What is the management of acute coronary syndrome (ACS)?

Management of Acute Coronary Syndrome

Immediately administer aspirin 150-300 mg loading dose and obtain a 12-lead ECG within 10 minutes of presentation to differentiate STEMI from NSTE-ACS, as this distinction determines whether the patient requires immediate reperfusion therapy or risk-stratified invasive management. 1, 2, 3

Initial Assessment and Diagnosis

Immediate Actions (Within 10 Minutes)

• Obtain 12-lead ECG to distinguish ST-segment elevation myocardial infarction (STEMI) from non-ST-segment elevation ACS (NSTE-ACS), as STEMI requires immediate reperfusion while NSTE-ACS follows a risk-stratified approach 1, 2, 3
• Administer aspirin 150-300 mg loading dose immediately to all patients without contraindications 1, 2
• Start continuous cardiac monitoring for arrhythmia detection and multi-lead ischemia monitoring 1, 2
• Assess vital signs with particular attention to hemodynamic instability (hypotension, pulmonary rales) and signs of heart failure 1, 2

Diagnostic Testing

• Measure high-sensitivity cardiac troponin at 0 hours and 1 hour using a validated algorithm for rapid rule-out/rule-in, with additional testing at 3-6 hours if initial measurements are inconclusive 1
• Perform echocardiography to evaluate regional and global left ventricular function and exclude differential diagnoses such as aortic stenosis, hypertrophic cardiomyopathy, or mechanical complications 1, 2
• Check hemoglobin to detect anemia that may contribute to ischemia 1
• Compare with previous ECG if available, particularly valuable in patients with left ventricular hypertrophy or known coronary disease 1

Initial Pharmacological Management

Antiplatelet Therapy

Dual antiplatelet therapy (DAPT) is mandatory for 12 months unless contraindicated. 1

• Ticagrelor (180 mg loading dose, 90 mg twice daily) is the preferred P2Y12 inhibitor for all patients at moderate to high risk of ischemic events (e.g., elevated cardiac troponins), regardless of initial treatment strategy, including those pretreated with clopidogrel which should be discontinued 1

  • Contraindications: previous intracranial hemorrhage or ongoing bleeding 1

• Prasugrel (60 mg loading dose, 10 mg daily) is recommended for patients proceeding to PCI with known coronary anatomy 1, 4

  • Do not administer prasugrel before coronary anatomy is known 1, 4
  • Contraindications: history of TIA or stroke, active bleeding, age ≥75 years (except high-risk situations with diabetes or prior MI), body weight <60 kg (consider 5 mg dose) 4

• 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

Anticoagulation

• Initiate parenteral anticoagulation with low molecular weight heparin (LMWH) or unfractionated heparin immediately 1, 2, 5
• Continue anticoagulation until revascularization is performed or hospital discharge 2

Additional Medical Therapy

• Administer sublingual or intravenous nitrates for ongoing chest pain 1, 2
• Initiate beta-blockers in the absence of contraindications (hypotension, bradycardia, acute heart failure) 1, 2
• Consider calcium channel blockers only for patients with contraindications to beta-blockers 1, 2
• Start high-intensity statin therapy as early as possible and maintain long-term 1, 5

Risk Stratification and Invasive Strategy

STEMI Management

For patients with persistent ST-segment elevation, perform primary PCI within 120 minutes of presentation, as this reduces mortality from 9% to 7%. 3

• If PCI within 120 minutes is not possible, administer fibrinolytic therapy (alteplase, reteplase, or tenecteplase at full dose for patients <75 years; half dose for ≥75 years), followed by transfer for PCI within 24 hours 3

NSTE-ACS Management: Risk-Stratified Invasive Approach

Immediate invasive strategy (<2 hours) for very-high-risk criteria: 1

• 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) for high-risk criteria: 1

• 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) for intermediate-risk criteria: 1

• 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, or recurrent symptoms or known ischemia on non-invasive testing

GP IIb/IIIa Inhibitors

• Administer GP IIb/IIIa receptor blocker in high-risk patients while waiting for angiography, continuing for 12 hours (abciximab) or 24 hours (tirofiban, eptifibatide) after PCI if performed 1

Revascularization Strategy

Percutaneous Coronary Intervention

• Radial access is the standard approach unless there are overriding procedural considerations 1
• Drug-eluting stents (DES) are recommended over bare-metal stents for any PCI irrespective of clinical presentation, lesion type, planned non-cardiac surgery, anticipated duration of DAPT, or concomitant anticoagulant therapy 1
• Base revascularization strategy (ad hoc culprit lesion PCI/multivessel PCI/CABG) on patient's clinical status, comorbidities, and disease severity (SYNTAX score), though immediate PCI of the culprit stenosis does not require Heart Team consultation 1

Cardiogenic Shock Management

• Emergency coronary angiography is mandatory in patients with cardiogenic shock complicating ACS 1
• Emergency PCI of the culprit lesion is recommended for cardiogenic shock due to NSTE-ACS, independent of time delay from symptom onset, if coronary anatomy is amenable to PCI 1
• Emergency CABG is recommended if coronary anatomy is not amenable to PCI 1
• Routine use of intra-aortic balloon pump (IABP) in patients with cardiogenic shock and no mechanical complications is not recommended 1
• Routine immediate revascularization of non-culprit lesions in NSTE-ACS patients with multivessel disease presenting with cardiogenic shock is not recommended 1

Special Populations

Elderly Patients (≥75 Years)

• Apply the same diagnostic and interventional strategies as for younger patients 1
• Adjust antithrombotic agent dosage based on renal function and specific contraindications 1
• Prasugrel is generally not recommended due to increased risk of fatal and intracranial bleeding, except in high-risk situations (diabetes or prior MI) 4

Chronic Kidney Disease

• Apply the same diagnostic and therapeutic strategies as for patients with normal renal function, with dose adjustments as necessary 1
• Assess kidney function by eGFR in all patients 1
• Use low- or iso-osmolar contrast media at the lowest possible volume in invasive strategies 1

Diabetes Mellitus

• Screen all patients with NSTE-ACS for diabetes and monitor blood glucose levels frequently in patients with known diabetes or admission hyperglycemia 1
• Avoidance of hypoglycemia is mandatory 1

Common Pitfalls to Avoid

• Delaying ECG beyond 10 minutes can lead to missed diagnosis and delayed treatment, particularly in STEMI where every minute counts 2, 3
• Waiting for troponin results before initiating antiplatelet therapy in high-risk patients delays critical treatment 2
• Administering prasugrel before coronary anatomy is known increases bleeding risk without established benefit and is contraindicated 1, 4
• Failing to recognize atypical presentations in women, elderly, and diabetic patients (who may present with dyspnea, nausea, or fatigue rather than chest pain) leads to delayed diagnosis 3
• Discontinuing prasugrel within 7 days of planned surgery is essential to minimize bleeding risk; do not start prasugrel in patients likely to undergo urgent CABG 4
• Failing to repeat troponin measurements at 1 hour (or 3-6 hours if initial measurements are inconclusive) can miss evolving MI 1
• Administering beta-blockers to patients with acute heart failure, hypotension, or bradycardia worsens hemodynamic status 1, 2