Prosthetic Aortic Valve Thrombosis

Prosthetic valve thrombosis is the second leading cause of prosthetic valve deterioration and is being more readily diagnosed with the use of echocardiography and multidetector cardiac CT. Presentation of valve thrombosis can be acute or subacute and any change in clinical status of a patient with a prosthetic valve should raise a suspicion of prosthetic valve thrombosis. Diagnosis entails detailed clinical examination and comprehensive imaging. The choice of therapeutic options includes anticoagulation, fibrinolytic therapy, or valve replacement. Antiplatelet and anticoagulation therapy remain the mainstay of thrombosis prevention in patients with a prosthetic valve and a personalized approach is required to optimize prosthetic valve function and minimize the risk of bleeding.

Role of oxidative stress in angiogenesis and the therapeutic potential of antioxidants in breast cancer

The escalation of cancer cases globally, especially breast cancer, is of concern. Angiogenesis is hallmark of cancer pathogenesis and plays an important role in cancer progression and metastasis. Pro-angiogenic agents, secreted by tumor cells, form new blood vessels, and produce reactive oxygen species (ROS). ROS promote angiogenesis via two major pathways: namely Vascular Endothelial Growth Factor (VEGF) dependent and non-VEGF dependent pathways. As a consequence of unbalanced ROS overproduction and low antioxidants levels, oxidative stress occurs and promotes angiogenesis in breast cancer tissues. Thus, the potential use of antioxidants as a preventive therapy in breast cancer. Preclinical studies depict that vitamins A and E may counter oxidative stress resulting in reduction of metastasis and viability of breast cancer. Furthermore, clinical studies demonstrate a decline in breast cancer risk in postmenopausal women upon the consumption of antioxidants. Herein, we discuss various pro-angiogenic agents that may play an important role in breast cancer angiogenesis. Moreover, the contribution of oxidative stress in inducing the angiogenic process is extensively reviewed here. Furthermore, the findings of pre-clinical and clinical studies on the use of antioxidants, namely vitamins A and E, in breast cancer are deliberated upon, along with the role of angiogenesis in cancer therapy.

Asymptomatic infection and transmission of COVID-19 among clusters: systematic review and meta-analysis

OBJECTIVES

Countries throughout the world are experiencing COVID-19 viral load in their populations, leading to potential transmission and infectivity of asymptomatic COVID-19 cases. The current systematic review and meta-analysis aims to investigate the role of asymptomatic infection and transmission reported in family clusters, adults, children and health care workers, globally.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

An online literature search of PubMed, Google Scholar, medRixv and BioRixv was performed using standard Boolean operators and included studies published up to 17 August 2021. For the systematic review, case reports, short communications and retrospective studies were included to ensure sufficient asymptomatic COVID-19 transmission data were reported. For the quantitative synthesis (meta-analysis), participant data from a collection of cohort studies focusing on groups of familial clusters, adults, children and health care workers were included. Inconsistency among studies was assessed using I² statistics. The data synthesis was computed using the STATA 16.0 software.

RESULTS

This study showed asymptomatic transmission among familial clusters, adults, children and health care workers of 15.72%, 29.48%, 24.09% and 0%, respectively. Overall, asymptomatic transmission was 24.51% (95% confidence interval [CI]: 14.38, 36.02) among all studied population groups, with a heterogeneity of I² = 95.30% (P < 0.001). No heterogeneity was seen in the population subgroups of children and health care workers. The risk of bias in all included studies was assessed using the Newcastle Ottawa Scale.

CONCLUSIONS

For minimising the spread of COVID-19 within the community, this study found that following the screening of asymptomatic cases and their close contacts for chest CT scan (for symptomatic patients), even after negative nucleic acid testing, it is essential to perform a rigorous epidemiological history, early isolation, social distancing and an increased quarantine period (a minimum of 14-28 days). This systematic review and meta-analysis supports the notion of asymptomatic COVID-19 infection and person-to-person transmission and suggests that this is dependent on the varying viral incubation period among individuals. Children, especially those of school age (i.e. <18 years), need to be monitored carefully and follow mitigation strategies (e.g. social distancing, hand hygiene, wearing face masks) to prevent asymptomatic community transmission of COVID-19.

Cross-species virus transmission and its pandemic potential

BACKGROUND

The majority of pandemics are known to be a result of either bacteria or viruses out of which viruses seem to be an entity of growing concern due to the sheer number of yet unidentified and potentially threatening viruses, their ability to quickly evolve and transform, their ability to transfer and change from one host organism to another and the difficulty in creating safe vaccines on time.

MAIN BODY

The present review attempts to bring forth the potential risks, prevention and its impact on the global society in terms of sociological and economic parameters. Taking hindsight from previously as well as ongoing current viral epidemics, this article aims to draw a concrete correlation between these viruses in terms of their origin, spread and attempts to compare how much they can affect the population. The study also assesses the worst-case scenarios and the amount of preparedness, required to fight against such pandemics and compares the required amount of preparedness to the current precautions and measures by different governments all across the world.

