Cardiogenetics

Brugada syndrome (BrS) is an inherited cardiac channelopathy with variable expressivity that can lead to sudden cardiac arrest (SCA). Studies worldwide suggest that BrS and Brugada pattern (BrP) have low prevalences in general. However, studies also note that BrS is most prevalent among certain Asian populations. Among the different global regions, the highest prevalence is believed to be in Southeast Asia, followed by the Middle East, South Asia, East Asia, Europe, and North America. It is not only important to recognize such varying degrees of BrS prevalence within Asia but also to understand that there may be significant differences in terms of presenting symptoms, occult risk factors, and the impact on clinical outcomes. The importance of identifying such differences lies in the necessity to develop improved risk assessment strategies to guide secondary prevention and treatment for these patients. Specifically, the decision to pursue placement of an implantable cardiac defibrillator (ICD) can be lifesaving for high-risk BrS patients. However, there remains a significant lack of consensus on how to best risk stratify BrS patients. While the current guidelines recommend ICD implantation in patients with spontaneous Type 1 ECG pattern BrS who present with syncope, there may still exist additional clinical factors that may serve as better predictors or facilitate more refined risk stratification before malignant arrhythmias occur. This carries huge relevance given that BrS patients often do not have any preceding symptoms prior to SCA. This review seeks to delineate the differences in BrS presentation and prevalence within the Asian continent in the hope of identifying potential risk factors to guide better prognostication and management of BrS patients in the future. Full article

(1) Background. One of the causes of myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) is thrombus formation in situ followed by lysis, resulting in a morphologically normal angiogram but with an underlying prothrombotic state that is potentially predisposed to recurrence. Recent studies have shown that a subset of MINOCA patients may have thrombophilic conditions at screening. Objective: To compare the prothrombotic trend in MINOCA patients with that of subjects with MI and obstructive coronary arteries (MIOCA) by testing for known congenital thrombophilias and markers of coagulation activation. (2) Materials and methods. Screening included congenital thrombophilias (factor V Leiden; assessment of protein C, protein S, and antithrombin III) and eight genes. Of these, four genes represented the folate pathway enzymes: MTHFR 677 C>T (rs1801133), MTHFR 1298 A>C (rs1801131), MTR 2756 A>G (rs1805087), and MTRR 66 A>G (rs1801394). The other four genes represented the blood coagulation system: F13 (163 G>T) rs5985, F1 (−455 G>A) rs1800790, GP IIb–IIIa (1565 T>C) rs5918, and PAI-I (−675 5G>4G) rs1799889. Additionally, we examined the levels of homocysteine and lipoprotein (LP) (a). (3) Results. Our study included 269 patients: 114 MINOCA patients and 155 MIOCA patients with lesions of one coronary artery. The frequencies of polymorphisms in the genes of the blood coagulation system and the folate pathway did not differ between the groups. The following genes were associated with in-hospital mortality in the MINOCA group: MTHFR 1298 A>C rs1801131 (OR 8.5; 95% CI 1.67–43.1) and F1 (−455 G>A) rs1800790 (OR 5.8; 95% CI 1.1–27.8). In the MIOCA group, the following genes were associated with in-hospital mortality: MTHFR 1298 A>C rs1801131 (OR 9.1; 95% CI 2.8–28.9), F1 (−455 G>A) rs1800790 (OR 11.4; 95% CI 3.6–35.9), GP IIb–IIIa (1565 T>C) rs5918 (OR 10.5; 95% CI 3.5–30.8), and PAI-I (−675 5G>4G) rs1799889 (OR 12.9; 95% CI 4.2–39.7). We evaluated long-term outcomes (case fatality rate, recurrent MI, and stroke) over a period of 12 months in both groups. The variables associated with these outcomes were laboratory parameters, such as protein C deficiency, hyperhomocysteinemia, and a content of LP (a) > 30 mg/dL. However, we did not reveal the prognostic value of polymorphisms of the studied genes representing the blood coagulation system and the folate pathway. (4) Conclusion. We established no statistically significant differences between the MINOCA and MIOCA groups in the prevalence of congenital thrombophilias and the prevalence of folate pathway enzyme genes and blood coagulation system genes. The MTHFR 1298 A>C (rs1801131) and F1 (−455 G>A) rs1800790 genes were associated with in-hospital mortality in both groups. More significant prognostic factors in both groups during the one-year period were protein C deficiency, hyperhomocysteinemia, and LP (a) > 30 mg/dL. Full article

