Subcutaneous Defibrillator Implantation With or Without Defibrillation Test: The Primary Results of the Randomized PRAETORIAN-DFT Trial

BACKGROUND: To improve survival of patients at risk of sudden cardiac death, subcutaneous implantable cardioverter defibrillators (S-ICDs) require optimal implant positioning for effective shocks. Defibrillation (DF) testing is recommended but carries serious risks. The PRAETORIAN score predicts defibrillation outcomes on the basis of chest X-ray. The PRAETORIAN-DFT (Prospective Randomized Comparative Trial of Subcutaneous Implantable Cardioverter Defibrillator Implantation With and Without Defibrillation Testing) trial evaluated whether omission of DF testing guided by the PRAETORIAN score is noninferior 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 end point was failed first shock for spontaneous ventricular arrhythmias, as a surrogate for defibrillation success, tested for noninferiority with a 3% absolute risk margin. Secondary end points included mortality, potential DF testing-related complications, and S-ICD revisions. RESULTS: