Ventricular arrhythmia inducibility predicts subsequent ICD activation in nonischemic cardiomyopathy patients: a DEFINITE substudy.

Published

Journal Article

OBJECTIVES: We evaluated whether electrophysiologic (EP) inducibility predicts the subsequent occurrence of spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) in the Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) trial. BACKGROUND: Inducibility of ventricular arrhythmias has been widely used as a risk marker to select implantable cardioverter defibrillator (ICD) candidates, but is believed not to be predictive in nonischemic cardiomyopathy patients. METHODS: In DEFINITE, patients randomized to the ICD arm, but not the conventional arm, underwent noninvasive EP testing via the ICD shortly after ICD implantation using up to three extrastimuli at three cycle lengths plus burst pacing. Inducibility was defined as monomorphic or polymorphic VT or VF lasting 15 seconds. Patients were followed for a median of 29 +/- 14 months (interquartile range = 2-41). An independent committee, blinded to inducibility status, characterized the rhythm triggering ICD shocks. RESULTS: Inducibility, found in 29 of 204 patients (VT in 13, VF in 16), was associated with diabetes (41.4% vs 20.6%, P = 0.014) and a slightly higher ejection fraction (23.2 +/- 5.9 vs 20.5 +/- 5.7, P = 0.021). In follow-up, 34.5% of the inducible group (10 of 29) experienced ICD therapy for VT or VF or arrhythmic death versus 12.0% (21 of 175) noninducible patients (hazard ratio = 2.60, P = 0.014). CONCLUSIONS: In DEFINITE patients, inducibility of either VT or VF was associated with an increased likelihood of subsequent ICD therapy for VT or VF, and should be one factor considered in risk stratifying nonischemic cardiomyopathy patients.

Full Text

Duke Authors

Cited Authors

  • Daubert, JP; Winters, SL; Subacius, H; Berger, RD; Ellenbogen, KA; Taylor, SG; Schaechter, A; Howard, A; Kadish, A; Defibrillators In Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) Investigators,

Published Date

  • June 2009

Published In

Volume / Issue

  • 32 / 6

Start / End Page

  • 755 - 761

PubMed ID

  • 19545338

Pubmed Central ID

  • 19545338

Electronic International Standard Serial Number (EISSN)

  • 1540-8159

Digital Object Identifier (DOI)

  • 10.1111/j.1540-8159.2009.02362.x

Language

  • eng

Conference Location

  • United States