Abstract 17368: Long-Term Arrhythmic Outcome of Non-Ischemic Dilated Cardiomyopathy: Prognostic Value of Contrast-Enhanced Cardiac Magnetic Resonance
Purpose: Although risk stratification for cardiac sudden death in non-ischemic dilated cardiomyopathy (DCM) relies on left ventricular (LV) dysfunction, predictors indicating the myocardial substrates of tissue heterogeneity causing arrhythmias in DCM remain to be established. The aim of the present study was to asses the role of presence and amount of late gadolinium enhancement (LGE) as detected by contrast-enhanced cardiac magnetic resonance (CE-CMR) for arrhythmic stratification in patients with non-ischemic DCM.
Methods: 136 consecutive patients (108 males, 79.4%; mean age 48.7±15 years) with non-ischemic DCM (EF ≤ 50%) were prospectively enrolled. All patients underwent initial CE-CMR and were followed for the primary end point of sustained ventricular tachycardia (SVT), and for the composite end-point of SVT, appropriate ICD intervention and sudden cardiac death (SCD) for a mean follow-up of 52±37 months. For each patient the LGE was classified as absent, "gray", midwall/subepicadial stria and "patchy" and quantified as percentage of LV mass.
Results: LGE was identified in 88 patients (65%) and affected 6.3%±8.8% (median value 4.5%) of LV wall. A "gray" pattern was observed in 13 (14.8%), a stria in 65 (73.8%), a septal junction in 35 (39.8%), a "patchy" pattern in 4 (4.5%). During the follow-up, 58/111 patients (42.6%) experienced adverse events, such as sustained VT (n=18), SCD (n=8), appropriate ICD interventions (n=12). On univariate analysis, the CE-CMR variables significantly associated with arrhythmic composite end point were the presence of LGE (HR 2.34; 95% CI 1.27-4.29, p < 0.006) and a total LGE amount ( 4.5%) (HR 1.07; 95% CI 1.03-1.1, p < 0.0001). Kaplan-Meier analysis revealed a significant correlation between the presence of LV-LGE and occurrence of malignant arrhythmic events (p=0.001). On multivariable analysis, after adjustment for LV volume and impaired EF, LGE remained an independent predictor of malignant arrhythmic outcome (HR= 4.7; CI:1.8-13; p=0.002).
Conclusions: In patients with DCM, LV myocardial scar measured by LGE on CE-CMR, is an independent predictor of adverse outcome and may contribute to assess the arrhythmogenic risk and to identify candidates for ICD therapy regardless EF.
- © 2012 by American Heart Association, Inc.