Which of the following is not an ideal indication for bioprosthetic valve (compared to mechanical prosthetic valve)?
A) Female planning pregnancy
B) Young adult male
C) Elderly female
D) History of endocarditis
Correct answer: B) Young adult male
It would be better to implant a mechanical prosthetic valve in an adult male because of the longer projected longevity of the individual and higher chance of degeneration of a bioprosthetic valve due to higher hemodynamic trauma.
Bioprosthetic heart valves (tissue valves)
- They are heart valves obtained from animals which undergo chemical procedures to make them suitable for implantation in the human heart.
- Porcine valves are the commonly used tissue valves (As the pig heart is the most similar to the human heart).
- Bioprosthetic valves do not require anticoagulant therapy after the valve gets endothelialized (about 3 months).
- In contrast, a mechanical valve requires lifelong anticoagulant therapy.
- They have a higher rate of degeneration due to hemodynamic trauma and hence have a lower projected longevity
They are preferred in:
- Elderly patients
- Elderly patients are more prone to develop bleeding complications when given anticoagulants.
- Due to lower haemodynamic stress, the valves have increased longevity.
- Females planning pregnancy
- Heparin is needed for anticoagulation in females planning pregnancy as warfarin can cause fetal anomalies
- But the long term use of heparin is costly, has injection site issues and is less effective compared to warfarin in preventing coagulation.
- It is also associated with risk of osteoporosis.
- Hence, bioprosthetic valves are preferred in females as they don’t require anticoagulation after the initial period of endothelialization.
- Patients with history of infective endocarditis
- Bioprosthetic valves are more resistant to endocarditis.
- Right sided valvular diseases
- The haemodynamic stress in the right side of the heart is lower and hence there is decreased deterioration of the valve.
Read more on candidates for bioprosthetic valves at: https://cardiophile.org/candidates-for-tissue-valve-replacement/
Based on image by Robertolyra. Accessed from http://en.wikipedia.org/wiki/File:BiologicalValves.jpg. Licensed under Creative Commons Attribution-ShareAlike license versions 3.0.