97 Single-centre long-term safety outcomes of patients implanted with subcutaneous implantable cardioverter defibrillators

IntroductionBoston Scientific (location) Emblem™ subcutaneous implantable cardioverter defibrillator (SICD) is an extrathoracic defibrillator system. Two landmark studies, S-ICD System IDE Clinical Investigation (IDE) and Boston Scientific Post Market S-ICD Registry (Effortless) demonstrated safety profiles similar to transvenous (TV) implantable cardioverter defibrillators (ICDs).AimThis study aimed to investigate the working safety profile of Boston Scientific SICD Emblem™ devices implanted in patients attending a hospital trust within the United Kingdom (UK) between February 2015 and 1st March 2020.MethodsThis was a single-center, retrospective study that investigated patients followed up at a single UK hospital trust. Data was collected using Boston Scientific Latitude™ NXT and patient electronic care records.ResultsA total of 116 patients with a Boston Scientific Emblem™ SICD were included in the study. 115 patients had the SICD implanted at the Hospital Trust whilst 1 patient had their implant completed at an external paediatric center. Patient characteristics including SICD indication are summarized in table 1. Over the course of the study follow-up 20 patients experienced at least one event, which were subsequently stratified into appropriate or inappropriate events. 7 (6%) patients received an appropriate shock for ventricular arrhythmias whilst 7 (6%) also received an inappropriate shock (IAS). Patients that received inappropriate therapies had a total of 12 shocks delivered overall. Of the total shocks delivered, 7 (58%) were secondary to non-physiological noise believed to be myopotential oversensing. Of note there were no IAS due to T-wave oversensing. A summary of observed outcomes is presented in table 2. Regarding reintervention, 9 (7.8%) patients required a repeat procedure over the course of the study with a total of 12 procedures. Overall 2 (1.7%) patients developed a device infection requiring extraction. Due to symptomatic bradycardia, 2 patients had a TV pacemaker programmed to work in tandem with the SICD. Both patients had bipolar pacing outputs programmed and received no IAS over the course of the study. The complete summary of details regarding the indication for reintervention are included in figure 2. A total of 3 (2.6%) patients died during the study follow-up but none of the deaths were directly attributable to the device or implant procedure. The mean age at death was 67±13yrs, with a mean duration from implant to death of 12