SHORT CONCLUSION

Learning from the current pandemic, we can implement certain measures to prevent the adverse effects of pandemics in the future and through severe preparedness can combat the challenges brought about by the pandemic.

A randomized comparative evaluation of C-MAC video-laryngoscope with Miller laryngoscope for neonatal endotracheal intubation

Background and Aims

An efficient neonatal airway management is peculiarly challenging even in the most experienced hands. Considering the recent interest in assessing the performance of various video-laryngoscopes (VL) in pediatric cohort, the prospective randomized study was contemplated to stage a comparative evaluation of C-MAC with Miller laryngoscope for neonatal endotracheal intubation.

Material and Methods

150 neonates were randomized to undergo intubation with either the C-MAC VL (n = 75) or the Miller laryngoscope (n = 75) performed by an experienced anesthesiologist in a tertiary care perioperative setting. The percentage of glottic opening (POGO), time to best glottic view (TTBGV), time to intubation (TTI), number of attempts, optimal external laryngeal manipulation (OELM) employed, and the complications were assessed and compared between the two groups.

Results

C-MAC group demonstrated a significantly higher POGO, compared to the Miller group (88 ± 26.7%;76.8 ± 32.1%, respectively, P = 0.022). TTBGV was significantly lower in the C-MAC (7.7 ± 0.1s) group as opposed to the Miller group (11.3 ± 1.1s). The C-MAC group displayed higher TTI values compared to the Miller group (25.4 ± 1.6s; 19.7 ± 1.2s, respectively, P < 0.01). The first-attempt intubation success rate and the number of attempts were comparable in both the groups. OELM was required in 24% of the patients in the Miller group as opposed to 10.7% in the C-MAC group (P = 0.031). Higher patient percentage in the C-MAC group required the need of stylet for assisting a successful intubation, although the difference between the two groups was not statistically significant.

Conclusion

Despite an improved view of the glottis, the TTI was higher for C-MAC compared to direct laryngoscopy with a comparable first-attempt success rate in the two techniques.

New era of education: mobile learning of coronary guidewires in cardiovascular medicine

Background

Online education has transformed the way we teach and learn, especially in the midst of a global pandemic. Multiple devices, including coronary guidewires, are required to perform a successful coronary intervention, and understanding the engineering aspect of coronary guidewire technology is paramount.

Purpose

We aim to develop and evaluate a novel teaching tool/mobile learning app to understand a complex guidewire architecture and appropriate wire selection based on a lesion characteristics.

Methods

A guidewire is incredibly complex, consisting of a multitude of technologies allowing a range of tip softness, trackability around curves, and precise torque control. Despite operator preference, the process of choosing an appropriate coronary guidewire has gone mostly unchanged. We envisioned developing the GuidewireAID app with three main parts: 1) wire basics, 2) lesion-based guidewire selection, and 3) cased-based approach. Appropriate teaching cases were selected from a large-volume catheterization laboratory and divided into non-chronic total occlusion (non-CTO) and CTO. Non-CTO cases include simple, calcified, angulated, and bifurcation lesions, as well as thrombotic occlusion and tortuous vessels (Figure 1). Each case is described and analysis is offered on how to select an appropriate wire, followed by teaching points pertinent to the topic.

Results

Twenty-three detailed clinical cases and more than a hundred wires are illustrated in the GuidewireAID app. Case presentation, angiographic analysis, and a thorough understanding of wire characteristics allows the operator to know which wire to use and when it is time to switch, especially when dealing with complex coronary cases.

Conclusion

The GuidewireAID app will help fellows in training (FIT), early career interventionists, and practicing interventional cardiologists understand the complex aspects of a coronary guidewire and appreciate how their nuances could overcome real-world clinical challenging scenarios.

Funding Acknowledgement

Type of funding sources: None. Figure 1

miRNAs in SARS-CoV 2: A Spoke in the Wheel of Pathogenesis

INTRODUCTION

The rapid emergence of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-- CoV-2) has resulted in an increased mortality rate across the globe. However, the underlying mechanism of SARS-CoV-2 altering human immune response is still elusive. The existing literature on miRNA mediated pathogenesis of RNA virus viz. Dengue virus, West Nile virus, etc. raises a suspicion that miRNA encoded by SARS-CoV-2 might facilitate virus replication and regulate the host's gene expression at the post-transcriptional level.

METHODS

We investigated this possibility via computational prediction of putative miRNAs encoded by the SARS-CoV-2 genome using a novel systematic pipeline that predicts putative mature-miRNA and their targeted genes transcripts. To trace down if viral-miRNAs targeted the genes critical to the immune pathway, we assessed whether mature miRNA transcripts exhibit effective hybridization with the 3'UTR region of human gene transcripts. Conversely, we also tried to study human miRNA-mediated viral gene regulation to get insight into the miRNA mediated offense and defense mechanism of virus and its host organisms in toto.

