Myocardial infarction in the absence of obstructive coronary artery disease: diagnostic work-up in the hemodynamics laboratory

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a heterogeneous clinical condition affecting 5% to 8% of patients presenting with acute myocardial infarction. Initially it was considered a favorable clinical diagnosis, nowadays it is known that MINOCA can significantly affect patient quality of life and portends a guarded prognosis. Therefore, it is of utmost importance to identify the specific pathophysiological mechanism underlying this clinical condition in order to set up a targeted pharmacological and non-pharmacological therapy. Coronary angiography is still a mandatory diagnostic test to rule out obstructive coronary artery disease but has limited capability to identify other potential functional and structural etiologies of MINOCA. The purpose of this review is to provide an overview of the invasive diagnostic work-up of patients with MINOCA, highlighting the diagnostic tools warranted beyond coronary angiography inside the cath lab (intracoronary provocation tests, intracoronary imaging and indexes for the assessment of coronary microvascular dysfunction), and the remaining essential knowledge gaps in this field.