Currently, and for the near future, well-managed
warfarin appears to be the most effective method to prevent
thromboembolism and
bleeding in patients with mechanical heart valves. These patients, when in an anticoagulation management service, have 50-90% fewer complications than patients not managed in this way. Further, the complication rate in such settings approximates that in patients with bioprosthetic, tissue valves not receiving anticoagulation. Oral
direct thrombin inhibitors are safe and effective in patients with
atrial fibrillation, but this is not proven in those with prosthetic heart valves. The idea of using a combination of different
antiplatelet agents is attractive on a theoretical basis, but the available data are limited and do not support this approach. Combined
aspirin (or another
antiplatelet agent) and
warfarin has been recommended, but close scrutiny of this combination suggests that it causes more
bleeding and may offer no more protection than well-managed
warfarin therapy. Recently, interest has been shown in the significance of high-intensity transient signals (HITS), which may represent gaseous or microemboli, and whether
therapy to reduce HITS might influence the development of neurological symptoms. However, present data related to HITS are too limited and conflicting to make any firm conclusions.