ABSTRACT
As valve thrombosis, thromboembolism and anticoagulant-related bleeding together account for about 75% of complications encountered by patients with prosthetic valves, and because each of these complications can have devastating consequences, their prevention by optimising antithrombotic management is arguably the most important aspect of postoperative and long-term care. Antithrombotic management after heart valve surgery should therefore be individualised for each patient, depending on the type of surgery (repair or replacement), the type of prosthesis and the patient’s own risk factors (see Box 8.1), bearing in mind that thrombosis and embolism may have other sources in addition to a repaired or replaced valve, and that some patients may be more prone to thrombosis or more prone to bleeding. This concept of patient-specific and prosthesis-specific antithrombotic management requires an understanding of the basic mechanisms of thrombosis and embolism in valve surgery patients, the limitations of anticoagulation and antiplatelet therapy and the subtle differences between one prosthesis and another, even within a broad design category. It thus involves much more detailed patient assessment and prosthesis evaluation than contained in previously published guidelines.1,2 Whereas a uniform approach, categorising patients only according to the position of the prosthesis within the heart and its broad design category (caged-ball, tilting-disc, bileaflet or bioprosthesis) may be more convenient for anticoagulation clinics and those supervising the care of large numbers of valve surgery patients, it may not benefit the individual patient, who may be under-anticoagulated or over-anticoagulated for his/her risk factors and particular type of prosthesis. Unfortunately, not all prostheses within a particular design category have the same thrombogenicity.
