Prognostic Importance of Late Gadolinium Enhancement in Ischaemic and Nonischaemic Cardiomyopathy: A Systematic Review and Meta-Analysis

Late Gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging is the most widely available modality to quantify the presence and extent of myocardial scar. The relationship between myocardial scar burden as determined by LGE and clinical outcomes remains an area of uncertainty. Whilst prior meta-analysis have examined only cardiac events and been limited in scope, we set out to examine the relationship between LGE and all-cause mortality, cardiovascular mortality, and ventricular arrhythmia/sudden cardiac death in a meta-analysis of CMR studies in ischaemic and non ischaemic patient populations. A Pubmed database search was conducted for studies reporting clinical outcome data stratified by the presence or quantity of myocardial scar. Two reviewers evaluated citations, with differences resolved by consensus. Randomised controlled trials, cohort studies, and case series data from patients with ischaemic or nonischaemic cardiomyopathy were included. 6042 citations were retrieved, from which 26 studies including 5095 patients published in the years 2006-15 were included. In patients with LGE, the HR for all-cause mortality was 2.60 (95%CI:2.14-3.17, P<0.0001), cardiovascular mortality HR 3.381 (95% CI: 2.269-5.037, P<0.0001), ventricular arrhythmia or sudden cardiac death HR 4.831 (95%CI:3.166-7.371, P < 0.0001) and major adverse cardiovascular events HR 2.957 (95%CI:2.363-3.700, P<0.0001). In the largest reported series todate, we find that the presence of LGE on CMR is a powerful prognostic predictor of arrhythmic events and absolute mortality in both NICM and ICM. Appropriate use criteria for cardiac imaging in NICM/ICM should give consideration to the use of LGECMR for prognosis in patients with cardiomyopathy.