Salt sensitivity is a trait in which high dietary sodium (Na⁺) intake causes an increase in blood pressure (BP). We previously demonstrated that in the gut, elevated dietary Na⁺ causes dysbiosis. The mechanistic interplay between excess dietary Na⁺-induced alteration in the gut microbiome and sex differences is less understood. The goal of this study was to identify novel metabolites in sex differences and blood pressure in response to a high dietary Na⁺ intake. We performed stool and plasma metabolomics analysis and measured the BP of human volunteers with salt intake above or below the American Heart Association recommendations. We also performed RNA sequencing on human monocytes treated with high salt in vitro. The relationship between BP and dietary Na⁺ intake was different in women and men. Network analysis revealed that fatty acids as top subnetworks differentially changed with salt intake. We found that women with high dietary Na⁺ intake have high levels of arachidonic acid related metabolism, suggesting a role in sex differences of the blood pressure response to Na⁺. The exposure of monocytes to high salt in vitro upregulates the transcription of fatty acid receptors and arachidonic acid-related genes. These findings provide potentially novel insights into metabolic changes underlying gut dysbiosis and inflammation in salt sensitivity of BP. Full article

Cell-free nuclear (cf-nDNA) and mitochondrial (cf-mDNA) DNA are released from damaged cells in type 2 diabetes mellitus (T2DM) patients, contributing to adverse cardiac remodeling, vascular dysfunction, and inflammation. The purpose of this study was to correlate the presence and type of cf-DNAs with HF in T2DM patients. A total of 612 T2DM patients were prescreened by using a local database, and 240 patients (120 non-HF and 120 HF individuals) were ultimately selected. The collection of medical information, including both echocardiography and Doppler imagery, as well as the assessment of biochemistry parameters and the circulating biomarkers, were performed at baseline. The N-terminal brain natriuretic pro-peptide (NT-proBNP) and cf-nDNA/cf-mtDNA levels were measured via an ELISA kit and real-time quantitative PCR tests, respectively. We found that HF patients possessed significantly higher levels of cf-nDNA (9.9 ± 2.5 μmol/L vs. 5.4 ± 2.7 μmol/L; p = 0.04) and lower cf-mtDNA (15.7 ± 3.3 μmol/L vs. 30.4 ± 4.8 μmol/L; p = 0.001) than those without HF. The multivariate log regression showed that the discriminative potency of cf-nDNA >7.6 μmol/L (OR = 1.07; 95% CI = 1.03–1.12; p = 0.01) was higher that the NT-proBNP (odds ratio [OR] = 1.10; 95% confidence interval [CI] = 1.04–1.19; p = 0.001) for HF. In conclusion, we independently established that elevated levels of cf-nDNA, originating from NT-proBNP, were associated with HF in T2DM patients. Full article

Background: Leptin is an obesity-associated adipokine that has been implicated in cardiac protection against ischemia-reperfusion injury (IRI). In this study, concentration-dependent effects of leptin on myocardial IRI were investigated in the isolated rat heart. In addition, we analyzed myocardial miRNAs expression in order to investigate their potential involvement in leptin-mediated cardioprotection. Methods: The effect of leptin on IRI was examined in Langendorff-perfused rat hearts preconditioned with two leptin concentrations (1.0 nM and 3.1 nM) for 60 min. The hearts were subjected to 30 min global ischemia and 120 min reperfusion with buffer containing leptin in the respective concentration. Heart function and arrhythmia incidence were analyzed. Infarct size was assessed histochemically. Expression of miRNA-144, -208a, -378, and -499 was analyzed in the ventricular myocardium using RT-PCR. Results: The addition of 1.0 nM leptin to the buffer exerted an infarct-limiting effect, preserved post-ischemic ventricular function, and prevented reperfusion arrhythmia compared to 3.1 nM leptin. Myocardial expression of miRNA-208a was decreased after heart exposure to 1.0 nM leptin and significantly elevated in the hearts perfused with leptin at 3.1 nM. Conclusion: Acute administration of leptin at low dose (1.0 nM) results in cardiac protection against IRI. This effect is associated with reduced myocardial expression of miRNA-208a. Full article

BACKGROUND. Spontaneous coronary artery dissection (SCAD) is a cause of myocardial infarction, especially in younger women without cardiovascular risk factors. Patient management and diagnostics are still largely based on retrospective and observational studies. Most patients with SCAD report chest pain and have elevated biomarkers with ECG findings. SCAD can lead to cardiogenic shock, ventricular arrhythmias and cardiac arrest, and is commonly associated with fibromuscular dysplasia (FMD). Genetic associations are still in their infancy with this disease process. METHODS. An Invitae 29 gene aortopathy panel was performed on a mother with a thoracic aortic aneurysm and her daughter who presented with SCAD and was noted to have FMD. RESULTS. The patient and her mother were both noted to have a heterozygous mutation of the Biglycan (BGN) gene (Variant c.1030T > G (p.Tyr344His)) of undetermined significance. An extensive literature review was performed, including a review of the UK Biobank. This is the first case to our knowledge showing a possible link between the BGN mutation and SCAD/FMD. CONCLUSIONS. The BGN mutation has been recognized to be correlated with aortic aneurysm and aortic dissection. It has not yet been explored to be associated with SCAD/FMD. This paper highlights the potential link between the BGN gene and SCAD/FMD. Further research looking at this association is warranted. Full article

