The no reflow phenomenon (NR) is the inability of blood to reperfuse an ischemic area despite a successful revascularization, mostly due to microvascular obstruction (MVO) [1].

Coronary angiography is the most used technique in NR evaluation: it is fast and can be assessed at the end of the PCI procedure. The presence of MVO is established based on angiographic scores. The two mainly used scores are the TIMI flow grade and Myocardial Blush Grade (MBG): NR is present when TIMI is <3 and/or MBG is <2 (see fig 1 and 2) [2,3].

On the other hand Cardiac Magnetic Resonance (CMR) is starting to be considered the best technique, validated by pathological studies, in the identification of MVO.

It is also considered the gold standard examination for the evaluation of myocardial infarction, providing information about volumes and function, myocardial viability and infarct size. 

Otherwise CMR is an additional and expensive examination and its role in AMI patients management has to be validated.

In this prospective study we compare coronary angiography and CMR in the evaluation of NR in AMI.