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 .
Low-intensity oral anticoagulation plus low-dose aspirin versus high-intensity oral anticoagulation alone: a randomized trial in patients with mechanical prosthetic heart valves.
BACKGROUND Mechanical heart valve replacement requires lifelong anticoagulant treatment . Aspirin has proved useful in further reducing thromboembolic events when added to oral anticoagulants . However , increased ( gastrointestinal ) bleeding was observed at the doses previously tested for this combination in heart valve prostheses . METHODS We performed a prospect i ve r and omized trial to compare the combination of low-intensity oral anticoagulants ( international normalized ratio 2.5 to 3.5 ) plus aspirin ( 100 mg/day ) ( arm A ) versus high-intensity oral anticoagulants alone ( arm B ) ( international normalized ratio 3.5 to 4.5 ) . Arm A included 258 patients and arm B 245 patients . The two groups were comparable for all baseline characteristics . RESULTS The outcomes of the study were embolism , valve thrombosis , and major hemorrhage . The median follow-up was 23 months . The two treatments offered similar antithrombotic protection . The incidence of embolic episodes was 1.32 per 100 patient-years ( 95 % confidence interval 0.53 to 2.7 ) for arm A and 1.48 per 100 patient-years ( 95 % confidence interval 0.59 to 3.03 ) for arm B. Major hemorrhage occurred in 1.13 per 100 patient-years ( 95 % confidence interval 0.41 to 2.45 ) for arm A and 2.33 per 100 patient-years ( 95 % confidence interval 1.17 to 4.14 ) for arm B. Gastrointestinal bleeding was not increased by this combined reduced dose of aspirin and coumarin
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 .