Impact of the presence and amount of myocardial fibrosis by cardiac magnetic resonance on arrhythmic outcome and sudden cardiac death in nonischemic dilated cardiomyopathy.
BACKGROUND
Current risk stratification for sudden cardiac death (SCD) in nonischemic dilated cardiomyopathy (NIDC) relies on left ventricular (LV) dysfunction, a poor marker of ventricular electrical instability. Contrast-enhanced cardiac magnetic resonance has the ability to accurately identify and quantify ventricular myocardial fibrosis (late gadolinium enhancement [LGE]).


OBJECTIVE
To evaluate the impact of the presence and amount of myocardial fibrosis on arrhythmogenic risk prediction in NIDC.


METHODS
One hundred thirty-seven consecutive patients with angiographically proven NIDC were enrolled for this study. All patients were followed up for a combined arrhythmic end point including sustained ventricular tachycardia (VT), appropriate implantable cardioverter-defibrillator (ICD) intervention, ventricular fibrillation (VF), and SCD.


RESULTS
LV-LGE was identified in 76 (55.5%) patients. During a median follow-up of 3 years, the combined arrhythmic end point occurred in 22 (16.1%) patients: 8 (5.8%) sustained VT, 9 (6.6%) appropriate ICD intervention, either against VF (n = 5; 3.6%) or VT (n = 4; 2.9%), 3 (2.2%) aborted SCD, and 2 (1.5%) died suddenly. Kaplan-Meier analysis revealed a significant correlation between the LV-LGE presence (not the amount and distribution) and malignant arrhythmic events (P < .001). In univariate Cox regression analysis, LV-LGE (hazard ratio [HR] 4.17; 95% confidence interval [CI] 1.56-11.2; P = .005) and left bundle branch block (HR 2.43; 95% CI 1.01-5.41; P = .048) were found to be associated with arrhythmias. In multivariable analysis, the presence of LGE was the only independent predictor of arrhythmias (HR 3.8; 95% CI 1.3-10.4; P = .01).


CONCLUSIONS
LV-LGE is a powerful and independent predictor of malignant arrhythmic prognosis, while its amount and distribution do not provide additional prognostic value. Contrast-enhanced cardiac magnetic resonance may contribute to identify candidates for ICD therapy not fulfilling the current criteria based on left ventricular ejection fraction.
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Martina
M
Perazzolo Marra
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Manuel
M
De Lazzari
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Alessandro
A
Zorzi
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Federico
F
Migliore
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Filippo
F
Zilio
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Chiara
C
Calore
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Giulia
G
Vettor
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Francesco
F
Tona
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Giuseppe
G
Tarantini
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Luisa
L
Cacciavillani
Department of Medical Diagnostic Sciences and Special Therapies; University of Padova, Padova, Italy.
Francesco
F
Corbetti
Department of Medical Diagnostic Sciences and Special Therapies; University of Padova, Padova, Italy.
Benedetta
B
Giorgi
Department of Medical Diagnostic Sciences and Special Therapies; University of Padova, Padova, Italy.
Diego
D
Miotto
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Gaetano
G
Thiene
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Cristina
C
Basso
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy.
Sabino
S
Iliceto
Department of Cardiac, Thoracic and Vascular Sciences; University of Padova, Padova, Italy. Electronic address: domenico.corrado@unipd.it.
Domenico
D
Corrado
D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology*; D017147:Defibrillators, Implantable; D005260:Female; D005355:Fibrosis / Q000150:complications / Q000175:diagnosis; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D017180:Tachycardia, Ventricular / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*
Arrhythmias; Cardiac magnetic resonance; Dilated cardiomyopathy; Heart failure; Late gadolinium enhancement; Risk stratification