Superior Rhythm Discrimination With the SmartShock Technology Algorithm　― Results of the Implantable Defibrillator With Enhanced Features and Settings for Reduction of Inaccurate Detection (DEFENSE) Trial

• Published in: Circulation Journal 2017/08/25, Vol.81(9), pp.1272-1277
• Main Authors: Oginosawa, Yasushi, Kohno, Ritsuko, Honda, Toshihiro, Kikuchi, Kan, Nozoe, Masatsugu, Uchida, Takayuki, Minamiguchi, Hitoshi, Sonoda, Koichiro, Ogawa, Masahiro, Ideguchi, Takeshi, Kizaki, Yoshihisa, Nakamura, Toshihiro, Oba, Kageyuki, Higa, Satoshi, Yoshida, Keiki, Tsunoda, Soichi, Fujino, Yoshihisa, Abe, Haruhiko
• Format: Article
• Language: English
• Subjects: Aged; Algorithms; Defibrillators, Implantable; Discrimination algorithm; Female; Humans; Implantable cardioverter defibrillator; Inaccurate tachycardia detection; Inappropriate shock; Male; Middle Aged; Prospective Studies; SST algorithm; Tachycardia, Ventricular - physiopathology; Tachycardia, Ventricular - therapy
• ISSN: 1346-9843; 1347-4820
• DOI: 10.1253/circj.CJ-16-1330

Background:Shocks delivered by implanted anti-tachyarrhythmia devices, even when appropriate, lower the quality of life and survival. The new SmartShock Technology®(SST) discrimination algorithm was developed to prevent the delivery of inappropriate shock. This prospective, multicenter, observational study compared the rate of inaccurate detection of ventricular tachyarrhythmia using the SST vs. a conventional discrimination algorithm.Methods and Results:Recipients of implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy defibrillators (CRT-D) equipped with the SST algorithm were enrolled and followed up every 6 months. The tachycardia detection rate was set at ≥150 beats/min with the SST algorithm. The primary endpoint was the time to first inaccurate detection of ventricular tachycardia (VT) with conventional vs. the SST discrimination algorithm, up to 2 years of follow-up. Between March 2012 and September 2013, 185 patients (mean age, 64.0±14.9 years; men, 74%; secondary prevention indication, 49.5%) were enrolled at 14 Japanese medical centers. Inaccurate detection was observed in 32 patients (17.6%) with the conventional, vs. in 19 patients (10.4%) with the SST algorithm. SST significantly lowered the rate of inaccurate detection by dual chamber devices (HR, 0.50; 95% CI: 0.263–0.950; P=0.034).Conclusions:Compared with previous algorithms, the SST discrimination algorithm significantly lowered the rate of inaccurate detection of VT in recipients of dual-chamber ICD or CRT-D.