Elsevier

Heart Rhythm

Volume 15, Issue 10, October 2018, Pages 1515-1522
Heart Rhythm

Clinical
Devices
Prospective blinded evaluation of a novel sensing methodology designed to reduce inappropriate shocks by the subcutaneous implantable cardioverter-defibrillator

https://doi.org/10.1016/j.hrthm.2018.05.011Get rights and content
Under a Creative Commons license
open access

Background

Most inappropriate shocks from the subcutaneous implantable cardioverter-defibrillator (S-ICD) are caused by cardiac oversensing. A novel sensing methodology, SMART Pass (SP; Boston Scientific Corporation, Natick, MA), aims to reduce cardiac oversensing.

Objective

The purpose of this study was to evaluate the effect of SP on shocks in ambulatory patients with S-ICD.

Methods

Patients implanted in 2015–2016 and enrolled in a remote patient monitoring system were included and followed for 1 year. Shocks were adjudicated by 3 independent blinded reviewers as appropriate or inappropriate. Shock incidence was calculated for patients with SP programmed enabled or disabled at implantation, censoring patients when SP programming changed or at the last transmission. The SP setting (enabled vs disabled) was modeled as a time-dependent Cox regression variable.

Results

The cohort consisted of 1984 patients, and a total of 880 shocks were adjudicated. At implantation, SP was enabled in 655 patients (33%) and disabled in 1329 patients (67%). SP reduced the risk for the first inappropriate shock by 50% (P < .001) and the risk for all inappropriate shocks by 68% (P < .001) in multivariate analysis adjusted for age and device programming. The incidence of inappropriate shocks was 4.3% in the SP enabled arm vs 9.7% in the SP disabled arm. The incidence of appropriate shocks was similar (5.2% vs 6.6%; P = .18) along with the time to treat the first appropriate shock (17.4 seconds vs 16.7 seconds; P = .92) for SP enabled vs disabled, respectively.

Conclusion

This prospective blinded evaluation of the SP filter demonstrates that enabling the SP filter results in a significant reduction of inappropriate shocks by the S-ICD without a negative effect on appropriate shocks.

Keywords

Arrhythmias
Appropriate shocks
Inappropriate shocks
Oversensing
Subcutaneous ICD

Cited by (0)

The first 2 authors contributed equally to this work.

This work was funded by Boston Scientific.

Dr Theuns has received research grants from Biotronik and Boston Scientific and consulting fees from Boston Scientific. Dr Brouwer has received from Boston Scientific research funding and consulting fees dedicated to the cardiology department's research budget. Dr Auricchio is a consultant for Boston Scientific, Medtronic, and LivaNova and receives speaker fees from Medtronic, Boston Scientific, and LivaNova. Dr Knops is a consultant and speaker for Boston Scientific, Medtronic, and St. Jude Medical/Abbott. Dr Burke has received consulting fees, research grants, and honoraria from Boston Scientific; research grants from Medtronic and St. Jude Medical; and consulting fees from AtaCor Medical; he also owns equity in AtaCor Medical. Mr Jones, Mr Allavatam, and Mr Donnelley are employees of Boston Scientific.