Thronlboernbolism remains a serious complication after valve replacement. Lifelong anticoagulation is requised for all patients with a prosthetic valve and in a few cases with bioprosthesis.
Bioprosthetic Valves
The risk of thromoboembolism is limited to the first three months, until the sewing ring gets endothelialised. The recommendation is to have less intense regimen of anticoagulation (INR 2-2.5) for all rnitral bioprostetic valves. As the incidence of thromoembolism is less for aortic bioprosthesis anticoagulation is considered to be optional in many centers. They are put on aspirin and persantin. However patients with lnitral bioprosthesis who are in AF, who has very large LA and has LA thrombus with history 01 thromboembolism should have long-term low-level anticoagulation.
Mechanical Prosthetic Valves
These patients should have life long anticoagulation. In the absence of anticoagulation systemic embolism and strokes have been reported to be 5-50 per cent. Anticoagulants have reduced this incidence to 1-3 per cent per y e a However the treatment itself can cause complications. This is related to the level o; anticoagulation. Low level of anticoagulatioil (INR 2-2.5) has shown to have fewer coillplications and at the same time as effective in preventing thro~nbo embolism. Standard anticoagulation (INR 3-4.5) which gives rise to more complications should be limited to high-risk group. It is generally believed that patients with prosthetic aortic valves in sinus rhythm need only lower levels of anticoagulation. In our country where control of anticoagulation is nlore difficult,a low level of anticoagulation is advisable.
Anticoagulation in Prosthetic Valves
Bioprosthetic Valves
The risk of thromoboembolism is limited to the first three months, until the sewing ring gets endothelialised. The recommendation is to have less intense regimen of anticoagulation (INR 2-2.5) for all rnitral bioprostetic valves. As the incidence of thromoembolism is less for aortic bioprosthesis anticoagulation is considered to be optional in many centers. They are put on aspirin and persantin. However patients with lnitral bioprosthesis who are in AF, who has very large LA and has LA thrombus with history 01 thromboembolism should have long-term low-level anticoagulation.
Mechanical Prosthetic Valves
These patients should have life long anticoagulation. In the absence of anticoagulation systemic embolism and strokes have been reported to be 5-50 per cent. Anticoagulants have reduced this incidence to 1-3 per cent per y e a However the treatment itself can cause complications. This is related to the level o; anticoagulation. Low level of anticoagulatioil (INR 2-2.5) has shown to have fewer coillplications and at the same time as effective in preventing thro~nbo embolism. Standard anticoagulation (INR 3-4.5) which gives rise to more complications should be limited to high-risk group. It is generally believed that patients with prosthetic aortic valves in sinus rhythm need only lower levels of anticoagulation. In our country where control of anticoagulation is nlore difficult,a low level of anticoagulation is advisable.
Anticoagulation in Prosthetic Valves
The usual anticoagulants used are: (I) Warfarin sodium, and (2) Acitrorn (coumarin derivative).In patients who had thromboembolism previously, addition of low dose aspirin (75 mg per day) is found to be useful along with anticoagulation.
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