Cardiovascular Magnetic Resonance for the Occluded Infarct-Related Artery Treatment (COAT)

Late Percutaneous Coronary Intervention of the Occluded Infarct-Related Artery in Patients With Preserved Infarct Zone Viability Determined With Magnetic Resonance Imaging

The purpose of this study is to determine whether opening an occluded infarcted artery 3-28 days after an acute myocardial infarction in high-risk asymptomatic patients with preserved infarct zone viability improves left ventricular systolic function and volumes at 6 months follow-up. The secondary purpose is to assess the changes in myocardial tissue characteristics after late percutaneous coronary intervention (PCI).

Rapid restoration of blood flow in the infarct-related artery (IRA), one of the cornerstones of contemporary treatment of acute myocardial infarction (MI) prevents myocardial necrosis and its consequences. However, due to late presentation or failed fibrinolytic therapy up to one third of patients have persistently occluded IRA after MI. Recently, the Occluded Artery Trial (OAT) has demonstrated that percutaneous coronary intervention (PCI) with optimal medical therapy does not reduce the frequency of major adverse events compared to optimal medical therapy alone when performed on days 3-28 post MI in stable patients. Assessment of infarct zone viability was not used as an inclusion/exclusion criterion in the main OAT trial. Several studies confirm that patients with left ventricular systolic dysfunction and preserved myocardial viability (necrosis transmurality<50% in most segments of the infarct zone) assessed with magnetic resonance imaging benefit from revascularization. Late opening of the occluded infarct-related artery only in patients with preserved myocardial tissue viability may lead to improvement of left ventricular volumes and function.

Acute Coronary Syndrome, Myocardial infarction, Infarct Related Artery, Percutaneous Coronary Intervention, Medical treatment, Tissue Viability, Magnetic Resonance

Conventional medical management, including aspirin, clopidogrel, statins, beta blockers, angiotensin converting enzyme (ACE) inhibitors and/or angiotensin receptor blocker (ARB) and/or aldosterone antagonist and risk factor modification

Conventional medical management, including aspirin, clopidogrel, statins, beta blockers, angiotensin converting enzyme (ACE) inhibitors and/or angiotensin receptor blocker (ARB) and/or aldosterone antagonist and risk factor modification plus percutaneous coronary intervention and coronary stenting

Inclusion Criteria: Enrollment 3-28 days after an acute myocardial infarction. Infarct related artery occlusion (TIMI 0 or 1). High risk: left ventricular ejection fraction (LVEF)<50% or LVEF>50% and proximal coronary occlusion. Preserved infarct zone viability (necrosis transmurality <50% in at least 4 segments out of 17 according to AHA classification). Exclusion Criteria: Unstable clinical condition

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