Late gadolinium enhancement dispersion for predicting malignant arrhythmic events in patient with non-ischaemic dilated cardiomyopathy

AIMS: Arrhythmic risk stratification in patients with non-ischaemic dilated cardiomyopathy (DCM) remains challenging. The LGE-dispersion mapping is a novel method for the quantification of tissue heterogeneity through the Global Dispersion Score (GDS). We sought to evaluate the usefulness of GDS in arrhythmic risk stratification of DCM patients. METHODS AND RESULTS: Consecutive non-ischaemic DCM patients underwent cardiac magnetic resonance imaging. GDS was calculated in LGE images. During a follow-up of 3.3 years (2 to 6 years), the combined endpoint of sudden cardiac death and appropriate implantable cardioverter-defibrillator intervention was considered. The final population included 510 patients (mean age was 56 ± 15 years). Left ventricular ejection fraction (LVEF) was >35% in 241 patients (47%). LGE was present in 225 patients (45%). Median extent of LGE was 12% of LV mass [interquartile range (IQR) 6-20%]. Among patients with positive LGE, GDS was 0.14 (IQR 0.08-0.20). During follow-up 81 patients had malignant ventricular arrhythmias (8 SCD, 73 appropriate ICD interventions). At Kaplan-Meier analysis, patients with GDS > 0.10 had worse prognosis than those with lower values of GDS (P < 0.0001). At multivariate analysis, GDS > 0.10 (HR 2.9, 95% CI: 1.7-5, P = 0.0002) was an independent predictor of events. The prognostic value of GDS was confirmed in subgroups of patients with LVEF ≤ 35% and >35%. CONCLUSION: GDS is a useful marker to identify DCM patients at higher risk for malignant arrhythmic events regardless of LVEF and extent of LGE.