The multinational PRAETORIAN-DFT RCT randomised 965 subcutaneous ICD recipients across 37 centres to defibrillation testing versus no testing — using the PRAETORIAN score (based on chest X-ray) to assess implant position in the no-DFT arm. First-shock failure for spontaneous ventricular arrhythmias was non-inferior without DFT, with comparable mortality and revisions. Routine defibrillation testing can therefore be omitted in patients with a favourable PRAETORIAN score, reducing implant-related risk.
Background: To improve survival in patients at risk of sudden cardiac death, subcutaneous ICDs (S-ICDs) require optimal implant positioning for effective shocks. Defibrillation (DF) testing is recommended but carries serious risks. The PRAETORIAN score predicts defibrillation outcomes based on chest X-rays. The PRAETORIAN-DFT trial evaluated whether omission of DF testing guided by the PRAETORIAN score is non-inferior for first-shock efficacy.Methods: In this multinational trial, S-ICD patients from 37 centers were randomized to DF testing or no DF testing. In the No-DF testing group, the PRAETORIAN score was evaluated before discharge. The primary endpoint was failed first shock for spontaneous ventricular arrhythmias, as a surrogate for defibrillation success, tested for non-inferiority with a 3% absolute risk margin. Secondary endpoints included mortality, potential DF testing-related complications, and S-ICD revisions.Results: The included 965 patients (No-DF testing, n=483;DF test
