Abstract 16544: Focal Fibrosis Predicts Monomorphic VT but Not Polymorphic VT or VF in Nonischemic Dilated Cardiomyopathy
Purpose: This study aimed to analyze the effect of focal myocardial fibrosis, assessed by late gadolinium enhancement MRI (LGE-MRI), on the occurrence and type of ventricular arrhythmia in patients with nonischemic dilated cardiomyopathy (NIDCM).
Methods: We included consecutive patients with NIDCM who underwent LGE-MRI before implantable cardioverter-defibrillator (ICD) implantation at two centers. LGE was defined by signal intensity ≥35% of maximal signal intensity and subdivided into core and border zone (≥50% and 35-50% of maximal signal intensity, respectively), and according to (non)basal location and transmurality. ICD recordings and 12-lead ECGs were reviewed to determine the occurrence and type of ventricular arrhythmia during follow-up.
Results: Of all 87 patients (62% male, age 56±13 years, LVEF 29±12%), 55 patients (63%) had LGE (median 6.3g, IQR 0.0-13.8g). During a median follow-up of 45 months (interquartile range, 23-67), monomorphic VT occurred in 18 (21%) patients, and polymorphic VT/VF in 10 (11%). LGE predicted monomorphic VT (Log-rank, p<0.001), but not polymorphic VT/VF (Log-rank, p=0.40). The optimal cut-off value for LGE to predict monomorphic VT was 7.2 grams (area under curve 0.84). Features associated with high risk for monomorphic VT were core extent, location in basal segments and area with 51-75% transmurality.
Conclusion: Focal fibrosis assessed by LGE-MRI predicts monomorphic VT, but not polymorphic VT/VF. The risk for monomorphic VT was particularly high when the LGE extent was ≥7.2 grams. The differences in underlying substrate and associated types of arrhythmia may have important implications for risk stratification and therapeutic interventions in patients with NIDCM.
Author Disclosures: S.R. Piers: None. K. Everaerts: None. R. Van der Geest: None. M.R. Hazebroek: None. J. Venlet: None. H. Siebelink: None. L. Pison: None. M.J. Schalij: None. S.C. Bekkers: None. S. Heymans: None. K. Zeppenfeld: Consultant/Advisory Board; Modest; Consulting fees from St. Jude Medical.
- © 2014 by American Heart Association, Inc.