Many factors contribute to the patient’s bleeding risk and the success of extracorporeal circulation, including the disease-associated disorders such as an elevated Sequential Organ Failure Assessment score, mechanical ventilation, heart failure with fluid overload; an elevated ionized calcium concentration, an elevated platelet count and fibrinogen concentration, red cell transfusion, platelet factor 4 antibodies, concomitant therapies such as antiplatelet drugs; biocompatibility of the filter membranes, vascular access, and medical staff-related factors [18]. This evidence concerns the gene PF4 and heart failure.