Cassandra speaks: a case series of unanticipated subcutaneous ICD premature battery depletion in a single-centre experience

Abstract

Abstract Background Subcutaneous ICDs (S-ICD) are a valuable option in sudden cardiac death prevention. The main advantage over conventional transvenous ICDs is the absence of intravascular hardware for patients without the need for cardiac stimulation, resynchronization therapy or anti-tachycardia pacing. The claim of reduced lead-related complications has on the contrary been challenged by recent warnings of unexpected lead fracture. Moreover, concerns related to premature battery depletion (PBD) leading to unanticipated device replacement are increasing. Purpose To evaluate retrospectively the incidence of unanticipated S-ICD premature battery depletion in a single-centre experience. Method 168 consecutive patients implanted with S-ICD from February 2015 to November 2022 in our tertiary cardiology centre were included in this study. 4 patients moved to other sites and were thus lost to follow-up, leaving a total of 164 patients. PBD was defined as the occurrence of battery depletion requiring generator replacement earlier than 60 months post-implantation in the absence of therapy being delivered, or as a result of manufacturer recommendations. Results Most patients were implanted for primary prevention (101 patients, 60%). The main aetiology was hypertrophic cardiomyopathy (47 patients, 28%), followed by arrhythmogenic (35, 21%) and dilated idiopathic cardiomyopathy (24, 14%). Mean age and left ventricular ejection fraction at baseline were 46±18yrs and 51±16%, respectively. Over a total follow up period of 44±25 months, at 58±17 months following implantation 19 (11,6%) patients needed early replacement due to PBD, while 2 (1.2%) patients had lead fracture after respectively 41 and 26 months, for a total of 12,8% of patients with system-related complications. In addition to those patients requiring early replacement due to PBD or lead fracture, two underwent S-ICD extraction due to infection. Analysis of freedom from unanticipated PBD per year of implantation showed higher rates in years 2016 and 2017, with 67% and 27% of all implanted patients, respectively (Figure 1). Conclusions In this study, the incidence of PBDs appear to be higher than reported in literature though confined to a limited device series. However, if on the contrary the trend should remain remarkably high, that would not only endanger patients health due to repeated replacements, but also pose a huge economic burden to health systems.