Possible Causes and Clinical Relevance of a "Ring-Like" Late Gadolinium Enhancement Pattern

Integrated role of cardiac magnetic resonance and genetics in predicting left ventricular reverse remodelling in dilated and non-dilated cardiomyopathy

AIMS

Left ventricular reverse remodelling (LVRR) is a prognostic marker in patients with dilated (DCM) and non-dilated left ventricular cardiomyopathy (NDLVC). The utility of combining late gadolinium enhancement (LGE) and genetic testing in predicting LVRR in DCM/NDLVC remains a knowledge gap. This study aimed to assess an integrated approach including LGE data and genetics to predict LVRR in DCM/NDLVC patients.

METHODS AND RESULTS

This multicentre observational study included DCM/NDLVC patients with: (i) baseline echocardiographic left ventricular ejection fraction (LVEF) <50%; (ii) genetic testing; (iii) baseline cardiac magnetic resonance (CMR); (iv) 12-month follow-up echocardiographic data. LVRR was defined as LVEF increase ≥10% or LVEF ≥50% (if baseline LVEF <45%) at 12 months. Outcome measures were: (i) all-cause mortality, heart transplant, or left ventricular assist device implantation (D/HT/LVAD); (ii) sudden cardiac death or major ventricular arrhythmias (SCD/MVA). Arrhythmogenic genes studied were LMNA, DSP, FLNC, and RBM20. Among 1757 DCM/NDLVC with genetic data, 616 met eligibility (462 DCM, 154 NDLVC; age 51 ± 14 years, 34% female). LVRR occurred in 314 patients (51%): 251 (54%) in DCM and 63 (41%) in NDLVC (p = 0.004). Independent predictors of LVRR within 1 year included titin truncating variants, absence of arrhythmogenic genes, and absence of LGE ring-like pattern. In patients with LVEF <35%, only the presence of LGE ring-like pattern and arrhythmogenic genes remained independently related to a lower rate of LVRR and increased SCD/MVA risk.

CONCLUSION

In a large genetically and CMR characterized DCM/NDLVC cohort, arrhythmogenic genotypes and LGE ring-like pattern were inversely related to LVRR, particularly in patients with LVEF <35%.

Shaping cardiac diagnostics: The role of myocardial tissue mapping in unraveling ring-like fibrosis

BACKGROUND

Patients with non-ischemic cardiomyopathy exhibit a range of myocardial fibrosis (MF) patterns on cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) imaging. Data suggests that ring-like MF is associated with worse prognosis. In the present study it was sought to analyze the prevalence of parametric mapping abnormalities in ring-like MF and their prognostic value for arrhythmic events.

METHODS

Patients undergoing clinical CMR at 1.5T/3T were evaluated for ring-like MF defined as midwall/subepicardial fibrosis involving ≥ 3 contiguous left ventricular segments. CMR protocol included cine imaging, T1 and T2 mapping, and LGE. Mean native T1, ECV, and T2 values and a number of mid short axis segments with elevated values were calculated. LGE extent was assessed segmentally. Arrhythmic outcomes were defined as appropriate device shock, premature ventricular contractions ≥ 10%, non-sustained/sustained ventricular tachycardia, or ventricular fibrillation.

RESULTS

In total 49 patients (53 ± 17 years, 26.5% female) were analyzed. Many patients had elevated global/segmental mapping values: 45%/76% in native T1, 57%/57% in T2, and 57%/78% in ECV. During median follow-up of 12 months, arrhythmic events occurred in 65% of patients. There was no association between native T1/T2 elevation or number of LGE segments and arrhythmic outcomes. There was a significant association between ECV and arrhythmic outcomes, both septal ECV (p = 0.036) and any segmental ECV elevation (p = 0.03).

CONCLUSION

T1 and T2 myocardial tissue abnormalities are common in patients with ring-like MF. ECV elevation was associated with arrhythmic events in this cohort. Further studies are needed to establish the diagnostic and prognostic value of parametric mapping in patients with ring-like MF.

