Log in to MyACC
High-Resolution LGE CMR for Diagnosis of MINOCA
Quick Takes
- Addition of HR LGE imaging using a free-breathing method in patients with MINOCA improves the detection and assessment of the transmural distribution of myocardial injuries.
- HR LGE imaging was particularly useful when the results of echocardiography, ventriculography, and conventional CMR were negative, with a 48% rate of modified diagnosis in this subpopulation.
- The management of patients with MINOCA and uncertain diagnosis is a major dilemma in clinical cardiology and the current study supports the systematic integration of free-breathing LGE in patients undergoing CMR in the context of MINOCA. Studies with larger cohorts are the next step to confirm these findings.
Study Questions:
What is the diagnostic yield of cardiac magnetic resonance (CMR) including high-resolution (HR) late gadolinium enhancement (LGE) imaging using a three-dimensional respiratory-navigated method in patients with myocardial infarction with nonobstructed coronary arteries (MINOCA)?
Methods:
The investigators prospectively recruited consecutive patients referred to the University Hospital of Bordeaux for the management of MINOCA. 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. Independent continuous variables were compared using independent-sample parametric (unpaired Student’s t-test or analysis of variance) or nonparametric (Mann-Whitney U test or Kruskal-Wallis test) tests depending on data normality. Independent categorical variables were compared using the chi-square test when expected frequencies were ≥5 and the Fisher exact test when they were <5.
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:
The authors concluded that HR LGE imaging has high diagnostic value in patients with MINOCA and inconclusive findings on conventional CMR.
Perspective:
This study reports that the addition of HR LGE imaging using a free-breathing method in patients with MINOCA improves the detection and assessment of the transmural distribution of myocardial injuries. This translates into changes in final diagnosis in about half of the patients with inconclusive findings after conventional CMR methods. Furthermore, HR LGE imaging can ascertain or rule out the diagnosis of MI in a significant number of patients. The management of patients with MINOCA and uncertain diagnosis is a major dilemma in clinical cardiology and the current study supports the systematic integration of free-breathing LGE in patients undergoing CMR in the context of MINOCA. Additional research is needed to develop LGE CMR methods with higher spatial resolution and acceptable acquisition times as standard of care for patients with MINOCA.
Clinical Topics: Acute Coronary Syndromes, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Prevention, Interventions and ACS, Interventions and Imaging, Angiography, Echocardiography/Ultrasound, Nuclear Imaging
Keywords: Acute Coronary Syndrome, Contrast Media, Coronary Angiography, Diagnostic Imaging, Echocardiography, Electrocardiography, Gadolinium, Magnetic Resonance Spectroscopy, Myocardial Infarction, Myocarditis, Secondary Prevention, Takotsubo Cardiomyopathy
< Back to Listings
