Diagnosis of some diseases through biomarkers

Muchos gatos, como los perros, sufren de diferentes enfermedades. que en ese momento no permiten mostrar síntomas o signos que permiten identificar que la mascota sufre una enfermedad grave, ya que las características de los gatos son diferentes a las de los perros, ya que estos son depredadores, por lo tanto, el diagnóstico de las enfermedades en esta especie son difíciles y, en la mayoría de los casos, el diagnóstico se realiza durante las etapas avanzadas, lo que provoca un tratamiento difícil y un mal pronóstico. Estas enfermedades incluyen: cardiomiopatía hipertrófica felina, lipidosis hepática felina, virus de inmunodeficiencia felina, insuficiencia renal crónica y peritonitis infecciosa felina. Se requiere conocimiento sobre biomarcadores para poder dar el resultado. Los biomarcadores son una herramienta que aún no se conoce ampliamente y esto es necesario. Dado que permite mejorar la calidad de vida de los gatos y sus dueños, ya que los gatos se han vuelto cada vez más importantes como mascotas. Se estima que un alto porcentaje de la población mundial ha elegido tener gatos como mascotas debido a sus características fisiológicas y de comportamiento

Cardiac MRI in Young Adults with Sedentary Lifestyle-Related Risks

Western society is characterized by a sedentary lifestyle combined with an unhealthy diet resulting in growing populations with overweight, high blood pressure and type 2 diabetes. In older populations, it was demonstrated that these risk factors trigger cardiac adaptation. If cardiac adaptation already occurs at younger age, these changes could potentially overlap with findings on cardiac MRI that are suggestive of cardiomyopathy, complicating diagnosis and treatment. In a prospectively recruited study cohort of 311 young adults (18-45 years old, 49% male), the impact of the aforementioned risk factors on cardiac MRI outcomes was investigated. It was shown that overweight, high blood pressure and type 2 diabetes cause alterations in wall mass, cardiac volumes and tissue characteristics. Therefore, reference values of cardiac outcomes have been reported for young risk populations to more reliably assess future MRI scans. Also, it was demonstrated that the body metric being used for indexation of body size has a significant impact. Furthermore, changes in ejection fraction were not found, whereas subtle wall motion abnormalities were present. With literature, the applicability of the tissue characteristics T2 (edema) and T2*-mapping (iron) was assessed for the differentiation of cardiac diseases, risk factors and healthy individuals. Further, it was demonstrated that aortic dimensions can be measured accurately with native imaging, thereby reducing potential health risks in especially risk populations. Lastly, a short-axis cardiac MRI contour-tracing protocol was validated which can be used to accurately assess morphology and function, and also to manually adjust automated tracings in a standardized fashion

Análisis genético y genómico de variantes asociadas a afecciones cardiacas hereditarias y su predisposición en población ecuatoriana

