Makindo Medical Notes

Related Subjects: |Atherosclerosis |Ischaemic heart disease |Assessing Chest Pain |Acute Coronary Syndrome (ACS): Complications |ACS - General |ACS - STEMI |ACS - NSTEMI |ACS - GRACE Score |ACS - ECG Changes |ACS -Cardiac Troponins |ACS - Post MI arrhythmias |ACS: Right Ventricular STEMI |ACS: Sgarbossa Criteria |Wellen's syndrome

All ACS including STEMI and NSTEMI can present atypically, especially in women, older adults, and people with diabetes. Risk assessment in patients with Non-ST-Elevation Myocardial Infarction (NSTEMI) is crucial for guiding treatment decisions and predicting outcomes. A more interventional approach - i.e. PCI may be suited for higher risk patients - these are older, diabetes, heart failure, CKD, hypotensive, tachycardic, prolonged or recurrent chest pain, high troponin and ST depression or T wave inversion and a prior history of MI or PCI/CABG. There are various scores such as GRACE and TIMI and HEART.

Acute Management of Non-ST Acute Coronary Syndrome: Standard + Angiography for high-risk patients

Introduction

• Presents typically as chest pain +/- ECG changes. If the Cardiac Troponin meets the definition of an MI then NSTEMI is diagnosed; otherwise, it is Unstable Angina or another cause of chest pain.
• It's important to consider other causes of chest pain and troponin rises such as PE, Myocarditis, and Takotsubo Cardiomyopathy.
• High-risk patients may require angiography.

Aetiology

• Usually due to a partially occluded coronary artery.
• Myocardial necrosis can occur, leading to a rise in troponin.

Classification

• If troponin is elevated = myocardial damage, then NSTEMI.
• If troponin is not elevated, then Unstable Angina.

Suspect Diagnosis If:

• Ischaemic-sounding chest pain + ECG changes (new/deeper T wave inversion, new ST depression).
• If the GRACE 2 score is >140 or there are other features of high-risk ACS (e.g., persistent ST depression >1mm, ongoing chest pain, T wave inversion in leads V1-V4, Wellen's syndrome), contact cardiology immediately.

Medications

• Oxygen: Maintain SaO₂ 94-98%.
• GTN 400 mcg per spray or S/L GTN tablet (300 or 500 mcg) for chest pain if SBP >110 mmHg.
• Pain relief: Morphine 5-10 mg IV or Diamorphine 2.5-5 mg IV.
• Antiemetic: Metoclopramide 10 mg IV.
• Antiplatelet: Aspirin 300 mg PO stat.
• Commence a P2Y12 antagonist (discuss with cardiology if risk of bleeding):
  • Clopidogrel 300-600 mg PO stat.
  • Ticagrelor 180 mg PO stat.
  • Prasugrel 60 mg PO stat.
• Metoprolol 5-15 mg IV or 50 mg PO BD if LV dysfunction/tachycardia (avoid in asthma or pulmonary oedema).
• Furosemide 40-80 mg IV if pulmonary oedema.
• Fondaparinux 2.5 mg SC daily if no reperfusion therapy planned.
• Hyperglycaemia: Monitor blood glucose; aim for 6-11 mmol/L.

Risk Assessment

• Patients with NSTEACS (USA/NSTEMI) should be evaluated for angiography based on risk scores like TIMI and GRACE scores.
• TIMI Risk Score for USA/NSTEMI: Online calculator
  • Age ≥ 65 years? Yes +1
  • ≥ 3 Risk Factors for CAD? Yes +1
  • Known CAD (stenosis ≥ 50%)? Yes +1
  • Aspirin use in the past 7 days? Yes +1
  • Severe angina (≥ 2 episodes < 24 hrs)? Yes +1
  • ST changes ≥ 0.5mm? Yes +1
  • + Cardiac Marker? Yes +1
• GRACE Score: Online calculator here
  • Age, Heart rate, Systolic BP, Creatinine, Killip class, Cardiac arrest at admission, Elevated biomarkers, ST segment deviation.

Two-Dimensional Echocardiography in ACS

• Useful in assessing patients with acute chest pain and indeterminate ECG changes.
• Regional wall motion abnormalities can indicate ischaemia or infarction.

High-Risk Cases Needing Angiography

• Haemodynamic instability or cardiogenic shock.
• Recurrent or ongoing chest pain refractory to medical treatment.
• Life-threatening arrhythmias or cardiac arrest.
• Mechanical complications of MI.

On Discharge

• Statin (e.g., Atorvastatin 80 mg PO nocte).
• ACE Inhibitor (e.g., Ramipril 2.5 mg PO daily, titrate to max tolerated).
• Aldosterone antagonist (e.g., Eplerenone 25 mg PO daily).
• Smoking cessation advice and support.
• Anticoagulation for patients with a long-term indication (e.g., atrial fibrillation).
• Dietary and exercise advice: Mediterranean diet, 150 minutes/week of moderate-intensity exercise.
• Home after a few days if uncomplicated, with follow-up in a cardiac rehabilitation program.