Most ECGs in European hospitals are recorded with equipment giving computer measured intervals and interpretation of the recording. In addition to measurements of interval and QRS axis, this interpretation frequently provides the Bazett’s-corrected QTc time. The introduction of computer-corrected QTc revealed QTc prolongation to be a frequent condition among medical patients. Nevertheless, the finding is frequently overlooked by the treating physician. The authors combine experience from a local hospital with a review of the current literature in this field in order to elucidate the importance of this risk factor both as congenital long QT syndrome and as acquired QT prolongation. Full article

22q11.2 deletion syndrome is a phenotypic spectrum that encompasses DiGeorge syndrome (OMIM: 188400) and velocardiofacial syndrome (OMIM: 192430). It is caused by a 1.5–3.0 Mb hemizygous deletion of locus 22q11.2, which leads to characteristic facies, conotruncal cardiovascular malformations, velopharyngeal insufficiency, T-lymphocyte dysfunction due to thymic aplasia, and parathyroid hypoplasia, and, less frequently, neurological manifestations such as delayed psychomotor development or schizophrenia. This study aimed to describe a screening method for the diagnosis of 22q11.2 deletion syndrome in patients with Conotruncal Congenital Heart Disease (CCHD), using qPCR to detect the copy number of the TBX1 gene in a single DNA sample. A total of 23 patients were included; 21 with a biallelic prediction of the TBX1 copy number gene and 2 with a monoallelic prediction who were suspected to be positive and subjected to MLPA confirmation. One patient (4.34%) with truncus arteriosus CCHD was confirmed to have 22q11.2 deletion syndrome. We propose this approach as a possible newborn screening method for 22q11.2 deletion syndrome in CCHD patients. Full article

Coronary artery embolism is a rare cause of acute myocardial infarction, attributed to approximately 10% of all paradoxical embolisms. It is a condition that should be considered in patients who present with chest pain and have a low overall risk of coronary heart disease. A major risk of coronary artery embolism is the existence of a patent foramen ovale (PFO), which can be shown on bubble transthoracic echocardiography. Here we describe a case report of a 68-year-old Caucasian lady who presented with recurrent episodes of myocardial infarction secondary to a paradoxical coronary artery embolism which was likely due to a PFO. We emphasize the need for more research on the role of PFO percutaneous device closure compared to just medical therapy in those with recurrent episodes of acute myocardial infarction secondary to paradoxical coronary artery embolism. This, in turn, should provide clearer guidance in managing such patients with high risk of mortality. Full article

Breast cancer (BC) and cardiometabolic diseases share a multifactorial and modifiable etiology, modulated by complex molecular pathways. Glutathione S-transferase (GST) plays a critical role, providing protection against xenobiotics and regulating levels of enzymes and proteins in the cell. GST variants have a significant impact on susceptibility to diseases whose pathogenesis involves oxidative stress, as is the case in many inflammatory diseases such as BC and cardiometabolic pathologies. However, the expression of these polymorphic variants has not been studied in BC. This study aimed to evaluate the presence of GST mRNA isoforms and their association with clinical and cardiometabolic parameters in women with BC. This was a case-control study, and a total of 57 participants were recruited. Concentrations of glucose and lipids in blood were measured in all the participants. GST variants (GSTT1, GSTM1 and GSTP1 Ile105Val polymorphism) were evaluated in all the participants by real-time PCR analysis. There was a significant association (p < 0.05) between the frequency of GSTP1 and LDL-c in the BC group. However, the control group showed significant associations between blood pressure with GSTT1 and GSTP1 variants with total cholesterol (TC), LDL-c, VLDL-c and triacylglycerols (TG). Therefore, GSTT1 and GSTP1 variants could be emerging biomarkers to discriminate between BC cases related or not to cardiometabolic disease factors. Full article

Epigenetics is defined as the study of inheritable changes in the gene expressions and phenotypes that occurs without altering the normal DNA sequence. These changes are mainly due to an alteration in chromatin or its packaging, which changes the DNA accessibility. DNA methylation, histone modification, and noncoding or microRNAs can best explain the mechanism of epigenetics. There are various DNA methylated enzymes, histone-modifying enzymes, and microRNAs involved in the cause of various CVDs (cardiovascular diseases) such as cardiac hypertrophy, heart failure, and hypertension. Moreover, various CVD risk factors such as diabetes mellitus, hypoxia, aging, dyslipidemia, and their epigenetics are also discussed together with CVDs such as CHD (coronary heart disease) and PAH (pulmonary arterial hypertension). Furthermore, different techniques involved in epigenetic chromatin mapping are explained. Among these techniques, the ChIP-on-chip guide is explained with regard to its role in cardiac hypertrophy, a final form of heart failure. This review focuses on different epigenetic factors that are involved in causing cardiovascular diseases. Full article