Ring-like late gadolinium enhancement: differential diagnosis and mimics

Advances in cardiac magnetic resonance have promoted tissue characterization with high spatial and contrast resolution, and late gadolinium enhancement (LGE) sequences have improved the detection of myocardial fibrosis. The distribution pattern of LGE facilitates differentiation between ischemic and nonischemic etiologies and aids in refining diagnoses within nonischemic cardiomyopathies, suggesting specific etiological factors. A distinctive nonischemic LGE pattern that has recently gained prominence is the ring-like pattern, defined as a subepicardial or mid-wall circumferential or semi-circumferential enhancement, which involves at least three contiguous segments within the same short-axis slice. Initially identified as a diagnostic marker for desmoplakin and filamin C-related cardiomyopathies, the pattern has been reported in nongenetic conditions; nevertheless, it remains an uncommon finding in these diseases. In this article, we aim to present the differential diagnoses of ring-like LGE and its mimics. The combination of epidemiological, clinical, electrocardiographic, and additional features enables a focused refinement of the differential diagnosis associated with ring-like LGE.

Myocardial Late Gadolinium Enhancement (LGE) in Cardiac Magnetic Resonance Imaging (CMR)-An Important Risk Marker for Cardiac Disease

Cardiovascular magnetic resonance (CMR) has significantly revolutionized the comprehension and diagnosis of cardiac diseases, particularly through the utilization of late gadolinium enhancement (LGE) imaging for tissue characterization. LGE enables the visualization of expanded extracellular spaces in conditions such as fibrosis, fibrofatty tissue, or edema. The growing recognition of LGE's prognostic capacity underscores its importance, evident in the increasing explicit recommendations within guidelines. Notably, the contemporary characterization of cardiomyopathies relies on LGE-based scar assessment by CMR to a large extent. This review describes the pattern and prognostic value of LGE in detail for various cardiac diseases. Despite its merits, establishing LGE as a reliable risk marker encounters challenges. Limitations arise from the fact that not all diseases show LGE, and it should always be analyzed in the context of all CMR sequences and the patient's medical history. In summary, LGE stands as a robust indicator of adverse outcomes in diverse cardiovascular diseases. Its further integration into routine practice is desirable, necessitating widespread availability and application to accumulate both individual and scientific experience.

The new European Society of Cardiology guideline for the management of cardiomyopathies: key messages for cardiac electrophysiologists

Electrocardiographic findings and arrhythmias are common in cardiomyopathies. Both may be an early indication of a specific diagnosis or may occur due to myocardial fibrosis and/or reduced contractility. Brady- and tachyarrhythmias significantly contribute to increased morbidity and mortality in patients with cardiomyopathies. Antiarrhythmic therapy including risk stratification is often challenging and plays a major role for these patients. Thus, an "electrophysiological" perspective on guidelines on cardiomyopathies may be warranted. As the European Society of Cardiology (ESC) has recently published a new guideline for the management of cardiomyopathies, this overview aims to present key messages of these guidelines. Innovations include a new phenotype-based classification system with emphasis on a multimodal imaging approach for diagnosis and risk stratification. The guideline includes detailed chapters on dilated and hypertrophic cardiomyopathy and their phenocopies, arrhythmogenic right ventricular cardiomyopathy, and restrictive cardiomyopathy as well as syndromic and metabolic cardiomyopathies. Patient pathways guide clinicians from the initial presentation to diagnosis. The role of cardiovascular magnetic resonance imaging and genetic testing during diagnostic work-up is stressed. Concepts of rhythm and rate control for atrial fibrillation have led to new recommendations, and the role of defibrillator therapy in primary prevention is discussed in detail. Whilst providing general guidelines for management, the primary objective of the guideline is to ascertain the disease etiology and disease-specific, individualized management.