From the Guidelines
Management of Non-Obstructive Coronary Artery disease (NOCA) and Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) involves a comprehensive approach. The primary goal is to identify the underlying cause of MINOCA, which can be categorized into four main groups: epicardial coronary artery disorders, imbalance between oxygen supply and demand, coronary endothelial dysfunction, and myocardial disorders without involvement of the coronary arteries 1.
Diagnostic Criteria
The diagnosis of MINOCA is made based on the following criteria:
- Detection of a rise or fall in cardiac troponin with at least one value above the 99th percentile upper reference limit
- Corroborative clinical evidence of infarction, such as symptoms of myocardial ischemia, new ischemic electrocardiographic changes, or imaging evidence of new loss of viable myocardium
- Non-obstructive coronary arteries on angiography, defined as the absence of obstructive disease on angiography (i.e., no coronary artery stenosis >50%) in any major epicardial vessel
- No specific alternate diagnosis for the clinical presentation 1
Management Strategies
The management of MINOCA involves a step-wise approach:
- Initial Assessment: Proper initial assessment of LV wall motion should be promptly performed in the acute setting using LV angiography or echocardiography
- Cardiac Magnetic Resonance (CMR): CMR is a key diagnostic tool in the differential diagnosis of Takotsubo syndrome, myocarditis, or true MI, and can identify the underlying cause in as many as 87% of patients with MINOCA
- Medical Therapy: Medical therapy based on coronary functional test results should be considered to improve symptoms and quality of life, including:
- ACE-I for symptom control in patients with endothelial dysfunction
- Beta-blockers for symptom control in patients with microvascular angina associated with reduced coronary/myocardial blood flow reserve
- Calcium channel blockers and nitrates for symptom control in patients with vasospastic angina
- Intracoronary Imaging: Intracoronary imaging with IVUS or OCT may be valuable for the detection of unrecognized causes at coronary angiography, especially when thrombus, plaque rupture or erosion, or SCAD are suspected
Treatment Considerations
Treatment should target the most probable causes of MINOCA, with negative provocative tests and CMR. The benefit of DAPT (aspirin + P2Y12 receptor inhibitor) should be considered based on pathophysiological considerations, although evidence is scarce 1.
In patients with ANOCA/INOCA, medical therapy based on coronary functional test results should be considered to improve symptoms and quality of life, including the use of nitrates, calcium channel blockers, and beta-blockers 1.
Overall, the management of NOCA and MINOCA requires a comprehensive and individualized approach, taking into account the underlying cause and pathophysiological mechanisms involved.
From the Research
Management of Non-Obstructive Coronary Artery Disease (NOCA) and Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA)
- The management of MINOCA is complex and requires a comprehensive assessment using various imaging modalities to evaluate the underlying cause of the condition 2, 3, 4, 5, 6.
- The cornerstone of managing MINOCA patients is to identify the underlying mechanism to achieve targeted treatment 4.
- Intravascular imaging, such as intravascular ultrasound and optical coherence tomography, can help identify pathological alterations of the epicardial vessels that are not visible by coronary angiography 3, 4, 5.
- Cardiac magnetic resonance imaging is the gold standard for detection of myocardial infarction in the setting of MINOCA 4, 5, 6.
- Coronary physiology testing and cardiac magnetic resonance imaging offer important investigative modalities to facilitate diagnosis and appropriate management of MINOCA patients 5.
- A high index of suspicion and a comprehensive diagnostic evaluation are critical for early recognition and successful management of MINOCA 5, 6.
Diagnostic Challenges
- MINOCA is a heterogeneous group of conditions that include both atherosclerotic and non-atherosclerotic causes resulting in myocardial damage that is not due to obstructive coronary artery disease 4.
- The demographic characteristics, risk factors, and management of patients with MINOCA differ from those with atherosclerotic acute coronary syndrome (ACS) 5.
- MINOCA accounts for approximately 5-15% of acute myocardial infarctions (MI) and poses an increased risk of morbidity and mortality after diagnosis 2, 6.
Treatment Options
- Targeted therapies for patients with MINOCA are essential to improve outcomes, but the process is not yet standardized 2.
- The objective of treatment is to identify the underlying cause of MINOCA and optimize treatment to improve prognosis and prevent recurrent myocardial infarction 3, 4, 5.
- Treatment options may include medications to manage symptoms, lifestyle modifications, and procedures to address underlying conditions such as coronary artery spasm or microvascular dysfunction 5.