Acute Coronary Syndrome (ACS) (UA/MI) - IHD/Coronary Heart Disease

Question 1

Background

Answer 1

ACS includes UA, STEMI, NSTEMI

Difference between the 3:
STEMI = ST elevation
NSTEMI = Troponin positive (showing heart damage)
Unstable angina = Troponin negative.

STEMI is full blockage of major coronary artery.
NSTEMI and UA are partial/intermittent blockage of major artery.
- Intermittent meaning a plaque ruptured making a blood clot (thrombus) that blocked smaller branches of the major artery. This still causes Myocardial damage and is NSTEMI.
- Partial - thrombus or plaque partial blocks a artery. No Myocardial damage occurs and there is risk of full blockage = STEMI.

For UA if its extensive some heart muscle will die and cause a MI

Question 2

Signs and symptoms

Answer 2

• Crushing central chest pain/tightness or discomfort (Spreads to arms, shoulders, throat, jaw, teeth, back or upper abdomen)
• Breathlessness/SOB
• Sweating
• Back pain, abdominal pain, syncope, Fatigue, Dizziness
  3 types share these symptoms.

STEMI
Symptoms more severe last >30 min and isn’t relieved by GTN/Rest
Other stemi symptoms: SOB, fear, pallor, sweating (clammy feeling), anxiety, vasoconstriction (peripheral) and shock.

NSTEMI
Symptoms develop over 24-72 or more hours.

Unstable angina (UA)
Frequent attacks of angina for the 1st time OR sudden worsening of previously stable angina OR recurrent angina at rest OR sudden onset of severe chest pain at rest.
Symptoms develop over 24-72 or more hours.

Differential diagnosis
Key feature PAIN responds to GTN within 2 to 5 minutes indicates its STABLE angina.
- UA and stable: Stable symptoms happen from exercise/activity/Stress and stop on REST. UA Chest pain for severe, lasts longer, reoccurs.

Question 3

ECG and troponin levels

Answer 3

SUS ACS then a ECG is done ASAP.
Troponin and Troponin T levels also tested initially then 10/12 hrs. after chest pain.

Troponin levels:
Low risk of MI: <0.1mcg/L
Medium risk of MI: 0.1-0.6 mcg/L
High risk of MI: >0.6 mcg/L

Troponin T levels:
<14ng/L = Normal
14 - <100ng/L = consistent with myocardial damage
=/>100ng/L = supports the diagnosis of MI

**STEMI*
ST elevation initially after a few hrs. T wave inverts and then over time a Q wave develops which shows myocardial damage.
Troponin >0.1 mcg/m or Troponin T =/>100 ng/L

NSTEMI
May have ST depression and deep T wave inversion.
2X 0.1mcg/mL troponin or troponin T =/>100 ng/L

Unstable Angina
May have ST depression and deep T wave inversion
May have NO/little troponin change (<0.1mcg/mL or Troponin T 14-100 ng/L)

Stable - is different due to response to GTN. And the blockage types

Question 4

STEMI/NSTEMI/UA Management

Answer 4

CHECK VISUAL SUMMARY PHONE - NICE guidelines

Initial ACS management
MONA
- Morphine IV - ASAP Pain Relief
- Oxygen - for SOB PRN
- Nitrates GTN (sublingual or buccal) ASAP - Pain relief
- Aspirin - ASAP 300mg loading dose
- Insulin - Keep blood Glucose >11 - prevent hyperglycaemia.

Fibrinolytics - Streptokinase, Tissue plasminogen activators (Reteplase, Alteplase, Tenecteplase) - MAINLY only used in STEMI

UA/NSETMI
IF Fondaparinux contraindicated due to High bleeding risk or PT under going immediate coronary angiography ALT is UFH.

Question 5

Secondary Prevention

Answer 5

PIC
Generally for drugs
- ACEi, Statin life long

• Dual antiplatelet therapy (Aspirin + 2nd antiplatelet) - up to 12 months
  OR
  Dual/Triple + Anticoagulant EG: Aspirin +/or clopidogrel + Rivaroxaban 2.5mg BD (ONLY this 1 can be used)
  NOTE: Anticoagulant/Triple used if very high cardiac biomarkers in blood
• Beta blocker
  ALT Diltiazem/Verapamil if b-blocker contraindicated and no pulmonary congestion or reduced LVEF) - Up to 12 months