The Systematic Evaluation of Identifying the Infarct Related Artery Utilizing Cardiac Magnetic Resonance in Patients Presenting with ST-Elevation Myocardial Infarction

Abstract

BackgroundIdentification of the infarct-related artery (IRA) in patients with STEMI using coronary angiography (CA) is often based on the ECG and can be challenging in patients with severe multi-vessel disease. The current study aimed to determine how often percutaneous intervention (PCI) is performed in a coronary artery different from the artery supplying the territory of acute infarction on cardiac magnetic resonance imaging (CMR).MethodsWe evaluated 113 patients from the Reduction of infarct Expansion and Ventricular remodeling with Erythropoetin After Large myocardial infarction (REVEAL) trial, who underwent CMR within 4±2 days of revascularization. Blinded reviewers interpreted CA to determine the IRA and CMR to determine the location of infarction on a 17-segment model. In patients with multiple infarcts on CMR, acuity was determined with T2-weighted imaging and/or evidence of microvascular obstruction.ResultsA total of 5 (4%) patients were found to have a mismatch between the IRA identified on CMR and CA. In 4/5 cases, there were multiple infarcts noted on CMR. Thirteen patients (11.5%) had multiple infarcts in separate territories on CMR with 4 patients (3.5%) having multiple acute infarcts and 9 patients (8%) having both acute and chronic infarcts.ConclusionsIn this select population of patients, the identification of the IRA by CA was incorrect in 4% of patients presenting with STEMI. Four patients with a mismatch had an acute infarction in more than one coronary artery territory on CMR. The role of CMR in patients presenting with STEMI with multi-vessel disease on CA deserves further investigation.

The Future of Cardiac Magnetic Resonance Clinical Trials

“…CMR provides assessment of necrosis (irreversible damage) and surrounding edema (salvage area, reversible damage) in AMI, in addition to scaling the severity of ischemic injury using novel quantitative tissue mapping techniques (8). CMR has high diagnostic and prognostic values in recent AMI clinical trials, (9) (10) and served as surrogate endpoints of various novel therapeutic interventions. Infarct size by CMR has demonstrated incremental prognostic performance in STEMI patients beyond left ventricular systolic function (11).…”