Programa Oficial de Doctorado en Biología Celular y Molecular. 5004V01[Resumen] Las enfermedades cardiovasculares son una de las principales causas de muerte en todo el mundo, y las cardiopatías hereditarias pueden causar morbilidad y mortalidad súbitas, especialmente en los jóvenes. Se llevó a cabo un proyecto de investigación para identificar genes relacionados con la predisposición a enfermedades cardiacas y su frecuencia en la población ecuatoriana mestiza. Se realizó un análisis bioinformático para identificar genes asociados a afecciones cardiacas y se utilizó la secuenciación de nueva generación para identificar variantes genómicas en 60 individuos con 37 diagnósticos clínicos diferentes. Se encontró un total de 108 variantes, incluidas 11 patogénicas y 11 probablemente patogénicas y 71 variantes VUS en 56 genes. También se observó que el origen étnico era un factor de enfermedad cardiovascular; en general, los individuos tenían una ascendencia mayoritaria de nativos americanos. El estudio también destaca la importancia no sólo de seleccionar pacientes con el mismo diagnóstico clínico, sino también de mapear varias enfermedades para identificar variantes poblacionales. En conjunto, el estudio demuestra el potencial de la bioinformática y la secuenciación de nueva generación para identificar asociaciones reales entre genes y cardiopatías hereditarias, lo que en última instancia puede contribuir a la prevención de muertes súbitas y a un tratamiento correcto.[Abstract] Cardiovascular diseases are a major cause of death worldwide, and hereditary heart diseases can cause sudden morbidity and mortality, especially in young people. A research project was conducted to identify genes related to heart disease predisposition and their frequency in the admixture Ecuadorian population. A bioinformatic analysis was performed to identify genes associated with cardiac conditions, and next-generation sequencing was used to identify genomic variants in 60 individuals with 37 different clinical diagnoses. A total of 108 variants were found, including 11 pathogenic and 11 likely pathogenic and 71 VUS variants in 56 genes. Ethnicity was also found to be a factor in cardiovascular disease, in general the individuals had a major Native American ancestry. The study also highlights the importance of not only selecting patients with the same clinical diagnosis but also mapping several diseases to identify population variants. Overall, the study demonstrates the potential of bioinformatics and next-generation sequencing to identifying real associations between genes and hereditary heart conditions, which can ultimately contribute to the prevention of sudden deaths and a correct treatment.[Resumo] As enfermidades cardiovasculares son unha das principais causas de morte en todo o mundo, e as cardiopatías hereditarias poden causar morbilidade e mortalidade súbitas, especialmente nos mozos. levou a cabo un proxecto de investigación para identificar xenes relacionados coa predisposición a enfermidades cardíacas e a súa frecuencia na poboación ecuatoriana mestiza. Realizouse unha análise bioinformático para identificar xenes asociados a afeccións cardíacas e utilizouse a ecuenciación de nova xeración para identificar variantes xenómicas en 60 individuos con 37 diagnósticos clínicos diferentes. Atopouse un total de 108 variantes, incluídas 11 patogénicas e 11 probablemente patogénicas e 71 variantes VUS en 56 xenes. Tamén se observou que a orixe étnica era un factor de enfermidade cardiovascular; en xeral, os individuos tiñan unha ascendencia maioritaria de nativos americanos. O estudo tamén destaca a importancia non só de seleccionar pacientes co mesmo diagnóstico clínico, senón tamén de mapear varias enfermidades para identificar variantes poboacionais. En conxunto, o estudo demostra o potencial da bioinformática e a secuenciación de nova xeración para identificar asociacións reais entre xenes e cardiopatías hereditarias, o que en última instancia pode contribuír á prevención de mortes súbitas e a un tratamento correcto

Improving the Clinical Application of Genetic Testing for Patients with Inherited Heart Disease

The difficulties associated with the clinical application of next generation sequencing (NGS) approaches can be substantial. However, the technology holds great potential to improve outcomes and risk management for inherited heart disease patients and their families. This PhD thesis focuses on three critical challenges associated with the clinical application of NGS technologies; (i) Understanding correlations between genetics and the clinical phenotype; (ii) the impact of uncertainty created by NGS-based genetic testing on the patient; and (iii) developing evidence-based approaches for improving current and future methods for returning complex genetic results. Two studies focused on understanding correlations between genetics and the clinical phenotype. Firstly, the study reported in Chapter two, which aimed to analyse genetic and phenotypic findings from a consecutive cohort of hypertrophic cardiomyopathy (HCM) families who had undergone comprehensive cardiac panel testing. We showed that increasing the number of genes included on HCM panels beyond the eight established sarcomere genes does not increase the diagnostic yield. However, identification of variants of uncertain significance increased dramatically from 13% to 36%. This result has important clinical implications. Increasing the number of genes screened does not necessarily improve the chance of identifying a family’s cause of disease but is likely to increase identification of uncertain results that can increase the complexity of discussions around inheritance and risk. We also showed that identification of multiple rare variants was associated with earlier disease onset, greater likelihood of family history of sudden cardiac death (SCD) and overall worse event-free survival (5/18 events versus 29/170 events, log-rank test p=0.008). Clinical heterogeneity is a hallmark feature of HCM and here we show one factor that can contribute to worse outcomes. The study reported in Chapter three aimed to describe the diverse genetic and phenotypic features of an international cohort of patients with a truncating variant in the desmoplakin (DSP) gene traditionally considered to cause arrhythmogenic right ventricular cardiomyopathy (ARVC). This is the first complete report of the diverse phenotype spectrum of DSP cardiomyopathy, suggesting that truncating variants in DSPshould be considered its own entity. We show that the phenotype associated with truncations in DSP is severe, with a high rate of SCD and characterised by left ventricular dysfunction and structural left ventricular involvement when compared with ‘classic’ ARVC. In addition, we show the functional domain in which DSP truncating variants reside has clinical significance. Key results from Chapter two and three emphasise the importance of correlating genetic variants with phenotype information. Data from this work is a step towards precision medicine whereby patients’ risk will be assessed and managed based on their genotype. In Chapter four we designed a qualitative study to explore attitudes, preferences, recall and psychosocial consequences of uncertain genetic results returned to HCM probands. The major themes we identified were knowledge and recall of complex genetic information, individual experiences with HCM genetic testing and communication and the value of information. In addition, those with uninformative results had a unique set of issues. We found that HCM probands undergoing genetic testing require additional support and information beyond the current practice model employed in the multidisciplinary specialist clinic setting. Importantly, many of the probands interviewed who received an uninformative or uncertain genetic result showed poor recall and understanding of genetic information. The final aim was to determine if a genetic counsellor led intervention using a communication aid for the delivery of HCM genetic test results improves the ability and confidence of the proband to communicate genetic results to at-risk relatives. This work is presented in Chapter five. We developed a study protocol for a randomised controlled trial with the primary outcome being the ability and confidence of the proband to communicate genetic results to at-risk relatives. We focused on transforming findings from the previous chapters into improved clinical practice. The a priori primary outcome did not show statistically significant differences between the control and intervention group, though the majority of probands in the intervention group achieved fair communication scores and had higher genetic knowledge scores than those in the control group. Importantly, we found that 29% of at-risk relatives were not informed of a genetic result in their family. We highlight the significant gap in our current approach to supporting family communication about genetics. The studies presented highlight that whilst genetic testing has significant potential for benefit in inherited heart disease families in terms of diagnosis, management and family screening there are issues to address in order to improve the clinical utility and application of a comprehensive approach to testing. Overall, the work contributes to understanding the genetic architecture of inherited heart diseases, the clinical impact of NGS results for patients, as well as highlighting that more work is needed to improve the clinical utility from an NGS approach to genetic testing

