Top Things to Know: Contemporary Diagnosis and Management of Patients With Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease
Published: March 27, 2019
- Clinical studies have reported a prevalence of myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) of 5%-6% with a larger range of 5%-15% depending on the study population.
- Although MINOCA can present with or without ST-segment elevation on the ECG, patients with MINOCA are less likely to have electrographic ST-elevation deviations and have smaller degrees of troponin elevation than their anterior myocardial infarction (AMI) counterparts with obstructive coronary artery disease (AMI-CAD).
- Patients with MINOCA are usually younger, with an average age of 58 years, with women making up about 50% of the MINOCA population.
- A clinical algorithm is presented for the diagnosis of MINOCA. Algorithm components include clinical presentation, additional investigations, and diagnosis. MINOCA diagnostic criteria are also outlined.
- Investigations that might be used in making the diagnosis of MINOCA are discussed in the paper, these are: coronary angiography, measurement of left ventricular (LV) function by echocardiogram or LV angiogram, contrast cardiac magnetic resonance imaging (MR), coronary vascular imaging [intravascular ultrasound (IVUS) or optical coherence tomography (OCT)] and coronary functional assessment.
- Specific causes of MINOCA are highlighted: atherosclerotic causes of myocardial necrosis (plaque disruption) and nonatherosclerotic causes of myocardial necrosis (epicardial coronary vasospasm, coronary microvascular dysfunction, coronary embolism/thrombosis, spontaneous coronary artery dissection, and supply-demand mismatch).
- Management of patients with a working diagnosis is an important aspect of understanding MINOCA. A working diagnosis of MINOCA should only be considered in those patients with a definite AMI (as defined by the Fourth Universal Definition of MI), non-obstructive disease on coronary angiography and no other clinical issues that would lead to myocardial injury with ischemia.
- Management strategies are discussed in this paper: emergency supportive care, MINOCA as a working diagnosis, and cardioprotective therapies.
- The prognosis of patients with MINOCA is dependent on the underlying cause and is currently under investigation in clinical studies. Most studies show that MINOCA patients have better outcomes compared to their AMI-CAD counterparts, but these findings are inconsistent between reports. A better understanding of outcomes is needed to truly understand prognosis.
- MINOCA is a distinct clinical diagnosis with many different pathophysiological causes. It is important that healthcare professionals are familiar with this syndrome so that patients are appropriately identified and treated.
Citation
Tamis-Holland JE, Jneid H, Reynolds HR, Agewall S, Brilakis ES, Brown TM, Lerman A, Cushman M, Kumbhani DJ, Arslanian-Engoren C, Bolger AF, MD, Beltrame JF, on behalf of the American Heart Association Interventional Cardiovascular Care Committee of the Council on Clinical Cardiology, Council on Cardiovascular and Stroke Nursing, Council on Epidemiology and Prevention, and Council on Quality of Care and Outcomes Research. 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. [published online ahead of print March 27, 2019]. Circulation. doi: 10.1161/CIR.0000000000000670.