Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography

Impact of the initial clinical presentation on the outcome of patients with infective endocarditis

Background: Infective endocarditis (IE) is a life-threatening disease. Despite advancements in diagnostic methods, the initial clinical presentation of IE remains a valuable asset. Therefore, the impact of clinical presentation on outcomes and its association with microorganisms and IE localization were assessed herein. Methods: This retrospective study included 183 patients (age 68.9 ± 14.2 years old, 68.9% men) with definite IE at two tertiary care hospitals in Belgium. Demographic data, medical history, clinical presentation, blood cultures, imaging data and outcomes were recorded. Results: In-hospital mortality rate was 22.4%. Sixty (32.8%) of the patients developed embolism, 42 (23%) shock, and 103 (56.3%) underwent surgery during hospitalization. Shock at admission predicted embolism during hospitalization (odds ratio [OR] 2.631, 95% confidence interval [CI] 1.119–6.184, p = 0.027). A new cardiac murmur at admission predicted cardiac surgery (OR 1.949, 95% CI 1.007–3.774, p = 0.048). Methicillin resistant Staphylococcus aureus predicted in-hospital mortality and shock (p = 0.005, OR 6.945, 95% CI 1.774–27.192 and p = 0.015, OR 4.691, 95% CI 1.348–16.322, respectively). Mitral valve and aortic valve IE respectively predicted in-hospital death (p = 0.039, OR 2.258, 95% CI 1.043–4.888) and embolism (p = 0.017, OR 2.328, 95% CI 1.163–4.659).  Conclusions: In this retrospective study, shock at admission independently predicted embolism during hospitalization in IE patients. Moreover, a new cardiac murmur at admission predicted the need for cardiac surgery. This emphasizes the importance of a comprehensive initial clinical evaluation in combination with imaging and microbiological data, in order to identify high-risk IE patients early

Troponin T in COVID-19 hospitalized patients: Kinetics matter

Background: Coronavirus disease 2019 (COVID-19) emerged as a worldwide health crisis, overwhelming healthcare systems. Elevated cardiac troponin T (cTn T) at admission was associated with increased in-hospital mortality. However, data addressing the role of cTn T in major adverse cardiovascular events (MACE) in COVID-19 are scarce. Therefore, we assessed the role of baseline cTn T and cTn T kinetics for MACE and in-hospital mortality prediction in COVID-19.Methods: Three hundred and ten patients were included prospectively. One hundred and eight patients were excluded due to incomplete records. Patients were divided into three groups according to cTn T kinetics: ascending, descending, and constant. The cTn T slope was defined as the ratio of the cTn T change over time. The primary and secondary endpoints were MACE and in-hospital mortality.Results: Two hundred and two patients were included in the analysis (mean age 64.4 ± 16.7 years, 119 [58.9%] males). Mean duration of hospitalization was 14.0 ± 12.3 days. Sixty (29.7%) patients had MACE, and 40 (19.8%) patients died. Baseline cTn T predicted both endpoints (p = 0.047, hazard ratio [HR] 1.805, 95% confidence interval [CI] 1.009–3.231; p = 0.009, HR 2.322, 95% CI 1.234–4.369). Increased cTn T slope predicted mortality (p = 0.041, HR 1.006, 95% CI 1.000–1.011). Constant cTn T was associated with lower MACE and mortality (p = 0.000, HR 3.080, 95% CI 1.914–4.954, p = 0.000, HR 2.851, 95% CI 1.828–4.447).Conclusions: The present study emphasizes the additional role of cTn T testing in COVID-19 patients for risk stratification and improved diagnostic pathway and management

Application of whole genome data for in silico evaluation of primers and probes routinely employed for the detection of viral species by RT-qPCR using dengue virus as a case study

Abstract Background Viral infection by dengue virus is a major public health problem in tropical countries. Early diagnosis and detection are increasingly based on quantitative reverse transcriptase real-time polymerase chain reaction (RT-qPCR) directed against genomic regions conserved between different isolates. Genetic variation can however result in mismatches of primers and probes with their targeted nucleic acid regions. Whole genome sequencing allows to characterize and track such changes, which in turn enables to evaluate, optimize, and (re-)design novel and existing RT-qPCR methods. The immense amount of available sequence data renders this however a labour-intensive and complex task. Results We present a bioinformatics approach that enables in silico evaluation of primers and probes intended for routinely employed RT-qPCR methods. This approach is based on analysing large amounts of publically available whole genome data, by first employing BLASTN to mine the genomic regions targeted by the RT-qPCR method(s), and afterwards using BLASTN-SHORT to evaluate whether primers and probes will anneal based on a set of simple in silico criteria. Using dengue virus as a case study, we evaluated 18 published RT-qPCR methods using more than 3000 publically available genomes in the NCBI Virus Variation Resource, and provide a systematic overview of method performance based on in silico sensitivity and specificity. Conclusions We provide a comprehensive overview of dengue virus RT-qPCR method performance that will aid appropriate method selection allowing to take specific measures that aim to contain and prevent viral spread in afflicted regions. Notably, we find that primer-template mismatches at their 3′ end may represent a general issue for dengue virus RT-qPCR detection methods that merits more attention in their development process. Our approach is also available as a public tool, and demonstrates how utilizing genomic data can provide meaningful insights in an applied public health setting such as the detection of viral species in human diagnostics

Quantification of Calcium Amount in a New Experimental Model: A Comparison between Ultrasound and Computed Tomography.

