title: Scar extent as a predictive factor of ventricular tachycardia cycle length after myocardial infarction: implications for implantable cardioverter-defibrillator programming optimization.
abstract: OBJECTIVE
  After an old myocardial infarction (MI), patients are at risk for reentrant ventricular tachycardia (VT) due to scar tissue that can be accurately identified by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Although the ability of LGE-CMR to predict sustained VT in implantable cardioverter-defibrillator (ICD) recipients has been well established, its use to predict monomorphic VT (sustained or not) cycle length (CL) and so, optimize ICD programming has never been investigated.
  
  
  RESULTS
  We included retrospectively 49 consecutive patients with an old MI who had undergone LGE-CMR before ICD implantation over a 4-year period (2006-09). Patients with amiodarone used were excluded. Scar extent was assessed by measuring scar mass, percent scar, and transmural scar extent. The endpoint was the occurrence of monomorphic VT, requiring an ICD therapy or not. The endpoint occurred in 26 patients. The median follow-up duration was 31 months. Scar extent parameters were significantly correlated with the study endpoint. With univariate regression analysis, the scar mass had the highest correlation with the VT CL (R = 0.671, P = 0.0002). Receiver-operating characteristic curve showed that scar mass can predict VT CL (area under the curve = 0.977, P < 0.0001). For a cut-off value of scar mass at 17.6 g, there is 100% specificity and 94.4% sensitivity.
  
  
  CONCLUSIONS
  In this observational and retrospective study, scar mass studied by LGE-CMR was specific and sensitive to predict VT CL and so could be a promising option to improve ICD post-implantation programming and decrease appropriate and inappropriate shocks. These conclusions must now be confirmed in a large and prospective study.
authors.affiliation: Department of Cardiology, CHU de Caen, Avenue de la côte de nacre, Caen F-14000, France.
authors.forename: Joachim
authors.initials: J
authors.lastname: Alexandre
authors.forename: Eric
authors.initials: E
authors.lastname: Saloux
authors.forename: Alain
authors.initials: A
authors.lastname: Lebon
authors.forename: Audrey Emmanuelle
authors.initials: AE
authors.lastname: Dugué
authors.forename: Adrien
authors.initials: A
authors.lastname: Lemaitre
authors.forename: Vincent
authors.initials: V
authors.lastname: Roule
authors.forename: Fabien
authors.initials: F
authors.lastname: Labombarda
authors.forename: Laure
authors.initials: L
authors.lastname: Champ-Rigot
authors.forename: Sophie
authors.initials: S
authors.lastname: Gomes
authors.forename: Arnaud
authors.initials: A
authors.lastname: Pellissier
authors.forename: Patrice
authors.initials: P
authors.lastname: Scanu
authors.forename: Paul
authors.initials: P
authors.lastname: Milliez
mesh_terms: D000368:Aged; D019540:Area Under Curve; D002921:Cicatrix / Q000209:etiology* / Q000473:pathology; D003287:Contrast Media; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D009942:Organometallic Compounds; D018579:Patient Selection; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine
keywords: Implantable cardioverter-defibrillator; Late gadolinium enhancement cardiac magnetic resonance; Myocardial infarction; Ventricular arrhythmias