Treatment for Acute Coronary Syndrome
The treatment of acute coronary syndrome (ACS) requires immediate administration of dual antiplatelet therapy with aspirin (75-150 mg) plus a P2Y12 inhibitor (preferably ticagrelor or prasugrel), anticoagulation with low-molecular-weight heparin or unfractionated heparin, and an invasive strategy based on risk stratification. 1
Initial Assessment and Diagnosis
- Perform immediate ECG (within 10 minutes) to distinguish between ST-elevation ACS and non-ST-elevation ACS 1
- Obtain high-sensitivity cardiac troponin measurements at presentation and after 6-12 hours 1
- Monitor for recurrent chest pain, hemodynamic instability, and arrhythmias 1
- Consider multi-lead ECG ischemia monitoring for ongoing surveillance 1
Immediate Pharmacological Management
Antiplatelet Therapy
- Aspirin: 150-300 mg loading dose (non-enteric formulation), followed by 75-100 mg daily maintenance dose 1
- P2Y12 inhibitor: Add to aspirin for dual antiplatelet therapy (DAPT) for 12 months unless contraindicated 1
- Ticagrelor: Preferred option (180 mg loading dose, 90 mg twice daily) for moderate to high-risk patients 1
- Prasugrel: Alternative for patients proceeding to PCI (60 mg loading dose, 10 mg daily) 1, 2
- Clopidogrel: Use when ticagrelor or prasugrel are contraindicated or unavailable (300-600 mg loading dose, 75 mg daily) 1
Anticoagulation
- Low-molecular-weight heparin (LMWH): Preferred over unfractionated heparin 1
- Unfractionated heparin (UFH): Alternative when LMWH unavailable 1
- Fondaparinux: 2.5 mg daily subcutaneously as another alternative 1
Additional Medications
- Beta-blockers: Administer if tachycardic or hypertensive without signs of heart failure 1
- Nitrates: For persistent or recurrent chest pain 1
- Calcium channel blockers: Alternative to beta-blockers in patients with contraindications 1
- High-intensity statin therapy: Initiate as early as possible 1
Risk Stratification and Invasive Strategy
Very High-Risk Criteria (Immediate invasive strategy <2 hours)
- Hemodynamic instability or cardiogenic shock 1
- Recurrent or ongoing chest pain refractory to medical treatment 1
- Life-threatening arrhythmias or cardiac arrest 1
- Mechanical complications of myocardial infarction 1
- Acute heart failure with refractory angina or ST deviation 1
- Recurrent dynamic ST or T-wave changes, particularly with intermittent ST elevation 1
High-Risk Criteria (Early invasive strategy <24 hours)
- Rise or fall in cardiac troponin compatible with myocardial infarction 1
- Dynamic ST or T-wave changes (symptomatic or silent) 1
- GRACE score >140 1
Intermediate-Risk Criteria (Invasive strategy <72 hours)
- Diabetes mellitus 1
- Renal insufficiency (eGFR <60 mL/min/1.73 m²) 1
- Left ventricular ejection fraction <40% or heart failure 1
- Early post-infarction angina 1
- Recent PCI or prior CABG 1
- GRACE risk score >109 and <140 1
Specific Management Based on ACS Type
ST-Segment Elevation Myocardial Infarction (STEMI)
- Immediate reperfusion therapy is indicated 1
- Primary PCI is preferred if available within 120 minutes 3
- If PCI cannot be performed within 120 minutes, administer fibrinolytic therapy followed by transfer to a PCI-capable facility 3
Non-ST-Segment Elevation ACS (NSTE-ACS)
- Add GPIIb/IIIa receptor inhibitor for high-risk patients undergoing PCI 1
- Timing of invasive strategy based on risk stratification as outlined above 1
- Avoid prasugrel in patients with unknown coronary anatomy 1, 2
Special Considerations
Bleeding Risk
- Consider lower maintenance dose of prasugrel (5 mg) in patients weighing <60 kg 2
- Avoid prasugrel in patients ≥75 years unless they have diabetes or prior MI 2
- Prasugrel is contraindicated in patients with history of stroke or TIA 2
- Consider proton pump inhibitors in patients at high risk of gastrointestinal bleeding 4
Surgical Considerations
- If CABG is anticipated, discontinue clopidogrel and ticagrelor 5 days before surgery 1
- Discontinue prasugrel at least 7 days before CABG when possible 2