Subcutaneous Defibrillator Implantation With or Without Defibrillation Test: The Primary Results of the Randomized PRAETORIAN-DFT Trial.
Knops RE., Marquie C., Nordbeck P., Tilz R., Dijkshoorn LA., Quast A-FBE., Brouwer TF., Lambiase PD., Cassidy C., Boersma LVA., Burke MC., Betts TR., Probst V., Manyam H., Bracke FALE., Bonnemeier H., Kuschyk J., Golovchiner G., de Weger A., Miller MA., de Jong JSSG., Ghani A., Lewis N., Marijon E., Bijsterveld NR., Defaye P., Martin C., Field DC., Elders J., Shaik NA., Boveda S., van der Stuijt W., de Veld JA., Kooiman KM., Pepplinkhuizen S., Kaiser L., Arya A., Tukkie R., van Woerkens LJPM., Feenema-Aardema MW., Glikson M., Maass AH., Zaidi A., Wilde AAM., Olde Nordkamp LRA., Smeding L., El-Chami MF., PRAETORIAN-DFT Investigators .
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 testing, n=482) were followed for a median of 41 months. Failed first shock for spontaneous ventricular arrhythmia occurred in 1.7% of the No-DF testing group versus 2.3% of the DF testing group (-0.6%, 95% CI [ -2.6 to 1.4]; p<0.001). There were no significant differences in all-cause mortality (HR 0.9 [95% CI 0.6-1.4]) or arrhythmic death (HR 0.4 [95% CI 0.04-3.4]). Potential DF testing-related complications occurred in 1.7% in the DF testing group. Postoperative S-ICD revisions due to inadequate positioning were identical between groups (n=2 each). CONCLUSIONS: PRAETORIAN score-guided omission of DF testing- after S-ICD implantation did not increase the risk of failed first shocks for spontaneous ventricular arrhythmias and reduced procedural risk without increasing S-ICD revisions. (Funded by Boston Scientific; PRAETORIAN-DFT).