CMR quantification of myocardial scar provides additive prognostic information in nonischemic cardiomyopathy.
OBJECTIVE
This study sought to determine whether the extent of late gadolinium enhancement (LGE) can provide additive prognostic information in patients with a nonischemic dilated cardiomyopathy (NIDC) with an indication for implantable cardioverter-defibrillator (ICD) therapy for the primary prevention of sudden cardiac death (SCD).


BACKGROUND
Data suggest that the presence of LGE is a strong discriminator of events in patients with NIDC. Limited data exist on the role of LGE quantification.


METHODS
The extent of LGE and clinical follow-up were assessed in 162 patients with NIDC prior to ICD insertion for primary prevention of SCD. LGE extent was quantified using both the standard deviation-based (2-SD) method and the full-width half-maximum (FWHM) method.


RESULTS
We studied 162 patients with NIDC (65% male; mean age: 55 years; left ventricular ejection fraction [LVEF]: 26 ± 8%) and followed up for major adverse cardiac events (MACE), including cardiovascular death and appropriate ICD therapy, for a mean of 29 ± 18 months. Annual MACE rates were substantially higher in patients with LGE (24%) than in those without LGE (2%). By univariate association, the presence and the extent of LGE demonstrated the strongest associations with MACE (LGE presence, hazard ratio [HR]: 14.5 [95% confidence interval (CI): 6.1 to 32.6; p < 0.001]; LGE extent, HR: 1.15 per 1% increase in volume of LGE [95% CI: 1.12 to 1.18; p < 0.0001]). Multivariate analyses showed that LGE extent was the strongest predictor in the best overall model for MACE, and a 7-fold hazard was observed per 10% LGE extent after adjustments for patient age, sex, and LVEF (adjusted HR: 7.61; p < 0.0001). LGE quantitation by 2-SD and FWHM both demonstrated robust prognostic association, with the highest MACE rate observed in patients with LGE involving >6.1% of LV myocardium.


CONCLUSIONS
LGE extent may provide further risk stratification in patients with NIDC with a current indication for ICD implantation for the primary prevention of SCD. Strategic guidance on ICD therapy by cardiac magnetic resonance in patients with NIDC warrants further study.
Non-invasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Radiology, Brigham and Women's Hospital, Boston, Massachusetts; Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts; Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
Tomas G
TG
Neilan
Otavio R
OR
Coelho-Filho
Stephan B
SB
Danik
Ravi V
RV
Shah
John A
JA
Dodson
Daniel J
DJ
Verdini
Michifumi
M
Tokuda
Caroline A
CA
Daly
Usha B
UB
Tedrow
William G
WG
Stevenson
Michael
M
Jerosch-Herold
Brian B
BB
Ghoshhajra
Raymond Y
RY
Kwong
D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D002921:Cicatrix / Q000150:complications / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D016277:Ventricular Function, Left
CMR; EF; FWHM; ICD; LGE; MACE; NIDC; SCD; VT; cardiac magnetic resonance; ejection fraction; full-width half-maximum; implantable cardioverter-defibrillator; implantable cardioverter-defibrillators; late gadolinium enhancement; late gadolinium enhancement; major adverse cardiac events; nonischemic cardiomyopathy; nonischemic dilated cardiomyopathy; sudden cardiac death; ventricular tachycardia