title: Implantable defibrillators with enhanced detection algorithms: detection performance and safety results from the PainFree SST study.
abstract: BACKGROUND
  Implantable defibrillators (ICD) are highly effective in reducing arrhythmia-related mortality. ICD shock therapy has been shown to increase psychological distress, health care utilization, and is associated with increased mortality. The Protecta ICDs (Medtronic Inc., Minneapolis, MN, USA) have algorithms designed to reduce unnecessary and inappropriate shock therapy.
  
  
  RESULTS
  The PainFree SmartShock™ Technology (PainFree SST) study is a prospective, multicenter, clinical trial with two consecutive phases, a premarket phase safety study and a postmarket phase effectiveness study. We report the results of the PainFree SST safety study. The premarket phase aimed to investigate safety in the first year postimplant, and to determine if the novel algorithms (T-wave discrimination, right ventricular lead noise discrimination and confirmation+) affect appropriate ventricular fibrillation (VF) detection. Patients (total: n = 246 [male 78%, mean age 63 year, primary prevention indication in 76%]) were implanted either with a Protecta XT dual-chamber ICD (n = 114 [46%]) or a defibrillator with cardiac resynchronization therapy (n = 132 [54%]). Appropriate VF detection was measured during VF induction at implantation when the novel algorithms were programmed ON. A two-second delay in VF detection was classified as clinically significant. No delay in VF detection was observed with all algorithms programmed ON. No unanticipated serious adverse device effects occurred during first year postimplant.
  
  
  CONCLUSIONS
  The results of the premarket phase of the PainFree SST trial demonstrate the safety of the Protecta XT defibrillators. Detection of induced VF was not delayed with SmartShock™ algorithms ON.
authors.affiliation: Hospital of St. Pölten-Lilienfeld, Department of Cardiology, St. Pölten, Austria; Karl Landsteiner Society, Institute of Cardiovascular Research, St. Pölten, Austria.
authors.forename: Christian G
authors.initials: CG
authors.lastname: Wollmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Lawo
authors.forename: Volker
authors.initials: V
authors.lastname: Kühlkamp
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Becker
authors.forename: Claudio
authors.initials: C
authors.lastname: Garutti
authors.forename: Troy
authors.initials: T
authors.lastname: Jackson
authors.forename: Mark L
authors.initials: ML
authors.lastname: Brown
authors.forename: Harald
authors.initials: H
authors.lastname: Mayr
mesh_terms: D000368:Aged; D000465:Algorithms; D000925:Anticoagulants / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000503:physiopathology / Q000628:therapy*; D017147:Defibrillators, Implantable; D015716:Electrocardiography, Ambulatory; D004869:Equipment Safety; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061214:Patient Safety; D011358:Product Surveillance, Postmarketing; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants
keywords: complications; implantable defibrillator; inappropriate shocks; shock reduction algorithm