Protocol summary

Background: Defibrillation testing (DFT) of TV-ICDs at the time of implant does not improve shock efficacy or reduce arrhythmic death. In addition, patients are also exposed to the risk of DFT related complications. During S-ICD implant, DFT is linked with mostly similar risks for complications and logistic burden for sedations as TV-ICDs. The conversion rate during DFT of S-ICD is high and the first shock efficacy for the S-ICD is similar to that of the TV-ICD. However, there are currently limited studies available on the efficacy of DFT in the S-ICD.

Objectives: The primary objective is to determine whether the S-ICD implant without DFT (with PRAETORIAN Score) is non-inferior to the S-ICD implant with DFT.
The secondary objectives are to evaluate the PRAETORIAN score and to evaluate anesthesia protocols for implantation.

Primary endpoint: Failed first shock during spontaneous episodes of fast ventricular arrhythmias (VT and VF).

Study design: This is a prospective multicenter trial with a 1:1 randomisation to the S- ICD implant with DFT or S-ICD implant without DFT. The median follow‐up of the patients in the trial will be 40 months. A total of 965 patients will be included in the study.

Inclusion criteria:

  • Patients must be ≥ 18 years of age
  • Patients who meet current guidelines for ICD therapy and intend to undergo a de novo implant procedure for an S-ICD
  • Patients must pass S-ICD screening per local routine
  • Patients willing and capable of complying with follow-up visits
  • Patients must be eligible for both DFT strategies per physician discretion

Exclusion criteria:

  • Patients with life expectancy shorter than 12 months due to any medical condition
  • Patients who are known to be pregnant
  • Patients with intracardiac thrombus
  • Patients with atrial fibrillation without appropriate anticoagulation
  • Patients likely to undergo heart transplant within 12 months
  • Patients with LVAD
  • Patients with other contra-indications for DFT per physician’s discretion