The growing proportion of sensitized cardiac recipients presents an additional challenge to the transplant practitioner attempting to minimize the occurrence of antibody mediated rejection (AMR). Patients pre-exposed or "sensitized" to antigen exposing events (i.e.: blood transfusions, multiple pregnancies, prior organ transplantations, ventricular support devices) are more likely to both possess preformed and develop de-novo antibodies. Sensitized patients with panel reactive antibodies > 25% are at risk for increased mortality after heart transplantation.