Coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) imaging in the assessment of patients presenting with chest pain suspected for acute coronary syndrome

Acute chest pain is an important clinical challenge and a major reason for presentation to the emergency department. Although multiple imaging techniques are available to assess patients with suspected acute coronary syndrome (ACS), considerable interest has been focused on the use of non-invasive imaging options as coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR). According to several recent evidences, CCTA has been shown to represent a useful tool to rapidly and accurately diagnose coronary artery disease (CAD) in patients with low to intermediate cardiovascular risk. CCTA examination has the unique ability to non-invasively depict the coronary anatomy, not only allowing visualization of the lumen of the arteries in order to detect severe stenosis or occlusion responsible of myocardial ischemia, but also allows the assessment of coronary artery wall by demonstrating the presence or absence of CAD. However, routine CCTA is not able to differentiate ischemic from non-ischemic chest pain in patients with known CAD and it does not provide any functional assessment of the heart. Conversely, CMR is considered the gold standard in the evaluation of morphology, function, viability and tissue characterization of the heart. CMR offers a wide range of tools for diagnosing myocardial infarction (MI) at least at the same time of the elevation of cardiac troponin values, differentiating infarct tissue and ischemic myocardium from normal myocardium or mimicking conditions, and distinguishing between new and old ischemic events. In high-risk patients, with acute and chronic manifestations of CAD, CMR may be preferable to CCTA, since it would allow detection, differential diagnosis, prognostic evaluation and management of MI.