From the Guidelines
Type 2 Non-ST-Elevation Myocardial Infarction (NSTEMI) is a heart attack that occurs due to an imbalance between oxygen supply and demand in the heart muscle, rather than a primary coronary artery blockage. This condition is characterized by cardiac cell damage and troponin elevation without the typical coronary plaque rupture seen in Type 1 NSTEMI, as defined in the third universal definition of myocardial infarction 1. Common causes of Type 2 NSTEMI include:
- Severe anemia
- Respiratory failure
- Sepsis
- Tachyarrhythmias
- Hypotension
- Hypertensive crisis Treatment of Type 2 NSTEMI focuses primarily on addressing the underlying cause, such as:
- Blood transfusions for anemia
- Antibiotics for sepsis
- Rate control medications for tachycardia In contrast to Type 1 NSTEMI, antiplatelet therapy and statins may not be appropriate for Type 2 NSTEMI unless underlying coronary artery disease exists, as noted in the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes 1. The distinction between Type 1 and Type 2 NSTEMI is important, as patients with Type 2 NSTEMI require different management strategies that target the oxygen supply-demand mismatch rather than coronary intervention, while still necessitating careful cardiac monitoring and follow-up due to their increased risk of future cardiovascular events.
From the Research
Definition of Type 2 NSTEMI
- Type 2 Non-ST-Elevation Myocardial Infarction (NSTEMI) is defined as a condition where there is evidence of myocardial oxygen supply-demand imbalance unrelated to acute coronary atherothrombosis 2, 3.
- This type of NSTEMI is characterized by a mismatch between myocardial oxygen supply and demand, which can occur due to various mechanisms, such as coronary artery spasm, coronary embolism, or other conditions that affect myocardial oxygen supply 3.
Causes and Characteristics of Type 2 NSTEMI
- Type 2 NSTEMI can result from conditions such as severe hypertension, coronary artery spasm, or other causes of myocardial oxygen supply-demand imbalance 2.
- Patients with Type 2 NSTEMI often have multiple comorbidities and the causes of in-hospital mortality among these patients are not always cardiovascular-related 3.
- Type 2 NSTEMI is less common than Type 1 NSTEMI, which is caused by acute atherothrombotic events, and accounts for approximately 10-35% of all NSTEMI cases 3.
Management of Type 2 NSTEMI
- The management of Type 2 NSTEMI is different from Type 1 NSTEMI, and it is essential to distinguish between the two types early in the clinical course to provide the most appropriate treatment 3.
- The treatment of Type 2 NSTEMI focuses on addressing the underlying cause of the myocardial oxygen supply-demand imbalance, such as controlling hypertension or treating coronary artery spasm 2.
- Antithrombotic therapy, including antiplatelet and anticoagulant agents, may be used in the management of Type 2 NSTEMI, but the specific treatment strategy depends on the individual patient's condition and risk factors 4, 5, 6.