Evaluation and treatment of premature ventricular contractions in heart failure with reduced ejection fraction

Premature ventricular complexes (PVCs) are often observed in patients presenting with heart failure with a reduced ejection fraction (HFrEF). PVCs may in some patients be considered to be the cause of heart failure, while in others it may be the consequence of heart failure. PVCs are important prognostic markers in HFrEF. The uncertainty whether PVCs are the cause or effect in HFrEF impacts clinical decision making. In this review, we discuss the complexity of the cause-effect relationship between PVCs and HFrEF. We demonstrate a workflow with the use of a trial period of amiodarone that may discover whether the reduced LVEF is reversible, the symptoms are due to PVCs and whether biventricular pacing can be increased by the reduction of PVCs. The use of non-invasive and invasive (high-density) mapping techniques may help to improve accuracy and efficacy in the treatment of PVC, which will be demonstrated. With these results in mind, we conclude this review highlighting the future directions for PVC research and treatment

Stress echo 2020 : the international stress echo study in ischemic and non-ischemic heart disease

Background: Stress echocardiography (SE) has an established role in evidence-based guidelines, but recently its breadth and variety of applications have extended well beyond coronary artery disease (CAD). We lack a prospective research study of SE applications, in and beyond CAD, also considering a variety of signs in addition to regional wall motion abnormalities. Methods: In a prospective, multicenter, international, observational study design, > 100 certified high-volume SE labs (initially from Italy, Brazil, Hungary, and Serbia) will be networked with an organized system of clinical, laboratory and imaging data collection at the time of physical or pharmacological SE, with structured follow-up information. The study is endorsed by the Italian Society of Cardiovascular Echography and organized in 10 subprojects focusing on: contractile reserve for prediction of cardiac resynchronization or medical therapy response; stress B-lines in heart failure; hypertrophic cardiomyopathy; heart failure with preserved ejection fraction; mitral regurgitation after either transcatheter or surgical aortic valve replacement; outdoor SE in extreme physiology; right ventricular contractile reserve in repaired Tetralogy of Fallot; suspected or initial pulmonary arterial hypertension; coronary flow velocity, left ventricular elastance reserve and B-lines in known or suspected CAD; identification of subclinical familial disease in genotype-positive, phenotype- negative healthy relatives of inherited disease (such as hypertrophic cardiomyopathy). Results: We expect to recruit about 10,000 patients over a 5-year period (2016-2020), with sample sizes ranging from 5,000 for coronary flow velocity/ left ventricular elastance/ B-lines in CAD to around 250 for hypertrophic cardiomyopathy or repaired Tetralogy of Fallot. This data-base will allow to investigate technical questions such as feasibility and reproducibility of various SE parameters and to assess their prognostic value in different clinical scenarios. Conclusions: The study will create the cultural, informatic and scientific infrastructure connecting high-volume, accredited SE labs, sharing common criteria of indication, execution, reporting and image storage of SE to obtain original safety, feasibility, and outcome data in evidence-poor diagnostic fields, also outside the established core application of SE in CAD based on regional wall motion abnormalities. The study will standardize procedures, validate emerging signs, and integrate the new information with established knowledge, helping to build a next-generation SE lab without inner walls

