Pilot study of prevalence of coronary microvascular dysfunction in myocardial infarction with non-obstructive coronary arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is common with a prevalence of 6-8 % of all myocardial infarctions.

Recent guidelines have emphasized the role of cardiac magnetic resonance (CMR) imaging in the investigation of the cause of MINOCA.

We have recently pefomed and published a prospective study showing that the diagnostic yield is improved by early investigation with the latest CMR technique. However, despite firm criteria for inclusion/exclusion 23 % of the 148 patients had a normal CMR investigation.

One possible cause for the MINOCA with normal CMR imaging is coronary microvascular dysfunction (CMD) that can be investigated by CMR with adenosine.

The main purpose of the planned investigations is to study the feasibility to perform CMR imaging with adenosine in patients with MINOCA with the aims to: 1. Study the prevalence of CMD in an unselected cohort of patients with MINOCA and 2.

Obtain information about the incremental diagnostic value of CMD to other CMR imaging diagnoses for a larger national multi-center study of MINOCA. 80 patients with MINOCA will be studied and the incremental diagnostic value of adding adenosine to CMR imaging will be evaluated.

The results will be used for a power calculation in the planning of a national multi-center study (klinisk behandlingsforskning).

The results of the final study are highly relevant for future MINOCA patients since they are often discharged from hospital without a definite diagnosis.