The novel oral anticoagulants (factor Xa inhibitors and direct thrombin inhibitors) are not indicated for the prevention of thromboembolism associated with mechanical heart valves. The randomized, phase II study to evaluate the safety and pharmaco- kinetics of oral dabigatran etexilate in patients after heart valve replacement (RE-ALIGN) trial showed an increase in thrombo- embolic and bleeding complications with dabigatran compared to warfarin in patients with mechanical heart valves.473 About 20% to 40% of patients with endocarditis suf- fer embolic events, the majority of which affect the central The rate of embolic events decreases rapidly after the initiation of antibiotic therapy.476 478 The risk of embolic stroke is associated with the size of the veg- etation, involvement of the mitral valve, and infection by Anticoagulant therapy does not reduce the risk of embolic stroke and may increase the risk of cerebral hemorrhage.474 Anticoagulant therapy should not be used to treat patients with infective endocarditis unless indicated for other cardiovascular conditions.459 Nonbacterial thrombotic endocarditis, also known as marantic endocardi- tis, is associated with malignant neoplasms, antiphospholipid antibodies (aPLs), and systemic lupus erythematosus (SLE) and may be a source of an embolic stroke.480 Anticoagulant therapy is indicated for patients with nonbacterial thrombotic endocarditis and systemic embolism.459 PFO and ASAs A PFO is present in 15% to 25% of the adult population, and ASA occurs in 1% to 4%. A PFO serves as a right-to- left conduit for paradoxical emboli originating in the veins, whereas ASA may be a nidus for thrombus formation. 