Cardiac allograft vasculopathy: current knowledge and future direction

Cardiac allograft vasculopathy (CAV) is a unique form of coronary artery disease affecting heart transplant recipients. Although prognosis of heart transplant recipients has improved over time, CAV remains a significant cause of mortality beyond the first year of cardiac transplantation. Many traditional and non-traditional risk factors for the development of CAV have been described. Traditional risk factors include dyslipidemia, diabetes and hypertension. Non-traditional risk factors include cytomegalovirus infection, HLA mismatch, antibody-mediated rejection, and mode of donor brain death. There is a complex interplay between immunological and non-immunological factors ultimately leading to endothelial injury and exaggerated repair response. Pathologically, CAV manifests as fibroelastic proliferation of intima and luminal stenosis. Early diagnosis is paramount as heart transplant recipients are frequently asymptomatic owing to cardiac denervation related to the transplant surgery. Intravascular ultrasound (IVUS) offers many advantages over conventional angiography and is an excellent predictor of prognosis in heart transplant recipients. Many non-invasive diagnostic tests including dobutamine stress echocardiography, CT angiography, and MRI are available; though, none has replaced angiography. This review discusses the risk factors, pathogenesis, and diagnosis of CAV and highlights some current concepts and recent developments in this field.