How to avoid missing Non-ST-Elevation Myocardial Infarction (NSTEMI)?

From the Guidelines

To not miss an NSTEMI, it is crucial to maintain a high index of suspicion in patients with concerning symptoms and use a comprehensive diagnostic approach, including obtaining a 12-lead ECG within 10 minutes of patient presentation and ordering serial cardiac troponin measurements at presentation and 3-6 hours later, as recommended by the 2020 ESC guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation 1. The diagnostic approach should include the use of high-sensitivity troponin assays, which provide higher diagnostic accuracy and can detect smaller amounts of myocardial damage 1. Consideration of risk factors, including age, diabetes, hypertension, smoking history, and family history of premature coronary disease, is also essential in the diagnostic process. It is important not to be falsely reassured by atypical presentations, especially in women, elderly patients, and those with diabetes who may present without classic chest pain. For patients with ongoing symptoms but initially negative workup, extended observation with additional troponin measurements or provocative testing should be considered. Early cardiology consultation is warranted for patients with high clinical suspicion despite inconclusive initial testing. Electrocardiographic monitoring for arrhythmia and ischemia should continue uninterrupted for a minimum of 24 to 48 hours, including during transportation within the hospital, until a definitive noncardiac diagnosis has been established or until appropriate reperfusion or therapy has been provided, as stated in the update to practice standards for electrocardiographic monitoring in hospital settings: a scientific statement from the American Heart Association 1. The need for monitoring should be reassessed every 24 hours on the basis of clinical and diagnostic findings and response to therapy. Rapid ‘rule-in’ and ‘rule-out’ algorithms, such as the 0 h/1 h algorithm or the 0 h/2 h algorithm, can be used to identify appropriate candidates for early discharge and outpatient management 1. Ischaemic risk assessment, including initial cTn levels and clinical and ECG variables, should be performed to determine the risk of death and guide management decisions. Bleeding risk assessment, using tools such as the ARC-HBR, should also be considered to inform decision making on DAPT duration. Pre-treatment with P2Y12 receptor inhibitors may be considered in selected cases, according to the bleeding risk of the patient. Overall, a comprehensive and timely diagnostic approach is crucial to ensure that NSTEMIs are not missed, allowing for timely intervention and improved patient outcomes.

From the FDA Drug Label

The CURE study included 12,562 patients with ACS without ST-elevation (UA or NSTEMI) and presenting within 24 hours of onset of the most recent episode of chest pain or symptoms consistent with ischemia Patients were required to have either ECG changes compatible with new ischemia (without ST-elevation) or elevated cardiac enzymes or troponin I or T to at least twice the upper limit of normal.

To not miss NSTEMI, consider the following:

• ECG changes: Look for ECG changes compatible with new ischemia (without ST-elevation)
• Cardiac enzymes: Check for elevated cardiac enzymes or troponin I or T to at least twice the upper limit of normal
• Symptoms: Consider symptoms consistent with ischemia, such as chest pain
• Timing: Presenting within 24 hours of onset of the most recent episode of chest pain or symptoms consistent with ischemia 2

From the Research

Diagnosis and Management of NSTEMI

To avoid missing Non-ST-segment elevation myocardial infarction (NSTEMI), it is crucial to understand its diagnosis and management. The following points highlight key aspects:

• NSTEMI is twice as common as ST-segment elevation myocardial infarction (STEMI) 3
• Chest pain is a common complaint in emergency departments, with a quarter of these patients being diagnosed with acute coronary syndromes, but nearly half will have nondiagnostic electrocardiograms 3
• Current national management guidelines for NSTEMI should be followed, and the evidence base supporting them should be considered 3

Special Patient Populations and Diagnostic Modalities

Special consideration should be given to:

• Issues surrounding special patient populations, such as those with multiple comorbidities 4
• New diagnostic and therapeutic modalities, including high-sensitivity CV biomarker assays and advanced cardiovascular imaging 4
• The use of optimized antithrombotic therapy with aspirin, clopidogrel, and enoxaparin in patients with NSTEMI 5

Treatment and Therapy

Treatment options for NSTEMI include:

• Dual antiplatelet therapy with aspirin plus either clopidogrel, prasugrel, or ticagrelor, depending on clinical circumstances 6
• Reduced-dose enoxaparin combined with dual-antiplatelet therapy, followed by triple-antiplatelet therapy alone during subsequent percutaneous coronary intervention (PCI) 7
• The importance of distinguishing between type 1 and type 2 NSTEMI to allow for the use of the most appropriate treatments 4

Key Considerations

Key considerations in the management of NSTEMI include:

• The need for early distinction between type 1 and type 2 NSTEMI to guide treatment 4
• The importance of considering the underlying pathophysiology of NSTEMI, including intracoronary atherothrombosis and myocardial oxygen supply-demand imbalance 4
• The potential benefits and risks of different treatment strategies, including the use of antiplatelet drugs and anticoagulants 7, 5, 6