Cancer and implantable cardiac defibrillator. Causality, confusion or chance?

INTRODUCTION AND OBJECTIVES: implantable cardiac defibrillator (ICD) has been established as a therapy for malignant ventricular arrhythmias in patients at high risk of suffering them. Some studies suggest a possible relationship between the development of cancer and some prosthetic materials. Likewise, some investigations describe a higher incidence of cancer in patients with an ICD that suggest a potential relationship.

METHODS: Retrospective cohort study of patients that underwent implantation of an ICD in the Complejo Hospitalario de Navarra between 2000 and 2016. The follow-up finished in June 2018. Sociodemographic, comorbidities and oncological data was analysed. Cancer incidence rates were estimated and compared with the general population data and with data of a cohort of patients with reduced LVEF heart failure. Risk of cancer models were adjusted by competitive risk models.

RESULTS: 497 patients were included, mostly male (89.1%), with a mean age of 59.98 (14.98) years and a proportion of smokers of 67.6% and of ischaemic heart disease of 51.6%. The cancer incidence rate in the sample was 1230.9 per 100.000 person-year. In our study, features associated with cancer were older age, higher tobacco use and ischaemic cardiopathy.

CONCLUSIONS: In our sample of ICD carriers the incidence of cancer is high. This finding mainly seems to be related to tobacco usage and higher age.