The prevalence of myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) is estimated at 5% to 6% among patients with acute myocardial infarction (AMI) undergoing angiography. This statement provides a formal and updated definition for the broadly labelled term MINOCA (incorporating the definition of acute myocardial infarction from the newly released “Fourth Universal Definition of Myocardial Infarction”) and provides a clinically useful framework and algorithms for the diagnostic evaluation and management of patients with myocardial infarction in the absence of obstructive coronary artery disease.
The Scientific Statement recommends cardiac magnetic resonance imaging, if available, because it can confirm AMI and exclude other diagnoses like myocarditis, takotsubo syndrome, and cardiomyopathies. The Statement discusses both atherosclerotic causes (that is, plaque disruption, which can include plaque rupture or erosion or calcific nodules) and nonatherosclerotic causes (i.e., coronary embolism/thrombosis, coronary microvascular dysfunction, epicardial coronary vasospasm, spontaneous coronary artery dissection, and supply-demand mismatch).
The Statement names four possible components of MINOCA management:
- Emergency supportive care
- Evaluation of patients with a “working diagnosis” approach
- Cardioprotective therapies, regardless of how the MINOCA was caused
- Therapies targeted at specific causes
In most, but not all, studies of prognosis, MINOCA patients had better outcomes than their AMI counterparts with coronary artery disease but faced a high risk for recurrent events, with one study finding that 25% of patients with MINOCA experience angina in the following year. In an analysis of MINOCA patients in the SWEDEHEART registry (mean follow-up, 4 years), mortality was 13%, but under half of all deaths were cardiovascular. Also, another MI occurred in 7%, ischemic stroke in 4%, and hospitalization for heart failure in 6%.
For further reference log on to:
Tamis-Holland JE et al. Contemporary diagnosis and management of patients with myocardial infarction in the absence of obstructive coronary artery disease: A scientific statement from the American Heart Association. Circulation 2019 Mar 27; [e-pub]. (https://doi.org/10.1161/CIR.