Objectives This study sought to investigate whether early post-infarction cardiac magnetic resonance (CMR) parameters provide additional long-term prognostic value beyond traditional outcome predictors in ST-segment elevation myocardial infarction (STEMI) patients.

Background Long-term prognostic significance of CMR in STEMI patients has not been assessed yet.

Methods This was a longitudinal study from a multicenter registry that prospectively included STEMI patients undergoing CMR after infarction. Between May 2003 and August 2015, 810 revascularized STEMI patients were included. CMR was performed at a median of 4 days after STEMI. Infarct size, microvascular obstruction (MVO), and left ventricular (LV) volumes and function were measured. Primary endpoint was a composite of all death and decompensated heart failure (HF).

Results During median follow-up of 5.5 years (range 1.0 to 13.1 years), primary endpoint occurred in 99 patients (39 deaths and 60 HF hospitalization). MVO was a strong predictor of the composite endpoint after correction for important clinical, CMR, and angiographic parameters, including age, LV systolic function, and infarct size. The independent prognostic value of MVO was confirmed in all multivariate models irrespective of whether it was included as a dichotomous (presence of MVO, hazard ratio [HR]: 1.985 to 1.995), continuous (MVO extent as % LV, HR: 1.095 to 1.097), or optimal cutoff value (MVO extent ≥2.6% of LV; HR: 3.185 to 3.199; p < 0.05 for all). MVO extent ≥2.6% of LV was a strong independent predictor of all death (HR: 2.055; 95% confidence interval: 1.076 to 3.925; p = 0.029) and HF hospitalization (HR: 5.999; 95% confidence interval: 3.251 to 11.069; p < 0.001). Finally, MVO extent ≥2.6% of LV provided incremental prognostic value over traditional outcome predictors (net reclassification improvement index: 0.16 to 0.30; p < 0.05 for all models).

Conclusions Early post-infarction CMR-based MVO is a strong independent prognosticator in revascularized STEMI patients. Remarkably, MVO extent ≥2.6% of LV improved long-term risk stratification over traditional outcome predictors.

目的本研究旨在探讨ST段抬高型心肌梗死（STEMI）患者早期梗死后心脏磁共振（CMR）参数是否能提供超出传统预后指标的其他长期预后价值。

背景技术尚未评估CEMI在STEMI患者中的长期预后意义。

方法这是一项来自多中心注册表的纵向研究，前瞻性纳入了梗死后接受CMR的STEMI患者。在2003年5月至2015年8月之间，纳入810例血运重建的STEMI患者。在STEMI后的中位数4天进行CMR。测量梗死面积，微血管阻塞（MVO）和左心室（LV）的体积和功能。主要终点指标是所有死亡和失代偿性心力衰竭（HF）的综合结果。

结果在5.5年的中位随访期间（1.0至13.1年），主要终点发生在99例患者中（39例死亡和60例HF住院）。在校正了重要的临床，CMR和血管造影参数（包括年龄，LV收缩功能和梗死面积）后，MVO是复合终点的有力预测指标。在所有多变量模型中均确认了MVO的独立预后价值，无论其是否被分为二分（MVO存在，危险比[HR]：1.985至1.995），连续（MVO程度为LV％，HR：1.095至1.097） ）或最佳截止值（MVO范围≥LV的2.6％； HR：3.185至3.199；所有p <0.05）。MVO≥2.6％LV是所有死亡（HR：2.055; 95％置信区间：1.076至3.925; p = 0.029）和HF住院（HR：5.999; 95％置信区间：3.251至11.069；p <0.001）。最后，MVO≥LV的2.6％提供了比传统结果预测指标更高的预后价值（净重分类改善指数：0.16至0.30；对于所有模型，p <0.05）。

结论早期基于CMR的MVO是血运重建STEMI患者的强独立预后指标。值得注意的是，MVO≥LV的2.6％改善了长期风险分层，优于传统的预后指标。