In this study, we investigate the role of Cardiac Magnetic Resonance Imaging in patients with suspected, but not yet proven "acute cardiac syndrome ACS". Patients are included, if they presented to the local Emergency Department with chest pain, but the first tests in the Emergency Department are negative or not clearly indicative of cardiac ischemia. For example, the first lab value Troponin T is negative or borderline elevated; or the first ECG is not clearly indicative of ischemia. The standard procedure for these patients is to wait 4-6 hours and then repeat the test; if they continue to be negative, the patients are discharged home, if the have become positive, an invasive coronary artery angiography has to be performed. We think, that a CMR study can shorten the time needed to make the decision of either "discharge" or "admit to CCU and perform a coronary artery angiography". CMR has been shown to be the gold standard for heart function (thus, can see even subtle wall motion abnormalities), for tissue characterization (so-called T2-weighted images can identify tissue edema (swelling); perfusion images can identify areas with reduced blood supply; late enhancement images can safely identify fibrotic or irreversibly damaged tissue) and can even be used to stress the patients to exclude a critical or non-critical narrowing of coronary arteries.

The primary endpoint of this study will be the impact of CMR on the time-to-decision in these patients.

It should be possible to a) identify all patients WITH an acute infarct by CMR and send them to a cath lab sooner compared to waiting for a second test; b) identify all patients WITHOUT an acute infarct and c) perform a stress test in those patients to exclude severe coronary artery disease.