title: Reassessment of Cardiac Function and Implantable Cardioverter-Defibrillator Use Among Medicare Patients With Low Ejection Fraction After Myocardial Infarction.
abstract: BACKGROUND
  Guidelines recommend that patients with low ejection fraction (EF) after myocardial infarction (MI) have their EF reassessed 40 days after MI for implantable cardioverter-defibrillator (ICD) candidacy. This study examines rates of EF reassessment and their association with 1-year ICD implantation in post-MI patients with low EF.
  
  
  METHODS
  We examined rates of postdischarge EF reassessment and ICD implantation among 10 289 Medicare-insured patients ≥65 years of age with an EF≤35% during the index MI admission from January 2007 through September 2010 in ACTION Registry-GWTG (Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines). Multivariable Cox models tested the association between time-dependent EF reassessment and 1-year ICD implantation, stratified by revascularization status during the index MI admission.
  
  
  RESULTS
  Among patients with EF ≤35% during the index MI admission, 66.8% (95% confidence interval [CI], 65.9-67.8) had EF reassessment within the next year. Revascularized patients were more likely to have EF reassessment (76.9% [95% CI, 75.8-78.0)] versus 53.7% [95% CI, 52.2-55.2]; P<0.001) and had shorter times to EF reassessment (median, 67 versus 84 days; P<0.001) than nonrevascularized patients. Among patients with EF reassessment, only 11% received an ICD within 1 year. Reassessment of EF was associated with a higher likelihood of ICD implantation for both revascularized (unadjusted, 12.1% versus 2.4%, P<0.001; adjusted hazard ratio, 10.6, 95% CI, 7.7-14.8) and nonrevascularized (unadjusted, 10.0% versus 1.7%, P<0.001; adjusted hazard ratio, 6.1, 95% CI, 4.1-9.2) patients.
  
  
  CONCLUSIONS
  In US practice, EF reassessments are commonly performed among patients with MI with an initially reduced EF. Although 1-year EF reassessment is associated with increased likelihood of ICD implantation, 1-year ICD implantation rates remain very low even among patients with EF reassessment, regardless of revascularization status.
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.). sean.pokorney@duke.edu.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Pokorney
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Amy L
authors.initials: AL
authors.lastname: Miller
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Anita Y
authors.initials: AY
authors.lastname: Chen
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Laine
authors.initials: L
authors.lastname: Thomas
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: James A
authors.initials: JA
authors.lastname: de Lemos
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Sana M
authors.initials: SM
authors.lastname: Al-Khatib
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Velazquez
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Eric D
authors.initials: ED
authors.lastname: Peterson
authors.affiliation: From Duke University Medical Center, Durham, NC (S.D.P., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Duke Clinical Research Institute, Durham, NC (S.D.P., A.Y.C., L.T., S.M.A.-K., E.J.V., E.D.P., T.Y.W.); Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.L.M.); UCLA Health System, Los Angeles, CA (G.C.F.); and UT Southwestern Medical Center, Dallas, TX (J.A.d.L.).
authors.forename: Tracy Y
authors.initials: TY
authors.lastname: Wang
mesh_terms: D000368:Aged; D016208:Databases, Factual; D017147:Defibrillators, Implantable; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D006278:Medicare; D009203:Myocardial Infarction / Q000401:mortality / Q000628:therapy*; D009204:Myocardial Revascularization; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D013318:Stroke Volume; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography; D014481:United States
keywords: Medicare; defibrillators, implantable; echocardiography; myocardial infarction; ventricular dysfunction