title: ICD Shock, Not Ventricular Fibrillation, Causes Elevation of High Sensitive Troponin T after Defibrillation Threshold Testing--The Prospective, Randomized, Multicentre TropShock-Trial.
abstract: BACKGROUND
  The placement of an implantable cardioverter defibrillator (ICD) has become routine practice to protect high risk patients from sudden cardiac death. However, implantation-related myocardial micro-damage and its relation to different implantation strategies are poorly characterized.
  
  
  METHODS
  A total of 194 ICD recipients (64±12 years, 83% male, 95% primary prevention of sudden cardiac death, 35% cardiac resynchronization therapy) were randomly assigned to one of three implantation strategies: (1) ICD implantation without any defibrillation threshold (DFT) testing, (2) estimation of the DFT without arrhythmia induction (modified "upper limit of vulnerability (ULV) testing") or (3) traditional safety margin testing including ventricular arrhythmia induction. High-sensitive Troponin T (hsTnT) levels were determined prior to the implantation and 6 hours after.
  
  
  RESULTS
  All three groups showed a postoperative increase of hsTnT. The mean delta was 0.031±0.032 ng/ml for patients without DFT testing, 0.080±0.067 ng/ml for the modified ULV-testing and 0.064±0.056 ng/ml for patients with traditional safety margin testing. Delta hsTnT was significantly larger in both of the groups with intraoperative ICD testing compared to the non-testing strategy (p≤0.001 each). There was no statistical difference in delta hsTnT between the two groups with intraoperative ICD testing (p = 0.179).
  
  
  CONCLUSIONS
  High-sensitive Troponin T release during ICD implantation is significantly higher in patients with intraoperative ICD testing using shock applications compared to those without testing. Shock applications, with or without arrhythmia induction, did not result in a significantly different delta hsTnT. Hence, the ICD shock itself and not ventricular fibrillation seems to cause myocardial micro-damage.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01230086.
authors.affiliation: Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Abteilung für Elektrophysiologie, Faculty of Medicine, Technische Universität München, Munich, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Semmler
authors.affiliation: Cardiology and Angiology I, Heart Center, Freiburg University, Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Biermann
authors.affiliation: Klinikum rechts der Isar, Institut für Medizinische Statistik und Epidemiologie, Technische Universität, Munich, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Haller
authors.affiliation: Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Abteilung für Elektrophysiologie, Faculty of Medicine, Technische Universität München, Munich, Germany; Schön Klinik Starnberger See, Kardiologie, Starnberg, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Jilek
authors.affiliation: Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Abteilung für Elektrophysiologie, Faculty of Medicine, Technische Universität München, Munich, Germany; Medizinische Klinik I und Poliklinik, Klinikum der Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Sarafoff
authors.affiliation: Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Abteilung für Elektrophysiologie, Faculty of Medicine, Technische Universität München, Munich, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Lennerz
authors.affiliation: Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Abteilung für Elektrophysiologie, Faculty of Medicine, Technische Universität München, Munich, Germany; University Hospital Dubrava, Division of Cardiology, Department of Internal Medicine, Zagreb, Croatia.
authors.forename: Hrvoje
authors.initials: H
authors.lastname: Vrazic
authors.affiliation: Krankenhaus Landshut-Achdorf, Medizinische Klinik I, Kardiologie, Landshut, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Zrenner
authors.affiliation: Cardiology and Angiology I, Heart Center, Freiburg University, Freiburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Asbach
authors.affiliation: Deutsches Herzzentrum München, Klinik für Herz- und Kreislauferkrankungen, Abteilung für Elektrophysiologie, Faculty of Medicine, Technische Universität München, Munich, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Kolb
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001145:Arrhythmias, Cardiac / Q000097:blood / Q000503:physiopathology / Q000517:prevention & control; D015415:Biomarkers / Q000097:blood; D058406:Cardiac Resynchronization Therapy / Q000379:methods; D052279:Creatine Kinase, MB Form / Q000097:blood; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000379:methods*; D023381:Endpoint Determination / Q000379:methods; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D020107:Troponin T / Q000097:blood*; D014693:Ventricular Fibrillation / Q000097:blood* / Q000503:physiopathology / Q000517:prevention & control
chemical_list: D015415:Biomarkers; D020107:Troponin T; D052279:Creatine Kinase, MB Form