AIMS: To report 5-year outcomes of EFFORTLESS registry patients with early generation subcutaneous implantable cardioverter-defibrillator (S-ICD) devices. METHODS AND RESULTS: Kaplan-Meier, trend and multivariable analyses were performed for mortality and late (years 2-5) complications, appropriate shock (AS) and inappropriate shock (IAS) rates. Nine hundred and eighty-four of 994 enrolled patients with diverse diagnoses (28% female, 48 ± 17 years, body mass index 27 ± 6 kg/m2, ejection fraction 43 ± 18%) underwent S-ICD implantation. Median follow-up was 5.1 years (interquartile range 4.7-5.5 years). All-cause mortality was 9.3% (95% confidence interval 7.2-11.3%) at 5 years; 703 patients remained in follow-up on study completion, 171 withdrew including 87 (8.8%) with device explanted, and 65 (6.6%) lost to follow-up. Of the explants, only 20 (2.0%) patients needed a transvenous device for pacing indications. First and final shock efficacy for discrete ventricular arrhythmias was consistent at 90% and 98%, respectively, with storm episode final shock efficacy at 95.2%. Time to therapy remained unaltered. Overall 1- and 5-year complication rates were 8.9% and 15.2%, respectively. Early complications did not predict later complications. There were no structural lead failures. Inappropriate shock rates at 1 and 5 years were 8.7% and 16.9%, respectively. Self-terminating inappropriately sensed episodes predicted late IAS. Predictors of late AS included self-terminating appropriately sensed episodes and earlier AS. CONCLUSION: In this diverse S-ICD registry population, spontaneous shock efficacy was consistently high over 5 years. Very few patients underwent S-ICD replacement with a transvenous device for pacing indications. Treated and self-terminating arrhythmic episodes predict future shock events, which should encourage more personalized device optimization.

• MeSH
• Defibrillators, Implantable * adverse effects   MeSH
• Humans MeSH
• Death, Sudden, Cardiac epidemiology   etiology   prevention & control   MeSH
• Follow-Up Studies MeSH
• Arrhythmias, Cardiac MeSH
• Stroke Volume MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) was developed to defibrillate ventricular arrhythmias, avoiding drawbacks of transvenous leads. The global EFFORTLESS S-ICD (Evaluation oF FactORs ImpacTing CLinical Outcome and Cost EffectiveneSS of the S-ICD) registry is collecting outcomes in 985 patients during a 5-year follow-up. OBJECTIVES: The primary goal of the EFFORTLESS registry is to determine the safety of the S-ICD by evaluating complications and inappropriate shock rate. METHODS: This is the first report on the full patient cohort and study endpoints with follow-up ≥1 year. The predefined endpoints are 30- and 360-day complications, and shocks for atrial fibrillation or supraventricular tachycardia. RESULTS: Patients were followed for 3.1 ± 1.5 years and 82 completed the study protocol 5-year visit. Average age was 48 years, 28% were women, ejection fraction was 43 ± 18%, and 65% had a primary prevention indication. The S-ICD system and procedure complication rate was 4.1% at 30 days and 8.4% at 360 days. The 1-year complication rate trended toward improvement from the first to last quartile of enrollment (11.3% [quartile 1]) to 7.8% [quartile 2], 6.6% [quartile 3], and 7.4% [quartile 4]; quartile 1 vs. quartiles 2 to 4; p = 0.06). Few device extractions occurred due to need for antitachycardia (n = 5), or biventricular (n = 4) or bradycardia pacing (n = 1). Inappropriate shocks occurred in 8.1% at 1 year and 11.7% after 3.1 years. At implant, 99.5% of patients had a successful conversion of induced ventricular tachycardia or ventricular fibrillation. The 1- and 5-year rates of appropriate shock were 5.8% and 13.5%, respectively. Conversion success for discrete spontaneous episodes was 97.4% overall. CONCLUSIONS: This registry demonstrates that the S-ICD fulfills predefined endpoints for safety and efficacy. Midterm performance rates on complications, inappropriate shocks, and conversion efficacy were comparable to rates observed in transvenous implantable cardioverter-defibrillator studies. (Evaluation oF Factors ImpacTing CLinical Outcome and Cost EffectiveneSS of the S-ICD [The EFFORTLESS S-ICD Registry]; NCT01085435).

