Prognostic impact of the extent, location, and pattern of late gadolinium enhancement in dilated cardiomyopathy
Authors: Goncalves T , Pezel T , Garot P , Unterseeh T , Hovasse T , Toupin S , Champagne S , Ah-Sing T , Hamzi L , Unger A , Dillinger J G , Henry P , Sanguineti F , Bousson V , Garot J 
Published: November 2023

Abstract

Background
Several studies have shown that the presence and extent of late gadolinium enhancement (LGE) defined by cardiac magnetic resonance imaging (CMR) are strong prognosticators of death in patients with dilated cardiomyopathy (DCM). The interest of LGE location and pattern to improve risk stratification is not well established.

Purpose
To assess the incremental prognostic value of LGE extent, location and pattern for predicting all-cause death over traditional risk factors in DCM patients.

Methods
Between 2008 and 2021, we conducted a bi-centre longitudinal study including all consecutive DCM patients referred for CMR. DCM was confirmed excluding patients with ischemic heart disease, history of acute myocarditis, hypertrophic cardiomyopathy, and infiltrative disease. The outcome was all-cause death using the electronic French National Registry of Death. The prognostic value of LGE parameters was assessed using Cox analyses after adjustment for traditional prognostic factors: LGE presence, extent (number of segments), pattern (midwall or subepicardial), location and multiple areas. The incremental prognostic value of these LGE parameters was assessed using C-statistic increment, the continuous net reclassification improvement (NRI), the integrative discrimination index (IDI) and the global Chi-2.

Results
In 2,752 DCM patients (52±8 years, 56% male), 408 (15%) died after a median (IQR) follow-up of 9.2 (6.8-11.5) years. A total of 737 (27%) patients had LGE, including 664 (90%) LGE mid-wall and 73 (10%) LGE sub-epicardial. In the whole cohort (n=2,752), the LGE presence and extent were strong predictors of death (HR: 2.42 [95% CI: 1.67-3.51] and HR: 1.78 [95% CI: 1.64-1.93]; both p&lt;0.001). In the subgroup of patients with LGE (n=737), the LGE multiple area was an independent predictor of death (HR: 5.12 with 95% CI: 3.53-7.41; p&lt;0.001). The LGE pattern wasn't associated with death (subepicardial: HR: 0.88; 95% CI: 0.56-1.39, p=0.58). The location in both septal and free-wall was strongly associated with death compared to septal LGE only (HR: 10.1; 95% CI: 7.53-13.6; p&lt;0.001), itself more at risk of death than free-wall LGE only (HR: 3.12; 95% CI: 2.03-4.78; p&lt;0.001). In the 537 patients with LGE single area, LGE in septal segments was a strong prognostic marker (HR: 17.0; 95% CI: 5.88-49.4; p&lt;0.001) compared to other locations (inferior: HR: 10.3; 95% CI: 3.45-30.5; p&lt;0.001; lateral: HR: 6.13; 95% CI: 1.95-19.2; p&lt;0.01; reference=anterior). A model combining the LGE extent, location and multiple area showed the best improvement in model discrimination and reclassification above traditional risk factors (C-statistic improvement: 0.19; NRI=11.8%; IDI=2.2%, all p&lt;0.001).

Conclusion
In a large cohort of DCM patients, the LGE extent, location, and multiple area were independent prognosticators of death. A model combining these LGE findings had an incremental prognostic value over traditional prognostic factors to predict all-cause death.Incremental prognostic value of LGEHazard ratios regarding LGE segments