title: Use of myocardial scar characterization to predict ventricular arrhythmia in cardiac resynchronization therapy.
abstract: OBJECTIVE
  There is insufficient evidence to implant a combined cardiac resynchronization therapy (CRT) device with defibrillation capabilities (CRT-D) in all CRT candidates. The aim of the study was to assess myocardial scar size and its heterogeneity as predictors of sudden cardiac death (SCD) in CRT candidates.
  
  
  RESULTS
  A cohort of 78 consecutive patients with dilated cardiomyopathy and class I indication for CRT-D were prospectively enrolled. Before CRT-D implantation, a contrast-enhanced cardiac magnetic resonance (ce-CMR) was performed. The core and border zone (BZ) of the myocardial scar were characterized and quantified with a customized post-processing software. The first appropriate implantable cardioverter defibrillator (ICD) therapy was considered as a surrogate of SCD. During a mean follow-up of 25 months (25-75th percentiles, 15-34), appropriate ICD therapy occurred in 11.5% of patients. In a multivariate Cox proportional hazards regression model for clinical and ce-CMR variables, the scar mass percentage [hazards ratio (HR) per 1% increase 1.1 (1.06-1.15), P < 0.01], the BZ mass [HR per 1 g increase 1.06 (1.04-1.09), P < 0.01], and the BZ percentage of the scar [HR per 1% increase 1.06 (1.02-1.11), P < 0.01], were the only independent predictors of appropriate ICD therapy. Receiver-operating characteristic curve analysis showed that a scar mass <16% and a BZ < 9.5 g had a negative predictive value of 100%.
  
  
  CONCLUSIONS
  The presence, size, and heterogeneity of myocardial scar independently predict appropriate ICD therapies in CRT candidates. The ce-CMR-based scar analysis might help identify a subgroup of patients at relatively low risk of SCD.
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Fernández-Armenta
authors.forename: Antonio
authors.initials: A
authors.lastname: Berruezo
authors.forename: Lluis
authors.initials: L
authors.lastname: Mont
authors.forename: Marta
authors.initials: M
authors.lastname: Sitges
authors.forename: David
authors.initials: D
authors.lastname: Andreu
authors.forename: Etelvino
authors.initials: E
authors.lastname: Silva
authors.forename: Jose Tomás
authors.initials: JT
authors.lastname: Ortiz-Pérez
authors.forename: Jose María
authors.initials: JM
authors.lastname: Tolosana
authors.forename: Teresa M
authors.initials: TM
authors.lastname: de Caralt
authors.forename: Rosario Jesús
authors.initials: RJ
authors.lastname: Perea
authors.forename: Naiara
authors.initials: N
authors.lastname: Calvo
authors.forename: Emilce
authors.initials: E
authors.lastname: Trucco
authors.forename: Roger
authors.initials: R
authors.lastname: Borràs
authors.forename: María
authors.initials: M
authors.lastname: Matas
authors.forename: Josep
authors.initials: J
authors.lastname: Brugada
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000401:mortality; D058409:Cardiac Resynchronization Therapy Devices; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000401:mortality / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D016009:Chi-Square Distribution; D002921:Cicatrix / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D003287:Contrast Media; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D005355:Fibrosis; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000473:pathology / Q000628:therapy; D016277:Ventricular Function, Left
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA