Related Experiment Videos
Imaging signatures of high-risk arrhythmogenic genotypes in dilated cardiomyopathy
Zhigang Zhang1, Yangjie Li1, Yuanwei Xu1
1Department of Cardiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China.
Insights
High-risk arrhythmogenic variant carriers (HRAv) in dilated cardiomyopathy (DCM) show distinct cardiac magnetic resonance (CMR) findings, including more myocardial injury and fibrosis, compared to TTNtv and genotype-negative DCM. CMR tissue characterization aids in identifying these genotype-associated differences.
Area of Science:
- Cardiology
- Genetics
- Medical Imaging
Background:
- Dilated cardiomyopathy (DCM) presents with genetic diversity and varied cardiac magnetic resonance (CMR) phenotypes.
- Understanding genotype-phenotype associations in DCM is crucial but remains incomplete.
Purpose of the Study:
- To investigate genotype-phenotype correlations in DCM using CMR.
- To differentiate CMR characteristics among DCM subtypes based on genetic variants.
Main Methods:
- Prospective enrollment of 90 DCM patients into three groups: high-risk arrhythmogenic variant carriers (HRAv), TTN truncating variant carriers (TTNtv), and genotype-negative (GN).
- Comprehensive CMR parameter analysis and logistic regression to identify genotype-CMR feature associations.
Main Results:
- HRAv patients exhibited significantly higher prevalence of late gadolinium enhancement (LGE) and elevated global native T1, T2 mapping, and extracellular volume (ECV) compared to TTNtv and GN groups.
- Ventricular volumes, systolic functions, and LV strain did not differ significantly across subtypes.
- Higher global T2, ECV, and LGE presence were independently associated with HRAv status.
Conclusions:
- HRAv in DCM is characterized by a distinct CMR tissue phenotype with increased myocardial injury and fibrosis.
- Despite similar ventricular remodeling, CMR tissue characterization can identify genotype-specific differences in DCM.
- These findings highlight the utility of CMR in DCM genetic subtyping.
Background:
Dilated cardiomyopathy (DCM) exhibits substantial genotypic heterogeneity, paralleled by diverse cardiac magnetic resonance (CMR) phenotypes and clinical presentations. However, the specific genotype-phenotype associations underlying this heterogeneity remain incompletely clear.
Methods:
Ninety DCM patients were prospectively enrolled and stratified into three subtypes: high-risk arrhythmogenic variant carriers (HRAv, n = 30), TTN truncating variant carriers (TTNtv, n = 30), and genotype-negative patients (GN, n = 30). High-risk arrhythmogenic variants were identified as DSP, FLNC, LMNA, and PLN variants. Comprehensive CMR parameter comparisons and logistic regression analyses were performed to identify the associations between genotypes and CMR features.
Results:
Among 90 participants (mean age, 46 years; 54 men), no significant differences were observed in ventricular volumes, systolic functions or LV strain among subtypes. HRAv patients presented with a higher prevalence of LGE (83%) compared with TTNtv (13%) and GN (40%) (p < 0.001), with typical linear midwall, ring-like, and subepicardial patterns. Global native T1 mapping(1379 vs. 1329 vs. 1335 ms, p = 0.037), T2 mapping (46.3 vs. 44.1 vs. 42.8 ms, p < 0.001), and extracellular volume (ECV)(35.8 vs. 31.3 vs. 30.5%, p < 0.001) were significantly elevated in HRAv compared with TTNtv and GN. In Firth penalized logistic regression models, higher global T2 (odds ratio[OR] = 1.22, 95%CI: 1.06-1.43, p = 0.004), higher global ECV(OR = 1.45, 95%CI: 1.17-1.86, p < 0.001), and LGE presence(OR = 9.22, 95%CI: 3.26-29.81, p < 0.001) were independently associated with HRAv status when separately added to the baseline model.
Conclusion:
Compared with TTNtv and genotype-negative DCM, HRAv is characterized by a distinct CMR tissue phenotype marked by more extensive myocardial injury and fibrosis, despite similar ventricular remodeling and systolic impairment. These findings suggest that CMR tissue characterization may help identify genotype-associated phenotypic differences in DCM.
Related Concept Videos
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:30Dysrhythmias V: Evaluating Dysrhythmias
01:22Aortic Regurgitation II: Clinical Features and Diagnostic Tests
01:20Imaging Studies for Cardiovascular System III: X-Ray
Definition and Purpose
An X-ray, or radiograph, is a non-invasive method that uses ionizing radiation to take images of internal structures. It is mainly used in cardiac imaging to examine the heart, lungs, and major blood vessels, aiming to identify abnormalities in the heart's size, shape, and position, such as heart failure, congenital defects, and vascular...
01:23Mitral Stenosis II: Clinical features and Diagnostic Tests