Objectives This study sought to evaluate the role of cardiac magnetic resonance (CMR) for the quantification of ischemic mitral regurgitation (IMR) and myocardial infarct size (MIS) in patients with ischemic cardiomyopathy (ICM). This study also sought to explore the interaction between IMR severity and MIS and its association with outcomes in patients with ICM. Background IMR occurs secondary to a disease of the left ventricle and is associated with poor outcomes. The role of CMR for the evaluation and risk stratification of patients with ICM and IMR remains uncertain. Methods Consecutive patients with ICM who underwent baseline CMR were included. MIS was quantified on late gadolinium enhancement imaging as the proportion of left ventricular mass. IMR was quantified with CMR by calculating the mitral regurgitant fraction (MRFraction). Cox proportional hazards models were built to assess the association of IMR and MIS quantification with the combined endpoint of all-cause death or heart transplant. Results We evaluated 578 patients (mean age: 62 ± 11 years, 76% males). The mean left ventricular ejection fraction was 25 ± 11%, with an MIS of 24 ± 16% and MRFraction of 18 ± 17%. Over a median follow-up time of 4.9 years, 198 (34%) patients experienced death or cardiac transplant. On multivariable analysis, after comprehensive medical risk score, subsequent revascularization, implantable cardioverter-defibrillator insertion, and surgical mitral valve intervention were controlled for, the interaction of IMR severity and MIS emerged as a powerful predictor of adverse outcomes (p = 0.008). For patients with significant IMR (MRFraction: ≥35%), the hazard ratio comparing moderate MIS (15% to 29%) versus small MIS (<15%) was 1.51 (0.57 to 3.98), and the hazard ratio comparing large MIS (≥30%) versus small MIS was 5.41 (2.34 to 12.7). Conclusions Risk associated with IMR is more comprehensively described as an interaction between IMR severity and MIS. Further studies in patients IMR using comprehensive CMR evaluation are needed to verify whether this approach can improve patient selection and procedural outcomes to address IMR.

中文翻译：

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缺血性二尖瓣关闭不全严重程度和心肌梗塞量化对心血管磁共振的预后影响。

目的 本研究旨在评估心脏磁共振 (CMR) 在量化缺血性心肌病 (ICM) 患者的缺血性二尖瓣关闭不全 (IMR) 和心肌梗死面积 (MIS) 方面的作用。本研究还试图探讨 IMR 严重程度与 MIS 之间的相互作用及其与 ICM 患者预后的关联。背景 IMR 继发于左心室疾病，与不良结局相关。CMR 在 ICM 和 IMR 患者评估和风险分层中的作用仍不确定。方法 包括接受基线 CMR 的连续 ICM 患者。MIS 在晚期钆增强成像中被量化为左心室质量的比例。通过计算二尖瓣反流分数 (MRFraction)，用 CMR 量化 IMR。建立 Cox 比例风险模型以评估 IMR 和 MIS 量化与全因死亡或心脏移植的联合终点之间的关联。结果 我们评估了 578 名患者（平均年龄：62 ± 11 岁，76% 为男性）。平均左心室射血分数为 25 ± 11%，MIS 为 24 ± 16%，MRFraction 为 18 ± 17%。在 4.9 年的中位随访时间中，198 名 (34%) 患者经历了死亡或心脏移植。在多变量分析中，在综合医疗风险评分、随后的血运重建、植入式心律转复除颤器插入和手术二尖瓣干预得到控制后，IMR 严重程度和 MIS 的相互作用成为不良结果的有力预测因素（p = 0.008）。对于具有显着 IMR（MRFraction：≥35%）的患者，比较中度 MIS（15% 至 29%）与小型 MIS（<15%）的风险比为 1.51（0.57 至 3.98），比较大型 MIS（≥30%）与小型 MIS 的风险比为 5.41（2.34 至 12.7） ）。结论 与 IMR 相关的风险被更全面地描述为 IMR 严重程度和 MIS 之间的相互作用。需要使用综合 CMR 评估对患者 IMR 进行进一步研究，以验证这种方法是否可以改善患者选择和程序结果以解决 IMR。