Pattern of late gadolinium enhancement predicts arrhythmic events in patients with non-ischemic cardiomyopathy

Background Left ventricular late gadolinium enhancement (LV-LGE) by cardiac magnetic resonance (CMR) imaging has been associated with adverse clinical outcomes in patients with non-ischemic cardiomyopathy (NICM). However, an association between the characteristics of the LGE and arrhythmic risk has not been demonstrated consistently. This study evaluated the impact of the LV-LGE characteristics on the arrhythmia risk in patients with NICM. Methods This study enrolled 365 consecutive patients (54 ± 15 years) with NICM who underwent CMR imaging. All patients were monitored for the following outcomes: major arrhythmic events (MA), including sustained ventricular tachycardia, an appropriate implantable cardioverter–defibrillator intervention, ventricular fibrillation and sudden cardiac death. Results During 44.3 ± 36.4 months of follow-up, 44 (12.1%) patients experienced MA. LV-LGE was observed in 40 (90.9%) and 221 (68.8%) patients with and without MA, respectively. LV-LGE was more frequently observed in the MA group (p = 0.002). The age- and sex-adjusted hazard ratio (HR) of MA was increased in patients with LGE extent ≥ 8% (HR 8.45, 95% confidence interval (CI) 2.91–24.6), and those with subendocardial (HR 6.98, 95% CI 1.74–28.0) and subepicardial LGE patterns (HR 7.2, 95% CI 1.61–35.6). In multivariable models adjusted for other clinical variables, only the subepicardial LGE pattern had 7.2 (95% CI, 1.61–32.6, p = 0.01) time increase in the MA risk. Conclusions LV-LGE in patients with NICM is not uncommon. The subepicardial pattern of the LV-LGE was an independent predictor of MA, suggesting that specific patterns of the LV-LGE are closely related to the severity of arrhythmic events.