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 .
Early and long-term (one-year) effects of the association of aspirin and oral anticoagulant on thrombi and morbidity after replacement of the mitral valve with the St. Jude medical prosthesis: a clinical and transesophageal echocardiographic study.
OBJECTIVES The aim of the study was to test the value of low dose aspirin associated with st and ard oral anticoagulants ( OAC )  after mechanical mitral valve replacement ( MMRV ) to reduce str and s , thrombi and thromboembolic events . BACKGROUND Str and s and thrombi are thought to increase the risk of embolic events after MMVR , particularly in the immediate postoperative period . METHODS Two hundred twenty-nine patients were prospect ively recruited : 109 patients ( group A+ ) were r and omly assigned to aspirin ( 200 mg per day ) with OAC and 120 patients ( group A- ) to OAC alone ( international normalized ratio 2.5 to 3.5 ) . All patients were subjected to multiplane transesophageal echocardiography at nine days and five months and were followed up for one year . RESULTS At nine days and five months , there was a high and comparable incidence of str and s in the two groups ( group A+ : 44 % , 58 % ; group A- : 49 % , 63 % ) . However , the incidence of nonobstructive periprosthetic valve thrombi was significantly lower in group A+ at 9 days : 5 % versus 13 % , p = 0.03 . Total thromboembolic events were reduced in group A+ ( 9 % vs. 25 % , p = 0.004 ) although there was an increased incidence of gastrointestinal hemorrhage ( 7 % vs. 0 % ) . Overall mortality was 9 % in group A+ and 4 % in group A- . Valve-related events were similar in both groups . Early thrombi , but not str and s , were associated with higher morbidity , especially thromboembolic events ( 30 % vs. 13 % , p = 0.003 ) . CONCLUSIONS One year after MMVR , the association of aspirin with OAC reduced thrombi and thromboembolic events , but not morbidity , due to an increase in hemorrhagic complications
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 .