SVT discrimination algorithms significantly reduce the rate of inappropriate therapy in the setting of modern-day delayed high-rate detection programming

J Cardiovasc Electrophysiol. 2019 Dec;30(12):2877-2884. doi: 10.1111/jce.14250. Epub 2019 Nov 5.

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.

Publication types

  • Multicenter Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Algorithms*
  • Cardiac Resynchronization Therapy / adverse effects*
  • Cardiac Resynchronization Therapy Devices*
  • Defibrillators, Implantable*
  • Diagnosis, Differential
  • Electric Countershock / adverse effects*
  • Electric Countershock / instrumentation*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • Prosthesis Design
  • Prosthesis Failure*
  • Signal Processing, Computer-Assisted*
  • Tachycardia, Supraventricular / diagnosis*
  • Tachycardia, Supraventricular / physiopathology
  • Tachycardia, Ventricular / diagnosis
  • Tachycardia, Ventricular / physiopathology
  • Tachycardia, Ventricular / therapy*
  • Time Factors
  • Treatment Outcome
  • Ventricular Fibrillation / diagnosis
  • Ventricular Fibrillation / physiopathology
  • Ventricular Fibrillation / therapy*