PURPOSE:Calcification is an important prognostic factor in aortic valve stenosis. However, there is no ultrasound (US) method available to accurately quantify calcification in this setting to date. We aimed to validate a new US method for measuring the amount of calcium in an in vitro model, and compare it to computed tomography (CT), the current imaging gold standard. MATERIALS AND METHODS:An agar phantom (2% agar) was made, containing 9 different amounts of calcium-hydroxyapatite Ca5(PO4)3OH (2 to 50 mg). The phantoms were imaged with micro-CT and US (10 MHz probe). The calcium area (areacalcium) and its maximum pixel value (PVmax) were obtained. These values were summed to calculate CT and US calcium scores (∑(areacalcium × PVmax)) and volumes (∑areacalcium). Both US- and CT-calcium scores were compared with the calcium amounts, and with each other. RESULTS:Both calcium scores correlated significantly with the calcium amount (R2 = 0.9788, p<0.0001 and R2 = 0.8154, p<0.0001 for CT and US respectively). Furthermore, there was a significant correlation between US and CT for calcium volumes (R2 = 0.7392, p<0.0001) and scores (R2 = 0.7391, p<0.0001). CONCLUSION:We developed a new US method that accurately quantifies the amount of calcium in an in vitro model. Moreover it is strongly correlated with CT

Impact of the initial clinical presentation on the outcome of patients with infective endocarditis

International audienceBackground: Infective endocarditis (IE) is a life-threatening disease. Despite advancements in diagnostic methods, the initial clinical presentation of IE remains a valuable asset. Therefore, the impact of clinical presentation on outcomes and its association with microorganisms and IE localization were assessed herein. Methods: This retrospective study included 183 patients (age 68.9 ± 14.2 years old, 68.9% men) with definite IE at two tertiary care hospitals in Belgium. Demographic data, medical history, clinical presentation, blood cultures, imaging data and outcomes were recorded. Results: In-hospital mortality rate was 22.4%. Sixty (32.8%) of the patients developed embolism, 42 (23%) shock, and 103 (56.3%) underwent surgery during hospitalization. Shock at admission predicted embolism during hospitalization (odds ratio [OR] 2.631, 95% confidence interval [CI] 1.119-6.184, p = 0.027). A new cardiac murmur at admission predicted cardiac surgery (OR 1.949, 95% CI 1.007-3.774, p = 0.048). Methicillin resistant Staphylococcus aureus predicted in-hospital mortality and shock (p = 0.005, OR 6.945, 95% CI 1.774-27.192 and p = 0.015, OR 4.691, 95% CI 1.348-16.322, respectively). Mitral valve and aortic valve IE respectively predicted in-hospital death (p = 0.039, OR 2.258, 95% CI 1.043-4.888) and embolism (p = 0.017, OR 2.328, 95% CI 1.163-4.659). Conclusions: In this retrospective study, shock at admission independently predicted embolism during hospitalization in IE patients. Moreover, a new cardiac murmur at admission predicted the need for cardiac surgery. This emphasizes the importance of a comprehensive initial clinical evaluation in combination with imaging and microbiological data, in order to identify high-risk IE patients early

Left atrium remodeling predicts late recurrence of paroxysmal atrial fibrillation after second generation cryoballoon ablation

Abstract Background Atrial fibrillation (AF) is the most common arrhythmia worldwide. Nowadays, AF ablation is a valuable treatment option. It has been shown that the left atrium (LA) diameter is a predictor of AF recurrence after cryoballoon ablation (CBA). Since it does not reflect the true LA size, we compared the role of different LA anatomical parameters using echocardiography for the prediction of AF recurrence after CBA. Methods We retrospectively included 209 patients (mean age 56.1 ± 13.6 years, male 62%) with paroxysmal AF undergoing CBA. A transthoracic echocardiography was performed in all patients. Results At a mean follow-up of 16.9 ± 6.3 months, AF recurred in 25.4% of the patients. LA anterior - posterior diameter (LAD), LA minimum volume (LAmin) and early AF recurrence were independent predictors of recurrence. Based on receiver operating characteristics, cut – off values for LAD and, LAmin were 41 mm, 23.69 mL, respectively. The negative predictive values for recurrence were 73% and 87.3% respectively. In patients with AF recurrence, a significant proportion (30.2%) showed LA longitudinal remodeling (LA superior – inferior diameter) even though classically measured LAD was normal. Conclusions Longitudinal LA remodeling plays an additional role for predicting AF recurrence after CBA, in patients without LAD dilation. Moreover, LAmin had a high negative predictive value and was an independent predictor of AF recurrence. Therefore, a more complete LA anatomical assessment allows a better prediction of AF recurrences after CBA

