A systematic review and meta-analysis on oncological radiotherapy in patients with a cardiac implantable electronic device: prevalence and predictors of device malfunction in 3121 patients

Background: The number of patients with cardiac implantable electronic devices (CIEDs) undergoing radiotherapy (RT) for cancer treatment is growing. At present, prevalence and predictors of RT-induced CIEDs malfunctions are not defined. Methods: Systematic review and meta-analysis conducted following the PRISMA recommendations. PubMed, Scopus, and Google Scholar were searched from inception to 31/01/2022 for studies reporting RT-induced malfunctions in CIEDs patients. Aim was to assess the prevalence of RT-induced CIEDs malfunctions and identify potential predictors. Results: Thirty-two out of 3962 records matched the inclusion criteria and were included in the meta-analysis. A total of 135 CIEDs malfunctions were detected among 3121 patients (6.6%, 95% confidence interval [CI]: 5.1%-8.4%). The pooled prevalence increased moving from pacemaker (PM) to implantable cardioverter defibrillator (ICD), and cardiac resynchronization therapy and defibrillator (CRT-D) groups (4.1%, 95%CI: 2.9-5.8; 8.2% 95%CI: 5.9-11.3; and 19.8%, 95%CI: 11.4-32.2 respectively). A higher risk ratio (RR) of malfunctions was found when neutron-producing energies were used as compared to non-neutron-producing energies (RR 9.98, 95%CI: 5.09-19.60) and in patients with ICD/CRT-D as compared to patients with PM/CRT-P (RR 2.07, 95%CI: 1.40-3.06). On the other hand, no association was found between maximal radiation dose at CIED > 2 Gy and CIEDs malfunctions (RR 0.93; 95%CI: 0.31-2.76). Conclusions: RT-related CIEDs malfunction had a prevalence ranging from 4% to 20%. The use of neutron-producing energies and more complex devices (ICD/CRT-D) were associated with higher risk of device malfunction, while the radiation dose at CIED did not significantly impact on the risk unless higher doses (>10Gy) were used.