Detection and imaging of cardiac allograft vasculopathy

Abstract

Cardiac allograft vasculopathy (CAV) is an important cause of morbidity and mortality among cardiac transplant recipients. CAV occurs in approximately 30% of patients by 5 years and 50% by 10 years, and is a major cause of graft loss and death. Early detection of CAV is important because it may allow alterations in medical therapy before progression to the stage that revascularization is required. This has led to routine screening for CAV in transplant recipients, traditionally by invasive coronary angiography (ICA). Recent advances in imaging technology, specifically intravascular ultrasound, now also permit detection of subangiographic CAV. Noninvasive stress testing and multislice coronary computed tomography angiography have been investigated as noninvasive alternatives to routine ICA. However, currently available noninvasive tests remain limited with respect to their sensitivity and specificity for CAV. Given the multiple available diagnostic modalities, no consensus definition for the classification of CAV has been widely accepted, although new guidelines that rely heavily on ICA have recently been published by the International Society of Heart and Lung Transplantation. This review summarizes imaging modalities that are utilized in the diagnosis and surveillance of CAV and explores newer imaging techniques that may play a future role.