Clinical utility of ischaemic late gadolinium enhancement granularity in ischaemic cardiomyopathy patients with reduced left ventricular ejection fraction
Authors: Unger A , Garot J , Toupin S , Duhamel S , Sanguineti F , Hovasse T , Akodad M , Goncalves T , Gall E , Dillinger J G , Henry P , Bondue A , Bousson V , Garot P , Pezel T 
Published: January 2025

Abstract

Background
Although the presence and extent of ischaemic late gadolinium enhancement (LGE) assessed by cardiovascular magnetic resonance (CMR) are robust predictors of outcomes in patients with ischaemic cardiomyopathy (ICM), the prognostic significance of other ischaemic-LGE parameters is not well established, and no integrated score exists.

Purpose
This study aims to evaluate the additional prognostic value of a model that assesses the granularity of ischaemic-LGE over traditional factors in predicting mortality in ICM patients. The granularity includes ischaemic-LGE extent, transmurality, location, and associated midwall-LGE (Figure 1). A simplified score based on these parameters will be implemented to facilitate its use in clinical practice.

Methods
This study is a bi-centric retrospective analysis of a prospective observational cohort consisting of 6,082 patients with ICM and left ventricular ejection fraction (LVEF)&lt;50% referred for viability assessment using CMR between 2008 and 2022. The primary outcome was all-cause mortality using the National French Registry of Death. Cox regression analysis was used to assess the incremental prognostic value of the LGE granularity model after adjustment for traditional prognosticators. Using a Cox model including all these LGE granularity parameters we built a new risk prediction score entitled "CMR-LGE score".

Results
Among the 6,082 patients (average age 65±12 years; 73% men), 3,591 (59%) exhibited ischaemic-LGE. Over a median follow-up period of 9 [7-12] years, 652 (11%) patients died. After adjustment, the presence of ischaemic-LGE was significantly associated with all-cause mortality (hazard ratio, HR=3.5, 99.5% CI: 2.6-4.7, p&lt;0.001). In patients with ischaemic-LGE (N=3,591), the LGE extent (HR=1.4, 99.5% CI: 1.3-1.5), LGE transmurality (subendocardial ≤50%, subendocardial &gt;50% HR=2.2, 99.5% CI: 1.5-3.2, and transmural HR=2.9, 99.5% CI: 1.9-4.4), and ischaemic LGE location (septal location HR=7.1, 99.5% CI: 4.9-10.4), and the presence of associated midwall-LGE were all independently associated with mortality (adjusted HR=1.9, 99.5% CI: 1.4-2.5, all p&lt;0.001). The LGE granularity model, which included all these LGE features, showed the greatest improvement in model discrimination over traditional prognostic factors and ischaemic-LGE extent alone (ROC-AUC: 0.90 vs 0.84, p&lt;0.001). The "CMR-LGE score" was highly effective ischaemic to predict mortality (ROC-AUC: 0.87, precision-recall-AUC: 0.61, Figure 2).

Conclusions
In a large cohort of ICM patients with reduced LVEF, a model incorporating the granularity of ischaemic-LGE—covering extent, transmurality, location, and associated midwall-LGE—provided additional prognostic value beyond traditional prognostic factors for predicting all-cause mortality.
The “Ischaemic-LGE granularity"
The “CMR-LGE Score”