Andreas Gruentzig Cardiovascular Center, Emory University School of Medicine, Atlanta, Georgia. Electronic address: https://twitter.com/arnavkumar.
Andreas Gruentzig Cardiovascular Center, Emory University School of Medicine, Atlanta, Georgia.
J Am Coll Cardiol. 2018 Oct 16;72(16):1926-1935. doi: 10.1016/j.jacc.2018.07.075.
Coronary lesions with low fractional flow reserve (FFR) that are treated medically are associated with higher revascularization rates. High wall shear stress (WSS) has been linked with increased plaque vulnerability.
This study investigated the prognostic value of WSS measured in the proximal segments of lesions (WSS) to predict myocardial infarction (MI) in patients with stable coronary artery disease (CAD) and hemodynamically significant lesions. The authors hypothesized that in patients with low FFR and stable CAD, higher WSS would predict MI.
Among 441 patients in the FAME II (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation II) trial with FFR ≤0.80 who were randomized to medical therapy alone, 34 (8%) had subsequent MI within 3 years. Patients with vessel-related MI and adequate angiograms for 3-dimensional reconstruction (n = 29) were propensity matched to a control group with no MI (n = 29) by using demographic and clinical variables. Coronary lesions were divided into proximal, middle, and distal, along with 5-mm upstream and downstream segments. WSS was calculated for each segment.
Median age was 62 years, and 46 (79%) were male. In the marginal Cox model, whereas lower FFR showed a trend (hazard ratio: 0.084; p = 0.064), higher WSS (hazard ratio: 1.234; p = 0.002, C-index = 0.65) predicted MI. Adding WSS to FFR resulted in a significant increase in global chi-square for predicting MI (p = 0.045), a net reclassification improvement of 0.69 (p = 0.005), and an integrated discrimination index of 0.11 (p = 0.010).
In patients with stable CAD and hemodynamically significant lesions, higher WSS in the proximal segments of atherosclerotic lesions is predictive of MI and has incremental prognostic value over FFR.
经药物治疗的低血流储备分数（FFR）的冠状动脉病变与更高的血运重建率相关。高壁切应力（WSS）与斑块易损性增加有关。
本研究旨在探讨病变近端节段测量的 WSS（WSS）对稳定型冠心病（CAD）和有血流动力学意义的病变患者发生心肌梗死（MI）的预测价值。作者假设在低 FFR 和稳定型 CAD 的患者中，较高的 WSS 将预测 MI。
在 FAME II 试验（血流储备分数与多血管评估 II 期血管造影）中，共有 441 例 FFR≤0.80 的患者被随机分为单纯药物治疗组，其中 3 年内有 34 例（8%）发生 MI。将与血管相关的 MI 患者和有足够的 3 维重建血管造影的患者（n=29），与无 MI 的对照组患者（n=29）进行倾向性匹配，匹配的变量包括人口统计学和临床变量。将冠状动脉病变分为近端、中段和远端，以及 5mm 的上游和下游节段。计算每个节段的 WSS。
中位年龄为 62 岁，46 例（79%）为男性。在边缘 Cox 模型中，虽然较低的 FFR 呈趋势（危险比：0.084；p=0.064），但较高的 WSS（危险比：1.234；p=0.002，C 指数=0.65）预测了 MI。将 WSS 添加到 FFR 中可显著增加预测 MI 的全局卡方值（p=0.045），净重新分类改善 0.69（p=0.005），综合鉴别指数提高 0.11（p=0.010）。
在稳定型 CAD 和有血流动力学意义的病变患者中，粥样硬化病变近端节段的较高 WSS 可预测 MI，且比 FFR 具有更高的预后价值。
