Department of Cardiology, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain.
Hospital Universitari Vall d'Hebron, Department of Cardiology, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
JACC Cardiovasc Imaging. 2018 Oct;11(10):1448-1457. doi: 10.1016/j.jcmg.2017.09.017. Epub 2017 Dec 13.
The aim of this study was to evaluate the prognostic value of strain as assessed by tissue tracking (TT) cardiac magnetic resonance (CMR) soon after ST-segment elevation myocardial infarction (STEMI).
The prognostic value of myocardial strain as assessed post-STEMI by TT-CMR is unknown.
The authors studied the prognostic value of TT-CMR in 323 patients who underwent CMR 1 week post-STEMI. Global (average of peak segmental values [%]) and segmental (number of altered segments) longitudinal (LS), circumferential, and radial strain were assessed using TT-CMR. Global and segmental strain cutoff values were derived from 32 control patients. CMR-derived left ventricular ejection fraction, microvascular obstruction, and infarct size were determined. Results were validated in an external cohort of 190 STEMI patients.
During a median follow-up of 1,085 days, 54 first major adverse cardiac events (MACE), which included 10 cardiac deaths, 25 readmissions for heart failure, and 19 readmissions for reinfarction were documented. MACE was associated with more severe abnormalities in all strain indexes (p < 0.001), although only global LS was an independent predictor (p < 0.001). The MACE rate was higher in patients with a global LS of ≥-11% (22% vs. 9%; p = 0.001). After adjustment for baseline and CMR variables, global LS (hazard ratio [HR]: 1.21; 95% confidence interval [CI]: 1.11 to 1.32; p < 0.001) was associated with MACE. In the external validation cohort, a global LS ≥-11% was seen in a higher proportion of patients with MACE (34% vs. 9%; p < 0.001). Global LS predicted MACE after adjustment for baseline and CMR variables (HR: 1.18; 95% CI: 1.04 to 1.33; p = 0.008). The addition of global LS to the multivariate models, including baseline and CMR variables, did not significantly improve the categorical net reclassification improvement index in either the study group (-0.015; p = 0.7) or in the external validation cohort (-0.019; p = 0.9).
TT-CMR provided prognostic information soon after STEMI. However, it did not substantially improve risk reclassification beyond traditional CMR indexes.
本研究旨在评估 ST 段抬高型心肌梗死（STEMI）后即刻通过组织追踪（TT）心脏磁共振（CMR）评估应变的预后价值。
STEMI 后通过 TT-CMR 评估心肌应变的预后价值尚不清楚。
作者研究了 323 例 STEMI 后 1 周行 CMR 检查的患者的 TT-CMR 预后价值。使用 TT-CMR 评估整体（节段峰值的平均值 [%]）和节段性（改变节段数）纵向（LS）、圆周和径向应变。从 32 例对照患者中得出整体和节段应变的截断值。确定 CMR 衍生的左心室射血分数、微血管阻塞和梗死面积。在 190 例 STEMI 患者的外部队列中验证结果。
中位随访 1085 天期间，记录了 54 例首次主要不良心脏事件（MACE），包括 10 例心脏死亡、25 例心力衰竭再入院和 19 例再梗死再入院。尽管只有整体 LS 是独立预测因子（p < 0.001），但所有应变指标的异常程度均与 MACE 相关（p < 0.001）。整体 LS 为≥-11%的患者中 MACE 发生率更高（22% vs. 9%；p = 0.001）。在校正基线和 CMR 变量后，整体 LS（危险比 [HR]：1.21；95%置信区间 [CI]：1.11 至 1.32；p < 0.001）与 MACE 相关。在外部验证队列中，MACE 患者中观察到更大比例的整体 LS ≥-11%（34% vs. 9%；p < 0.001）。在校正基线和 CMR 变量后，整体 LS 预测 MACE（HR：1.18；95%CI：1.04 至 1.33；p = 0.008）。在包括基线和 CMR 变量的多变量模型中，整体 LS 的加入并没有显著提高研究组（-0.015；p = 0.7）或外部验证队列（-0.019；p = 0.9）的分类净重新分类改善指数。
TT-CMR 在 STEMI 后即刻提供预后信息。然而，与传统 CMR 指标相比，它并未显著提高风险再分类。
