Latest Updates in Myocardial Infarction Management
Key Paradigm Shift
The 2023 ESC guidelines represent a fundamental change by unifying STEMI and NSTE-ACS management into a single continuum framework, replacing the previously separated 2017 STEMI and 2020 NSTE-ACS guidelines. 1, 2
This reflects the expert consensus that acute coronary syndrome exists on a spectrum from unstable angina through cardiogenic shock, rather than as distinct entities. 2
Immediate Diagnosis: The "Think A.C.S." Approach
The 2023 guidelines introduce a new procedural framework: 2
- Abnormal ECG: 12-lead ECG must be obtained and interpreted within 10 minutes of first medical contact 3, 4
- Clinical context: Evaluate the complete clinical presentation, not just chest pain (40% of men and 48% of women present without typical chest pain) 5
- Stable patient: Assess hemodynamic stability to guide urgency of intervention 2
ECG monitoring with defibrillator capacity must be initiated immediately in all suspected cases. 3, 4
Reperfusion Strategy for STEMI
Primary PCI Pathway
Primary PCI remains the definitive reperfusion strategy and must be performed within 90-120 minutes of STEMI diagnosis. 3, 6, 4
The time clock starts at STEMI diagnosis (when the ECG is interpreted as showing ST-elevation), not at symptom onset. 3
Key procedural standards: 3, 6
- Radial artery access is preferred over femoral (Class I recommendation)
- Drug-eluting stents are standard of care
- Patients bypass the emergency department and go directly to the catheterization laboratory
- Routine thrombus aspiration is contraindicated (Class III)
- Deferred stenting is contraindicated (Class III)
Fibrinolysis When PCI Unavailable
If primary PCI cannot be performed within 120 minutes of STEMI diagnosis, fibrinolytic therapy must be initiated immediately—ideally within 10 minutes. 3, 6
- Use fibrin-specific agents: tenecteplase, alteplase, or reteplase (Class I, Level B) 3
- Administer preferably in the pre-hospital setting 3, 6
- All patients receiving fibrinolysis must be transferred immediately to a PCI-capable center (Class I, Level A) 3, 6
- Angiography should be performed 2-24 hours after successful fibrinolysis 3
Revised Antithrombotic Therapy
For Primary PCI
The 2023 guidelines include revised antiplatelet and anticoagulant recommendations: 2
- Aspirin 150-325 mg oral or IV immediately (Class I, Level B)
- Potent P2Y12 inhibitor (prasugrel 60 mg or ticagrelor 180 mg) before or at the time of PCI (Class I, Level A)
- Clopidogrel only if prasugrel/ticagrelor unavailable or contraindicated
Anticoagulation: 3
- Unfractionated heparin as weight-adjusted IV bolus (preferred)
- Enoxaparin or bivalirudin are alternatives
- Fondaparinux is contraindicated for primary PCI (Class III, Level B) 3
For Fibrinolysis
- Aspirin oral or IV
- Clopidogrel (not prasugrel/ticagrelor)
- Enoxaparin IV followed by subcutaneous (preferred over unfractionated heparin, Class I, Level A)
Long-term DAPT
Dual antiplatelet therapy with aspirin plus prasugrel/ticagrelor must continue for 12 months (Class I, Level A) 3, 6, 4
A proton pump inhibitor should be co-prescribed for patients at high gastrointestinal bleeding risk (Class I, Level B) 6, 4
Management of Non-Infarct Related Arteries
The 2023 guidelines provide revised recommendations for multivessel disease: 1
- In stable patients: Treatment of severe non-IRA stenosis should be considered before hospital discharge, either during index PCI or staged later 3
- In cardiogenic shock: Non-IRA PCI should be considered during the index procedure 3
- Evaluation by angiography or FFR is recommended 3
NSTE-ACS: Updated Timing of Invasive Strategy
The 2023 guidelines revise the timing recommendations for invasive diagnostics in NSTE-ACS: 1, 2
- Very high-risk patients: Immediate invasive strategy (<2 hours) for hemodynamic instability, cardiogenic shock, life-threatening arrhythmias, or mechanical complications 2
- High-risk patients: Early invasive strategy within 24-48 hours reduces mortality from 6.5% to 4.9% 5
- The guidelines now emphasize a more nuanced, risk-stratified approach rather than rigid time windows 2
Cardiac Arrest Management
Revised 2023 recommendations for out-of-hospital cardiac arrest: 2
- Primary PCI strategy is mandatory for resuscitated patients with ST-elevation on post-resuscitation ECG (Class I, Level B) 3
- For patients without ST-elevation but high suspicion of ongoing ischemia, urgent angiography within 2 hours after excluding non-coronary causes 3
- Targeted temperature management is indicated early for unresponsive patients (Class I, Level B) 3
- Pre-hospital cooling with rapid infusion of cold IV fluids is not recommended (Class III, Level B) 3
Special Populations and Holistic Approach
The 2023 guidelines introduce new recommendations for frail patients: 2
- A holistic approach considering functional status, comorbidities, and patient preferences
- Dose adjustments are critical for: 3, 4
- Elderly patients
- Renal insufficiency
- Patients on oral anticoagulants
- Diabetic patients
What NOT to Do: Key Contraindications
Routine oxygen is not recommended unless SaO2 <90% (Class III, Level B) 3, 6
NSAIDs are prohibited for pain relief due to prothrombotic effects 6
Routine PCI of an occluded infarct-related artery >48 hours after STEMI onset in asymptomatic patients is not indicated (Class III, Level A) 3
MINOCA Recognition
A sizeable proportion of STEMI patients show no significant coronary stenosis on angiography. 3, 4
Additional diagnostic tests must be performed to identify the etiology (CMR, IVUS, OCT) and tailor therapy, which may differ substantially from typical STEMI management. 3, 4
Quality Indicators and Systems of Care
The guidelines emphasize regional STEMI networks with: 3
- 24/7 high-volume PCI centers
- Direct transfer protocols bypassing emergency departments
- Common written protocols between EMS and hospitals
- Measurement of validated quality indicators to audit practice