Treatment of Acute Coronary Syndrome (ACS)
The treatment of Acute Coronary Syndrome requires immediate dual antiplatelet therapy with aspirin plus a P2Y12 inhibitor (preferably ticagrelor), anticoagulation, and risk stratification for early invasive management, followed by long-term secondary prevention with statins, beta-blockers, and ACE inhibitors. 1
Initial Assessment and Diagnosis
- Immediate ECG (within 10 minutes of presentation) is essential to differentiate between ST-elevation MI (STEMI) and non-ST-elevation ACS (NSTE-ACS) 2
- Laboratory assessment should include high-sensitivity cardiac troponin, hemoglobin, and markers of myocardial damage 1
- Continuous multi-lead ECG monitoring for ischemia and arrhythmias should be initiated 1
- Echocardiography is recommended to evaluate regional and global left ventricular function and rule out differential diagnoses 1
Immediate Medical Management
Antiplatelet Therapy
- Aspirin: 150-300 mg loading dose followed by 75-100 mg daily maintenance dose for all patients with suspected ACS 1
- P2Y12 inhibitor: Should be added to aspirin for 12 months unless contraindicated 1
- Ticagrelor (180 mg loading dose, 90 mg twice daily) is recommended as first choice for moderate to high-risk patients 1
- Prasugrel (60 mg loading dose, 10 mg daily) is recommended for patients proceeding to PCI 1
- Clopidogrel (300-600 mg loading dose, 75 mg daily) is recommended for patients who cannot receive ticagrelor or prasugrel, or who require oral anticoagulation 1, 3
Anticoagulation
- Parenteral anticoagulation is recommended for all ACS patients 1
- Options include:
Symptom Relief and Supportive Care
- Nitrates (sublingual followed by intravenous) for relief of ischemia and symptoms 1
- Morphine for persistent severe chest pain or acute pulmonary congestion 1
- Beta-blockers for symptom control and to reduce myocardial oxygen demand 1
- Oxygen therapy if oxygen saturation <90% or respiratory distress 1
Risk Stratification and Invasive Management
Very High-Risk Criteria (Immediate Invasive Strategy <2h)
- Hemodynamic instability or cardiogenic shock
- Recurrent or ongoing chest pain refractory to medical treatment
- Life-threatening arrhythmias or cardiac arrest
- Mechanical complications of MI
- Acute heart failure with refractory angina or ST deviation
- Recurrent dynamic ST or T-wave changes, particularly with intermittent ST elevation 1
High-Risk Criteria (Early Invasive Strategy <24h)
- Rise or fall in cardiac troponin compatible with MI
- Dynamic ST or T-wave changes
- GRACE score >140 1
Intermediate-Risk Criteria (Invasive Strategy <72h)
- Diabetes mellitus
- Renal insufficiency (eGFR <60 mL/min/1.73 m²)
- LVEF <40% or heart failure
- Early post-infarction angina
- Recent PCI or prior CABG
- GRACE score >109 and <140 1
Specific Management Based on ACS Type
STEMI Management
- Primary PCI within 120 minutes of first medical contact is the preferred reperfusion strategy 2
- If PCI cannot be performed within 120 minutes, fibrinolytic therapy should be administered, followed by transfer to a PCI-capable facility 2
- Continue dual antiplatelet therapy and anticoagulation 1
NSTE-ACS Management
- Risk stratification to determine timing of invasive strategy 1
- High-risk patients benefit from early invasive approach with coronary angiography within 24-48 hours 2
- GPIIb/IIIa inhibitors may be considered for high-risk patients undergoing PCI 1
Long-Term Secondary Prevention
- High-intensity statin therapy should be started as early as possible and maintained long-term 1
- Beta-blockers are recommended, especially in patients with reduced left ventricular function (LVEF ≤40%) 1
- ACE inhibitors are recommended for patients with LVEF ≤40%, heart failure, hypertension, or diabetes 1
- Angiotensin receptor blockers (ARBs) are alternatives for patients who cannot tolerate ACE inhibitors 1
- Mineralocorticoid receptor antagonists (preferably eplerenone) for patients with LVEF ≤35% and either heart failure or diabetes 1
- Lifestyle modifications including smoking cessation, regular physical activity, and healthy diet 1
- Cardiac rehabilitation program enrollment 1
Common Pitfalls and Caveats
- Prasugrel should not be administered in patients with unknown coronary anatomy 1
- Prasugrel is contraindicated in patients with previous intracranial hemorrhage, previous ischemic stroke, or ongoing bleeds 1
- Prasugrel is generally not recommended for patients ≥75 years or with body weight <60 kg 1
- Fondaparinux should not be used to support PCI due to risk of catheter thrombosis 1
- Clopidogrel has diminished antiplatelet effect in patients with two loss-of-function alleles of the CYP2C19 gene 3
- Avoid concomitant use of clopidogrel with omeprazole or esomeprazole as they significantly reduce its antiplatelet activity 3