Guidelines for Managing Acute Coronary Syndrome (ACS)
The management of Acute Coronary Syndrome requires a risk-stratified approach with immediate diagnosis, appropriate antiplatelet therapy, and timely invasive intervention based on risk classification to reduce mortality and improve outcomes. 1, 2
Diagnosis and Initial Assessment
- Rapid Troponin Protocol: Use high-sensitivity cardiac troponin tests with a 0h/1h algorithm for rapid diagnosis. Additional testing at 3-6h if initial results are inconclusive 1
- ECG Assessment: Obtain 12-lead ECG within 10 minutes of presentation to differentiate between STEMI and NSTEMI/unstable angina 2
- Echocardiography: Perform to evaluate regional and global left ventricular function and rule out differential diagnoses 1
- Risk Stratification: Use GRACE Risk Score (preferred over TIMI) to predict in-hospital and long-term outcomes 2
Risk-Based Invasive Strategy
Very High-Risk Criteria (Immediate Invasive Strategy <2h)
- Hemodynamic instability or cardiogenic shock
- Recurrent/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/T-wave changes, particularly with intermittent ST elevation 1
High-Risk Criteria (Early Invasive Strategy <24h)
- Rise/fall in cardiac troponin compatible with MI
- Dynamic ST or T-wave changes (symptomatic or silent)
- GRACE score >140 1
Intermediate-Risk Criteria (Invasive Strategy <72h)
- Diabetes mellitus
- Renal insufficiency (eGFR <60 mL/min/1.73 m²)
- LVEF <40% or congestive heart failure
- Early post-infarction angina
- Recent PCI or prior CABG
- GRACE score >109 and <140 1
Antiplatelet Therapy
Aspirin: Administer 150-325 mg loading dose, followed by 75-100 mg daily indefinitely 2
P2Y12 Inhibitor: Add to aspirin for 12 months unless contraindicated due to bleeding risk 1
- Ticagrelor (180 mg loading, 90 mg twice daily): First choice for moderate-to-high risk patients regardless of initial treatment strategy 1
- Prasugrel (60 mg loading, 10 mg daily): For patients proceeding to PCI with known coronary anatomy; contraindicated in patients with history of stroke/TIA or active bleeding 1, 3
- Clopidogrel (300-600 mg loading, 75 mg daily): For patients who cannot receive ticagrelor/prasugrel or require oral anticoagulation 1
Important Contraindications and Precautions
- Prasugrel: Not recommended in patients ≥75 years (except high-risk patients with diabetes or prior MI), weight <60 kg (consider 5 mg maintenance dose), or unknown coronary anatomy 3
- Ticagrelor: Contraindicated with previous intracranial hemorrhage or ongoing bleeding 1
Anti-Ischemic Therapy
- Nitroglycerin: 0.4 mg sublingually every 5 minutes up to 3 doses; consider IV if pain persists 2
- Beta-blockers: Initiate within 24 hours if no contraindications 2
- Calcium channel blockers: Consider non-dihydropyridines (verapamil/diltiazem) when beta-blockers are contraindicated 2
Secondary Prevention
- Statins: Start high-intensity statin therapy as early as possible and maintain long-term 1, 2
- Beta-blockers: Continue long-term, especially with reduced LVEF 2
- ACE inhibitors/ARBs: Consider for all patients, especially with reduced LVEF 2
- Lifestyle modifications: Smoking cessation, daily exercise, and healthy diet 2
Special Considerations
- Diabetic patients: Similar medical treatment as non-diabetic patients but with strict glucose control; consider CABG over PCI for multivessel disease 2
- Low body weight patients (<60 kg): Higher risk of bleeding with standard antiplatelet doses; consider dose reduction 3
- Patients requiring CABG: When possible, discontinue prasugrel at least 7 days prior to surgery 3
Follow-up
- High-risk patients: 1-2 weeks
- Low-risk patients: 2-6 weeks 2
Common Pitfalls to Avoid
- Administering prasugrel before knowing coronary anatomy
- Delaying invasive strategy in very high-risk patients
- Overlooking bleeding risk in elderly and low body weight patients
- Using NSAIDs (except aspirin) during ACS hospitalization due to increased risk of mortality and complications
- Failing to recognize MINOCA (myocardial infarction with non-obstructive coronary arteries) which requires different management 4