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Clotting properties in diverse valve prostheses
Insights
Mechanical heart valves like St. Jude Medical cause minor changes, while Starr-Edwards prostheses significantly impact platelets and hemolysis. Tissue valves also show clotting alterations, necessitating careful anticoagulation management.
Area of Science:
- Cardiovascular Medicine
- Hematology
Background:
- Heart valve prostheses, including mechanical and tissue types, can affect blood coagulation and red blood cell integrity.
- Understanding these effects is crucial for managing anticoagulation therapy and patient outcomes.
Purpose of the Study:
- To compare the hematological and thrombotic effects of different heart valve prostheses (St. Jude Medical, Starr-Edwards, tissue valves).
- To provide recommendations for anticoagulation management based on prosthesis type and patient condition.
Main Methods:
- Comparative analysis of hemolysis and thrombophilia markers in patients with various heart valve prostheses.
- Review of current anticoagulation guidelines for different valve types and patient populations.
Main Results:
- St. Jude Medical prostheses showed minimal alterations in hemolysis and thrombophilia compared to normal.
- Starr-Edwards prostheses exhibited the most significant changes in platelets and hemolysis.
- Tissue valves also demonstrated notable alterations in the clotting system and intravascular hemolysis.
Conclusions:
- Vitamin K antagonists are preferred for long-term anticoagulation in mechanical prostheses.
- Heparin is recommended during the initial months of pregnancy.
- Anticoagulation can potentially be discontinued three months after tissue valve implantation if no additional risk factors are present.
Abstract:
With regard to both hemolysis and thrombophilia the St. Jude Medical prosthesis shows only minor alterations in comparison to normals. The most significant alterations concerning platelets and hemolysis have been found in patients with Starr-Edwards prostheses. Even in tissue valves, major alterations of the clotting system and chronic intravascular hemolysis were found. For long-term anticoagulation in mechanical prostheses--even with sinus rhythm--vitamin K antagonists should be preferred. During the first months of gravidity only heparin can be recommended. In St. Jude Medical valves anticoagulation with dicumarolum must be recommended; whether antiaggregation drugs can be recommended is not yet proved. Anticoagulation may be discontinued three months after tissue valve implantation if there are no additional risk factors. Diminishing platelet adhesivity in tissue valves may support these conclusions.