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 .
Pharmacologic control of thromboembolic complications of cardiac-valve replacement.
Abstract Either dipyridamole , a vasodilator known to reduce platelate adhesiveness and aggregation , or a placebo was given in a daily dose of 400 mg as a r and om , blind trial to 70 patients who had undergone prosthetic cardiac-valve replacement . Patients in both groups were given anticoagulation with warfarin sodium . Of 36 patients in the placebo group followed for 557 months systemic arterial embolism occurred in 17 per cent . Twenty-seven patients in the dipyridamole group followed for 393 months gave no clinical evidence of arterial embolism .  Dipyridamole was discontinued shortly after surgery in seven patients , and these were followed for 110 months . In two of them cerebral emboli developed six months after treatment was discontinued . It is tentatively concluded that the addition of dipyridamole to a program of anticoagulation reduces the frequency of postoperative arterial emboli originating on prosthetic cardiac valves in patients who can tolerate the drug
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 .