential to calculate the PSM in coronary lesions rapidly. However, further studies are warranted to investigate the use of biomechanical stress profiling for the prognostic evaluation of patients with atherosclerosis.

中文翻译：

---

冠状动脉粥样硬化的生物力学应力分析确定多因素指标以评估斑块破裂风险

目标 本研究的目的是推导一种生物力学应力指标，该指标基于冠状动脉斑块形态的多因素评估，可能与患者斑块破裂的倾向有关。背景 斑块破裂是冠状动脉血栓形成的最常见原因，发生在坏死核心纤维粥样硬化 (NCFA) 中拉伸应力升高的位置。通常用于计算拉伸应力的有限元建模 (FEM) 是计算密集型的，并且作为用于定位易破裂斑块的临床工具是不切实际的。本研究推导了一个多因素应力方程 (MSE)，该方程通过结合多个形态参数的影响准确计算 NCFA 中的峰值应力。方法对30例患者行血管内超声及光频域成像，和斑块形态学参数在 61 个 NCFA 中定义。应用多元回归分析来推导 MSE 并计算基于斑块形态参数分析的峰值应力指标 (PSM)。MSE 的准确性是通过比较 PSM 与 FEM 派生的峰值应力值来确定的。在另外 3 名患者中测试了 PSM 定位斑块破裂部位的能力。结果 发现以下参数与峰值应力独立相关：纤维帽厚度 (p < 0.0001)、坏死核角 (p = 0.024)、坏死核厚度 (p < 0.0001)、管腔面积 (p < 0.0001)、坏死核核心包括钙区域 (p = 0.017) 和斑块区域 (p = 0.003)。PSM 与 FEM 派生的峰值应力显示出极好的相关性（R = 0.85；p < 0.0001），从而证实了 MSE 的准确性。在仅 56% (n = 34) 的斑块中，最薄的纤维帽厚度是识别具有最高 PSM 的横截面的决定性参数。在有斑块破裂的冠状动脉节段中，MSE 精确定位了破裂部位。结论 MSE 显示出快速计算冠状动脉病变 PSM 的潜力。然而，需要进一步的研究来调查生物力学应力分析在动脉粥样硬化患者预后评估中的应用。