Abstract
AIMS: Genotype and left ventricular scar on cardiac magnetic resonance (CMR) are increasingly recognized as risk markers for adverse outcomes in non-ischaemic dilated cardiomyopathy (DCM). We investigated the combined influence of genotype and late gadolinium enhancement (LGE) in assessing prognosis in a large cohort of patients with DCM. METHODS AND RESULTS: Outcomes of 600 patients with DCM (53.3 ± 14.1 years, 66% male) who underwent clinical CMR and genetic testing were retrospectively analysed. The primary endpoints were end-stage heart failure (ESHF) and malignant ventricular arrhythmias (MVA). During a median follow-up of 2.7 years (interquartile range 1.3-4.9), 24 (4.00%) and 48 (8.00%) patients had ESHF and MVA, respectively. In total, 242 (40.3%) patients had pathogenic/likely pathogenic variants (positive genotype) and 151 (25.2%) had LGE. In survival analysis, positive LGE was associated with MVA and ESHF (both, p < 0.001) while positive genotype was associated with ESHF (p = 0.034) but not with MVA (p = 0.102). Classification of patients according to genotype (G+/G-) and LGE presence (L+/L-) revealed progressively increasing events across L-/G-, L-/G+, L+/G- and L+/G+ groups and resulted in optimized MVA and ESHF prediction (p < 0.001 and p = 0.001, respectively). Hazard ratios for MVA and ESHF in patients with either L+ or G+ compared with those with L-/G- were 4.71 (95% confidence interval: 2.11-10.50, p < 0.001) and 7.92 (95% confidence interval: 1.86-33.78, p < 0.001), respectively. CONCLUSION: Classification of patients with DCM according to genotype and LGE improves MVA and ESHF prediction. Scar assessment with CMR and genotyping should be considered to select patients for primary prevention implantable cardioverter-defibrillator placement.