Prosthetic valves and warfarin

Question 1

Mechanical heart valves - complications

Answer 1

Thrombus formation (blood stagnates and clots)

Infective endocarditis (infection in prosthesis)

Haemolysis causing anaemia (blood gets churned up in the valve)

Question 2

What would you hear on auscultation with a mechanical valve?

Answer 2

A click

S1 click - metallic mitral valve

S2 click - metallic aortic valve

Question 3

What is the surgical treatment for severe AS?

Answer 3

TAVI

Open surgery is still first line option for younger, fitter patients (Long term outcomes for TAVI are still not clear as it is a relatively new procedure)

Question 4

Warfarin target INRs

Answer 4

Target 2.5 (2-3) recommended for:

• DVT/PE treatment
• AF
• Bioprosthetic valves

Target 3.5 (3-4)
- Recurrent DVT/PE in people receiving anticoagulation currently and with INR >2

Mechanical heart valves
- INR target depends on the location of the valve and patient risk factors

Question 5

Raised INR on warfarin management

Answer 5

Major bleeding - stop warfarin and give Vitamin K by slow IV injection, give prothrombin complex (or FFP if that isn’t available)

INR >8 with minor bleeding:

• Stop warfarin
• Give vitamin K by slow IV injection
• Repeat dose of vitamin K if INR still too high after 24 hours
• Restart warfarin when INR <5

INR >8 no bleeding:

• Stop warfarin
• Give oral Vitamin K
• Repeat dose of vitamin K if INR still too high after 24 hours
• Restart warfarin when INR <5

INR 5-8 minor bleeding:

• Stop warfarin
• Give vitamin K slow IV injection
• Restart warfarin when INR <5

INR 5-8 no bleeding:

• Withhold 1-2 doses of warfarin
• Reduce subsequent doses

Question 6

Major bleeding on warfarin

Answer 6

Stop warfarin and give Vitamin K by slow IV injection, give prothrombin complex (or FFP if that isn’t available)

Question 7

INR >8 with minor bleeding, on warfarin

Answer 7

• Stop warfarin
• Give vitamin K by slow IV injection
• Repeat dose of vitamin K if INR still too high after 24 hours
• Restart warfarin when INR <5

Question 8

INR >8 no bleeding and on warfarin

Answer 8

• Stop warfarin
• Give oral Vitamin K
• Repeat dose of vitamin K if INR still too high after 24 hours
• Restart warfarin when INR <5

Question 9

INR 5-8, minor bleeding, on warfarin

Answer 9

• Stop warfarin
• Give vitamin K slow IV injection
• Restart warfarin when INR <5

Question 10

INR 5-8, no bleeding, on warfarin

Answer 10

• Withhold 1-2 doses of warfarin

- Reduce subsequent doses