The subcutaneous implantable cardioverter-defibrillator (S-ICD) was developed to prevent complications associated with transvenous leads. Due to its extra-thoracic design, the S-ICD requires more energy to defibrillate the heart resulting in a generator twice the size of the transvenous ICD. We investigated pain perception after S-ICD implantation and explore predictors for severe pain. The PRAETORIAN-DFT trial included 965 patients undergoing S-ICD implant in 37 centers across Europe, the USA and Israel. Pain was assessed using the Numerical Rating Scale (NRS), with zero indicating no pain and 10 indicating the worst pain possible. NRS was measured before implantation, and 1-4 hours, 5-7 hours, 1 day and 1-4 months after implantation and two questions about the implant experience were asked at follow-up. Logistic regression analysis was used to identify predictors. Implanting physicians were asked their expectations on pain experience. In the PRAETORIAN-DFT trial, 24% of patients were female, the mean age was 54±14 years and the most common diagnosis was ischemic cardiomyopathy (45%). The median NRS in the 24 hours after implantation was 4 points. Pain was most frequently experienced at the pocket. There were 262/918 (29%) patients who reported severe pain (NRS≥7) within 24 hours after implantation. Independent predictors for severe pain were female sex (p<0.001, OR 2.23), a procedure duration >48 minutes (p<0.001, OR 1.84) and severe pain at baseline (p=0.026, OR 3.97). Additionally, female sex was an independent predictor for disappointment in pain perception during and after implantation. Physician anticipated NRS and location corresponded with reported pain and females were expected to have more pain by 4/24 physicians. In the period surrounding S-ICD implantation, attention should be paid to per- and postoperative analgesia and expectation management in patients with longer procedure duration, severe pre-existing pain, and especially female sex.Percentage of patients experiencing pain

Background The subcutaneous implantable cardioverter-defibrillator (S-ICD) overcomes transvenous lead-related complications. Its extrathoracic design results in a generator twice the size of transvenous ICDs. Objective We investigated pain after S-ICD implantation and explore predictors for severe pain. Methods The PRAETORIAN-DFT (PRospective randomized compArative trial of subcutanEous implanTable cardiOverter-defibrillatoR ImplANtation with and without DeFibrillation Testing) trial included 965 patients undergoing S-ICD implantation in 37 centers across Europe, the United States, and Israel. Pain was assessed using the numeric rating scale (NRS), ranging from no pain to unbearable pain. The NRS was measured before implantation, and 1 to 4 hours, 5 to 7 hours, 1 day, and 1 to 4 months after implantation. Two questions about implantation experience were asked at follow-up. Logistic regression analysis was used to identify predictors. Implanting physicians were asked their expectations on pain experience. Results In the PRAETORIAN-DFT trial, 24% was female, mean age was 54 ± 14 years and 45% had ischemic cardiomyopathy. The median NRS within 1 day after implantation was 4. Pain was most frequently experienced at the pocket. There were 262 (29%) of 918 patients who reported severe pain (NRS ≥7) within 1 day after implantation. Predictors for severe pain were female sex (adjusted odds ratio [aOR] 2.23, P < .001), procedure duration >48 minutes (aOR 1.84, P < .001), and severe pain at baseline (aOR 3.97, P = .026). Additionally, female sex was a predictor for disappointment in pain perception during and after implantation. Physician anticipated NRS and location corresponded with reported pain, and females were expected to have more pain by 4 of 24 physicians. Conclusion In the period surrounding S-ICD implantation, attention should be paid to analgesia and expectation management in patients with longer procedure duration, severe pre-existing pain, and especially female sex.

AIMS:Intercostal extravascular implantable cardioverter defibrillator (EV-ICD) leads may work better in contact with the pericardium thereby directing pacing and defibrillation energy towards excitable myocytes. We report 3-month safety and performance outcomes with a second-generation intercostal EV-ICD lead paired with standard, commercially available ICD pulse generators (PGs). METHODS AND RESULTS:Subjects undergoing a transvenous ICD (TV-ICD) procedure received a concomitant intercostal EV-ICD lead system. The intercostal EV-ICD lead was connected sequentially to a PG in a left pectoral and then a left mid-axillary location. Extravascular ICD lead assessment included sensing and defibrillation of induced ventricular arrhythmias and pacing capture. The intercostal EV-ICD system was followed in a 'recording-only' mode and the control TV-ICD system in 'therapy delivery' mode to compare stored events. Devices were evaluated prior to hospital discharge, 2 weeks, 1 month, 2 months, and 3 months post-implant. Defibrillation testing was repeated prior to lead removal; 20/20 (100%) were successfully implanted (median implant time of 9 min). Two major lead complications were reported over a mean of 82 days: (i) lead movement and (ii) infection of both the TV-ICD and EV-ICD systems. Intraoperative pacing capture was achieved with the integrated bipolar configuration in 19 of 20 (95%) subjects. Pacing capture with the EV-ICD system was tolerated in all subjects, with over 90% feeling no pain after a 1-month recovery from the procedure. Induced VF episodes were sensed in all subjects and defibrillated successfully in 17 of 17 patients (100%) with a left mid-axillary PG and 19 of 20 patients (95%) with a left pectoral PG. Sensing and defibrillation were successful in 18 of 18 (100%) tested prior to lead removal. CONCLUSION:In this pilot experience with a second-generation intercostal EV-ICD lead implantation, sensing and defibrillation of induced VF were successful when paired with a standard ICD PG from either a left mid-axillary or pectoral pocket. CLINICAL TRIAL REGISTRATION:NCT number: NCT05791032; URL: https://clinicaltrials.gov/study/NCT05791032.