RESULTS

Our analysis led us to shortlist six putative miRNAs that target, majorly, genes related to cell proliferation/ differentiation/signaling, and senescence. Nonetheless, they also target immune-related genes that directly/ indirectly orchestrate immune pathways like TNF (Tumor Necrosis Factor) signaling and Chemokine signaling pathways putatively serving as the nucleus to cytokine storms.

CONCLUSION

Besides, these six miRNAs were found to be conserved so far across 80 complete genomes of SARS-CoV-2 (NCBI Virus, last assessed 12 April 2020) including Indian strains that are also targeted by 7 human miRNAs and can, therefore, be exploited to develop MicroRNA-Attenuated Vaccines.

Impact of renin-angiotensin system inhibitors on clinical outcomes in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement: an analysis of from the PARTNER 2 trial and registries

AIMS

Left ventricular pressure overload is associated with activation of the cardiac renin-angiotensin system, which may contribute to myocardial fibrosis and worse clinical outcomes. We sought to assess the association between treatment with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) at baseline and clinical outcomes in patients with symptomatic, severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) in the PARTNER 2 trial and registries.

METHODS AND RESULTS

A total of 3979 intermediate, high, or prohibitive risk patients who underwent TAVR in the PARTNER 2 trial and registries (excluding the valve in valve registry) were included in the study. Clinical outcomes at 2 years were compared according to baseline ACEI/ARB treatment status using Kaplan-Meier event rates and study-stratified multivariable Cox proportional hazards regression models. Sensitivity analysis was conducted using propensity score matching. Of 3979 patients who were included in the current analysis, 1736 (43.6%) were treated and 2243 (56.4%) were not treated with ACEI/ARB at baseline. Treatment with ACEI/ARB was associated with lower 2-year all-cause mortality (18.6% vs. 27.5%, P < 0.0001), cardiovascular mortality (12.3% vs. 17.9%, P < 0.0001), and non-cardiovascular mortality (7.2% vs. 11.7%, P < 0.0001). Angiotensin-converting enzyme inhibitor/ARB treatment at baseline remained independently associated with a lower hazard of 2-year all-cause and cardiovascular mortality after multivariable adjustment, and propensity score matching.

CONCLUSION

In a large cohort of patients with severe symptomatic AS from the PARTNER 2 trial and registries, ACEI/ARB treatment at baseline was independently associated with a lower risk of 2-year all-cause and cardiovascular mortality.

Kikuchi Necrotising Lymphadenitis in a Child: A Rare Case Report

<b><i>Introduction:</i></b> Kikuchi-Fujimoto disease (KFD) is a rare benign disease with a self-limiting course. Patients usually present with clinical features of tender cervical lymphadenopathy (LAP), fever, malaise, weight loss, and night sweats. The disease may mimic infective LAP or lymphoma on clinical and histopathological examination (HPE). <b><i>Case Report:</i></b> We report a case of 3-year-old male child who presented to us with bilateral cervical LAP not responding to conservative management. Excision biopsy was done and HPE revealed KFD. <b><i>Conclusion:</i></b> Clinicians should have high index of suspicion for diagnosis of KFD in patients with cervical LAP not responding to conservative management. Excision biopsy is important for accurate diagnosis and to avoid aggressive interventions like chemotherapy.

Interfacial Tension of the Water-Diluted Bitumen Interface at High Bitumen Concentrations Measured Using a Microfluidic Technique

The interfacial tension (IFT) is a critical parameter to inform our understanding of the phenomena of drop breakup and droplet-droplet coalescence in sheared water-in-diluted bitumen (dilbit) emulsions. A microfluidic extensional flow device (MEFD) was used to determine the IFT of the dilbit-water emulsion system for bitumen concentrations of 33%, 50%, and 67% by weight (solvent to bitumen ratio (S/B) = 2, 1, and 0.5, respectively) and two different pH values of water: 8.3 and 9.9. The IFT was observed to increase with the bitumen concentration and decrease significantly upon lowering the water pH. The time scale for achieving the steady state IFT increased with bitumen concentration and was less sensitive to the water pH. But the most important feature of our measurements is that the IFTs recorded were significantly smaller than the values reported in the literature. We recognized two important differences between our studies and prior investigations: measurement of the IFT of water drops in dilbit as opposed to dilbit drops in water in earlier studies, and time scales of measurement of IFT that ranged from hundreds of milliseconds to a few seconds, as compared to a minute or longer in past investigations. These differences were examined carefully, but neither was found to explain the low IFTs measured in our studies. Our work leads to the following hypothesis: the mechanical properties of the interface of a sheared water drop in bitumen are significantly different from a stagnant one.