A lower daily dose of aspirin ( < 100 mg ) may be associated with a lower major bleeding risk than higher doses .
Adding antiplatelet therapy , either dipyridamole or low-dose aspirin , to oral anticoagulation decreases the risk of systemic embolism or death among patients with prosthetic heart valves .
The risk of major bleeding is increased with antiplatelet therapy .
These results apply to patients with mechanical prosthetic valves or those with biological valves and indicators of high risk such as atrial fibrillation or prior thromboembolic events .
The effectiveness and safety of low-dose aspirin ( 100 mg daily ) appears to be similar to higher-dose aspirin and dipyridamole .
BACKGROUND Patients with prosthetic heart valves are at increased risk for valve thrombosis and arterial thromboembolism .
Oral anticoagulation alone , or the addition of antiplatelet drugs , has been used to minimise this risk .
An important issue is the effectiveness and safety of the latter strategy .
OBJECTIVES This is an up date of our previous review ; the goal was to create a valid synthesis of all available , method ologically sound data to further assess the safety and efficacy of combined oral anticoagulant and antiplatelet therapy versus oral anticoagulant monotherapy in patients with prosthetic heart valves .
Anticoagulation therapy with combined low dose aspirin and warfarin following mechanical heart valve replacement.
INTRODUCTION This study was design ed to evaluate safety and efficacy of combined low dose aspirin and warfarin therapy following mechanical heart valve replacement . METHODS A total of 1496 patients ( 686 males , mean age 35±8.5 years ) undergoing mechanical heart valvular replacement were r and omly divided into study ( warfarin plus 75 - 100 mg aspirin ) or control ( warfarin only ) group . International normalized ratio ( INR ) and prothrombin time was maintained at 1.8 - 2.5 and 1.5 - 2.0 times of the normal value , respectively . Thromboembolic events and major bleedings were registered during follow up . RESULTS Patients were followed up for 24±9 months . The average dose of warfarin in the study and control group was 2.92±0.87 mg and 2.89±0.79 mg , respectively ( p>0.05 ) . The overall thromboembolic events in study group were lower than in control group ( 2.1 % vs. 3.6 % , p=0.044 ) . No statistically significant differences were found in hemorrhage events ( 3.5 % vs. 3.7 % , p>0.05 ) or mortality ( 0.3 % vs 0.4 % , p>0.05 ) between the two groups . CONCLUSIONS Following mechanical valve replacement , combined low dose aspirin and warfarin therapy was associated with a greater reduction in thromboembolism events  than warfarin therapy alone . This combined treatment was not associated with an increase in the rate of major bleeding or mortality
A lower daily dose of aspirin ( < 100 mg ) may be associated with a lower major bleeding risk than higher doses .
Adding antiplatelet therapy , either dipyridamole or low-dose aspirin , to oral anticoagulation decreases the risk of systemic embolism or death among patients with prosthetic heart valves .
The risk of major bleeding is increased with antiplatelet therapy .
These results apply to patients with mechanical prosthetic valves or those with biological valves and indicators of high risk such as atrial fibrillation or prior thromboembolic events .
The effectiveness and safety of low-dose aspirin ( 100 mg daily ) appears to be similar to higher-dose aspirin and dipyridamole .
BACKGROUND Patients with prosthetic heart valves are at increased risk for valve thrombosis and arterial thromboembolism .
Oral anticoagulation alone , or the addition of antiplatelet drugs , has been used to minimise this risk .
An important issue is the effectiveness and safety of the latter strategy .
OBJECTIVES This is an up date of our previous review ; the goal was to create a valid synthesis of all available , method ologically sound data to further assess the safety and efficacy of combined oral anticoagulant and antiplatelet therapy versus oral anticoagulant monotherapy in patients with prosthetic heart valves .