The burden of radiation exposure in congenital heart disease: the Italian cohort profile and bioresource collection in HARMONIC project.

BACKGROUND: The European-funded Health Effects of Cardiac Fluoroscopy and Modern Radiotherapy in Pediatrics (HARMONIC) project aims to improve knowledge on the effects of medical exposure to ionizing radiation (IR) received during childhood. One of its objectives is to build a consolidated European cohort of pediatric patients who have undergone cardiac catheterization (Cath) procedures, with the goal of enhancing the assessment of long-term radiation-associated cancer risk. The purpose of our study is to provide a detailed description of the Italian cohort contributing to the HARMONIC project, including an analysis of cumulative IR exposure, reduction trend over the years and an overview of the prospective collection of biological samples for research in this vulnerable population. METHODS: In a single-center retrospective cohort study, a total of 584 patients (323 males) with a median age of 6 (2-13) years, referred at the Pediatric Cardiology in Niguarda Hospital from January 2015 to October 2023, were included. Biological specimens from a subset of 60 patients were prospectively collected for biobanking at baseline, immediately post-procedure and after 12 months. RESULTS: Two hundred fifty-nine (44%) patients were under 1 year old at their first procedure. The median KAP/weight was 0.09 Gy·cm2/kg (IQR: 0.03-0.20), and the median fluoroscopy time was 8.10 min (IQR: 4.00-16.25). KAP/weight ratio showed a positive correlation with the fluoroscopy time (Spearman's rho = 0.679, p < 0.001). Significant dose reduction was observed either after implementation of an upgraded technology system and a radiation training among staff. The Italian cohort includes 1858 different types of specimens for Harmonic biobank, including blood, plasma, serum, clot, cell pellet/lymphocytes, saliva. CONCLUSIONS: In the Italian Harmonic cohort, radiation dose in cardiac catheterization varies by age and procedure type. An institution's radiological protection strategy has contributed to a reduction in radiation dose over time. Biological samples provide a valuable resource for future research, offering an opportunity to identify potential early biomarkers for health surveillance and personalized risk assessment.

Thoracic radiotherapy as a risk factor for heart ischemia in subjects treated with chest irradiation and chemotherapy and without classic cardiovascular RISK factors.

BACKGROUND AND PURPOSE: Radiation Induced Heart Disease (RIHD) represents a late effect of chest irradiation, contributing in increasing mortality rate in oncological patients by affecting pericardium, myocardium, valvs and coronaries. Currently, regarding the risk of Coronary Artery Disease (CAD), a cardiological screening involving exercise stress electrocardiography after 5-10 years from radiotherapy is advised. We sought to determine the rate of ischemia at exercise stress electrocardiography in a population of patients without cardiovascular risk factors who sustained radiotherapy, using a cohort of patients presenting with at least one cardiovascular risk factor as control group. DESIGN AND METHODS: A population of 115 patients who sustained chest irradiation (and associated chemotherapy), presenting without classic cardiovascular risk factors or typical symptoms suggesting CAD, was evaluated with exercise stress electrocardiography. 135 patients with at least one risk factor for cardiovascular disease candidate to stress testing for primary prevention or for atypical symptoms served as control group. RESULTS: The cohort of irradiated patients without classical cardiovascular risk factors is younger (48.7 ± 10.1 vs 60.5 ± 10.8 years, p < 0.001) and presents a lower percentage of males when compared with the control group. In this latter group 25.9% of subjects has diabetes, 62.9% dyslipidaemia, 67.4% hypertension and 19.2% actively smoke. Despite this important differences regarding classic cardiovascular risk factors, no significant differences were found in the number of positive exercise stress electrocardiography (10.4 vs 5.9%, p = ns). CONCLUSIONS: Chest irradiation represents a strong cardiovascular risk factor. In fact, prevalence of positive ECG-stress test is not different (nor higher and nor lower) in irradiated subjects without cardiovascular risk and not irradiated patients with classic cardiovascular risk.