title: Time-dependent benefit of preventive cardiac resynchronization therapy after myocardial infarction.
abstract: OBJECTIVE
  Cardiac remodelling is a progressive process after myocardial infarction (MI). However, currently there are no data regarding the effect of s:elapsed time from MI on the benefit of cardiac resynchronization therapy with defibrillator (CRT-D). The present study was designed to evaluate the relationship between elapsed time from MI and the benefit of preventive CRT-D therapy in patients with ischaemic cardiomyopathy (ICM).
  
  
  RESULTS
  The risk of heart failure (HF) or death as a function of elapsed time from MI to enrolment, by treatment with CRT-D vs. implantable cardioverter defibrillator (ICD)-only therapy, was assessed among 704 ICM patients with a documented MI enrolled in MADIT-CRT, and separately in a subset of ICM patients without a documented prior MI (n = 237). In ICD patients, the adjusted risk of HF or death increased by 4% (P = 0.01) for each year elapsed from MI. Multivariate analysis demonstrated that patients with remote MI [categorized at the median value (≥8 years)] derived a significantly greater benefit from CRT-D [HR = 0.42 (P < 0.001)] than those with a more recent MI [HR = 1.26 (P = 0.35); P-value for interaction <0.001]. Consistently, the benefit of CRT-D was directly related to increasing quartiles of elapsed time from MI [Q(1) (<3 years): HR = 1.67; P = 0.20, Q(2) (3-8 years): HR = 1.12; P = 0.71, Q(3) (8-15 years): HR = 0.47; P = 0.02, and Q(4) (≥15 years): HR = 0.38; P = 0.001]. The ICM subgroup with no documented MI also derived enhanced benefit from CRT-D (HR = 0.43; P = 0.003).
  
  
  CONCLUSIONS
  In patients with ischaemic cardiomyopathy, the risk of HF or death and the magnitude of CRT-D benefit are directly related to elapsed time from MI.
authors.affiliation: Cardiology Division, Heart Research Follow-up Program, University of Rochester Medical Center, Rochester, NY, USA. alon.barsheshet@heart.rochester.edu
authors.forename: Alon
authors.initials: A
authors.lastname: Barsheshet
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
authors.forename: Michael
authors.initials: M
authors.lastname: Eldar
authors.forename: David T
authors.initials: DT
authors.lastname: Huang
authors.forename: W Jackson
authors.initials: WJ
authors.lastname: Hall
authors.forename: Helmut U
authors.initials: HU
authors.lastname: Klein
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Steinberg
authors.forename: David J
authors.initials: DJ
authors.lastname: Wilber
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zareba
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods* / Q000401:mortality; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D017202:Myocardial Ischemia / Q000150:complications / Q000401:mortality / Q000473:pathology; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome; D020257:Ventricular Remodeling / Q000502:physiology*