title: Wearable cardioverter-defibrillator use in patients perceived to be at high risk early post-myocardial infarction.
abstract: OBJECTIVE
  The aim of this study was to describe usage of the wearable cardioverter-defibrillator (WCD) during mandated waiting periods following myocardial infarction (MI) for patients perceived to be at high risk for sudden cardiac arrest (SCA).
  
  
  BACKGROUND
  Current device guidelines and insurance coverage require waiting periods of either 40 days or 3 months before implanting a cardioverter-defibrillator post-myocardial infarction (MI), depending on whether or not acute revascularization was undertaken.
  
  
  METHODS
  We assessed characteristics of and outcomes for patients who had a WCD prescribed in the first 3 months post-MI. The WCD medical order registry was searched for patients who were coded as having had a "recent MI with ejection fraction ≤35%" or given an International Classification of Diseases, Ninth Revision 410.xx diagnostic code (acute MI), and then matched to device-recorded data.
  
  
  RESULTS
  Between September 2005 and July 2011, 8,453 unique patients (age 62.7 ± 12.7 years, 73% male) matched study criteria. A total of 133 patients (1.6%) received 309 appropriate shocks. Of these patients, 91% were resuscitated from a ventricular arrhythmia. For shocked patients, the left ventricular ejection fraction (LVEF) was ≤30% in 106, 30% to 35% in 17, >36% in 8, and not reported in 2 patients. Of the 38% of patients not revascularized, 84% had a LVEF ≤30%; of the 62% of patients revascularized, 77% had a LVEF ≤30%. The median time from the index MI to WCD therapy was 16 days. Of the treated patients, 75% received treatment in the first month, and 96% within the first 3 months of use. Shock success resulting in survival was 84% in nonrevascularized and 95% in revascularized patients.
  
  
  CONCLUSIONS
  During the 40-day and 3-month waiting periods in patients post-MI, the WCD successfully treated SCA in 1.4%, and the risk was highest in the first month of WCD use. The WCD may benefit individual patients selected for high risk of SCA early post-MI.
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: andrew.epstein@uphs.upenn.edu.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Epstein
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Ohio State University, Columbus, Ohio.
authors.forename: William T
authors.initials: WT
authors.lastname: Abraham
authors.affiliation: ZOLL, Pittsburgh, Pennsylvania.
authors.forename: Nicole R
authors.initials: NR
authors.lastname: Bianco
authors.affiliation: Division of Cardiology, Department of Medicine, University of Arizona, Tucson, Arizona.
authors.forename: Karl B
authors.initials: KB
authors.lastname: Kern
authors.affiliation: Parkview Health System, Fort Wayne, Indiana.
authors.forename: Michael
authors.initials: M
authors.lastname: Mirro
authors.affiliation: Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Rao
authors.affiliation: Eller Congenital Heart Center, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Edward K
authors.initials: EK
authors.lastname: Rhee
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Harvard Medical School, Boston, Massachusetts.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Solomon
authors.affiliation: ZOLL, Pittsburgh, Pennsylvania.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Szymkiewicz
mesh_terms: D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left
keywords: AED; ICD; LVEF; MVT; OMT; PMVT; SCA; SCD; SSDMF; Social Security Death Master File; VF; VFl; WCD; automated external defibrillator; defibrillation; implantable cardioverter-defibrillator; left ventricular ejection fraction; monomorphic ventricular tachycardia; optimized medical therapy; polymorphic ventricular tachycardia; resuscitation; sudden cardiac arrest; sudden cardiac death; ventricular fibrillation; ventricular flutter; wearable cardioverter-defibrillator