The Ten Commandments from the New Guidelines on Infarction Without ST-Segment Elevation

In 2020, the European Society of Cardiology guidelines for the management of patients with acute coronary syndromes without ST-segment elevation (Non-ST-Segment Elevation Myocardial Infarction, NSTEMI) were presented.

10 mandamientos de las nuevas guías de infartos sin supradesnivel del ST

This document went somewhat unnoticed in the context of the COVID-19 pandemic, so this seems a good time to review it and set out some practical “commandments” (something we have done regarding previous guides).

The key in NSTEMI patients is the diagnostic process, including symptoms of ischemia, electrocardiography, and high-sensitivity troponins. We should be able to rule out or confirm the diagnosis—and, eventually, decide to watch the patient a bit longer—within the hour of admission.

The 10 Commandments

Diagnosis: Chest pain without persistent ST-segment elevation is the key symptom to initiate the diagnostic and therapeutic cascade. This correlates with myocardial necrosis, measurable by high-sensitivity troponins. No cell damage (unstable angina) is less frequent.
High-sensitivity troponins: High-sensitivity troponin measurement is recommended over less sensitive assays. Other pathologies other than infarction may also result in their elevation (COVID-19 infection is one of them).
Rapid rule-out and confirm algorithms: Guidelines recommend using the one-hour algorithm or, eventually, the two-hour one. This allows for the identification of appropriate candidates for early discharge and outpatient management.
Ischemic/hemorrhagic risk: Initial high-sensitivity troponin T levels provide short- and long-term prognosis information. The Global Registry of Acute Coronary Events score is superior to subjective physician assessment for death or infarction risk. Likewise, the Academic Research Consortium-High Bleeding Risk may be used to assess the bleeding risk.
Non-invasive imaging: Even after not confirming the diagnosis of infarction, elective non-invasive imaging may be indicated according to clinical assessment of the patient. To adjust risk level, tomography and stress imaging are the best options.
Risk stratification for an invasive approach: An early routine invasive approach within 24 hours of admission is recommended for NSTEMI patients based on high-sensitivity troponin T, a Global Registry of Acute Coronary Events risk score >140, and dynamic new or presumably new ST-segment changes. Immediate angiography is required for highly unstable patients, arrhythmias, acute heart failure, or persistent pain. In all other clinical situations, a selective angiography is recommended depending on non-invasive testing or clinical risk assessment.
Revascularization strategies: Radial access and culprit lesion angioplasty is the treatment of choice in patients requiring invasive assessment. In patients with multivessel disease, functional relevance of lesions, age, general condition, comorbidities, and ventricular function should be used to decide whether to advance over other lesions and when to do so.
MINOCA: Myocardial infarction with non-obstructive coronary arteries incorporates a heterogeneous group of patients where physiopathology may affect coronary arteries or not. Magnetic resonance imaging is the key diagnostic tool that allows for the identification of the underlying cause in the majority of patients.
Antiplatelet therapy: Dual antiplatelet therapy consisting of a potent P2Y12 receptor inhibitor in addition to aspirin is recommended for a year, unless there are contraindications. This scheme may be shortened (<12 months), extended (>12 months), or modified by de-escalation of strength. All decisions are driven by ischemic and bleeding risk.
Triple antithrombotic therapy: Direct inhibitors are preferred over vitamin K inhibitors in patients who underwent angioplasty with an indication for long-term oral anticoagulation. The ideal strategy for a year, after a short period (a week) of triple therapy, is a direct thrombin inhibitor plus an antiplatelet agent. Triple therapy may be prolonged to one month when the ischemic risk clearly outweighs the bleeding risk.