The document discusses the risks and management of prosthetic heart valves, particularly focusing on mechanical versus bioprosthetic valves during pregnancy. It highlights the complications associated with mechanical valves, such as maternal mortality and increased risks of thromboembolism, advocating for alternative anticoagulation methods. Additionally, it emphasizes the importance of careful planning around pregnancy in women with mechanical heart valves and includes guidelines for preoperative care and postoperative management.

1. Prosthetic Heart
Valves
General public

2. Mechanical valve is worse than bioprosthetic

3. Prosthetic Heart Valves disease
• A prosthetic valve brings more morbidity than health(sometimes). Pregnancy
is a prothrombotic state because of the relative increases in fibrinogen,
plasminogen activator inhibitors, clotting factors, Von Willebrand factor, and
platelet adhesion molecules, and concomitant decreases in protein S activity.
These hypercoaguable changes begin in early pregnancy and persist for at
least 6 to 12 weeks postpartum. pregnant women are at the highest risk for
complications of mechanical valves at a time when it is the most difficult to
maintain adequate anticoagulation.

4. Risk for the mother and foetus
Mother
• Still birth
• Abortion
• Stuck valve
• Bleeding during 3rd trimester
FETUS
• Warfarin in the 1ST trimester
suggest an embryopathy rate of
≈5% to 7%
• warfarin embryopathy characterized
by nasal bone hypoplasia and
stippled epiphyses

5. Warfarin ≥5mg /day
• Brings hazards
• Use altenative anticoagulation like LMW at a dose of 1-1.5mg/kg B.D doses
to maintain anti-Xa level at 0.8-1.2
• Caesarean section on Warfarin brings more bleeding related maternal death
• Try vaginal delivery as far as possible

6. Prosthetic Heart Valves disease
• 1.4% risk of maternal mortality
• 23% risk of haemorrhage
• 18.4% risk of foetal loss
• Valve thrombosis occurred in 4.7%
• 20% of stuck valve die
• 50% of the Stuck valve in occurred during the 1st trimester
• >40% suffers serious complications

7. Preoperative
• Clinical status
• Imaging
• Essential general health screen
• Counselling and consent
• Operation
• Option
• Cost
• Post op
• Anticoagulation
• Marital life
• Pregnancy

8. What types of prosthetic valves
Mechanical(STENT+)
• Double disc
• Single disc- minor and major orifice
of polycarbonate
• Ball in cage
Bio prosthesis(Stented or
stentless)
• Stent less bio prosthesis
• bovine or porcine heart valve implanted
without a metallic/plastic frame
• Stented bioprosthesis :Wired frame that
provides the structure for the biologic
material. The biologic material is usually
bovine or porcine pericardium, which is
specially treated to reduce antigenicity

9. First mechanical valve
• The first successful valve was the Bjork-Shiley valve, introduced in 1969.
• 1977 by St. Jude Medical

10. Most common mechanical heart valves Now
• Double disc

11. TAVI is 10 year old
• Most commonly used in Europe
• Strict use in USA

12. Implantation tech
Surgical
• Guidelines
Percutaneous
• Pilot studies

13. Valve tissue
• Autograft:Ross procedure
• Heterograft(Different genes)
• Allograft: same species-Human cadaver
• Xenograft :other species(Bovine/porcine)

14. How to choose
Mechanical
• Young <65 Years
Bioprostheis
• Old
• Pregnancy yet to come
• Risk of OAC

15. With mechanical valve prostheses before
elective surgery or invasive procedures?
• warfarin must be discontinued for elective procedures
• UFH to maintain aPTT= 55-70 seconds while INR decreases <2
• Stop UFH before night
• Start UFH at earliest after surgery
• Low-molecular-weight heparin (LMWH) is not approved
• No Vit K to quickly reduce INR

16. Mechanical valves became pregnant?
• Stop Warf during embryogenesis(6-12 weeks) and keep on UFH -20000U BD SC
• Start Warf after 12 weeks
• Stop Warf at 36 weeks
• Start UFH at 36 weeks till completion of Delivery
• aPTT between 55 and 70 seconds by 6 hours after injection
• Weight-adjusted subcutaneous LMWH twice a day throughout the whole pregnancy
(plasma level of anti-Xa 0.7-1.2 U/mL by 4-6 hours after injection)
• UFH/LMW is not effective as Warf

17. Prosthetic valve thrombosis
Right side-TV
• Thrombolysis if thrombus is
<8mm ,is preferred over surgery
Left side-AOV/MV
• Surgery is preferred over surgery

19. Guidelines
• If warfarin dose is >5 mg/d, then replace with LMWHs be used in the first
trimester (target anti-Xa level of 0.8–1.2 U/mL, 4–6 hours post dose)
• A low dose of Aspirin is always indicated especially around 3rd trimester

20. Endocarditis(ACC-2007)
• TEE
• At least 4 to 6 weeks of antibiotic therapy
•

21. Follow patients
• Echocardiography
• PT/INR
• If ecchymosis-Check INR and consult
• IF breathlessness –valve leaflet are caught in thrombus
• If fever for more than >4 days –check for IE

22. MRI for Prosthetic valve
MR conditional
• Consult MR specialist
MR safe
• Up to 4.7 tesla MRI can be used

23. Counselling
1. No pregnancy is safe with mechanical heart valve and that this must be
taken into account when counselling women of reproductive age in need
of a mechanical prosthetic heart valve surgery
2. Bioprosthesis is preferred whenever possible

24. Bibliography
1. Cotrufo M, De Feo M, De Santo LS, Romano G, Della Corte A, Renzulli A, Gallo C. Risk of warfarin during
pregnancy with mechanical valve prostheses. Obstet Gynecol. 2002;99:35–40
2. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP 3rd,Guyton RA, O’Gara PT, Ruiz CE, Skubas NJ,
Sorajja P, Sundt TM 3rd,Thomas JD; ACC/AHA Task Force Members. 2014 AHA/ACC Guideline for the
Management of Patients With Valvular Heart Disease: a report of the American College of
Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;129:e521–e643.
3. Berresheim M, Wilkie J, Nerenberg KA, Ibrahim Q, Bungard TJ.A case series of LMWH use in pregnancy:
should trough anti-Xa levels guide dosing? Thromb Res. 2014;134:1234–1240.
4. Yinon Y, Siu SC, Warshafsky C, Maxwell C, McLeod A, Colman JM, Sermer M, Silversides CK. Use of low
molecular weight heparin in pregnant women with mechanical heart valves. Am J Cardiol. 2009;104:1259–1263.

25. Absence of darkness is light