Mechanisms of myocardial infarction in women without angiographically obstructive coronary artery disease

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Women's Health

Background:

• A significant minority of myocardial infarction (MI) patients, especially women, lack obstructive coronary artery disease (CAD).
• Determining the underlying mechanisms of MI in this population is crucial for effective treatment.

Purpose of the Study:

• To investigate the mechanisms of MI in women with no angiographically obstructive CAD.
• To utilize intravascular ultrasound (IVUS) and cardiac magnetic resonance imaging (CMR) for mechanistic insights.

Main Methods:

• Prospective enrollment of women with MI before angiography, excluding those with significant stenosis or vasospastic agents.
• Performance of IVUS during angiography and CMR within one week.
• Analysis of coronary angiography, IVUS findings, and CMR for myocardial injury patterns.

Main Results:

• Thirty percent of women had normal coronary angiograms; median stenosis was 20%.
• Plaque disruption was identified in 38% of patients via IVUS.
• CMR revealed abnormal findings in 59%, including ischemic late gadolinium enhancement (LGE) in 17 patients and edema in 9.

Conclusions:

• Plaque rupture/ulceration are common in women with MI and non-obstructive CAD.
• Ischemic LGE patterns are prevalent, suggesting vasospasm or embolism as potential causes.
• IVUS and CMR offer complementary insights for identifying causes and guiding therapies in this patient group.