Cardiac Magnetic Resonance for Diagnosis and Risk Stratification

The Establishment of Hypertrophic Cardiomyopathy Diagnosis Model via Artificial Neural Network and Random Decision Forest Method

Hypertrophic cardiomyopathy is a hereditary disease characterized by asymmetric ventricular hypertrophy as the key anatomical feature. Currently, there exists no effective method for the early diagnosis of hypertrophic cardiomyopathy. In this analysis, we incorporated multiple GEO datasets containing RNA profiles of hypertrophic cardiomyopathic patient tissues, identified 642 differentially expressed genes, and performed GO and KEGG analyses. Furthermore, we narrowed down 46 characteristic genes from these differentially expressed genes using random decision forests and conducted transcription factor regulation analysis on them. Using 40 genes that showed overlap between the training set and the verification set, the artificial neural network was trained, and the final MPS scoring model was constructed, and a receiver-operating characteristic (ROC) curve was drawn. We used the MPS model to predict the verification dataset and drew the ROC curve, which demonstrated the good prediction performance of the model. In conclusion, this study combines a random decision forest and artificial neural network to build a diagnostic model for hypertrophic cardiomyopathy to predict the disease, aiming at early detection and treatment, prolonging the survival time, and improving the quality of life of patients.

Cardiac Imaging in Athlete's Heart: The Role of the Radiologist

Athlete’s heart (AH) is the result of morphological and functional cardiac modifications due to long-lasting athletic training. Athletes can develop very marked structural myocardial changes, which may simulate or cover unknown cardiomyopathies. The differential diagnosis between AH and cardiomyopathy is necessary to prevent the risk of catastrophic events, such as sudden cardiac death, but it can be a challenging task. The improvement of the imaging modalities and the introduction of the new technologies in cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) can allow overcoming this challenge. Therefore, the radiologist, specialized in cardiac imaging, could have a pivotal role in the differential diagnosis between structural adaptative changes observed in the AH and pathological anomalies of cardiomyopathies. In this review, we summarize the main CMR and CCT techniques to evaluate the cardiac morphology, function, and tissue characterization, and we analyze the imaging features of the AH and the key differences with the main cardiomyopathies.

Additive effect of hypertension on left ventricular structure and function in patients with asymptomatic type 2 diabetes mellitus

OBJECTIVE

We aimed to comprehensively determine the effects of hypertension on left ventricular (LV) structure, microcirculation, tissue characteristics, and deformation in type 2 diabetes mellitus (T2DM) using multiparametric cardiac magnetic resonance (CMR) imaging.

METHODS

We prospectively enrolled 138 asymptomatic patients with T2DM (80 normotensive and 58 hypertensive individuals) and 42 normal glucose-tolerant and normotensive controls and performed multiparametric CMR examination to assess cardiac geometry, microvascular perfusion, extracellular volume (ECV), and strain. Univariable and multivariable linear analysis was performed to analyze the effect of hypertension on LV deformation in patients with T2DM.

RESULTS

Compared with controls, patients with T2DM exhibited decreased strain, decreased microvascular perfusion, increased LV remodeling index, and increased ECV. Hypertension lead to greater deterioration of LV strain (peak strain-radial, P = 0.002; peak strain-longitudinal, P = 0.006) and LV remodeling index (P = 0.005) in patients with T2DM after adjustment for covariates; however, it did not affect microvascular perfusion (perfusion index, P = 0.469) and ECV (P = 0.375). In multivariable analysis, hypertension and diabetes were independent predictors of reduced LV strain, whereas hypertension is associated with greater impairment of diastolic function (P = 0.009) but not systolic function (P = 0.125) in the context of diabetes, independent of clinical factors and myocardial disorder.

CONCLUSION

Hypertension in the context of diabetes is significantly associated with LV diastolic function and concentric remodeling; however, it has little effect on systolic function, myocardial microcirculation, or fibrosis independent of covariates, which provide clinical evidence for understanding the pathogenesis of comorbidities and explaining the development of distinct heart failure phenotypes.

Safe and efficient magnetic resonance imaging of acute myocardial infarction with gadolinium-doped carbon dots

Aim: The magneto-fluorescent gadolinium-doped carbon dots (Gd-CDs) were developed as a cardiac MR imaging contrast agent to detect the infarcted myocardium on a myocardial ischemia/reperfusion (I/R) mice model. Materials & methods: The chemophysical features, cardiac MR imaging effect, biodistribution and biocompatibility of Gd-CDs were studied. Results: The ultrasmall size and good aqueous dispersibility endows Gd-CDs with high longitudinal relaxivity, intense fluorescence, excellent physiological stability and superior biocompatibility. More importantly, Gd-CDs preferentially target the infarcts as determined by the confocal microscopy and MR imaging on the I/R mice at the acute stage of myocardial infarction. Conclusion: Gd-CDs manifest great potential for development as an MR imaging contrast agent to facilitate accurate visualization and image-guided therapy of acute myocardial infarction.

The potential roles of Von Willebrand factor and neutrophil extracellular traps in the natural history of hypertrophic and hypertensive cardiomyopathy

Inflammation is often applied broadly to human disease. Despite its general familiarity, inflammation is highly complex. There are numerous injurious, immune and infectious determinants, functional elements and signaling pathways, ranging from genetic to epigenetic, environmental, racial, molecular and cellular that participate in disease onset and progression, phenotypic heterogeneity, and treatment selection and response. In addition, inflammation can be tissue and organ specific, adding a layer of complexity to achieving a detailed and translatable understanding of its role in health and disease. The following review takes a close look at inflammation in the context of two common heart diseases, hypertrophic cardiomyopathy and hypertensive cardiomyopathy.

