Coronary CT for CAV detection in paediatric patients; a single centre experience

Abstract Introduction Cardiac allograft vasculopathy (CAV) is a feared complication after heart transplant (1). CT imaging is an attractive option for screening of CAV, especially in paediatric patients, a population in which CAV is diagnosed in only 4% in routine screening (2). Although increasingly reported in adult population, little data exist on the use of CT in CAV detection in paediatric patients (3,4). Purpose This report summarizes the experience and protocol of CT imaging in evaluating CAV in paediatric heart transplant patients. Methods Coronary CT replaced invasive angiography in the paediatric cardiac post-transplant surveillance protocol from 2/2022 in our institution (Figure 1). Since then, 35 paediatric cardiac transplant patients (16 males) have been assessed (Revolution CT, GE Healthcare, Chicago, USA). Of note, only three patients received isosorbide dinitrate prior to imaging as the routine use in paediatric population is not recommended (5). The CT images were analysed and reformatted with syngo.via software (Siemens Healthineers, Erlangen, Germany). Results The median age was 13.4 years (range 2.0-19.6 years). CT was performed at median of 5.0 years (range 1.0-18.2 years) post-transplant. No sedation was performed solely for the CT. Eight patients required sedation due to MRI scan performed at the same visit. The mean heart rate was 80 bpm (range 60-127 bpm), with 20 patients with heart rate above the intended age-specific limits regardless of the medication (Figure 1). CAV was found in two patients (6%) by CT, both confirmed in subsequent angiography (Figure 2). After the start of CT screening for CAV, no unplanned angiographies have been performed. The median radiation dose was 53.7 mGy.cm (range 21.3-206.26), median effective dose 1.85 mSv (range 0.72-5.6 mSv). Conclusions CAV screening may be performed in paediatric heart transplantation patients also by CT, even with higher heart rates and without the routine use of isosorbide dinitrate. Larger studies and longer follow-up will be needed to assess the role and optimal timing for CAV screening.