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The 10 commandments of prosthetic valve - ESC 2014 1. Mechanical heart valve- life-long OA. Antiplatelet medications does not provide adequate protection against thromboembolic risk. The combination of low-dose aspirin and vitamin K antagonists (VKAs) is recommended for all patients with mechanical valve prostheses by the ACC)/AHA & selective aspirin – ACCP/ESC/EACTS . 2. Bioprosthetic - avoid the need for life-long anticoagulation. 3.INR- 2.5 for aortic without additional risk factors for thromboembolism (e.g., Afib, prior thromboembolism, left ventricular dysfunction, and hypercoagulable states). INR range of 3.0 (or 3.5) for mitral and any aortic valve prosthesis associated with thromboembolic risk factors. 4. INR variability - increased mortality . INR variability is dictated by genetic polymorphisms of cytochrome P450 2C9, genotyping of patients treated with VKA is not currently recommended. 5. INR (>6.0) but no severe bleeding, management includes transient withdrawal of the OA and administration of oral vitamin K according to the actual and target INR values. Patients with severe bleeding should be treated with immediate anticoagulant reversal (usually prothrombin concentrates or fresh frozen plasma) and vitamin K. 6. PTCA- 3-6 months of triple antithrombotic therapy (VKA, aspirin, and a P2Y12 inhibitor) are recommended. The combination of clopidogrel and VKA without aspirin should be considered because it may decrease the risk of bleeding without a significantly increased risk of thromboembolism. 7.DOA (dabigatran, rivaroxaban, apixaban, and edoxaban) –NOT to use 8. Thromboembolism risk x10 s higher in the first month following valve replacement surgery. Use of heparin 12-24 hours following surgery is recommended. Use of either UFH or LMWH is reasonable. Use of low-dose aspirin can lower the thromboembolic risk while increasing the bleeding risk postoperatively. Anticoagulation with VKA is recommended for the first 3 months in most patients receiving a bioprosthetic valve. ESC/EACTS/ ACCP - aspirin therapy in the first 3 months following a bioprosthetic aortic valve replacement. ACC/AHA/ACCP aspirin beyond 3 months in all patients with bioprosthetic valves. 9. Noncardiac surgery- can often be performed safely without interruption of VKA therapy if they are at low risk for bleeding (e.g., dental care, ophthalmologic and demographic surgery, many gastrointestinal endoscopic procedures). Major surgery- INR should be
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Prosthetic Heart Valves
General public
Prosthetic Heart Valves disease
A prosthetic valve brings more morbidity than health(sometimes)
Preoperative
• Clinical status • Imaging• Essential general health screen • Counselling and consent
• Operation• Option• Cost• Post op• Anticoagulation• Marital life• Pregnancy
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
First mechanical valve
• The first successful valve was the Bjork-Shiley valve, introduced in 1969.• 1977 by St. Jude Medical
Most common mechanical heart valves Now• Double disc
TAVI is 10 year old
• Most commonly used in Europe• Strict use in USA
Implantation tech
Surgical• Guidelines
Percutaneous• Pilot studies
Valve tissue
• Autograft:Ross procedure• Heterograft(Different genes)• Allograft: same species-Human cadaver• Xenograft :other species(Bovine/porcine)
How to choose
Mechanical• Young <65 Years
Bioprostheis• Old• Pregnancy yet to come• Risk of OAC
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
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
Prosthetic valve thrombosis
Right side-TV• Thrombolysis if thrombus is
<8mm ,is preferred over surgery
Left side-AOV/MV• Surgery is preferred over surgery
Endocarditis(ACC-2007)
• TEE• At least 4 to 6 weeks of antibiotic therapy•
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
MRI
MR conditional • Consult MR specialist
MR safe • Up to 4.7 tesla MRI can be used
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