Supplementary Material for: Predictive Value of Four-Dimensional Strain Echocardiography for Adverse Cardiovascular Outcomes in ST-Elevation Myocardial Infarction Patients Treated with Primary Percutaneous Coronary Intervention

Objectives: To investigate the predictive value of four-dimensional (4D) strain echocardiography for major adverse cardiovascular events (MACE) in ST-elevation acute myocardial infarction (STEMI) patients. Methods: Consecutive STEMI patients who underwent successful primary coronary interven tion (PCI) were enrolled and followed, with 2D and 4D strain echocardiography performed within 1 week after PCI. Results: Twenty-six first MACE were recorded in 81 patients who finished a ∼3.0 year follow-up. Compared with those without MACE, subjects with MACE were more likely to have anterior MI (73.08 vs. 38.18%, p = 0.003), significantly decreased 2D left ventricular ejection fraction (2DLVEF) and 4DLVEF (all p < 0.05), as well as an overtly compromised 4D strain parameters. The prediction models incorporating infarct location with either 2DLVEF or 4D strain parameters were then developed. Model comparisons revealed that the global area strain (GAS)-based model had the highest discriminative capacity (c statistics = 0.774) and was well calibrated for MACE. Additionally, the clinical utility of the GAS-based prediction model was verified by decision curve analysis showing a consistent positive and larger net benefit compared to the 2DLVEF-based model. Conclusions: Our data support a superiority of 4D strain echocardiography over conventional 2D echocardiography, especially GAS, for risk stratification in STEMI patients after successful primary PCI.研究目的：探讨四维应变超声心动图（four-dimensional strain echocardiography）对ST段抬高型急性心肌梗死（ST-elevation acute myocardial infarction, STEMI）患者发生主要不良心血管事件（major adverse cardiovascular events, MACE）的预测价值。 研究方法：纳入成功接受经皮冠状动脉介入治疗（percutaneous coronary intervention, PCI）的连续性STEMI患者并进行随访，于PCI术后1周内完成二维及四维应变超声心动图检查。 研究结果：共81例患者完成了约3.0年的随访，其中26例首次发生MACE。与未发生MACE的患者相比，发生MACE的患者更易出现前壁心肌梗死（73.08% vs 38.18%，p=0.003），二维左心室射血分数（2DLVEF）与四维左心室射血分数（4DLVEF）均显著降低（均p<0.05），同时四维应变参数存在明显受损。随后构建了联合梗死部位与2DLVEF或四维应变参数的预测模型。模型对比显示，基于整体面积应变（global area strain, GAS）的模型鉴别能力最高（c统计量=0.774），且对MACE的预测校准良好。此外，决策曲线分析验证了基于GAS的预测模型的临床实用性，其相较于基于2DLVEF的模型，始终呈现出更优的正向净获益。 研究结论：本研究数据支持在成功接受PCI的STEMI患者术后危险分层中，四维应变超声心动图（尤其是整体面积应变）优于传统二维超声心动图。