Intravascular imaging with coronary optical coherence tomography (OCT) and magnetic resonance imaging allow for the identification of the cause of heart attack in 85% of women without coronary obstructions in angiography.
Myocardial infarction with non-obstructive coronary arteries (MINOCA) affects women disproportionately and we have considered these events as “false positives” for far too long.
The HARP Study included 301 women, 170 of whom presented angina-like symptoms and troponin elevation without coronary obstruction (all below 50%). These 170 women were diagnosed with MINOCA.
Nuclear magnetic resonance imaging plus OCT allowed researchers to find the infarction mechanism in most of them.
OCT identified definitely or at least possibly culprit lesions with 6% plate rupture, 3% non-ruptured thrombus, 21% intra-plaque cavity, 13% dissected plaque, 2% intimal thickening/spasm, and 1% spontaneous dissection.
Magnetic resonance imaging showed ischemic patterns in most with myocardial edema in the culprit artery. A non-ischemic pattern was observed in 20.7% of patients, thus suggesting myocarditis, Tako Tsubo syndrome, or non-ischemic cardiomyopathy.
When the OCT and magnetic resonance findings are combined, it is possible to identify the cause of MINOCA in 84.5% of the cases.
Authors believe that intravascular ultrasound (IVUS) and tomography could play a role when magnetic resonance and OCT are not available.
The 2020 European guidelines for infarction without ST-segment elevation provide a class IB recommendation for resonance imaging use in MINOCA. Resonance imaging was also recommended in the 2019 American guidelines.
None of these documents formally recommend OCT. They only suggest intravascular imaging could be useful if plaque rupture, plaque erosion, coronary dissection, etc., are suspected.
Original title: Coronary optical coherence tomography and cardiac magnetic resonance imaging to determine underlying causes of MINOCA in women.
Reference: Reynolds HR et al. Presentado en el congreso AHA 2020 y publicado simultáneamente en Circulation. 2020 Nov 14. doi:10.1161/CIRCULATIONAHA.120.052008.