Week 12: Acute Coronary Syndrome (ACS)

Question 1

W. is the common underlying pathology of ACS? (2)

Answer 1

Plaque rupture, thrombosis and coronary artery inflammation.

Rarely due to emboli, coronary spasm or vasculitis.

Question 2

W. is myocardial infarction? (1)

Answer 2

Myocardial cell death releasing cardiac troponin with ischaemia.

Question 3

W. are the non-modifiable risk factors of ACS?

Answer 3

Age
Male
Family Hx
Ethnicity

Question 4

W. are the modifiable risk factors of ACS? (3)

Answer 4

Diabetes
Hypertension
Dyslipidaemia

Question 5

W. are the symptoms of ACS? (4)

Answer 5

Acute chest discomfort > 15 mins or past 12 hrs.
Dull, central +/or crushing
Not relieved by rest.
May radiate.

Question 6

W. associated symptoms are linked with ACS? (6)

Answer 6

Anxiety
Nausea
Pallor
Sweatiness
Dyspnoea
Palpitations

Question 7

What are the signs of ACS? (6)

Answer 7

Haemodynamic instability (systolic BP = < 90mmHg)
- Sympathetic activation - Tachycardia + sweating
- Vagal activation - Bradycardia, N+V.

4th Heart Sound

Low grade fever

Signs of HF: Basal Crepitations, increased JVP, 3rd heart sound

Question 8

W. causes chest pain?

Answer 8

Pain in the thorax

Question 9

W. are the cardiac causes of chest pain? (8)

Answer 9

ACS (unstable angina + MI)
Stable angina
Dissecting thoracic aneurysm
Pericarditis
Cardiac Tamponade
Myocarditis
Acute Congestive Cardiac Failure
Arrhythmias

Question 10

W. are the non-cardiac causes of chest pain? (10)

Answer 10

Respiratory:
- PE, Pneumothorax, CAP, Asthma pleural effusion

Other:
- Acute pancreatitis
- GORD
- Oesophagitis
- Rib Fracture
- Spinal disorders
- Cancer
- Psychogenic

Non-specific chest pain.

Question 11

W. investigations are carried out to diagnose ACS? (12)

Answer 11

12-lead ECG:
- Pathological Q waves
- Left bundle branch block
- ST changes

Blood sample for high sensitivity troponin I or T

Basic Observations: BP, HR, O2 sats.

CXR: Signs of HF, Pulmonary causes

Other:
- FBC
- U+E
- Lipid
- LFTs
- TFTs
- HbA1c
- CRP
- ESR

Question 12

W. is the universal definition of MI? (3)

Answer 12

New Ischaemic ECG changes

Imaging evidence of new loss of viable myocardium or new regional wall motion abnormalities in pattern consistent with ischaemic aetiology.

Identification of coronary thrombus by angiography or autopsy.

Question 13

W. is the initial management of suspected ACS?

Answer 13

Pain relief:
- GTN +/or opioid (IV diamorphine 2.5-5mg over 5 mins)

Question 14

W. are the main features of PPCI? (5)

Answer 14

Preferred reperfusion strategy for STEMI given within 120 mins of ECG based diagnosis.

Angiography first

Access via the radial or femoral artery.

X-ray guided insertion through the aorta and into affected coronary artery.

Balloon insertion - restore blood flow

Question 15

W. are the main features of Fibrinolysis? (5)

Answer 15

Reperfusion strategy for STEMI patients presenting with 12 hrs of symptom onset where PCPI can’t be performed within 120 mins.

Fibrin-specific agent (Tenecteplase, Alteplase or Reteplase) = preferred agent.

Administer antithrombin therapy simultaneously.

ECG 60-90 mins after Fibrinolysis

If persistent ST-segment elevation suggesting failed coronary reperfusion.
- Offer coronary angiography with follow-on PCI.

Question 16

Explain the use of medications in managing ACS.

Answer 16

DAPT for PCI:
- Aspirin lifelong + P2Y12i for 12 months:
- Prasugrel (PCI) or Ticagrelor (PCI and high bleed risk/delayed or no PCI)
- Clopidogrel (if high bleed risk or on anticoagulant)

Fibrinolytics:
- Activates plasminogen to form plasmin, degrages fibrin and breaks up trombin.
- Streptokinase, Alteplase, Tenecteplase

Antithrombin therapy:
- Unfractionated heparin with bailout glycoprotein IIb/IIa inhibitor (Eptifibatide/Tirofiban). Bivalirudin if femoral access needed.
- with antiplaletelet therapy.

Medical management of STEMI:
- Unsuitable for PCI or Fibrinolysis
- Aspirin + Ticagrelor (or Clopidogrel if high bleed risk)

Initial antithrombin therapy:
- Fondaparinaux- binds antithrombin III, neutralising factor Xa interrupts clotting cascade.

Consider angiography + PCI within 72 hrs
- If PCI eligible, give unfractionated heparin.

Question 17

Explain the secondary prevention of ACS. (5)

Answer 17

ACEi (ARB if intolerant):
- As soon as haemodynamically stable. Continue indefinitely.
- Titrate upwards every 12-24 hrs, complete titration within 6 weeks to max tolerated dose.
- Monitor: Renal function, U+E, BP before starting and every 2-4 weeks.

Beta-blocker:
- As soon as haemodynamically stable.
- Titrate slowly up to max. tolerated dose.
- Monitor HR + BP
- 12 months all patients, lifelong if HF with reduced LVEF.

DAPT:
- Aspirin lifelong
- P2y12 inhibitor: 12 months
- GI protection

Statin:
- Atorvastatin 80mg
- Monitor liver enzymes, cholesterol HbA1c at 3 months then annually, CK if persistent muscle pain, TFTs + HbA1c before starting.

Aldosterone antagonist:
- HF with reduced LVEF
- Initiate after ACEi within 14 days of MI.
- Monitor renal function and U+E.

Question 18

Explain the use of novel therapies in ACS. (3)

Answer 18

Rivaroxaban 2.5mg BD:
- Primary prevention of ACS in px with high risk of ischaemic events.
- Secondary prevention of ACS (12 months) with aspirin

Question 19

Explain the process of cardiac rehabilitation. (2)

Answer 19

Refer whilst inpatient.
Structured education and lifestyle support:
- Physical activity
- Stress management
- Lifestyle including sexual health.

Question 20

W. lifestyle advice is given to patients with ACS? (6)

Answer 20

Healthy eating: Mediterranean diet, bread, fruit + veg, fish and plant-based products.

Alcohol: Max. 14 units/week

Regular physical activity: 20-30mins daily to point of slight SOB.

Smoking cessation

Aim for healthy BMI

Annual influenza vaccine.