Initial Management of Acute Coronary Syndrome (ACS)
The initial management of Acute Coronary Syndrome requires immediate risk stratification, antiplatelet therapy, anticoagulation, and timely invasive strategy based on risk assessment. 1
Immediate Assessment and Diagnosis
- Obtain a 12-lead ECG within 10 minutes of presentation to differentiate between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation ACS (NSTE-ACS) 1
- Collect blood samples for high-sensitivity cardiac troponin measurement at presentation (0h) and after 1-3 hours to rapidly rule-in or rule-out myocardial infarction 1
- Perform echocardiography to evaluate regional and global left ventricular function and rule out differential diagnoses 1
- Monitor cardiac rhythm continuously for detection of arrhythmias 1
- Assess vital signs with particular attention to hemodynamic stability and signs of heart failure 1
Initial Pharmacological Management
Antiplatelet Therapy
- Administer aspirin 150-300mg loading dose immediately to all patients without contraindications 1
- Initiate a P2Y12 inhibitor in addition to aspirin for 12 months unless contraindicated 1:
- Ticagrelor (180mg loading dose, 90mg twice daily) is recommended for moderate to high-risk patients regardless of initial treatment strategy 1
- Prasugrel (60mg loading dose, 10mg daily) is recommended for patients proceeding to PCI without contraindications 1, 2
- Clopidogrel (300-600mg loading dose, 75mg daily) for patients who cannot receive ticagrelor or prasugrel or who require oral anticoagulation 1
Anticoagulation
- Administer parenteral anticoagulation with low molecular weight heparin (LMWH) or unfractionated heparin 1
- Continue anticoagulation until revascularization is performed or hospital discharge 1
Anti-ischemic Therapy
- Administer sublingual or intravenous nitrates for ongoing chest pain 1
- Initiate beta-blockers in the absence of contraindications (hypotension, bradycardia, acute heart failure) 1
- Consider calcium channel blockers for patients with contraindications to beta-blockers 1
Risk Stratification and Invasive Strategy
Very High-Risk Criteria (Immediate invasive strategy <2h)
- 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 <24h)
- 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 <72h)
- Diabetes mellitus 1
- Renal insufficiency (eGFR <60 mL/min/1.73m²) 1
- Left ventricular ejection fraction <40% or congestive heart failure 1
- Early post-infarction angina 1
- Recent PCI or prior CABG 1
- GRACE risk score >109 and <140 1
Special Considerations
- For patients with STEMI, immediate reperfusion therapy is indicated (not covered in this guidance) 1, 3
- For patients with NSTE-ACS and high-risk features, early coronary angiography and revascularization improve outcomes 1
- Patients with cardiogenic shock require immediate invasive management regardless of ECG changes or biomarker status 1
- In patients ≥75 years of age, prasugrel is generally not recommended due to increased bleeding risk 2
- For patients <60kg, consider reducing prasugrel maintenance dose to 5mg daily due to increased bleeding risk 2
- Do not administer prasugrel in patients with unknown coronary anatomy 1, 2
- Initiate high-intensity statin therapy as early as possible 1
Common Pitfalls to Avoid
- Delaying ECG beyond 10 minutes of presentation can lead to missed diagnosis and delayed treatment 1
- Administering prasugrel to patients with history of stroke or TIA (contraindicated) 2
- Waiting for troponin results before initiating antiplatelet therapy in high-risk patients 1
- Failing to recognize atypical presentations of ACS, particularly in women, elderly, and diabetic patients 1, 3
- Discontinuing dual antiplatelet therapy prematurely, especially in the first few weeks after ACS 2