Impact of Late Gadolinium Enhancement onmortality, sudden death and major adverse cardiovascular events in ischemic and nonischemic cardiomyopathy: A systematic review and meta-analysis

Background: The central role of left ventricular ejection fraction (LVEF) as the definitive risk marker of adverse outcomes in ischemic and nonischemic cardiomyopathy is increasingly uncertain. The current study aimed to conduct a systematic review and meta-analysis with the objective of evaluating the prognostic importance of Late Gadolinium Enhancement (LGE) in ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM) on the key endpoints of all-cause mortality, cardiovascular mortality and sudden death. Methods: The study was prospectively registered in PROPSERO (CRD 42016039034). Electronic databases and reference lists were searched for studies evaluating the impact of LGE-CMR on all-cause mortality, cardiovascular mortality, ventricular arrhythmia or sudden death, or major adverse cardiovascular events. Data were extracted from 36 studies including n = 7882 patients. Results: LGE was strongly associated with all-cause mortality HR 2.96 (95%CI: 2.37, 3.70, P < 0.001), cardiovascular mortality HR 3.27 (95% CI: 2.05, 5.22, P < 0.001), ventricular arrhythmia and sudden cardiac death HR 3.76 (95% CI: 3.14, 4.52, P < 0.001), and major adverse cardiovascular events HR 3.24 (95% CI: 2.32, 4.52, P < 0.001). In subgroup analyses, LGE was associated with all-cause mortality and cardiovascular mortality in both LVEF ≤ 35% and LVEF > 35% patients (P < 0.001 all endpoints), as well as in nonischemic and ischemic cardiomyopathy. Conclusion: Late Gadolinium Enhancement (LGE) in CMR predicts all-cause mortality, cardiovascular mortality, ventricular arrhythmia and sudden death, and major adverse cardiovascular events, independent of LVEF. Future trials of investigational therapies in NICM and ICM should consider the utilization of LGE to identify patients at risk of adverse outcomes.