Article
Author: de Veld, Jolien A. ; Jansen, Ward P.J. ; Nemirovsky, Dmitry ; Richter, Sergio ; Allaart, Cornelis P. ; Quast, Anne-Floor B.E. ; Knaut, Michael ; Surber, Ralf ; de Groot, Joris R. ; Philbert, Berit T. ; Lambiase, Pier D. ; Whinnett, Zachary I. ; Burke, Martin C. ; Behr, Elijah R. ; Brouwer, Tom F. ; de Jong, Jonas S.S.G. ; van der Stuijt, Willeke ; Chicos, Alexandru B. ; Mittal, Suneet ; Neuzil, Petr ; Bracke, Frank A.L.E. ; Borger van der Burg, Alida E. ; Kooiman, Kirsten M. ; Alings, Marco ; Nordbeck, Peter ; Wright, David J. ; Wilde, Arthur A.M. ; Ghani, Abdul ; Betts, Timothy R. ; Weiss, Raul ; Vernooy, Kevin ; Knops, Reinoud E. ; Kääb, Stefan ; Bijsterveld, Nick R. ; Dizon, Jose M. ; Smeding, Lonneke ; Brouwer, Marc A. ; Tijssen, Jan G.P. ; El-Chami, Mikhael F. ; Miller, Marc A. ; Pepplinkhuizen, Shari ; Upadhyay, Gaurav A. ; Olde Nordkamp, Louise R.A. ; de Weger, Anouk ; van Opstal, Jurren M. ; Boersma, Lucas V.A. ; Kuschyk, Juergen
BACKGROUND:Inappropriate therapy (IAT) is an undesirable side effect of implantable cardiac defibrillator (ICD) therapy. Early studies with the subcutaneous ICD (S-ICD) showed relatively high inappropriate shock (IAS) rates. The PRAETORIAN (Prospective Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) trial demonstrated that the S-ICD is noninferior to the transvenous ICD (TV-ICD) with regard to the combined end point of IAS and complications. This secondary analyses evaluates all IAT in the PRAETORIAN trial.METHODS:This international, multicenter trial randomized 849 patients with an indication for ICD therapy between S-ICD (n=426) and TV-ICD therapy (n=423). ICD programming was mandated by protocol. All analysis were performed in the modified intention-to-treat population.RESULTS:
In both groups 42 patients experienced IAT (48-month Kaplan-Meier estimated cumulative incidence, 9.9% and 10.1%, respectively; hazard ratio (HR), 0.99 [95% CI, 0.65–1.52];
P
=0.97). There was no significant difference in patients experiencing IAS between both groups (
P
=0.14). In the S-ICD group, 81 IAT episodes with 124 IAS and 1 inappropriate antitachycardia pacing occurred versus 89 IAT episodes with 130 IAS and 124 inappropriate antitachycardia pacing in the TV-ICD group. IAT episodes were most frequently caused by supraventricular tachycardias in the TV-ICD group (n=83/89) versus cardiac oversensing in the S-ICD group (n=40/81). In the TV-ICD group, a baseline heart rate >80 bpm (HR, 1.99 [95% CI, 1.05–3.76];
P
=0.03), a history of atrial fibrillation (HR, 2.66 [95% CI, 1.41–5.02];
P
=0.003), and smoking (HR, 2.46 [95% CI, 1.31–4.09];
P
=0.005) were independent predictors for IAT. A QRS duration >120 ms was an independent predictor for IAT caused by cardiac oversensing in the S-ICD group (HR, 3.13 [95% CI, 1.34–7.31];
P
=0.008). Post-IAS interventions significantly reduced IAS recurrence in both groups (
P
=0.046).
CONCLUSIONS:There was no significant difference in IAT and IAS rates between the S-ICD and TV-ICD in a conventional ICD population, but causes and predictors for IAT differed between the devices. After the first IAS, an intervention significantly reduced the recurrence rate of IAS.REGISTRATION:
URL:
https://www.clinicaltrials.gov
; Unique identifier: NCT01296022.