BACKGROUND:The PRAETORIAN trial (A Prospective, Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) investigated the efficacy and safety of the subcutaneous implantable cardioverter defibrillator (S-ICD) compared with a transvenous ICD (TV-ICD) and showed noninferiority of the S-ICD with regard to the composite end point of device-related complications and inappropriate shocks after 49.1 months. Complications associated with transvenous leads are expected to occur after longer follow-up. The PRAETORIAN-XL trial aims to investigate whether the S-ICD is superior to the TV-ICD with respect to device-related complications at 8-year follow-up. METHODS:The PRAETORIAN trial randomized patients with a class I or IIa indication for ICD therapy without the need for pacing to either S-ICD or TV-ICD among 39 centers in the United States and Europe between March 2011 and January 2017. The follow-up was extended after 49.1 months by an additional 4 years for the PRAETORIAN-XL trial. The primary end point was the composite of all device-related complications. Complications could be related or unrelated to the lead and minor or major, with major complications being those requiring an invasive intervention. End points were analyzed according to the modified intention-to-treat principle using a Fine-Gray subdistribution hazards model to account for competing risks. An as-treated analysis was performed using a Cox proportional hazards model with device type as time-dependent variable. RESULTS:Patients were randomized to S-ICD (n=426) and TV-ICD (n=423). Twenty-one percent of the S-ICD group versus 18% of the TV-ICD group were women. The median age at implantation was 63 (interquartile range, 54-69) years for the S-ICD and 64 (interquartile range, 56-69) years for the TV-ICD. After a median follow-up of 87.5 months, all device-related complications (major and minor combined) were not significantly different in the modified intention-to-treat analysis (subdistribution hazard ratio, 0.73 [95% CI, 0.48-1.12]); P=0.15). However, TV-ICD patients more often had a major complication or lead-related complication (P=0.03 and P<0.001, respectively). Moreover, the as-treated analysis showed significantly more complications in patients with a TV-ICD compared with an S-ICD (hazard ratio, 0.64 [95% CI, 0.41-0.99]; P=0.047). CONCLUSIONS:The PRAETORIAN-XL trial demonstrated that there was no significant difference between the S-ICD and TV-ICD in all device-related complications during long-term follow-up. However, the TV-ICD carries a higher risk of major and lead-related complications compared with S-ICD therapy. The S-ICD should therefore be considered for all patients without a pacing indication who are evaluated for ICD therapy. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.

INTRODUCTION:The use of insertable cardiac monitors (ICM) for arrhythmia monitoring continues to grow steadily. However, ICM performance remains less than perfect, and the volume of transmitted data poses a challenge to clinics. Here, we evaluate the impact of three improvements implemented in the LUX-Dx II+ ICM for atrial fibrillation (AF), pause, and bradycardia detection. METHODS:Enhanced AF and pause algorithms were evaluated using real-world ECG data and compared against the predecessor LUX-Dx algorithms. Optimized nighttime (11 p.m.-7 a.m.) programming settings were simulated on LUX-Dx data to evaluate the reduction of non-actionable nocturnal bradycardia (>30 bpm) and pause (<5 s) detections. RESULTS:The novel AF algorithm reduced false positives by 34% in the training dataset and 38% in the test dataset while maintaining >98% sensitivity relative to the legacy algorithm. False positive reduction and relative sensitivity were even higher (74% and 100%, respectively) in a subset of patients with more sensitive AF programming settings. The enhanced pause algorithm reduced false positives by 62.5% in the training set and 48.6% in the test set, while maintaining 100% relative sensitivity. Application of adjusted nocturnal detection thresholds reduced the number of nighttime bradycardia and pause episodes by 98% and 90%, corresponding to an overall episode reduction of 75% and 56%, respectively. CONCLUSION:The enhanced ICM algorithms and programming settings substantially reduced false positive AF and pause detections as well as non-actionable nighttime bradycardia and pause detections. These enhancements are expected to improve ICM performance and workflow in the device clinic.