OBJECTIVES The aim of this study was to assess the diagnostic yield of cardiac magnetic resonance (CMR) including high-resolution (HR) late gadolinium enhancement (LGE) imaging using a 3-dimensional respiratory-navigated method in patients with myocardial infarction with nonobstructed coronary arteries (MINOCA). BACKGROUND CMR plays a pivotal role for the diagnosis of patients with MINOCA. However, the diagnosis remains inconclusive in a significant number of patients, the results of CMR being either negative or uncertain (i.e., compatible with multiple diagnoses). METHODS Consecutive patients categorized as having MINOCA after blood testing, electrocardiography, coronary angiography, and echocardiography underwent conventional CMR, including cine, T2-weighted, first-pass perfusion, and conventional breath-held LGE imaging. HR LGE imaging using a free-breathing method allowing improved spatial resolution (voxel size 1.25 × 1.25 × 2.5 mm) was added to the protocol when the results of conventional CMR were inconclusive and was optional otherwise. Diagnoses retained after reviewing conventional CMR were compared with those retained after the addition of HR LGE imaging. RESULTS From 2013 to 2016, 229 patients were included (mean age 56 ± 17 years, 45% women). HR LGE imaging was performed in 172 patients (75%). In this subpopulation, definite diagnoses were retained after conventional CMR in 86 patients (50%): infarction in 39 (23%), myocarditis in 32 (19%), takotsubo cardiomyopathy in 13 (8%), and other diagnoses in 2 (1%). In the remaining 86 patients (50%), results of CMR were inconclusive: negative in 54 (31%) and consistent with multiple diagnoses in 32 (19%). HR LGE imaging led to changes in final diagnosis in 45 patients (26%) and to a lower rate of inconclusive final diagnosis (29%) (p < 0.001). In particular, HR LGE imaging could reveal or ascertain the diagnosis of infarction in 14% and rule out the diagnosis of infarction in 12%. HR LGE imaging was particularly useful when the results of transthoracic echocardiography, ventriculography, and conventional CMR were negative, with a 48% rate of modified diagnosis in this subpopulation. CONCLUSIONS HR LGE imaging has high diagnostic value in patients with MINOCA and inconclusive findings on conventional CMR. This has major diagnostic, prognostic, and therapeutic implications.

中文翻译：

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高分辨率晚期Ga增强磁共振对无阻塞性冠状动脉心肌梗死的诊断。

目的本研究旨在评估三维梗阻性心肌梗死患者的心脏磁共振（CMR）的诊断率，包括高分辨率（HR）晚期late增强（LGE）成像（使用3维呼吸导航方法）动脉（MINOCA）。背景技术CMR对于MINOCA患者的诊断起着举足轻重的作用。但是，在许多患者中诊断仍无定论，CMR的结果为阴性或不确定（即与多种诊断兼容）。方法连续患者经血液检查，心电图，冠状动脉造影和超声心动图检查后分类为MINOCA，接受常规CMR检查，包括电影，T2加权，首过灌注和常规屏气LGE显像。当常规CMR的结果尚无定论时，使用自由呼吸方法进行HR LGE成像可提高空间分辨率（体素尺寸1.25×1.25×2.5 mm），这是不可行的，否则是可选的。将检查常规CMR后保留的诊断与添加HR LGE成像后保留的诊断进行比较。结果2013年至2016年，共纳入229例患者（平均年龄56±17岁，女性占45％）。HR LGE成像在172例患者中进行（75％）。在该亚人群中，常规CMR后86例（50％）得以明确诊断：梗死39例（23％），心肌炎32例（19％），takotsubo心肌病13例（8％）和其他2例诊断（ 1％）。在其余的86例患者中（50％），CMR的结果尚无定论：54例（31％）为阴性，与32例（19％）的多次诊断一致。HR LGE成像可导致45例患者的最终诊断发生变化（26％），不确定的最终诊断率较低（29％）（p <0.001）。特别是，HR LGE成像可以发现或确定梗死的诊断率为14％，而排除梗死的诊断为12％。当经胸超声心动图，心室描记法和常规CMR结果均为阴性时，HR LGE成像特别有用，该亚群中有48％的改良诊断率。结论HR LGE成像对MINOCA患者具有较高的诊断价值，对常规CMR尚无定论。这具有重大的诊断，预后和治疗意义。HR LGE成像可以发现或确定梗死的诊断率为14％，而排除梗死的诊断为12％。当经胸超声心动图，心室描记法和常规CMR结果均为阴性时，HR LGE成像特别有用，该亚群中有48％的改良诊断率。结论HR LGE成像对MINOCA患者具有较高的诊断价值，对常规CMR尚无定论。这具有重大的诊断，预后和治疗意义。HR LGE成像可以发现或确定梗死的诊断率为14％，而排除梗死的诊断为12％。当经胸超声心动图，心室描记法和常规CMR结果均为阴性时，HR LGE成像特别有用，该亚群中有48％的改良诊断率。结论HR LGE成像对MINOCA患者具有较高的诊断价值，对常规CMR尚无定论。这具有重大的诊断，预后和治疗意义。结论HR LGE成像对MINOCA患者具有较高的诊断价值，对常规CMR尚无定论。这具有重大的诊断，预后和治疗意义。结论HR LGE成像对MINOCA患者具有很高的诊断价值，对常规CMR尚无定论。这具有重大的诊断，预后和治疗意义。