Network Medicine: A Clinical Approach for Precision Medicine and Personalized Therapy in Coronary Heart Disease

Early identification of coronary atherosclerotic pathogenic mechanisms is useful for predicting the risk of coronary heart disease (CHD) and future cardiac events. Epigenome changes may clarify a significant fraction of this "missing hereditability", thus offering novel potential biomarkers for prevention and care of CHD. The rapidly growing disciplines of systems biology and network science are now poised to meet the fields of precision medicine and personalized therapy. Network medicine integrates standard clinical recording and non-invasive, advanced cardiac imaging tools with epigenetics into deep learning for in-depth CHD molecular phenotyping. This approach could potentially explore developing novel drugs from natural compounds (i.e. polyphenols, folic acid) and repurposing current drugs, such as statins and metformin. Several clinical trials have exploited epigenetic tags and epigenetic sensitive drugs both in primary and secondary prevention. Due to their stability in plasma and easiness of detection, many ongoing clinical trials are focused on the evaluation of circulating miRNAs (e.g. miR-8059 and miR-320a) in blood, in association with imaging parameters such as coronary calcifications and stenosis degree detected by coronary computed tomography angiography (CCTA), or functional parameters provided by FFR/CT and PET/CT. Although epigenetic modifications have also been prioritized through network based approaches, the whole set of molecular interactions (interactome) in CHD is still under investigation for primary prevention strategies.

[LEOPARD syndrome]

LEOPARD syndrome with multiple lentigines (cardiomyopathic lentiginosis) is a rare, genetically predetermined disease with autosomal dominant inheritance. Prevalence of this syndrome is unknown. One of pathognomonic clinical manifestations of this syndrome is the presence of multiple lentiginous pigment spots all over the body. The most common cardiac manifestation (approximately 80%) is myocardial hypertrophy. We presented a rare clinical case of detecting LEOPARD syndrome with multiple lentigines in a 32-year old female patient with major manifestations evident as pronounces morpho-functional alterations, myocardial hypertrophy, and heart rhythm disorders.

Practical Guide to Evaluating Myocardial Disease by Cardiac MRI

OBJECTIVE. A spectrum of pathophysiologic mechanisms can lead to the development of myocardial disorders including ischemia, genetic abnormalities, and systemic disorders. Cardiac MRI identifies different myocardial disorders, provides prognostic information, and directs therapy. In comparison with other imaging modalities, cardiac MRI has the advantage of allowing both functional assessment and tissues characterization in a single examination without the use of ionizing radiation. Newer cardiac MRI techniques including mapping can provide additional information about myocardial disease that may not be detected using conventional techniques. Emerging techniques including MR spectroscopy and finger printing will likely change the way we understand the pathophysiology mechanisms of the wide array of myocardial disorders. CONCLUSION. Imaging of myocardial disorders encompasses a large variety of conditions including both ischemic and nonischemic diseases. Cardiac MRI sequences, such as balanced steady-state free precession and late gadolinium enhancement, play a critical role in establishing diagnosis, determining prognosis, and guiding therapeutic management. Additional sequences-including perfusion imaging, T2*, real-time cine, and T2-weighted sequences-should be performed in specific clinical scenarios. There is emerging evidence for the use of mapping in imaging of myocardial disease. Multiple other new techniques are currently being studied. These novel techniques will likely change the way myocardial disorders are understood and diagnosed in the near future.

Characterization of the human myocardium by optical coherence tomography

Imaging of cardiac tissue structure plays a critical role in the treatment and understanding of cardiovascular disease. Optical coherence tomography (OCT) offers the potential to provide valuable, high-resolution imaging of cardiac tissue. However, there is a lack of comprehensive OCT imaging data of the human heart, which could improve identification of structural substrates underlying cardiac abnormalities. The objective of this study was to provide qualitative and quantitative analysis of OCT image features throughout the human heart. Fifty human hearts were acquired, and tissues from all chambers were imaged with OCT. Histology was obtained to verify tissue composition. Statistical differences between OCT image features corresponding to different tissue types and chambers were estimated using analysis of variance. OCT imaging provided features that were able to distinguish structures such as thickened collagen, as well as adipose tissue and fibrotic myocardium. Statistically significant differences were found between atria and ventricles in attenuation coefficient, and between adipose and all other tissue types. This study provides an overview of OCT image features throughout the human heart, which can be used for guiding future applications such as OCT-integrated catheter-based treatments or ex vivo investigation of structural substrates.

Fibrosis and Ventricular Arrhythmogenesis: Role of Cardiac MRI

Cardiac fibrosis is a significant increase in collagen volume fraction of myocardial tissue. It plays an important role in the pathophysiology of many cardiovascular abnormalities. Electrophysiologically, myocardial fibrosis produces anisotropic conduction, inhomogeneity, and conduction delay. Several markers are available to detect myocardial fibrosis. CMRI is the most common imaging technique; late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) provides markers for tissue characterization, disease progression and arrhythmic events. LGE-CMR can be used as risk marker of occurrence of pathologic conditions. LGE-CMR demonstrates specific patterns related to different pathologic substrates. We discuss the role of CMRI in ventricular arrhythmogenesis.