Prognostic impact of non-ischaemic late gadolinium enhancement in patients with ischaemic cardiomyopathy
Authors: Unger A , Toupin S , Hovasse T , Garot P , Champagne S , Unterseeh T , Duhamel S , Hamzi L , Goncalves T , Dillinger J G , Henry P , Bousson V , Sanguineti F , Garot J , Pezel T 
Published: January 2025

Abstract

Background
Although the presence and extent of ischaemic late gadolinium enhancement (LGE) as assessed by cardiovascular magnetic resonance (CMR) have emerged as robust predictors of outcomes in patients with ischaemic cardiomyopathy (ICM), the prognostic significance of non-ischaemic LGE is not well established.

Objective
To assess the prognostic impact of the presence of non-ischaemic LGE in a large cohort of patients with ICM with reduced left ventricular ejection fraction (LVEF) undergoing CMR for myocardial viability.

Methods
Between 2008 and 2022, all consecutive patients referred for myocardial viability assessment using CMR with a history of ICM (≥70% stenosis in ≥1 epicardial coronary vessel on angiography and/or history of myocardial infarction and/or coronary revascularisation) and LVEF &lt;50% were included. Non-ischaemic was defined as midwall-LGE corresponding to non-specific myocardial fibrosis. Patients with a history of acute myocarditis and/or sub-epicardial LGE were excluded. The primary outcome was all-cause mortality using the National Registry of Death. Nested Cox proportional hazard models were used to assess the additional prognostic value of the presence of non-ischaemic LGE, including its location (lateral and/or septal and other locations) and its extent (1 or ≥2 segments), beyond the presence of ischaemic-LGE and traditional prognostic factors. The incremental prognostic value of non-ischaemic LGE extent and location was assessed by the C-statistic increment.

Results
Among the 6,082 patients (average age 65±12 years, 73% male), 702 (12%) had additional midwall-LGE. Over a median follow-up of 9 years (IQR 7-12), 652 (11%) patients died. Non-ischaemic LGE alone was associated with a higher risk of mortality (HR: 2.9; 95% CI: 2.4-3.4, p&lt;0.001). Figure 1 shows an increased all-cause mortality rate, regardless of ischaemic-LGE extent and transmurality. In patients with non-ischaemic LGE (N=702), survival curves indicated higher risk for lateral and/or septal locations, larger extent, and the presence of ischaemic-LGE (all p&lt;0.001, Figure 2). After adjustment for traditional prognosticators and ischaemic-LGE extent, non-ischaemic LGE in septal and/or lateral locations (adjusted HR: 2.6; 95% CI: 1.8-3.6) and extent ≥2 segments (adjusted HR: 2.6; 95% CI: 1.8-3.7, both p&lt;0.001) were independently associated with mortality. A comprehensive LGE model including all non-ischaemic LGE characteristics improved reclassification compared to traditional factors with and without ischaemic-LGE (C-statistic improvement: 0.13 and 0.05, all p&lt;0.001).

Conclusion
In a large cohort of ICM patients, the presence of non-ischaemic LGE is an independent predictor of all-cause death, particularly for larger extent or in the septal and/or lateral segments.
All-cause mortality rates
Prognostic impact of non-ischaemic LGE