Impact of the LGE granularity to guide coronary revascularisation in ischaemic cardiomyopathy

Background The role of cardiovascular magnetic resonance (CMR) in guiding coronary revascularisation based on myocardial viability remains debated, particularly after the REVIVED trial. Our group has recently introduced the concept of "late gadolinium enhancement (LGE) granularity", incorporating LGE extent and location to refine myocardial characterization. Objective To assess whether CMR-guided coronary revascularisation, based on the LGE granularity, predicts mortality in patients with ischaemic cardiomyopathy (ICM), reduced left ventricular ejection fraction (LVEF <50%), and viable myocardium (ischaemic-LGE transmurality <50%). Methods We conducted a retrospective analysis of a multicentre study including consecutive ICM patients referred for CMR-based viability assessment between 2008 and 2022. Eligibility criteria included left ventricular ejection fraction (LVEF) <50%, viable myocardium, and at least one of the following: ≥70% stenosis in ≥1 epicardial coronary artery, prior myocardial infarction, or previous coronary revascularization. LGE parameters and revascularization within 90 days of CMR were collected. The primary endpoint was all-cause mortality. Cox proportional hazards regression analysis was performed to assess the predictive value of LGE parameters and revascularization status for all-cause mortality. Results Among 1,698 patients (mean age 64±12 years; 74% male), 1,502 (88%) underwent revascularisation within 90 days. LGE extent was low (1–2 segments) in 729 (43%), moderate (3–5 segments) in 922 (54%), and high (≥6 segments) in 47 (3%). Antero-septal LGE was present in 318 patients (19%) (Figure 1). Over a median follow-up of 8.9 years (IQR 6.7–11.5 years), 79 patients (4.7%) died. In univariate analysis, revascularisation was associated with lower mortality (HR: 0.28, 95% CI: 0.17–0.45, p<0.001). Subgroup analyses revealed that revascularisation particularly improved survival in patients with moderate LGE extent (3–5 segments, p=0.002) and antero-septal LGE (p<0.001, Figure 2). Conclusion Using the LGE granularity concept, we showed that in ICM patients with viable myocardium, revascularisation was associated with improved survival, particularly in those with moderate ischaemic LGE extent and an antero-septal distribution.