Defibrillation Testing During Implantation of Subcutaneous Implantable Cardioverter Defibrillators

Area of Science:

• Cardiology
• Medical Devices
• Electrophysiology

Background:

• Defibrillation testing (DT) is recommended for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation despite limited evidence.
• The necessity of DT in S-ICD recipients requires further investigation.

Purpose of the Study:

• To evaluate the long-term impact of performing defibrillation testing (DT) during S-ICD implantation.
• To determine if omitting DT affects patient outcomes.

Main Methods:

• The HONEST study is a nationwide, observational cohort of S-ICD recipients in France (2012-2019).
• Propensity score-weighted analyses compared outcomes between patients who underwent DT and those who did not.
• Five-year endpoints were centrally adjudicated.

Main Results:

• Defibrillation testing (DT) was performed in 82.6% of 4,924 patients, decreasing over time.
• Nontested patients had distinct demographic and clinical characteristics.
• DT omission was not associated with increased risks of overall mortality, cardiovascular mortality, sudden cardiac death, or inappropriate shocks.
• Rates of ineffective shocks or undetected ventricular arrhythmias were similar between groups.

Conclusions:

• Defibrillation testing (DT) can be safely omitted in the majority of S-ICD recipients.
• Selective DT may be considered for specific higher-risk patient subgroups.