Efficacy and Safety of Appropriate Shocks and Antitachycardia Pacing in Transvenous and Subcutaneous Implantable Defibrillators: Analysis of All Appropriate Therapy in the PRAETORIAN Trial
Authors: Reinoud E. Knops, Willeke van der Stuijt, Peter Paul H.M. Delnoy, Lucas V.A. Boersma, Juergen Kuschyk, Mikhael F. El-Chami, Hendrik Bonnemeier, Elijah R. Behr, Tom F. Brouwer, Stefan Kääb, Suneet Mittal, Anne-Floor B.E. Quast, Lonneke Smeding, Jan G.P. Tijssen, Nick R. Bijsterveld, Sergio Richter, Marc A. Brouwer, Joris R. de Groot, Kirsten M. Kooiman, Pier D. Lambiase, Petr Neuzil, Kevin Vernooy, Marco Alings, Timothy R. Betts, Frank A.L.E. Bracke, Martin C. Burke, Jonas S.S.G. de Jong, David J. Wright, Ward P.J. Jansen, Zachary I. Whinnet, Peter Nordbeck, Michael Knaut, Berit T. Philbert, Jurren M. van Opstal, Alexandru B. Chicos, Cornelis P. Allaart, Alida E. Borger van der Burg, Jude F. Clancy, Jose M. Dizon, Marc A. Miller, Dmitry Nemirovsky, Ralf Surber, Gaurav A. Upadhyay, Raul Weiss, Anouk de Weger, Arthur A.M. Wilde, Louise R.A. Olde Nordkamp, Marco Alings, Cornelis P. Allaart, Elijah R. Behr, Timothy R. Betts, Nick R. Bijsterveld, Lucas V.A. Boersma, Hendrik Bonnemeier, Alida E. Borger van der Burg, Frank A.L.E. Bracke, Marc A. Brouwer, Tom F. Brouwer, Martin C. Burke, Jim W. Cheung, Alexandru B. Chicos, Jude F. Clancy, Peter Paul H.M. Delnoy, Jose M. Dizon, Mikhael F. El-Chami, Tjeerd Germans, Joris R. de Groot, Ward P.J. Jansen, Jonas S.S.G. de Jong, Stefan Kaab, Michael Knaut, Reinoud E. Knops, Kirsten M. Kooiman, Juergen Kuschyk, Pier D. Lambiase, Francisco Leyva, Marc A. Miller, Suneet Mittal, Dmitry Nemirovsky, Petr Neuzil, Peter Nordbeck, Louise R.A. Olde Nordkamp, Jurren M. van Opstal, Berit T. Philbert, Anne-Floor B.E. Quast, Sergio Richter, Lonneke Smeding, Willeke van der Stuijt, Ralf Surber, Dominic A.M.J. Theuns, Jan G.P. Tijssen, Gaurav A. Upadhyay, Kevin Vernooy, Anouk de Weger, Raul Weiss, Zachary I. Whinnet, Arthur A.M. Wilde, David J. Wright
Journal: Circulation (2021)

The PRAETORIAN trial (A Prospective, Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) showed noninferiority of subcutaneous implantable cardioverter defibrillator (S-ICD) compared with transvenous implantable cardioverter defibrillator (TV-ICD) with regard to inappropriate shocks and complications. In contrast to TV-ICD, S-ICD cannot provide antitachycardia pacing for monomorphic ventricular tachycardia. This prespecified secondary analysis evaluates appropriate therapy and whether antitachycardia pacing reduces the number of appropriate shocks. The PRAETORIAN trial was an international, investigator-initiated randomized trial that included patients with an indication for implantable cardioverter defibrillator (ICD) therapy. Patients with previous ventricular tachycardia <170 bpm or refractory recurrent monomorphic ventricular tachycardia were excluded. In 39 centers, 849 patients were randomized to receive an S-ICD (n=426) or TV-ICD (n=423) and were followed for a median of 49.1 months. ICD programming was mandated by protocol. Appropriate ICD therapy was defined as therapy for ventricular arrhythmias. Arrhythmias were classified as discrete episodes and storm episodes (≥3 episodes within 24 hours). Analyses were performed in the modified intention-to-treat population. In the S-ICD group, 86 of 426 patients received appropriate therapy, versus 78 of 423 patients in the TV-ICD group, during a median follow-up of 52 months (48-month Kaplan-Meier estimates 19.4% and 17.5%; P=0.45). In the S-ICD group, 83 patients received at least 1 shock, versus 57 patients in the TV-ICD group (48-month Kaplan-Meier estimates 19.2% and 11.5%; P=0.02). Patients in the S-ICD group had a total of 254 shocks, compared with 228 shocks in the TV-ICD group (P=0.68). First shock efficacy was 93.8% in the S-ICD group and 91.6% in the TV-ICD group (P=0.40). The first antitachycardia pacing attempt successfully terminated 46% of all monomorphic ventricular tachycardias, but accelerated the arrhythmia in 9.4%. Ten patients with S-ICD experienced 13 electrical storms, versus 18 patients with TV-ICD with 19 electrical storms. Patients with appropriate therapy had an almost 2-fold increased relative risk of electrical storms in the TV-ICD group compared with the S-ICD group (P=0.05). In this trial, no difference was observed in shock efficacy of S-ICD compared with TV-ICD. Although patients in the S-ICD group were more likely to receive an ICD shock, the total number of appropriate shocks was not different between the 2 groups. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.