Thoracic aortic aneurysms and dissections often have inter-related pathologies that are increasingly recognized to have a genetic basis. A patient with a vascular history consisting of a spontaneous aorto-iliac dissection and thoracic aortic aneurysm belonged to a family with a significant self-reported history of aneurysmal disease. Suspecting a genetic component, genetic investigation was undertaken. Three variants of unknown significance were found in the ZNF469 gene, which is responsible for the production of a collagen-related zinc finger protein involved in multiple aspects of the development and regulation of major extracellular matrix components. This is the first report to associate this gene with vasculopathy, and further investigation by our group is underway to understand the role it plays in the development of aneurysmal diseases. Full article

Restrictive cardiomyopathy (RCM) is a rare disease of the myocardium caused by mutations in several genes including TNNT2, DES, TNNI3, MYPN and FLNC. Individuals affected by RCM often develop heart failure at a young age, requiring early heart transplantation. A 7-year-old patient was referred for genetic testing following a diagnosis of restrictive cardiomyopathy. Clinical exome sequencing analysis identified a likely pathogenic mutation in the FLNC gene [(NM_001458.5 c.6527_6547dup p.(Arg2176_2182dup)]. Its clinical relevance was augmented by the fact that this variant was absent in the parents and was thus interpreted as de novo. Genetic testing is a powerful tool to clarify the diagnosis, guide intervention strategies and enable cascade testing in patients with pediatric-onset RCM. Full article

In this study we performed a next generation sequencing of 210 genes in 140 patients with cardiac failure requiring a heart transplantation. We identified a total of 48 candidate variants in 47 patients. Forty-three patients (90%) presented a single variant, and fourpatients (10%) were carriers of two variants. After refining the classification, we identified a pathogenic or likely pathogenic variant in 13 patients (10% of our cohort). In 34 additional cases (25%) the variants were classified as of unknown significance (VUS). In reference to the cause of cardiac failure in the 13 carriers of pathogenic variants, 5 were of dilated non-ischemic cause, 4 hypertrophic and 1 restrictive cardiomyopathy. In the ischemic cases (n = 3) no family history of cardiac disease was recorded, while nineof the non-ischemic had other relatives who were also diagnosed. In conclusion, the NGS of a cardiac transplanted cohort identified a definite or very likely genetic cause in 10% of the cases. Most of them had a family history of cardiac disease, and were thus previously studied as part of a routine screening by a genetic counselor. Pathogenic variants in cases without a family history of cardiac disease were mainly of ischemic origin. Full article

The nutritional assessment is gaining clinical relevance since cardiac cachexia and malnutrition are emerging as novel markers of functional status and prognosis in many cardiovascular disorders, including cardiac amyloidosis (CA). This study aimed to evaluate the prognostic role of different nutritional indices for cardiovascular mortality in patients with CA and subgroups. Fifty CA patients (26 AL and 24 ATTR wild-type) were retrospectively analyzed. All patients underwent a comprehensive clinical and laboratory evaluation. Conventional body mass index (cBMI), modified BMI (mBMI), new BMI (nBMI) and prognostic nutritional index (PNI) were analyzed. Multivariate regression analysis was performed to identify the association between nutritional and other clinical-laboratory parameters with cardiovascular death. Compared to ATTRwt patients, those with AL showed lower mBMI values. No significant difference was observed for the other nutritional indices. During a median follow-up of 11.2 months, a lower mBMI quartile was associated with worse survival, in both groups. In multivariate analysis, mBMI emerged as an independent predictor for cardiovascular death. This study showed that mBMI is a novel index of malnutrition and an independent risk factor for cardiovascular mortality in patients with CA in both AL and ATTRwt form. Full article

Left ventricular non-compaction (LVNC) is an extremely heterogeneous disorder with a highly variable clinical presentation, morphologic appearance at imaging testing, and prognosis. It is still unclear whether LVNC should be classified as a separate cardiomyopathy or if it is a mere morphological trait shared by many phenotypically distinct cardiomyopathies. Moreover, the hypertrabeculated phenotype may be reversible in some cases, possibly reflecting the left ventricular physiological response of the cardiac muscle to chronic overload. The current diagnostic criteria have several limitations, leaving many patients in a grey area. Here, we review the available literature on LVNC in order to provide an overview of the current knowledge on this complex disorder. Full article