2021/01 - Left ventricular functional recovery of infarcted and remote myocardium after ST-segment elevation myocardial infarction (METOCARD-CNIC randomized clinical trial substudy) [ Journal Club ]-Video

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Video Summary

The JCMR Journal Club opened with an introduction to its monthly format, CME access, and the plan for recording and sharing the session. Dr. Raymond Kwong then presented a study on left ventricular recovery after STEMI using feature-tracking cardiac MRI, emphasizing MRI’s value in evaluating remodeling, infarct characteristics, and therapeutic effects in acute myocardial infarction.<br /><br />Dr. Tomas Palashnika presented findings from a substudy of the randomized METOCARD-CNIC trial, which enrolled 222 patients with first anterior STEMI treated with primary PCI and randomized to early intravenous metoprolol or standard care. CMR was performed at one week and six months. The study assessed LV volumes, ejection fraction, infarct size, microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and regional circumferential strain in infarcted versus remote myocardium.<br /><br />Key results: infarct-zone strain improved significantly over six months, while remote-zone strain remained stable overall. Early IV metoprolol had a lasting beneficial effect on infarct-zone strain, but not on remote myocardium. Patients with MVO or IMH had worse infarct-zone strain, though it still improved over time. In patients who developed adverse LV remodeling, infarct-zone strain improved, but remote-zone strain worsened.<br /><br />During discussion, questions addressed methodologic choices, such as excluding basal/apical slices, the decision to focus on circumferential rather than longitudinal strain, and the definition of infarct versus remote zones. The panel also discussed possible mechanisms of metoprolol’s benefit, the role of other strain techniques, and clinical implications. The session concluded that feature-tracking CMR offers a powerful way to evaluate myocardial recovery and cardioprotective therapy.

Keywords

JCMR Journal Club

feature-tracking cardiac MRI

STEMI

left ventricular recovery

METOCARD-CNIC trial

primary PCI

metoprolol

myocardial strain

microvascular obstruction

adverse LV remodeling