Deepening of In Silico Evaluation of SARS-CoV-2 Detection RT-qPCR Assays in the Context of New Variants

For 1 year now, the world is undergoing a coronavirus disease-2019 (COVID-19) pandemic due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The most widely used method for COVID-19 diagnosis is the detection of viral RNA by RT-qPCR with a specific set of primers and probe. It is important to frequently evaluate the performance of these tests and this can be done first by an in silico approach. Previously, we reported some mismatches between the oligonucleotides of publicly available RT-qPCR assays and SARS-CoV-2 genomes collected from GISAID and NCBI, potentially impacting proper detection of the virus. In the present study, 11 primers and probe sets investigated during the first study were evaluated again with 84,305 new SARS-CoV-2 unique genomes collected between June 2020 and January 2021. The lower inclusivity of the China CDC assay targeting the gene N has continued to decrease with new mismatches detected, whereas the other evaluated assays kept their inclusivity above 99%. Additionally, some mutations specific to new SARS-CoV-2 variants of concern were found to be located in oligonucleotide annealing sites. This might impact the strategy to be considered for future SARS-CoV-2 testing. Given the potential threat of the new variants, it is crucial to assess if they can still be correctly targeted by the primers and probes of the RT-qPCR assays. Our study highlights that considering the evolution of the virus and the emergence of new variants, an in silico (re-)evaluation should be performed on a regular basis. Ideally, this should be done for all the RT-qPCR assays employed for SARS-CoV-2 detection, including also commercial tests, although the primer and probe sequences used in these kits are rarely disclosed, which impedes independent performance evaluation

Use of Whole Genome Sequencing Data for a First in Silico Specificity Evaluation of the RT-qPCR Assays Used for SARS-CoV-2 Detection

The current COronaVIrus Disease 2019 (COVID-19) pandemic started in December 2019. COVID-19 cases are confirmed by the detection of SARS-CoV-2 RNA in biological samples by RT-qPCR. However, limited numbers of SARS-CoV-2 genomes were available when the first RT-qPCR methods were developed in January 2020 for initial in silico specificity evaluation and to verify whether the targeted loci are highly conserved. Now that more whole genome data have become available, we used the bioinformatics tool SCREENED and a total of 4755 publicly available SARS-CoV-2 genomes, downloaded at two different time points, to evaluate the specificity of 12 RT-qPCR tests (consisting of a total of 30 primers and probe sets) used for SARS-CoV-2 detection and the impact of the virus&rsquo; genetic evolution on four of them. The exclusivity of these methods was also assessed using the human reference genome and 2624 closely related other respiratory viral genomes. The specificity of the assays was generally good and stable over time. An exception is the first method developed by the China Center for Disease Control and prevention (CDC), which exhibits three primer mismatches present in 358 SARS-CoV-2 genomes sequenced mainly in Europe from February 2020 onwards. The best results were obtained for the assay of Chan et al. (2020) targeting the gene coding for the spiking protein (S). This demonstrates that our user-friendly strategy can be used for a first in silico specificity evaluation of future RT-qPCR tests, as well as verifying that the former methods are still capable of detecting circulating SARS-CoV-2 variants

A new multiplex RT-qPCR method for the simultaneous detection and discrimination of Zika and chikungunya viruses

International audienceObjective: The re-emergence and spread of tropical viruses to new areas has raised a wave of concern worldwide. In order to treat patients at an early stage and prevent the diffusion of an outbreak, early diagnosis, and therefore fast and adequate detection, is needed. To this end, a multiplex reverse transcription real-time polymerase chain reaction TaqMan method was designed to detect Zika (ZIKV) and chikungunya (CHIKV) viruses simultaneously.Methods: Two methods targeting different genome segments were selected from the literature for each virus. These were adapted for high genome coverage and combined in a four-plex assay that was thoroughly validated in-house. The SCREENED tool was used to evaluate the sequence coverage of the method.Results: The full validation approach showed that the new four-plex method allows the specific and sensitive identification and discrimination of ZIKV and CHIKV in routine samples. The combination of two targets per virus allowing almost 100% coverage of about 500 genomes is shown for the first time.Conclusions: PCR is a reliable user-friendly technique that can be applied in remote areas. Such multiplex methods enable early and efficient diagnosis, leading to rapid treatment and effective confinement in outbreak cases. They may also serve as an aid for surveillance, and the full validation permits easy method-transfer allowing worldwide harmonization