title: Long-term arrhythmia-free survival in patients with severe left ventricular dysfunction and no inducible ventricular tachycardia after myocardial infarction.
abstract: BACKGROUND
  A negative electrophysiology study (EPS) may delineate a subgroup of patients with severely impaired left ventricular ejection fraction (LVEF) whose care can be safely managed long-term without an implantable cardioverter-defibrillator.
  
  
  RESULTS
  Consecutive patients treated with primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction underwent early (median 4 days) LVEF assessment. Patients with LVEF ≤40% underwent EPS. A prophylactic implantable cardioverter-defibrillator was implanted for a positive (inducible monomorphic ventricular tachycardia) but not a negative (no inducible ventricular tachycardia or inducible ventricular fibrillation/flutter) EPS result. Patients who would have become eligible for a late primary prevention implantable cardioverter-defibrillator with LVEF ≤30% or ≤35% with New York Heart Association class II/III heart failure were included and analyzed according to EPS result. Patients with LVEF >40%, ineligible for EPS, were followed up as control subjects (n=1286). The primary end point was survival free of death or arrhythmia (resuscitated cardiac arrest or sustained ventricular tachycardia/ventricular fibrillation). EPS performed in 128 patients with LVEF ≤30% or with LVEF ≤35% and heart failure was negative in 63% (n=80) and positive in 37% (n=48). Implantable-cardioverter defibrillators were implanted in <0.1%, 4%, and 90% of control, EPS-negative, and EPS-positive patients, respectively. The distribution of time to death or arrhythmia was comparable in control patients and EPS-negative patients with LVEF ≤30% or with LVEF ≤35% and heart failure (P=0.738), who both differed significantly from EPS-positive patients (P<0.001). At 3 years, 91.8 ± 3.2%, 93.4 ± 1.0%, and 62.7 ± 7.5% of control, EPS-negative, and EPS-positive patients were free of death or arrhythmia, respectively.
  
  
  CONCLUSIONS
  Revascularized patients with ST-segment-elevation myocardial infarction with severely impaired left ventricular function but no inducible ventricular tachycardia have a favorable long-term prognosis without the protection of an implantable cardioverter-defibrillator.
authors.affiliation: From Westmead Hospital, Sydney, Australia (S.Z., A.N., G.S., A.T., S.T., D.L.R., P.K.); and the Department of Medicine, University of Sydney, Sydney, Australia (S.Z., A.T., S.T., P.K.).
authors.forename: Sarah
authors.initials: S
authors.lastname: Zaman
authors.forename: Arun
authors.initials: A
authors.lastname: Narayan
authors.forename: Aravinda
authors.initials: A
authors.lastname: Thiagalingam
authors.forename: Gopal
authors.initials: G
authors.lastname: Sivagangabalan
authors.forename: Stuart
authors.initials: S
authors.lastname: Thomas
authors.forename: David L
authors.initials: DL
authors.lastname: Ross
authors.forename: Pramesh
authors.initials: P
authors.lastname: Kovoor
mesh_terms: D000368:Aged; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D017147:Defibrillators, Implantable; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology / Q000628:therapy; D009204:Myocardial Revascularization; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology; D017180:Tachycardia, Ventricular / Q000401:mortality*; D018487:Ventricular Dysfunction, Left / Q000401:mortality* / Q000503:physiopathology / Q000628:therapy; D014693:Ventricular Fibrillation / Q000401:mortality; D054141:Ventricular Flutter / Q000401:mortality
keywords: death, sudden; electrophysiology; myocardial infarction; tachycardia