[Anticoagulants in therapy of patients with heart valve prostheses]

Thrombosis in subjects with valvular prostheses is primarily attributable to the tendency of platelets to adhere to non-natural surfaces. In addition, the release of ADP and serotonin leads to their clumping. Anticoagulant management is based on the employment of dicumarols, which inhibit the synthesis of factors VII, IX & X, and anti-clumping substances. When using the former, care must be taken to prevent unwanted side-effects and to watch for possible interactions with drugs that may enhance or diminish their effectiveness. Among the latter, a preference should be shown for those that act on the release of endogenous ADP; these are free from toxicity and significant side-effects. The main remedy, however, remains that elaborating prostheses coated with protein material to prevent adhesion by platelets and so obtain a non-thrombogenic surface.