• MeSH
• Time Factors MeSH
• Defibrillators, Implantable * MeSH
• Tachycardia, Ventricular therapy   MeSH
• Middle Aged MeSH
• Humans MeSH
• Follow-Up Studies MeSH
• Registries * MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Observational Study MeSH

BACKGROUND: The Nanostim leadless pacemaker (LP) met the primary endpoints in an investigational device exemption trial, and was shown to be fully retrievable percutaneously. In October 2016, St Jude Medical issued a worldwide alert of a battery malfunction that caused lost pacing output and LP communication. OBJECTIVE: To report the battery failure mechanism and incidence and the worldwide patient management, including device retrieval experiences. METHODS: The affected LP battery is a custom lithium-carbon monofluoride cell. These were returned after failure and underwent analysis assessing electronics and battery performance. Data were collected in ongoing clinical studies when LPs were abandoned or retrieved. RESULTS: Of 1423 LPs implanted worldwide, there were 34 battery failures, occurring at 2.9 ± 0.4 years with no instances of associated patient injury. Analysis of returned batteries revealed an increase in battery resistance caused by insufficient electrolyte availability at the cathode/anode interface. A total of 66 of 73 retrieval attempts were successful (90.4%; implant duration range: 0.2-4.0 years). The LP docking button was inaccessible in 6 patients, and the docking button detached from the LP during retrieval in 1 patient. There was 1 case of arteriovenous fistula and another case of the LP docking button migrating into the pulmonary artery. There were also 115 non-LP retrieval patients after the advisory who received an additional pacemaker, with no adverse device-to-device interactions reported. CONCLUSION: As with standard pacers, LPs can have critical battery failures. Chronic retrieval of LPs is safe and efficacious.

• MeSH
• Patient Safety MeSH
• Time Factors MeSH
• Equipment Design MeSH
• Pacemaker, Artificial adverse effects   MeSH
• Humans MeSH
• Disease Management * MeSH
• Follow-Up Studies MeSH
• Device Removal methods   MeSH
• Retrospective Studies MeSH
• Equipment Failure MeSH
• Aged MeSH
• Arrhythmias, Cardiac therapy   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Randomized Controlled Trial MeSH

AIMS: The totally subcutaneous implantable-defibrillator (S-ICD) is a new alternative to the conventional transvenous ICD system to minimize intravascular lead complications. There are limited data describing the long-term performance of the S-ICD. This paper presents the first large international patient population collected as part of the EFFORTLESS S-ICD Registry. METHODS AND RESULTS: The EFFORTLESS S-ICD Registry is a non-randomized, standard of care, multicentre Registry designed to collect long-term, system-related, clinical, and patient reported outcome data from S-ICD implanted patients since June 2009. Follow-up data are systematically collected over 60-month post-implant including Quality of Life. The study population of 472 patients of which 241 (51%) were enrolled prospectively has a mean follow-up duration of 558 days (range 13-1342 days, median 498 days), 72% male, mean age of 49 ± 18 years (range 9-88 years), 42% mean left ventricular ejection fraction. Complication-free rates were 97 and 94%, at 30 and 360 days, respectively. Three hundred and seventeen spontaneous episodes were recorded in 85 patients during the follow-up period. Of these episodes, 169 (53%) received therapy, 93 being for Ventricular Tachycardia/Fibrillation (VT/VF). One patient died of recurrent VF and severe bradycardia. Regarding discrete VT/VF episodes, first shock conversion efficacy was 88% with 100% overall successful clinical conversion after a maximum of five shocks. The 360-day inappropriate shock rate was 7% with the vast majority occurring for oversensing (62/73 episodes), primarily of cardiac signals (94% of oversensed episodes). CONCLUSION: The first large cohort of real-world data from an International patient S-ICD population demonstrates appropriate system performance with clinical event rates and inappropriate shock rates comparable with those reported for conventional ICDs. Clinical trial registration URL: http://www.clinicaltrials.gov. Unique identifier NCT01085435.

• MeSH
• Time-to-Treatment MeSH
• Defibrillators, Implantable adverse effects   standards   statistics & numerical data   MeSH
• Child MeSH
• Adult MeSH
• Prosthesis Implantation methods   MeSH
• Quality of Life MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Prospective Studies MeSH
• Registries MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Arrhythmias, Cardiac therapy   MeSH
• Treatment Outcome MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Multicenter Study MeSH
• Observational Study MeSH
• Research Support, Non-U.S. Gov't MeSH