What is the recommended acute and discharge management for a patient with non‑ST‑segment elevation myocardial infarction (NSTEMI)?

NSTEMI Management

All patients with NSTEMI should receive immediate dual antiplatelet therapy (aspirin plus ticagrelor), anticoagulation, and undergo risk stratification to determine timing of invasive coronary angiography within 24 hours for high-risk features, with discharge on guideline-directed medical therapy including high-intensity statins, beta-blockers, and ACE inhibitors.

Acute Management

Initial Assessment and Diagnosis

• Obtain a 12-lead ECG within 10 minutes of first medical contact to confirm non-ST-segment elevation pattern, which may show transient ST-depression, T-wave inversions, or be normal 1, 2
• Draw high-sensitivity cardiac troponin at presentation (0 hours) and repeat at 1-2 hours using the ESC 0h/1h or 0h/2h algorithm for rapid rule-in/rule-out 1
• Perform immediate echocardiography if hemodynamic instability, cardiac arrest, or ongoing chest pain with inconclusive ECG to assess wall motion abnormalities and exclude mechanical complications 1
• Monitor continuously for arrhythmias until NSTEMI is confirmed or ruled out, with minimum 24 hours of telemetry monitoring 1, 3

Immediate Pharmacologic Therapy

Antiplatelet Therapy:

• Administer aspirin 150-325 mg loading dose (chewed, non-enteric), followed by 75-100 mg daily indefinitely 2, 3
• Add ticagrelor 180 mg loading dose, then 90 mg twice daily for 12 months as the preferred P2Y12 inhibitor for all moderate-to-high risk patients, regardless of initial treatment strategy 1, 2, 3
• Prasugrel (60 mg loading, 10 mg daily) is reserved only after coronary angiography and prior to PCI in patients proceeding to invasive management 1

Anticoagulation:

• Choose one anticoagulant based on management strategy: fondaparinux 2.5 mg subcutaneously once daily (preferred for conservative management), enoxaparin, or unfractionated heparin 2
• Adjust all anticoagulant and antiplatelet doses according to renal function (eGFR) and body weight 1, 2

Anti-Ischemic Therapy:

• Administer sublingual or intravenous nitroglycerin for persistent chest pain 1
• Initiate beta-blockers early if ongoing ischemic symptoms without contraindications (heart failure, hypotension, bradycardia) 2
• Avoid routine oxygen therapy unless oxygen saturation <90% or respiratory distress 1
• Reserve morphine only for severe refractory chest pain, as it may delay P2Y12 inhibitor absorption 1

Risk Stratification and Timing of Invasive Strategy

Immediate Invasive Strategy (<2 hours):

• 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 MI (acute mitral regurgitation, ventricular septal defect) 1
• Acute heart failure with refractory angina or ST-segment deviation 1

Early Invasive Strategy (<24 hours):

• Elevated cardiac troponin compatible with NSTEMI 1, 2
• Dynamic ST-segment or T-wave changes (symptomatic or silent) 1
• GRACE risk score >140 1, 4
• New or presumed new ST-segment depression 2

Invasive Strategy (<72 hours):

• Diabetes mellitus 1
• Renal insufficiency (eGFR <60 mL/min/1.73 m²) 1
• LVEF <40% or congestive heart failure 1
• GRACE risk score 109-140 with recurrent symptoms 1
• Prior PCI or CABG 1

Selective Invasive Strategy:

• Low-risk patients with no recurrence of chest pain, normal ECG, normal troponin should undergo non-invasive stress testing (preferably with imaging) or coronary CT angiography before deciding on invasive approach 1

Procedural Considerations

• Use radial artery access as the standard approach for coronary angiography and PCI to reduce bleeding complications 1
• Implant drug-eluting stents over bare-metal stents for any PCI, regardless of clinical presentation or anticipated DAPT duration 1
• Perform immediate PCI of culprit lesion only in cardiogenic shock; avoid routine immediate multivessel revascularization in this setting 1
• Base revascularization strategy (PCI vs CABG) on disease severity, SYNTAX score, and patient comorbidities without requiring Heart Team consultation for culprit lesion PCI 1

Special Populations

Cardiogenic Shock:

• Proceed to emergency coronary angiography and emergency PCI of culprit lesion if anatomy amenable, or emergency CABG if not 1, 2
• Perform emergency echocardiography to assess LV function and exclude mechanical complications 1
• Routine IABP use is not recommended in cardiogenic shock without mechanical complications 1

Chronic Kidney Disease:

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

Diabetes Mellitus:

• Screen all patients for diabetes and monitor blood glucose frequently 1
• Avoid hypoglycemia during acute phase 1

Older Patients:

• Apply same diagnostic and invasive strategies as younger patients 1
• Adapt antithrombotic agent dosing and secondary prevention to renal function and contraindications 1

Discharge Management

Discharge Criteria

Low-risk patients can be safely discharged on day 3-4 if all criteria met:

• Hemodynamically stable 3
• No major arrhythmias 3
• LVEF ≥40% 3
• Successful reperfusion without complications if PCI performed 3
• No additional critical coronary stenoses requiring intervention 3
• GRACE risk score ≤140 3
• No recurrent chest pain or ischemia at rest or with minimal activity 3

High-risk patients require extended monitoring until stabilized if any of the above criteria are not met 3

Discharge Medications ("ABCDE" Regimen)

Antiplatelet Therapy:

• Aspirin 81 mg daily indefinitely 3
• P2Y12 inhibitor (ticagrelor 90 mg twice daily preferred, or prasugrel 10 mg daily, or clopidogrel 75 mg daily) for 12 months unless excessive bleeding risk 1, 3

Beta-Blockers:

• Mandatory for all patients with LVEF ≤40%, continued indefinitely 1, 3
• Recommended for all other NSTEMI patients unless contraindicated, with gradual titration for moderate-to-severe LV dysfunction 3

Cholesterol Management:

• High-intensity statin (atorvastatin 40-80 mg or rosuvastatin 20-40 mg) to achieve LDL-C <1.4 mmol/L (<55 mg/dL) with ≥50% reduction from baseline 3
• Start immediately regardless of baseline cholesterol for plaque stabilization and anti-inflammatory effects 2

ACE Inhibitors or ARBs:

• Mandatory for patients with heart failure, LVEF <40%, hypertension, diabetes, or anterior MI 1, 3
• Start within 24 hours unless contraindicated 3
• ARB provides alternative if ACE inhibitor not tolerated 1

Mineralocorticoid Receptor Antagonists:

• Eplerenone recommended for patients with LVEF ≤35% and either heart failure or diabetes, without significant renal dysfunction or hyperkalemia 1

Additional Medications:

• Diastolic blood pressure goal <90 mmHg (<85 mmHg in diabetic patients) 1
• Proton pump inhibitor if high bleeding risk or history of GI bleeding 1

Follow-Up Care

Early Follow-Up (1-2 weeks post-discharge):

• Assess medication tolerance and adherence 3
• Evaluate symptom status and functional capacity 3
• Review risk factor modification plans including smoking cessation, diet, exercise 3

Intermediate Follow-Up (4-6 weeks):

• Reassess functional status 3
• Consider stress testing if not performed during hospitalization 3
• Optimize medical therapy doses, particularly beta-blockers and ACE inhibitors 3

Long-Term Follow-Up (3 months and beyond):

• Monitor for recurrent symptoms 3
• Assess achievement of LDL-C goals (<55 mg/dL) 3
• Reinforce lifestyle modifications and cardiac rehabilitation enrollment 3
• Enroll in secondary prevention/cardiac rehabilitation program 1

Common Pitfalls to Avoid

• Do not delay invasive angiography in high-risk patients to perform noninvasive testing first, as this represents inappropriate risk stratification 4
• Do not routinely transfuse blood in anemic patients without determining optimal hemoglobin threshold, as overtransfusion may worsen outcomes 1
• Do not discontinue P2Y12 inhibitor before 12 months unless life-threatening bleeding occurs 1, 3
• Do not use clopidogrel when ticagrelor is available and not contraindicated, as ticagrelor provides superior outcomes 1, 2
• Do not administer prasugrel before coronary anatomy is known, as it should only be given after angiography prior to PCI 1