Identifying the Infarct-Related Artery in Patients With Non-ST-Segment-Elevation Myocardial Infarction

Area of Science:

• Cardiology
• Medical Imaging
• Diagnostic Techniques

Background:

• Identifying the infarct-related artery (IRA) in non-ST-segment-elevation myocardial infarction (MI) is clinically challenging.
• Delayed-enhancement cardiac magnetic resonance (DE-CMR) is effective in detecting small myocardial infarctions.
• Accurate IRA identification is crucial for guiding treatment strategies in MI patients.

Purpose of the Study:

• To evaluate the efficacy of DE-CMR in improving IRA identification in patients with non-ST-segment-elevation MI.
• To assess the diagnostic yield of DE-CMR compared to coronary angiography.
• To determine if DE-CMR can identify nonischemic causes of myocardial necrosis.

Main Methods:

• A prospective, 3-center study involving 114 patients with their first MI.
• Patients underwent DE-CMR followed by coronary angiography, with the interventional cardiologist blinded to DE-CMR results.
• Independent, blinded review of coronary angiography and DE-CMR images for IRA identification and assessment of myocardial necrosis pathogenesis.

Main Results:

• Coronary angiography failed to identify the IRA in 37% of patients.
• DE-CMR identified the IRA or a noncoronary artery disease diagnosis in 60% and 19% of these cases, respectively.
• DE-CMR led to a new IRA diagnosis in 31%, identified nonischemic pathogenesis in 15%, or both in 46% of patients. Revascularization of nonculprit arteries occurred in 27% of cases.

Conclusions:

• DE-CMR significantly enhances the ability to identify the IRA in non-ST-segment-elevation MI.
• The technique is valuable for diagnosing nonischemic myocardial injury, which can alter management decisions.
• Findings suggest DE-CMR plays a vital role in optimizing revascularization strategies by differentiating culprit and nonculprit lesions.