Cardiac allograft vasculopathy: pathology, prevention and treatment

Purpose of review Cardiac transplantation is a recognized therapy for end-stage heart failure. Graft coronary artery disease is a chief determinant of long-term survival following cardiac transplantation. There are multiple purported etiologies for graft coronary artery disease including both immunologic and nonimmunologic factors. Immunologic factors include human leukocyte antigen mismatching, cytokine production, and activation of the cellular immune system. Nonimmunologic factors include diabetes, hypertension, hyperlipidemia, and cytomegalovirus infection, just to name a few. There are also donor and recipient factors including age, prior coronary artery disease in the donor heart, and mode of donor brain death. Recent findings The diagnosis of graft coronary artery disease is especially difficult, partially due to the de-innervated allograft, as well as to its inherent predilection to affect the medium-sized and smaller arteries in a concentric and diffuse nature. Conventional angiography can overlook this condition because of the lack of eccentric plaques in larger epicardial arteries. Intravascular ultrasonography, by contrast, is more sensitive in detecting graft coronary artery disease but is unable to visualize the entire arterial system. Treatment is challenging and often unrewarding, leading to re-transplantation. Prevention is therefore ideal and involves protection against endothelial injury before and during transplantation as well as after transplantation, with decreased ischemic time, aggressive attention to early rejection, risk factor modification, and close follow-up. Summary This review will look at the pathophysiology of graft coronary artery disease, current diagnostic and therapeutic choices, as well as existing and future directions.