Radiotherapy-induced Cardiac Implantable Electronic Device Dysfunction in Patients with Cancer

Abstract Radiotherapy can affect the electronic components of a cardiac implantable electronic device (CIED) resulting in malfunction and/or damage. We sought to assess the incidence, predictors and clinical impact of CIED dysfunction (CIED-D) following radiotherapy for cancer treatment. Clinical characteristics, cancer and different types of CIEDs as well as radiation-dose were evaluated. The investigation identified 230 patients; mean age 78±8 years and 70% were male. A total of 199 (86%) patients had pacemakers (59% dual-chamber), 21 (9%) cardioverter-defibrillators and 10 (4%) resynchronizators/defibrillators. The left pectoral (n=192, 83%) was the most common CIED location. Sixteen (7%) patients experienced 18 events of CIED-D after radiotherapy. Reset to back-up pacing mode was the most common encountered dysfunction, and only 1 (6%) patient of those with CIED-D experienced symptoms of atrio-ventricular dys-synchrony. Those who had CIED-D had a shorter device-age at the time of radiotherapy compared to those who did not (2.5±1.5 vs. 3.8±3.4 years, P =0.005). The total dose prescribed to the tumor (66±30 vs. 42±23 Gy) was significantly higher among those who had CIED-D (P