目的·基于心脏磁共振（cardiac magnetic resonance，CMR）评估急性ST段抬高型心肌梗死（ST-segment elevation myocardial infarction，STEMI）患者早期发生中重度继发性三尖瓣反流（secondary tricuspid regurgitation，STR）的相关危险因素。方法·回顾性分析2013年8月至2023年6月在上海交通大学医学院附属仁济医院接受经皮冠状动脉介入治疗（percutaneous coronary intervention，PCI）的STEMI患者729例，所有患者PCI术后2~7 d内完成CMR和经胸超声心动图（transthoracic echocardiography，TTE）检查。根据TTE结果将患者分为显著STR组（中度和重度）和非显著STR组（轻度或无），比较2组临床特征、CMR参数及主要不良心脑血管事件（major adverse cardiovascular and cerebrovascular events，MACCEs）发生率。采用单因素和多因素Logistic回归分析筛选显著STR的预测因素。结果·纳入的729例STEMI患者中，53例（7.3%）发生显著STR。与非显著STR组（n=676）相比，显著STR组年龄更大、男性比例更低，且发生高脂血症的比例更低（均P<0.05）。生存分析结果显示，显著STR组MACCEs累计发生率显著高于非显著STR组（log-rank P<0.001）。CMR特征对比分析显示，显著STR组存在更明显的左心室重构和心肌应变受损，表现为左心室收缩末期容积指数（left ventricular end-systolic volume index，LVESVi）升高，左心室射血分数（left ventricular ejection fraction，LVEF）降低，以及左心室整体径向应变（left ventricular global radial strain，LV-GRS）、左心室整体周向应变（left ventricular global circumferential strain，LV-GCS）绝对值、舒张早期峰值径向应变速率（radial peak early diastolic strain rate，rPEDSR）绝对值和舒张早期峰值周向应变速率（circumferential peak early diastolic strain rate，cPEDSR）降低（均P<0.05）。多因素Logistic回归分析显示，LVESVi（OR=1.030，95%CI 1.011~1.049，P=0.002）、LVEF（OR=0.963，95%CI 0.940~0.986，P=0.002）、LV-GRS（OR=0.953，95%CI 0.913~0.994，P=0.026）和LV-GCS（OR=1.091，95%CI 1.011~1.178，P=0.025）均为STEMI患者急性期发生显著STR的独立相关因素，且这些参数在识别显著STR中均表现出良好的判别效能（均AUC>0.83）。结论·急性STEMI患者早期显著STR与不良预后密切相关，左心室结构重构及功能障碍是其关键病理生理基础。基于CMR评估的参数可为显著STR的早期识别和风险分层提供重要依据。

Objective ·To evaluate the relevant risk factors and pathophysiological mechanisms of moderate-to-severe secondary tricuspid regurgitation (STR) in acute ST-segment elevation myocardial infarction (STEMI) patients using cardiac magnetic resonance (CMR) imaging. Methods ·A total of 729 STEMI patients who underwent percutaneous coronary intervention (PCI) at Renji Hospital, Shanghai Jiao Tong University School of Medicine, from August 2013 to June 2023 were analyzed. All patients underwent both CMR and transthoracic echocardiography (TTE) examinations within 2‒7 d post-PCI. Patients were stratified into two groups based on TTE findings: significant STR (moderate-to-severe) and non-significant STR (mild or absent). Clinical characteristics, CMR parameters, and the incidence of major adverse cardiovascular and cerebrovascular events (MACCEs) were compared between the groups. Univariate and multivariate Logistic regression analyses were performed to identify independent predictors of significant STR. Results ·Of the 729 enrolled STEMI patients, 53 (7.3%) developed significant STR. Compared to the non-significant STR group (n=676), patients with significant STR were older, had a lower proportion of males, and had a lower prevalence of hyperlipidemia (all P<0.05). Survival analysis revealed a significantly higher cumulative incidence of MACCEs in the significant STR group than in the non-significant STR group (log-rank P<0.001). CMR analysis revealed that the significant STR group exhibited more pronounced left ventricular remodeling and myocardial strain impairment, characterized by an increased left ventricular end-systolic volume index (LVESVi) and reduced left ventricular ejection fraction (LVEF). Additionally, this group showed significantly decreased left ventricular global radial strain (LV-GRS), the absolute value of left ventricular global circumferential strain (LV-GCS), the absolute value of radial peak early diastolic strain rate (rPEDSR), and circumferential peak early diastolic strain rate (cPEDSR) (all P<0.05). Multivariate Logistic regression analysis identified LVESVi (OR=1.030, 95%CI 1.011‒1.049, P=0.002), LVEF (OR=0.963, 95%CI 0.940‒0.986, P=0.002), LV-GRS (OR=0.953, 95%CI 0.913‒0.994, P=0.026), and LV-GCS (OR=1.091, 95%CI 1.011‒1.178, P=0.025) as independent factors associated with significant STR, all of which demonstrated good discriminative performance (all AUC>0.83). Conclusion ·STR occurring acutely in STEMI patients is significantly associated with adverse clinical outcomes. Left ventricular structural remodeling and dysfunction are the key pathophysiological basis for its development. CMR-derived parameters provide crucial evidence for early identification and risk stratification of significant STR.