What is the stepwise management of acute coronary syndrome (ACS) in chronological order?

Management of Acute Coronary Syndrome in Chronological Order

The management of acute coronary syndrome follows a time-sensitive, stepwise approach beginning with immediate ECG acquisition within 10 minutes, followed by risk-stratified invasive strategies ranging from immediate (<2 hours) to delayed (<72 hours) based on clinical presentation and biomarkers. 1, 2

Step 1: Immediate Assessment (0-10 Minutes)

All patients with suspected ACS must have a 12-lead ECG performed within 10 minutes of first medical contact. 1, 2, 3

• Obtain vital signs including blood pressure, heart rate, oxygen saturation, and perform cardiopulmonary auscultation with Killip classification 1
• Initiate continuous cardiac rhythm monitoring immediately to detect life-threatening arrhythmias 1, 2
• Assess chest pain characteristics (quality, duration, radiation, precipitating factors) and perform symptom-oriented physical examination 1
• Evaluate probability of coronary artery disease based on age, gender, cardiovascular risk factors, and known CAD 1
• Administer oxygen therapy only if blood oxygen saturation is <90% or respiratory distress is present 1

Based on ECG findings, immediately classify the patient into one of four categories: 1

• STEMI (requires separate management protocol)
• NSTE-ACS with ongoing ischemia or hemodynamic instability
• NSTE-ACS without ongoing ischemia or hemodynamic instability
• NSTE-ACS unlikely

Step 2: Initial Laboratory Testing (0-60 Minutes)

Draw blood samples immediately for high-sensitivity cardiac troponin (results must be available within 60 minutes), along with serum creatinine, hemoglobin, hematocrit, platelet count, blood glucose, and INR in patients on vitamin K antagonists. 1, 2

• Repeat troponin measurement at 1-3 hours if high-sensitivity assays are used, or at 6-12 hours for standard assays 1, 3
• If the first two troponin measurements are not conclusive and clinical suspicion remains high, perform additional testing at 3-6 hours 1
• Obtain lipid profile in the early phase of admission once NSTE-ACS diagnosis is confirmed 1
• Consider echocardiography to evaluate regional and global left ventricular function and exclude alternative diagnoses (pulmonary embolism, pericarditis, aortic dissection) 1

Step 3: Immediate Pharmacological Management (Within First Hour)

Administer aspirin 150-300 mg loading dose immediately to all patients without contraindications. 2, 4

Initiate sublingual or intravenous nitrates for ongoing chest pain unless contraindicated (hypotension, right ventricular infarction, recent phosphodiesterase inhibitor use). 1, 2

Administer parenteral anticoagulation immediately with either low molecular weight heparin or unfractionated heparin. 1, 2, 4

• Reserve morphine (intravenous or subcutaneous) or alternative opiates only for patients with persisting severe chest pain despite nitrates 1
• Place defibrillator patches in cases of ongoing ischemia until urgent revascularization is performed 1

Step 4: Risk Stratification and P2Y12 Inhibitor Selection (1-2 Hours)

Calculate GRACE score to determine timing of invasive strategy. 1

For patients proceeding to an invasive strategy, select the appropriate P2Y12 inhibitor: 1, 4

• Ticagrelor (180 mg loading dose, 90 mg twice daily) is recommended for all patients at moderate to high risk of ischemic events (elevated cardiac troponins), regardless of initial treatment strategy 1
• Prasugrel (60 mg loading dose, 10 mg daily) is recommended only after coronary anatomy is known and patient is proceeding to PCI, with contraindications including previous intracranial hemorrhage, previous ischemic stroke/TIA, age ≥75 years, or body weight <60 kg 1
• Clopidogrel (300-600 mg loading dose, 75 mg daily) is reserved for patients who cannot receive ticagrelor or prasugrel, or who require oral anticoagulation 1, 5

A critical pitfall: Do not administer prasugrel before coronary anatomy is known 1

Step 5: Timing of Invasive Strategy

Immediate invasive strategy (<2 hours) is mandatory for patients with any of the following very-high-risk criteria: 1, 2

• 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

Early invasive strategy (<24 hours) is recommended for patients with any of the following high-risk criteria: 1, 2

• Rise or fall in cardiac troponin compatible with MI
• Dynamic ST- or T-wave changes (symptomatic or silent)
• GRACE score >140

Invasive strategy (<72 hours) is recommended for patients with any of the following intermediate-risk criteria: 1, 2

• 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 risk score >109 and <140, or recurrent symptoms or known ischemia on non-invasive testing

Step 6: Additional Pharmacological Management (First 24 Hours)

Initiate high-intensity statin therapy as early as possible and maintain long-term unless contraindicated. 1, 2

Initiate beta-blockers in the absence of contraindications (hypotension, bradycardia, acute heart failure). 2

Consider ACE inhibitors or ARBs, particularly in patients with left ventricular dysfunction, heart failure, hypertension, or diabetes. 4

Step 7: Coronary Angiography and Revascularization

Perform coronary angiography at the time determined by risk stratification (immediate, early, or delayed). 1, 2

• Revascularization strategy (PCI vs. CABG) should be determined based on coronary anatomy, extent of disease, and patient factors 1
• Continue anticoagulation until revascularization is performed or hospital discharge 1, 2

Step 8: Long-Term Secondary Prevention (Before Discharge)

Continue dual antiplatelet therapy (aspirin plus P2Y12 inhibitor) for 12 months unless there are contraindications such as excessive bleeding risk. 1, 4

Maintain high-intensity statin therapy long-term. 1, 2

Provide smoking cessation counseling and enroll in cardiac rehabilitation program. 1

Continue beta-blockers, ACE inhibitors/ARBs, and ensure tight control of blood pressure, diabetes, and other cardiovascular risk factors. 4

Critical Pitfalls to Avoid

• Never delay ECG beyond 10 minutes as this leads to missed diagnosis and delayed treatment 2, 3
• Do not wait for troponin results before initiating antiplatelet therapy in high-risk patients 2
• Avoid administering prasugrel before coronary anatomy is known 1
• Do not use clopidogrel as first-line P2Y12 inhibitor in moderate-to-high risk patients when ticagrelor is available 1
• Recognize atypical presentations particularly in women, elderly, and diabetic patients to avoid delayed diagnosis 2
• Avoid concomitant use of clopidogrel with omeprazole or esomeprazole as these significantly reduce antiplatelet activity 5