A perfect storm: Understanding hemostasis, coagulation and inflammation with artificial material

Mechanical circulatory support (MCS) devices have revolutionized the treatment of acute and chronic heart failure in both the pediatric and adult communities over the past decades, but they are not without complications. The presence of a foreign body, especially within the vasculature, evokes a response by the body to try to rid itself of the invader via myriad mechanisms that include the coagulation system, the innate immune system and even the adaptive immune system. While these responses have allowed us (and other species) to survive to this day, they pose a particular challenge to the safe and effective use of implantable device technologies. There have been many clinical reports of thrombosis and inflammation associated with MCS devices; the discussion below centers on the physiologic and pathophysiologic mechanisms that are the underpinnings of these phenomena.