title: Incidence and predictors of implantable cardioverter-defibrillator therapy in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy undergoing implantable cardioverter-defibrillator implantation for primary prevention.
abstract: OBJECTIVE
  The purpose of this study was to define the incidence and predictors of implantable cardioverter-defibrillator (ICD) therapy in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) after placement of an ICD for primary prevention.
  
  
  BACKGROUND
  Patients with a diagnosis of ARVD/C often receive an ICD for prevention of sudden cardiac death.
  
  
  METHODS
  Patients (n = 84) from the Johns Hopkins registry with definite or probable ARVD/C who underwent ICD implantation for primary prevention were studied. Detailed phenotypic, genotype, and ICD event information was obtained and appropriate ICD therapies were adjudicated based on intracardiac electrograms.
  
  
  RESULTS
  Over a mean follow-up of 4.7 ± 3.4 years, appropriate ICD therapy was seen in 40 patients (48%), of whom 16 (19%) received interventions for potentially fatal ventricular fibrillation/flutter episodes. Proband status (p < 0.001), inducibility at electrophysiologic study (p = 0.005), presence of nonsustained ventricular tachycardia (p < 0 .001), and Holter premature ventricular complex count >1,000/24 h (p = 0.024) were identified as significant predictors of appropriate ICD therapy. The 5-year survival free of appropriate ICD therapy for patients with 1, 2, 3, and 4 risk factors was 100%, 83%, 21%, and 15%, respectively. Inducibility at electrophysiologic study (hazard ratio: 4.5, 95% confidence interval: 1.4 to 15, p = 0.013) and nonsustained ventricular tachycardia (hazard ratio: 10.5, 95% confidence interval: 2.4 to 46.2, p = 0.002) remained as significant predictors on multivariable analysis.
  
  
  CONCLUSIONS
  Nearly one-half of the ARVD/C patients with primary prevention ICD implantation experience appropriate ICD interventions. Inducibility at electrophysiologic study and nonsustained ventricular tachycardia are independent strong predictors of appropriate ICD therapy. An increase in ventricular ectopy burden was associated with progressively lower event-free (appropriate ICD interventions) survival. Incremental risk of ventricular arrhythmias and ICD therapy was observed with the presence of multiple risk factors.
authors.affiliation: Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Aditya
authors.initials: A
authors.lastname: Bhonsale
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: James
authors.forename: Crystal
authors.initials: C
authors.lastname: Tichnell
authors.forename: Brittney
authors.initials: B
authors.lastname: Murray
authors.forename: Dmitri
authors.initials: D
authors.lastname: Gagarin
authors.forename: Binu
authors.initials: B
authors.lastname: Philips
authors.forename: Darshan
authors.initials: D
authors.lastname: Dalal
authors.forename: Ryan
authors.initials: R
authors.lastname: Tedford
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Russell
authors.forename: Theodore
authors.initials: T
authors.lastname: Abraham
authors.forename: Harikrishna
authors.initials: H
authors.lastname: Tandri
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Judge
authors.forename: Hugh
authors.initials: H
authors.lastname: Calkins
mesh_terms: D000293:Adolescent; D000328:Adult; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000453:epidemiology* / Q000517:prevention & control* / Q000628:therapy; D058406:Cardiac Resynchronization Therapy / Q000379:methods; D002648:Child; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011322:Primary Prevention / Q000379:methods; D055815:Young Adult