41.5 Prevention and Treatment of CV disease

Question 1

What lifestyle choices can be made to prevent the development of cardiovascular disease?

Answer 1

• Smoking
• Obesity
• Physical activity
• Blood pressure
• Diet

Question 2

What surgical interventions can be performed as CV disease treatment?

Answer 2

Balloon angioplasty, stenting. coronary bypass.

Question 3

What is a coronary artery bypass graft?

Answer 3

surgical reattachment of vessel distal to obstructed region in order to restore blood flow.

Question 4

What is Balloon angioplasty + stenting?

Answer 4

widening of stenosed artery via inflation of balloon inserted into artery (via catheter). Stent then inserted to keep vessel open + restore adequate blood flow.

Question 5

What risk are surgical interventions associated with?

Answer 5

Surgical procedures still carry risk of restenosis + require maintenance therapy to maintain widened lumen.

Question 6

What is a lipid lowering drug and what is its mechanism of action?

Answer 6

Statins (1st line)
Inhibit HMG-CoA reductase (hepatic enzyme) → ↓ de novo cholesterol synthesis in liver → compensatory ↑-reg of LDLRs on hepatocytes → ↑ LDL-C uptake.

Question 7

Give an example of a statin

Answer 7

Simvastatin

Question 8

What are some types of drug that can be used to prevent arterial thrombosis?

Answer 8

• Thrombolytic agents -> Dissolve existing thrombi
  
  • Streptokinase
  • Recombinant tissue plasminogen activator (tPA)
• Antiplatelet agents -> Interfere with platelet activity
  
  • Aspirin
  • Clopidogrel
  • Abciximab
• Anticoagulants -> Prevent clot formation and extension
  
  • Heparin (Warfarin)

Question 9

What is streptokinase and how is it useful?

Answer 9

• It is an enzyme of beta-haemolytic Streptococci
• It dissolves blood clots by converting plasminogen into plasmin, so it is good at treating thrombi
• It is mostly used to treat acute myocardial infarction with aspirin

Question 10

What is recombinant tPA and how is it useful?

Answer 10

• Recombinant tissue plasminogen activator
• This works by speeding up the conversion of plasminogen to plasmin
• It is mostly used to treat acute myocardial infarction with aspirin and heparin

Question 11

What is aspirin used for in arterial thrombosis? How does it work?

Answer 11

• Non-competitive inhibitor of COX-1 and COX-2
• Low dose aspirin blocks platelet TxA₂ production
• This prevents platelet activation and aggregation
• It is used mostly after myocardial infarction, ischaemic stroke or in TIA Unstable angina. It can also be used prophylactically.

Question 12

What are some examples of anticoagulant drugs for treatment and prevention of venous thromboembolism?

Answer 12

• Heparin [IMPORTANT]
• Warfarin [IMPORTANT]
• Apixaban
• Rivaroxaban
• Dabigatran

Question 13

How does heparin work?

Answer 13

• ATIII (anti-thrombin III) is an endogenous inhibitor of coagulation factors, especially Factor Xa and Thrombin (IIa)
• Heparin stabilises these interactions, slowing the clotting cascade
• Therefore, it is useful for prevention and treatment of thrombosis

Question 14

What conditions is heparin effective against?

Answer 14

• Venous thrombosis (esp. Hip replacement)
• Pulmonary Embolism

Question 15

What can be used for heparin reversal?

Answer 15

Protamine sulphate

Question 16

What can be used for Warfarin reversal?

Answer 16

Vitamin K
Drugs which induce hepatic P450 enzymes (rifampicin and carbamazepine) as they will increase the break down of warfarin
Drugs that bind warfarin in the gut (Colestyramine)