Personalized Screening Before Subcutaneous Cardioverter Defibrillator Implantation: Usefulness and Outcomes in Clinical Practice – the S-ICD Screening SIS Prospective Study

BackgroundElectrocardiographic (ECG) screening prior to S-ICD implantation is unsuccessful in around 10% of cases. A personalized screening method, by slightly moving the electrodes, to obtain a better R/T ratio has been described to overcome traditional screening failure.ObjectiveTo assess to what extent a personalized screening method improves eligibility for S-ICD implantation and evaluate the inappropriate shock rate after such screening success.MethodsAll consecutive patients eligible for an S-ICD implantation were prospectively recruited across 20 French centers between December 2019 to January 2022 (NCT04101253). In case of traditional screening failure, patients received a second personalized screening. If at least one vector was positive, the personalized screening was considered as successful, and the patient was eligible for implantation.Results474 patients were included in the study (mean age 50.4 ±14.1 years; 77.4% men). Traditional screening was successful in 456 (96.2%) cases. This figure rose to 98.3% (n=466; P=.002) when personalized screening was performed. All patients implanted after successful personalized screening had correct signal detection on initial device interrogation. Nevertheless, after one year follow-up, 3 (43%) of the 7 patients implanted with personalized experienced inappropriate shock (vs 18 (4.2%) out of the 427 patients with traditional screening and S-ICD implantation P=.003).ConclusionTraditional S-ICD screening was successful in our study in a very high proportion of patients. Considering the small improvement in success of screening and a higher rate of inappropriate shock, a strategy of personalized screening cannot be routinely recommended.