From the Guidelines
Non-ST-Elevation Myocardial Infarction (NSTEMI) Definition
NSTEMI is a type of heart attack where the coronary artery is not completely blocked, and the electrocardiogram (ECG) does not show a persistent ST-segment elevation 1.
Key Characteristics
- It is characterized by myocardial necrosis due to an abrupt reduction in coronary blood flow, often caused by atherosclerotic plaque disruption or erosion 1.
- The ECG may show ST-segment depression, T-wave inversion, or be normal 1.
- Cardiac biomarkers, such as troponin, are elevated, indicating myocardial damage 1.
- NSTEMI is a part of the acute coronary syndrome (ACS) spectrum, which also includes unstable angina (UA) and ST-elevation myocardial infarction (STEMI) 1.
Diagnosis and Management
- The diagnosis of NSTEMI is based on a combination of clinical presentation, ECG findings, and elevated cardiac biomarkers 1.
- Management involves immediate coronary angiography and revascularization if appropriate, as well as medical therapy to reduce ischemia and prevent further complications 1.
Important Considerations
- NSTEMI can present with atypical symptoms, especially in women, diabetic patients, and the elderly 1.
- The Third Universal Definition of Myocardial Infarction provides a framework for classifying MI into different types, including type 1 (spontaneous MI) and type 2 (MI due to supply-demand imbalance) 1.
From the Research
Definition of Non-ST-Elevation Myocardial Infarction (NSTEMI)
There are no research papers provided that directly define Non-ST-Elevation Myocardial Infarction (NSTEMI). However, the studies provided discuss Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA), which may be related to NSTEMI.
Characteristics of MINOCA
- MINOCA is a syndrome with different causes, characterized by clinical evidence of myocardial infarction with normal or near-normal coronary arteries on angiography 2.
- The prevalence of MINOCA ranges between 5% and 25% of all myocardial infarction 2, 3.
- MINOCA disproportionately affects women, but men are also affected 4, 5.
- The pathogenesis of MINOCA is more variable than in MI with obstructive coronary artery disease (MI-CAD) 4.
Diagnosis and Management of MINOCA
- The key principle in the management of MINOCA is to clarify the underlying individual mechanisms to achieve patient-specific treatments 2.
- A standardized approach that includes multimodality imaging, such as coronary intravascular imaging, cardiac magnetic resonance, and in selected cases, coronary reactivity testing, is necessary to determine underlying etiology and direct treatment 5, 6.
- Intravascular ultrasound and optical coherence tomography can help identify pathological alterations of the epicardial vessels that are not visible by coronary angiography 3, 6.
- Cardiovascular magnetic resonance has a key role among the non-invasive modalities, allowing the differentiation between MINOCA and its non-ischaemic mimics and providing prognostic information 6.