title: The association between ICD interventions and mortality is independent of their modality: clinical implications.
abstract: BACKGROUND
  Patients with severe structural heart disease have increased mortality after implantable cardioverter-defibrillator (ICD) shocks. Whether this is limited to ICD shock therapy only or extends also to no-shock therapies, such as antitachycardia pacing (ATP), is unclear. We investigated the impact of different ICD therapies on long-term mortality.
  
  
  METHODS
  We enrolled 573 patients who underwent ICD implantation at our institution from 2004 to 2011. The population was divided into 3 groups: no device interventions (group 1), ATP interventions (group 2), and shock interventions (group 3). The endpoint was the all-cause mortality.
  
  
  RESULTS
  Over a follow-up period of 48 months (range 1-110), 447 (78%) had no device interventions, 71 (12%) had ATP therapy only, and 55 (10%) had at least one shock intervention. All-cause mortality occurred in 94 patients in group 1 (21%), 23 patients (43%) in group 2, and 21 patients (38%) in group 3. At multivariable Cox regression analysis, ATP intervention (HR: 1.8; 95% CI 1.1-3; P < 0.001), shock intervention (HR: 1.39; 95% CI 1.09-1.77; P = 0.008), age (HR: 1.05; 95% CI 1.02-1.07; P < 0.001), and LVEF (HR: 0.95; 95% CI 0.93-0.98; P = 0.001) were predictors of all-cause mortality. No significant difference in mortality was found between group 2 and 3.
  
  
  CONCLUSIONS
  Patients with ICDs who receive appropriate interventions are at increased risk of mortality. Such risk is not dependent on different types of ICD therapy, such as shocks or ATP. Our data suggest that sustained ventricular arrhythmias per se have a negative impact on prognosis rather than modality of ICD therapy.
authors: Department of Cardiovascular Medicine, Catholic University of the Sacred Heart, Rome, Italy.
authors: Gianluigi
authors: G
authors: Bencardino
authors: Antonio
authors: A
authors: Di Monaco
authors: Teresa
authors: T
authors: Rio
authors: Antonio
authors: A
authors: Frontera
authors: Pasquale
authors: P
authors: Santangeli
authors: Milena
authors: M
authors: Leo
authors: Gemma
authors: G
authors: Pelargonio
authors: Francesco
authors: F
authors: Perna
authors: Maria Lucia
authors: ML
authors: Narducci
authors: Francesca
authors: F
authors: Gabrielli
authors: Gaetano Antonio
authors: GA
authors: Lanza
authors: Fulvio
authors: F
authors: Bellocci
authors: Antonio
authors: A
authors: Rebuzzi
authors: Filippo
authors: F
authors: Crea
mesh_terms: D000368:Aged; D015897:Comorbidity; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004554:Electric Countershock / Q000295:instrumentation / Q000401:mortality*; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000401:mortality / Q000517:prevention & control*; D016896:Treatment Outcome
keywords: ICD shock; antitachycardia pacing; heart failure; implantable cardioverter-defibrillator; mortality; ventricular arrhythmias