What is the initial management for a patient presenting with Acute Coronary Syndrome (ACS)?

Initial Management of Acute Coronary Syndrome

All patients presenting with suspected ACS require immediate 12-lead ECG within 10 minutes of arrival, aspirin 150-300mg loading dose, and continuous cardiac monitoring, followed by risk-stratified invasive strategy timing based on clinical presentation. 1, 2

Immediate Assessment (First 10 Minutes)

Obtain 12-lead ECG within 10 minutes of first medical contact to differentiate STEMI from NSTE-ACS, as this determines the entire treatment pathway. 1, 2, 3

Perform focused clinical evaluation including:

• Chest pain characteristics, duration, and persistence 1
• Vital signs: blood pressure, heart rate, oxygen saturation 1, 2
• Physical examination for hemodynamic instability, heart failure signs (Killip classification), and cardiopulmonary findings 1
• Assessment of CAD probability based on age, gender, cardiovascular risk factors 1

Initiate continuous cardiac rhythm monitoring immediately to detect life-threatening arrhythmias. 1, 2

Immediate Pharmacological Management

Administer aspirin 150-300mg loading dose immediately to all patients without contraindications—this is non-negotiable and should not wait for troponin results. 2, 4, 5

Start parenteral anticoagulation with either unfractionated heparin or low-molecular-weight heparin, adjusting doses for age and renal function. 1, 2, 4

Administer sublingual or intravenous nitrates if chest pain persists, unless contraindicated by hypotension or recent phosphodiesterase inhibitor use. 1, 2

Diagnostic Workup (Within 60 Minutes)

Draw blood for high-sensitivity cardiac troponin at presentation (0 hour) with results available within 60 minutes. 1, 2

Repeat troponin measurement at 1-3 hours using validated 0h/1h algorithms if high-sensitivity assays are available; otherwise use 0h/3h protocol. 1, 2

Obtain additional laboratory tests including serum creatinine, hemoglobin, hematocrit, platelet count, blood glucose, and INR (if on anticoagulation). 1

Perform echocardiography to evaluate regional wall motion abnormalities, global left ventricular function, and rule out differential diagnoses (pericarditis, aortic dissection, pulmonary embolism). 1, 2

P2Y12 Inhibitor Selection and Timing

For NSTE-ACS with confirmed diagnosis (elevated troponin):

• Ticagrelor is preferred (180mg loading dose, then 90mg twice daily) for all moderate-to-high risk patients, regardless of whether invasive strategy is planned. 1, 2, 4
• Prasugrel (60mg loading dose, then 10mg daily) is recommended for patients proceeding to PCI without contraindications (prior stroke/TIA, age ≥75 years, weight <60kg). 1
• Clopidogrel (300-600mg loading dose, then 75mg daily) is reserved for patients who cannot receive ticagrelor or prasugrel, or who require oral anticoagulation. 1, 6

Continue dual antiplatelet therapy for 12 months unless excessive bleeding risk exists. 1, 2

Risk Stratification and Invasive Strategy Timing

Immediate invasive strategy (<2 hours) is mandatory for very-high-risk patients with any of: 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) for high-risk patients with any of: 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) for intermediate-risk patients with any of: 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 score 109-140, or recurrent symptoms

Additional Therapies

Initiate high-intensity statin therapy as early as possible during admission. 2

Start beta-blockers in the absence of contraindications (hypotension, bradycardia, acute heart failure). 2, 5

Consider ACE inhibitors particularly for patients with heart failure, left ventricular dysfunction, diabetes, or hypertension. 5

Special Considerations and Common Pitfalls

For ongoing ischemia with hemodynamic compromise, proceed to immediate coronary angiography regardless of ECG or biomarker findings, and place defibrillator patches until revascularization is performed. 1, 2

Do not delay antiplatelet therapy while waiting for troponin results in high-risk patients—this is a critical error that worsens outcomes. 2

Recognize atypical presentations particularly in women, elderly patients, and those with diabetes who may present with dyspnea, nausea, or fatigue rather than classic chest pain. 2, 3

For STEMI patients, primary PCI within 120 minutes reduces mortality from 9% to 7%; if PCI is not available within this timeframe, administer fibrinolytic therapy followed by transfer for PCI within 24 hours. 3

Assess lipid profile in the early phase of admission once NSTE-ACS diagnosis is confirmed. 1