Clinical implications of intracoronary imaging in cardiac allograft vasculopathy.

Abstract

Despite improvements in survival and outcomes, cardiac allograft vasculopathy (CAV), a unique form of coronary artery disease, continues to remains the leading cause of late morbidity and mortality in heart transplantation (HTx) recipients and accounts for ≈30% of all-cause mortality in this group.1 CAV can develop at any stage after HTx with an incidence of ≈7% within the first year of transplantation and 30% within 5 years.2 CAV is clinically silent and asymptomatic in its initial stages, making early diagnosis particularly challenging. Annual coronary angiography is currently the imaging modality of choice for screening and surveillance of graft coronary arteries for signs of CAV.3 However, low sensitivity of coronary angiography for detecting early-stage CAV necessitates the use of more advanced intracoronary imaging to diagnose the disease in its initial stages. Recent advances in invasive coronary imaging such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have shown promising results in detecting subangiographic CAV, predicting prognosis and guiding therapy.4–6 The current article reviews the present state and future directions for the use of intracoronary imaging in the diagnosis, prognosis, and treatment of CAV. Several invasive and noninvasive imaging tools have been used to screen and diagnose CAV. Some of the noninvasive tests such as dobutamine stress echocardiography, myocardial perfusion imaging (exercise and pharmacological), cardiac MRI, and coronary computed tomography angiography have been studied extensively for this purpose.7–9 Although these noninvasive tests are highly specific for angiographic CAV, they lack sensitivity in detecting subangiographic CAV.7 The diffuse nature of CAV may result in inability to identify differences in radionuclide uptake in myocardial scintigraphy testing. A 2014 meta-analysis by Wever-Pinzon et al9 demonstrated that compared with coronary angiography, coronary computed tomography angiography was 97% sensitive for detecting any CAV. However, when …