Real-World Experience With the Extravascular Implantable Cardioverter Defibrillator Through 1 Year: The Enlighten Post Approval Registry Study

BACKGROUND: The extravascular implantable cardioverter defibrillator (EV-ICD) was developed to provide defibrillation and antitachycardia pacing therapy without the need for intravascular lead placement. Premarket clinical trials reported EV-ICD safety and efficacy through 3 years, but a real-world assessment of the Aurora EV-ICD system, which includes a novel sensing discriminator, is needed. The objective of this analysis was to assess real-world therapy efficacy and safety of the EV-ICD through 1 year. METHODS: Enlighten: The EV-ICD Post Approval Registry is a prospective, global, real-world registry that included patients who underwent an EV-ICD implantation attempt. The main safety analysis was freedom from all system- or procedure-related major complications through 1 year. Event rates at 1 year were calculated using the Kaplan-Meier method. RESULTS: EV-ICD system implantation was attempted by 168 implanters in 787 patients (49.1±15.2 years old; 28.7% women; 34.1% secondary prevention). Tunneling and lead placement in the substernal space were achieved in 781 of 787 patients (99.2%), with 758 patients (96.3%) remaining implanted following defibrillation and electrical testing. One-year freedom from major system- or procedure-related complications was 89.1% (95% CI, 86.3%–91.3%). The 1-year rate of first appropriate therapy (shock, antitachycardia pacing, or both) was 7.3% (95% CI, 5.5–9.6). Shock success for discrete spontaneous episodes was 100% (61 of 61), and the generalized estimating equations antitachycardia pacing success rate, to account for multiple episodes per patient, was 74.2% for monomorphic ventricular tachycardia. The 1-year rate of first inappropriate shock was 7.1% (95% CI, 5.4–9.4), with noncardiac oversensing as the main cause (40.5% of inappropriately shocked episodes). CONCLUSIONS: In the largest prospective worldwide cohort of patients with an EV-ICD to date, both antitachycardia pacing and shock therapy were effective, while the rate of major complications agreed with the premarket experience through 1 year. These data demonstrate that positive outcomes of the EV-ICD are retained in everyday clinical practice in a large, global cohort with an expanded number of implanters. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT06048731.