Coronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in Women

Abstract

Background: Myocardial infarction with non-obstructive coronary arteries (MINOCA) occurs in 6-15% of MI and disproportionately affects women. Scientific statements recommend multi-modality imaging in MINOCA to define the underlying cause. We performed coronary optical coherence tomography (OCT) and cardiac magnetic resonance imaging (CMR) to assess mechanisms of MINOCA. Methods: In this prospective, multicenter, international, observational study, we enrolled women with a clinical diagnosis of MI. If invasive coronary angiography revealed <50% stenosis in all major arteries, multi-vessel OCT was performed, followed by CMR (cine imaging, late gadolinium enhancement, and T2-weighted imaging and/or T1 mapping). Angiography, OCT, and CMR were evaluated at blinded, independent core laboratories. Culprit lesions identified by OCT were classified as definite or possible. The CMR core laboratory identified ischemia-related and non-ischemic myocardial injury. Imaging results were combined to determine the mechanism of MINOCA, when possible. Results: Among 301 women enrolled at 16 sites, 170 were diagnosed with MINOCA, of whom 145 had adequate OCT image quality for analysis; 116 of these underwent CMR. A definite or possible culprit lesion was identified by OCT in 46.2% (67/145) of participants, most commonly plaque rupture, intra-plaque cavity or layered plaque. CMR was abnormal in 74.1% (86/116) of participants. An ischemic pattern of CMR abnormalities (infarction or myocardial edema in a coronary territory) was present in 53.4% of participants undergoing CMR (62/116). A non-ischemic pattern of CMR abnormalities (myocarditis, takotsubo syndrome or non-ischemic cardiomyopathy) was present in 20.7% (24/116). A cause of MINOCA was identified in 84.5% of the women with multi-modality imaging (98/116), higher than with OCT alone (p<0.001) or CMR alone (p=0.001). An ischemic etiology was identified in 63.8% of women with MINOCA (74/116), a non-ischemic etiology was identified in 20.7% (24/116), and no mechanism was identified in 15.5% (18/116). Conclusions: Multi-modality imaging with coronary OCT and CMR identified potential mechanisms in 84.5% of women with a diagnosis of MINOCA, three-quarters of which were ischemic and one-quarter of which were non-ischemic, alternate diagnoses to MI. Identification of the etiology of MINOCA is feasible and has the potential to guide medical therapy for secondary prevention. Clinical Trial Registration: URL: https://clinicaltrials.gov Unique Identifier: NCT02905357

What an Interventionalist Needs to Know About MI with Non-obstructive Coronary Arteries

“…[ 16 , 17 ] Reynolds et al visualised plaque rupture, intraplaque cavity or layered plaque using OCT in 46% of women enrolled in a recent study (STEMI at presentation in 3.5%) and OCT combined with CMR identified the underlying MINOCA diagnosis in 85% of included patients (64% ischaemic aetiology). [ 18 ] However, while providing insights into MINOCA patients with atherosclerosis, a limitation of that study was that enrolment was limited to 14% (170/1,173) of eligible patients, and so the results may not be representative of all patients with MINOCA.…”

The year in cardiovascular medicine 2020: interventional cardiology

“… 27 Finally, a recent study on women ( n = 301) presenting with MI and angiographically non-obstructed coronary arteries demonstrated the value of optical coherence tomography (OCT) and cardiac magnetic resonance imaging (CMR) to identify a potential mechanism for the acute event in 84.5% of patients (63.8% had a ischaemic- and 20.7% a non-ischaemic aetiology). 28 …”

Optical coherence tomography’s current clinical medical and dental applications: a review

“…In a recent study, it has been reported that OCT-based fractional flow reserve learning can be used for enhanced treatment of intermediate coronary artery stenosis. 19 This technique can also be used for coronary imaging, 20 guiding percutaneous coronary intervention, 21 diagnosing myocardial infarction with non-obstructive coronary arteries, 22 and observing healed coronary plaques. 23 Otology OCT can be used to accurately diagnose otology conditions such as otitis media and conductive hearing loss.…”