Next generation sequencing for the molecular analysis of sarcomeric and non-sarcomeric genes in patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common genetic heart disorder characterized by unexplained left ventricle hypertrophy associated with non-dilated ventricular chambers. Several genes encoding heart sarcomeric proteins have been associated to HCM, but a small proportion of HCM patients harbor alterations in other non-sarcomeric loci. The variable expression of HCM seems influenced by genetic modifier factors and new sequencing technologies are redefining the understanding of genotype-phenotype relationships, even if the interpretations of the numerous identified variants pose several challenges.We investigated 62 sarcomeric and non-sarcomeric genes in 41 HCM cases and in 3 HCM-related disorders patients. We found that 82% of the patients harbored at least one rare nsSNV: 11% of the patients showed only sarcomere nsSNVs, 20% of cases harbored at least one sarcomeric nsSNV with at least a desmosomal one and 14% displayed at least one desmosomal nsSNV but no other sarcomere change. We reported an association between desmosomal variations and the pathogenesis of HCM that has not been described to date. We employed an integrated approach that combines multiple tools for the prediction, annotation and visualization of functional variants. Several different methods were employed to predict the functional consequences of alleles that result in amino acid substitutions, to study the effect of some variants over the splicing process and to investigate the impact of these changes respect to the evolutionary conservation. Genotype-phenotype correlations were carried out for inspecting the involvement of each gene in age onset and clinical variability of HCM. Statistical analyses revealed an inverse correlation between the number of nsSNVs and age at onset, and a relationship between the clinical variability and number and type of variants. Then, we describe the clinical, pathological, and molecular features of the novel LAMP2 c.453delT mutation in one of our HCM-related disorders patients affected by Danon disease characterized by severe hypertrophic cardiomyopathy, mild intellectual impairment and rapid progression to heart failure, requiring heart transplant. Immunohistochemical analysis of LAMP2 in the explanted heart revealed a mosaic pattern of distribution, with discrete clusters of either stained or unstained cardiac myocytes, the latter being more frequent in the septum. Interestingly, multiple foci of microscarring were found on histology in the Left Ventricle (LV) free wall and septum. Our findings suggest that several features may contribute to the early and severe cardiac phenotype in female patients affected by Danon disease. In conclusion, this work aims to extend the mutational spectrum of HCM and to contribute in defining the molecular pathogenesis and inheritance pattern(s) of this condition. Besides, we delineate a specific procedure for the identification of the most likely pathogenetic variants for a next generation sequencing approach embodied in a clinical contex

Stress echo 2020: the international stress echo study in ischemic and non-ischemic heart disease

BACKGROUND: Stress echocardiography (SE) has an established role in evidence-based guidelines, but recently its breadth and variety of applications have extended well beyond coronary artery disease (CAD). We lack a prospective research study of SE applications, in and beyond CAD, also considering a variety of signs in addition to regional wall motion abnormalities. METHODS: In a prospective, multicenter, international, observational study design, > 100 certified high-volume SE labs (initially from Italy, Brazil, Hungary, and Serbia) will be networked with an organized system of clinical, laboratory and imaging data collection at the time of physical or pharmacological SE, with structured follow-up information. The study is endorsed by the Italian Society of Cardiovascular Echography and organized in 10 subprojects focusing on: contractile reserve for prediction of cardiac resynchronization or medical therapy response; stress B-lines in heart failure; hypertrophic cardiomyopathy; heart failure with preserved ejection fraction; mitral regurgitation after either transcatheter or surgical aortic valve replacement; outdoor SE in extreme physiology; right ventricular contractile reserve in repaired Tetralogy of Fallot; suspected or initial pulmonary arterial hypertension; coronary flow velocity, left ventricular elastance reserve and B-lines in known or suspected CAD; identification of subclinical familial disease in genotype-positive, phenotype- negative healthy relatives of inherited disease (such as hypertrophic cardiomyopathy). RESULTS: We expect to recruit about 10,000 patients over a 5-year period (2016-2020), with sample sizes ranging from 5,000 for coronary flow velocity/ left ventricular elastance/ B-lines in CAD to around 250 for hypertrophic cardiomyopathy or repaired Tetralogy of Fallot. This data-base will allow to investigate technical questions such as feasibility and reproducibility of various SE parameters and to assess their prognostic value in different clinical scenarios. CONCLUSIONS: The study will create the cultural, informatic and scientific infrastructure connecting high-volume, accredited SE labs, sharing common criteria of indication, execution, reporting and image storage of SE to obtain original safety, feasibility, and outcome data in evidence-poor diagnostic fields, also outside the established core application of SE in CAD based on regional wall motion abnormalities. The study will standardize procedures, validate emerging signs, and integrate the new information with established knowledge, helping to build a next-generation SE lab without inner walls