Abstract Background Paediatric patients with congenital heart disease (CHD) often undergo medical imaging procedures, including cardiac catheterisation (CC), which can result in relatively high cumulative lifetime exposure to ionising radiation (IR) and potentially increase cancer risk. Leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNAcn) have been suggested as biomarkers for cancer risk. In this prospective study, we investigated whether IR exposure from CC interventions is linked to changes in LTL and mtDNAcn. Methods LTL and mtDNAcn were assessed using qRT-PCR in 167 paediatric CHD patients (median age: 6 years; male/female: 82/85) undergoing CC at three children's hospitals: Niguarda Hospital (Milan, Italy), Marie-Lannelongue Hospital, and Necker Hospital (Paris, France). Samples were collected immediately before (T0) and after (T1) the procedure, with additional samples obtained approximately one year later (T2) in a subgroup of 37 patients. Results The median total dose area product (DAP) and fluoroscopy time (FT) were 1.9 Gy·cm² and 8.7 minutes for diagnostic catheterisations, and 1.7 Gy·cm² and 11.0 minutes for interventional catheterisations. Immediately after the procedure, patients exhibited significantly shorter LTL and higher mtDNAcn compared to baseline (p0.001 for both biomarkers, Figure). Delta changes in LTL (p0.0001) and mtDNAcn (p=0.03) were inversely correlated with baseline values, suggesting a greater response in patients with initially shorter LTL and lower mtDNAcn. No correlation was observed between delta changes in LTL or mtDNAcn and DAP or FT. In the subset of patients assessed at three time points, LTL remained significantly shorter at T1 (p=0.002) and T2 (p=0.006) compared to T0. Conclusion Significant changes in LTL and mtDNAcn were observed following CC procedures, with telomeres appearing particularly sensitive to IR exposure. These changes occur acutely and persist for at least one year post-exposure, suggesting that even low-dose IR may have a lasting impact on cellular aging.
Campolo et al. (Sat,) studied this question.