Cardiac Diagnoses and Long-Term Outcomes in Ring-Like Late Gadolinium Enhancement Evaluated by Cardiac Magnetic Resonance

Abstract Aims Non-ischemic ring-like late gadolinium enhancement (LGE) in the left ventricle (LV) detected by cardiac magnetic resonance (CMR) is an emerging biomarker associated with adverse outcomes. Data regarding ring-like LGE are limited to small patient cohorts. We aimed to assess the prevalence of ring-like LGE, its association with morpho-functional phenotypes, aetiologic background, and prognostic implications. Methods and Results This single-center observational retrospective study included consecutive patients undergoing LGE-CMR between 2002 and 2024. Ring-like LGE was defined as continuous enhancement in ≥3 adjacent segments. Ischemic and amyloid cardiomyopathies were excluded. Clinical records were reviewed for etiologic diagnosis and clinical outcomes. The primary endpoint was a composite of all-cause mortality, heart transplantation, or LV assist device implantation. The secondary endpoint included sustained ventricular tachycardia, appropriate implantable cardioverter-defibrillator therapies, or sudden cardiac death. Among 14,091 unique patients who underwent LGE-CMR, ring-like LGE was identified in 152 patients (1.1%) with a median number of 10 segments, mostly involving the inferolateral segments. The most frequent morpho-functional phenotypes were dilated and non-dilated LV cardiomyopathy. Genetic testing identified likely pathogenic/pathogenic variants in 59 (58.4%) patients, affecting both desmosomal and non-desmosomal genes. Inflammatory cardiomyopathy was diagnosed in 15.8%. Other rare aetiologies included genetic neuromuscular diseases and inborn errors of metabolism. Primary and secondary endpoints occurred in 17.8% and 17.1%, respectively, over a median follow-up of 3 years. Conclusion Ring-like LGE is an uncommon, non-disease-specific feature found in various morpho-functional CMP phenotypes. It is associated with frequent genetically determined aetiologies and a high burden of adverse outcomes.