Efficacy and Safety of an Extravascular Implantable Cardioverter-Defibrillator.

Authors

• Paul Friedman
• Francis Murgatroyd
• Lucas V A Boersma
• Jaimie Manlucu
• David O'Donnell
• Bradley P Knight
• Nicolas Clémenty
• Christophe Leclercq
• Anish Amin, OhioHealth
• Béla P Merkely
• Ulrika M Birgersdotter-Green
• Joseph Y S Chan
• Mauro Biffi
• Reinoud E Knops
• Greg Engel
• Ignacio Muñoz Carvajal
• Laurence M Epstein
• Venkata Sagi
• Jens B Johansen
• Maciej Sterliński
• Clemens Steinwender
• Troy Hounshell
• Richard Abben
• Amy E Thompson
• Christopher Wiggenhorn
• Sarah Willey
• Ian Crozier
• Extravascular ICD Pivotal Study Investigators

Document Type

Article

Publication Title

The New England journal of medicine

Abstract

BACKGROUND: The extravascular implantable cardioverter-defibrillator (ICD) has a single lead implanted substernally to enable pause-prevention pacing, antitachycardia pacing, and defibrillation energy similar to that of transvenous ICDs. The safety and efficacy of extravascular ICDs are not yet known.

METHODS: We conducted a prospective, single-group, nonrandomized, premarket global clinical study involving patients with a class I or IIa indication for an ICD, all of whom received an extravascular ICD system. The primary efficacy end point was successful defibrillation at implantation. The efficacy objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients with successful defibrillation was greater than 88%. The primary safety end point was freedom from major system- or procedure-related complications at 6 months. The safety objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients free from such complications was greater than 79%.

RESULTS: A total of 356 patients were enrolled, 316 of whom had an implantation attempt. Among the 302 patients in whom ventricular arrhythmia could be induced and who completed the defibrillation testing protocol, the percentage of patients with successful defibrillation was 98.7% (lower boundary of the one-sided 97.5% confidence interval [CI], 96.6%; P< 0.001 for the comparison with the performance goal of 88%); 299 of 316 patients (94.6%) were discharged with a working ICD system. The Kaplan-Meier estimate of the percentage of patients free from major system- or procedure-related complications at 6 months was 92.6% (lower boundary of the one-sided 97.5% CI, 89.0%; P< 0.001 for the comparison with the performance goal of 79%). No major intraprocedural complications were reported. At 6 months, 25 major complications were observed, in 23 of 316 patients (7.3%). The success rate of antitachycardia pacing, as assessed with generalized estimating equations, was 50.8% (95% CI, 23.3 to 77.8). A total of 29 patients received 118 inappropriate shocks for 81 arrhythmic episodes. Eight systems were explanted without extravascular ICD replacement over the 10.6-month mean follow-up period.

CONCLUSIONS: In this prospective global study, we found that extravascular ICDs were implanted safely and were able to detect and terminate induced ventricular arrhythmias at the time of implantation. (Funded by Medtronic; ClinicalTrials.gov number, NCT04060680.).

First Page

1292

Last Page

1302

DOI

10.1056/NEJMoa2206485

Publication Date

10-6-2022

Recommended Citation

Friedman P, Murgatroyd F, Boersma LVA, Manlucu J, O'Donnell D, Knight BP, Clémenty N, Leclercq C, Amin A, Merkely BP, Birgersdotter-Green UM, Chan JYS, Biffi M, Knops RE, Engel G, Muñoz Carvajal I, Epstein LM, Sagi V, Johansen JB, Sterliński M, Steinwender C, Hounshell T, Abben R, Thompson AE, Wiggenhorn C, Willey S, Crozier I; Extravascular ICD Pivotal Study Investigators. Efficacy and Safety of an Extravascular Implantable Cardioverter-Defibrillator. N Engl J Med. 2022 Oct 6;387(14):1292-1302. doi: 10.1056/NEJMoa2206485. Epub 2022 Aug 28. PMID: 36036522.