@article{af1e8832ffd247c39c5ff73419cafb8b,
title = "SVT discrimination algorithms significantly reduce the rate of inappropriate therapy in the setting of modern-day delayed high-rate detection programming",
abstract = "Background: Contemporary implantable cardioverter-defibrillator (ICD) programming involving delayed high-rate detection and use of supraventricular tachycardia (SVT) discriminators has significantly reduced the rate of inappropriate shocks. The extent to which SVT algorithms alone reduce inappropriate therapies is poorly understood. Methods and Results: PainFree SST enrolled 2770 patients with a single- or dual-chamber ICD or cardiac resynchronization defibrillator. Patients were followed for 22 ± 9 months with SVT discriminators on in 96% of patients. Sustained ventricular tachyarrhythmias and SVT episodes were adjudicated by an independent physician committee. For this analysis, all episodes were subjected to postprocessing computer simulation with SVT discriminators off with and without delayed high-rate detection criteria (ventricular fibrillation zone only, 30/40 at 320 ms). There were 3282 adjudicated SVT episodes of which 115 resulted in an ICD shock and 113 received only ATP (2-year inappropriate shock and therapy rates of 3.1% and 4.1%). Therapy was appropriately withheld for the remaining 3054 SVT episodes. With both SVT discriminators and delayed high-rate detection simulated off, the 2-year inappropriate therapy rate would have been 22.9% (hazard ratio [HR] = 6.24; 95% confidence interval [CI]: 5.20-7.49). With SVT discriminators simulated off and delayed high-rate detection simulated on in all patients, the 2-year rate would have been 6.4% (HR = 1.63; CI: 1.44-1.85). Conclusions: The use of SVT discriminators has a significant role in reducing the rate of inappropriate ICD therapy even in the setting of delayed high-rate detection settings. Deactivating SVT discriminators would have resulted in an overall increase in the inappropriate ICD therapy rate by 63% and 524% with and without delayed high-rate detection programming, respectively.",
keywords = "atrial fibrillation, cardiac resynchronization therapy, heart failure, implantable cardioverter-defibrillator, inappropriate shock",
author = "Alan Cheng and Angelo Auricchio and Schloss, {Edward J.} and Takashi Kurita and Sterns, {Laurence D.} and Bart Gerritse and Brown, {Mark L.} and Fagan, {Dedra H.} and Lexcen, {Daniel R.} and Ellenbogen, {Kenneth A.}",
note = "Funding Information: Early implantable cardioverter-defibrillator (ICD) programming was designed to rapidly detect and treat ventricular arrhythmias. Unfortunately, this resulted in therapies that were either inappropriate or unnecessary. In particular, among patients receiving ICDs for primary prevention of sudden cardiac death, almost 40% of the therapies delivered were deemed inappropriate or unnecessary. Recent advancements in our understanding of arrhythmia outcomes and improvements in ICD diagnostics and algorithms have placed greater focus on treating longer, faster ventricular arrhythmias through strategic device programming (ie, delayed high-rate detection), antitachycardia pacing (ATP) use, and/or the application of supraventricular tachycardia (SVT) discriminators. While the programming options are similar across the different device manufacturers, recent Heart Rhythm Society (HRS) guidance has cautioned against generalizing learnings from one manufacturer's device platform to another because operation details differ. Hence, there is a need to better understand patient outcomes from these interventions that are contemporary and device manufacturer-specific. The PainFree SST trial was a prospectively enrolling study that included primary and secondary prevention Medtronic ICD recipients to assess the effectiveness of SmartShock Technology (SST), a suite of six proprietary SVT and nonarrhythmia discriminators (for rejection of lead noise, T-wave oversensing, and lead integrity alert) aimed at reducing overall inappropriate ICD therapies in the setting of modern-day use of delayed high-rate detection programming and ATP. This study demonstrated an overall inappropriate ICD shock rate of 1.5% at 12 months in dual and triple chamber ICDs and 2.5% in single-chamber ICDs, the lowest reported in any large prospective trial. Whether the primary benefit was derived from delayed high-rate programming or from the use of SVT discriminators remains poorly understood. This analysis aims to better understand the individual contributions of these two strategies in reducing overall inappropriate therapies. Publisher Copyright: {\textcopyright} 2019 Wiley Periodicals, Inc.",
year = "2019",
month = dec,
day = "1",
doi = "10.1111/jce.14250",
language = "English (US)",
volume = "30",
pages = "2877--2884",
journal = "Journal of cardiovascular electrophysiology",
issn = "1045-3873",
publisher = "Wiley-Blackwell",
number = "12",
}