Multimodality Imaging to Detect Rejection, and Cardiac Allograft Vasculopathy in Pediatric Heart Transplant Recipients—An Illustrative Review

Abstract

The three most common modalities of graft surveillance in pediatric heart transplant (HT) recipients include echocardiography, coronary angiography, and endomyocardial biopsy (EMB). The survival outcomes after HT in children have improved considerably in recent years. However, allograft rejection and cardiac allograft vasculopathy remain the leading cause of death or re-transplantation. The routine surveillance by EMB and coronary angiography are invasive and risky. Newer noninvasive echocardiographic techniques, including tissue Doppler imaging (TDI), 2-D speckle tracking echocardiography, CT coronary angiography (CTCA), cardiovascular magnetic resonance (CMR), single-photon emission computed tomography (SPECT), and positron emission tomography (PET) and invasive techniques such as intravascular ultrasound (IVUS), functional flow reserve (CFR) of coronary arteries, optical coherence tomography (OCT), have emerged as powerful tools which may help early recognition of sub-clinical rejection, response to treatment, early detection, and progression of CAV. The multimodality imaging approach, including noninvasive and invasive tests, is the future for the transplanted heart to detect dysfunction, rejections, and early CAV. This review illustrates noninvasive and invasive imaging techniques currently used or could be considered for clinical use in detecting heart transplant rejection, dysfunction, and CAV in children.

Cardiac Allograft Vasculopathy: Challenges and Advances in Invasive and Non-Invasive Diagnostic Modalities

“…In the presence of coronary stenosis, there is already vasodilation of the coronary artery distal to the stenosis, so administration of adenosine fails to cause significant further dilation distally and, thus, the FFR is reduced [ 19 ]. In the absence of significant epicardial stenosis, a decreased FFR after adenosine administration could indicate microvascular disease [ 20 ]. Hiraishi et al demonstrated this in a study of 33 pediatric patients with Kawasaki disease, reporting reduced FFR to be correlated with histopathologic and angiographic evidence of microvascular disease [ 21 ].…”