title: Primary prevention of sudden cardiac death in a nonischemic dilated cardiomyopathy population: reappraisal of the role of programmed ventricular stimulation.
abstract: BACKGROUND
  We considered the role of programmed ventricular stimulation in primary prevention of sudden cardiac death in an idiopathic dilated cardiomyopathy population.
  
  
  RESULTS
  One hundred fifty-eight patients with idiopathic dilated cardiomyopathy underwent programmed ventricular stimulation. Ventricular tachycardia/ventricular fibrillation was triggered in 44 patients (group I, 27.8%) versus 114 patients (group II), where ventricular tachycardia/ventricular fibrillation was not induced. Sixty-nine patients with idiopathic dilated cardiomyopathy underwent implantable cardioverter-defibrillator (ICD) implantation: 41/44 in group I and 28/114 in group II. The major end points of the study were overall mortality and appropriate ICD activation. Overall mortality during the 46.9 months of mean follow-up was not significantly different between the 2 groups. Patients with left ventricular ejection fraction ≤35% (n=119) demonstrated a higher overall mortality rate compared with the patients with left ventricular ejection fraction >35% (n=39; 16.8% versus 10.3%, log-rank P=0.025). Advanced New York Heart Association class (III and IV versus I and II) was the single independent and strongest prognostic factor of overall mortality (hazard ratio, 11.909; P<0.001; confidence interval, 3.106-45.65), as well as of cardiac mortality (hazard ratio, 14.787; P=0.001; confidence interval, 2.958-73.922). Among ICD recipients, ICD activation rate was significantly higher in group I compared with group II (30 of 41 patients-73.2% versus 5 of 28 patients-17.9%; log-rank P=0.001), either in the form of antitachycardia pacing (68.3% versus 17.9%; log-rank P=0.001) or in the shock delivery form (51.2% versus 17.9%; log-rank P=0.05). Induction of ventricular tachycardia/ventricular fibrillation during programmed ventricular stimulation in contrast to left ventricular ejection fraction was the single independent prognostic factor for future ICD activation (hazard ratio, 4.195; P=0.007; confidence interval, 1.467-11.994).
  
  
  CONCLUSIONS
  Inducibility of ventricular tachycardia/ventricular fibrillation was associated with an increased likelihood of subsequent ICD activation and sudden cardiac death surrogate.
authors.affiliation: First Cardiology Clinic, University of Athens, Hippokration Hospital, Athens, Greece. kgatzoul@med.uoa.gr
authors.forename: Konstantinos A
authors.initials: KA
authors.lastname: Gatzoulis
authors.forename: Apostolos-Ilias
authors.initials: AI
authors.lastname: Vouliotis
authors.forename: Dimitris
authors.initials: D
authors.lastname: Tsiachris
authors.forename: Maria
authors.initials: M
authors.lastname: Salourou
authors.forename: Stefanos
authors.initials: S
authors.lastname: Archontakis
authors.forename: Polychronis
authors.initials: P
authors.lastname: Dilaveris
authors.forename: Theodoros
authors.initials: T
authors.lastname: Gialernios
authors.forename: Petros
authors.initials: P
authors.lastname: Arsenos
authors.forename: Georgios
authors.initials: G
authors.lastname: Karystinos
authors.forename: Skevos
authors.initials: S
authors.lastname: Sideris
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kallikazaros
authors.forename: Christodoulos
authors.initials: C
authors.lastname: Stefanadis
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D015331:Cohort Studies; D016001:Confidence Intervals; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000150:complications / Q000175:diagnosis; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000150:complications / Q000175:diagnosis
keywords: dilated cardiomyopathy; electrophysiology test; implantable cardioverter-defibrillator; primary prevention; risk stratification