Aims: To guarantee uninterrupted function of the subcutaneous implantable cardioverter-defibrillator (S-ICD), the pulse generator needs to be surgically replaced before the battery is depleted. The risks related to this replacement substantially impact long-term outcome for S-ICD recipients, as the majority will undergo one or several of these procedures in their lifetime. We aim to describe the procedural characteristics of the replacement procedure and to provide an insight in the complications associated with these replacements. Methods and results: In this retrospective analysis, data from replacement procedures and follow-up visits were collected from all patients who underwent elective S-ICD generator replacement in our tertiary centre from June 2014 until November 2019. Original device position was assessed using the PRAETORIAN score. Complications were defined as those requiring surgical intervention, systemic antibiotic treatment, or device extraction. Seventy-two patients were included, with a median follow-up of 1.9 years (IQR 0.6–3.3 years) after replacement. Battery depletion occurred after 5.9 ± 0.7 years. The pulse generator was repositioned in patients with a PRAETORIAN score ≥90 to minimize the defibrillation threshold. Although there was an increase in impedance compared to the implant procedure, first shock conversion rate during defibrillation testing was 91.4% with a success rate of 100% after multiple attempts. Two patients developed a complication after, respectively, 9 and 21 months, resulting in a complication rate of 1.4% per year. Conclusion: With a median follow-up of 1.9 years, this study shows a low complication rate after S-ICD replacement, with a first shock conversion rate of 91.4%.

Introduction The two‐incision implantation technique of the subcutaneous implantable cardioverter defibrillator (S‐ICD) was introduced as an alternative to the standard three‐incision approach by omitting the superior parasternal incision. Thereby, complications may be prevented. Short‐term follow‐up demonstrated the safety and efficacy of the two‐incision technique. However, long‐term results are lacking. Methods This retrospective study included patients implanted between February 2009 and June 2020. Patients were divided into a group of patients who were implanted with the standard three‐incision technique and a group who were implanted with the two‐incision technique. Outcomes were defibrillation impedance and efficacy and complications requiring intervention. Results A total of 268 patients were included (age 42.4±16.6 years, 35.4% female, BMI 25.1±4.5kg/m²). Thirty‐one patients underwent S‐ICD implantation with the three‐incision technique and 237 patients with the two‐incision technique. First shock efficacy during defibrillation testing was 93% in the three‐incision group versus 94% in the two‐incision group (P = 0.69) and shock impedance was 85 versus 68 ohms (P = 0.04). First shock success was 75% versus 76% for spontaneous episodes (P = 1.00). Complication‐free survival at five year follow‐up in the three‐incision group was estimated at 0.96 (95%CI 0.90‐1.00) versus 0.98 (95%CI 0.96‐1.00) in the two‐incision group (P = 0.20) and for inappropriate shocks at five year 0.77 (95%CI 0.63‐0.94) versus 0.83 (95%CI 0.77‐0.89, P = 0.30), respectively. Conclusion Five‐year follow‐up in this S‐ICD cohort showed similar complication rates and effectiveness of two‐incision technique compared to the three‐incision technique. This technique offers physicians a less invasive and more simplified implantation procedure for the S‐ICD, with a better cosmetic result. This article is protected by copyright. All rights reserved

Thoracoscopic surgical ablation (SA) for atrial fibrillation (AF) has shown to be an effective treatment to restore sinus rhythm in patients with advanced AF. Identifying patients who will not benefit from this procedure would be valuable to improve personalized AF therapy. Machine learning (ML) techniques may assist in the improvement of clinical prediction models for patient selection. The aim of this study is to investigate how available baseline characteristics predict AF recurrence after SA using ML techniques. One-hundred-sixty clinical baseline variables were collected from 446 AF patients undergoing SA in our tertiary referral center. Multiple ML models were trained on five outcome measurements, including either all or a number of key variables selected by using the least absolute shrinkage and selection operator (LASSO). There was no difference in model performance between different ML techniques or outcome measurements. Variable selection significantly improved model performance (AUC: 0.73, 95% CI: 0.68–0.77). Subgroup analysis showed a higher model performance in younger patients (55 years, AUC 0.66). Recurrences of AF after SA can be predicted best when using a selection of baseline characteristics, particularly in young patients.

Introduction The third-generation subcutaneous implantable cardioverter-defibrillator (S-ICD) (EMBLEM (TM) A219, Boston Scientific) contains a new diagnostic tool to detect atrial fibrillation (AF) in S-ICD patients, without the use of an intracardiac lead. This is the first study to evaluate the performance of the S-ICD AF monitor (AFM). Methods The AFM algorithm analyzes a subcutaneous signal for the presence of AF, similar to the signals collected by implantable and wearable diagnostic devices. The AFM algorithm combines heart rate (HR) scatter analysis with an HR histogram. The algorithm was tested against publicly available electrocardiogram databases (simulated performance). Real-world performance of the algorithm was evaluated by using the S-ICD LATITUDE remote monitoring (RM) database. Results The simulated performance of the AFM algorithm resulted in a sensitivity of 95.0%, specificity of 100.0%, and positive predictive value (PPV) of 100.0%. To evaluate the real-world performance of the AFM, 7744 S-ICD devices were followed for up to 30 months by RM, whereof 99.5% had the AFM enabled. A total of 387 AF episodes were randomly chosen for adjudication, resulting in a PPV of 67.7%. The main cause of misclassification was atrial and ventricular ectopy. Conclusion The AFM exhibited a very high sensitivity and specificity in a simulated setting, designed to maximize PPV in order to minimize the clinical burden of reviewing falsely detected AF events. The real-world performance of the AFM, enabled in 99.5% of S-ICD patients, is a PPV of 67.7%.