Cardiovascular disease in older patients with end-stage renal disease and chronic dialysis in Vietnam

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with chronic kidney disease, especially end-stage renal disease, exhibit a very high cardiovascular risk. In Vietnam, chronic kidney disease and cardiovascular disease (CVD) are very common in older people. However, there is limited studies on the complexity of CVD and other geriatric syndromes in older patients with end-stage renal disease and chronic dialysis.

Purpose

In this study in older patients with end-stage renal disease and chronic dialysis, we aim to: (1) Examine the prevalence of CVD and its impact on hospitalization, and (2) Compare the burden of common geriatric syndromes in patients with and without CVD.

Methods

This is a prospective, observational, multi-centre study conducted at two dialysis units of two major hospitals in Vietnam. Consecutive patients aged 60 years or older who were diagnosed with end-stage renal disease and on chronic dialysis were recruited from November 2020 to June 2021. CVD was defined as having one of these conditions: heart failure, ischemic heart disease, and stroke. Participants were assessed for these common geriatric conditions: frailty (defined as a Clinical Frailty Scale total score ≥5), malnutrition (defined as a total score ≤7 from the Mini Nutritional Assessment Short Form), impairment in activities of daily living (defined as ADL score <6), impairment in instrumental activities of daily living (defined as IADL score <8), high risk of falls (assessed by the STEADI questionnaire), and polypharmacy (defined as the concurrent use of ≥5 medications). Participants were followed for 6 months after discharge. Multivariable logistic regression analysis was applied to examine the impact of CVD on 6-month hospitalization, adjusting for age, sex, and the geriatric conditions. Results were presented as odds ratios (ORs) and 95% confidence intervals (CIs).

Results

There were 175 participants (mean age 72.4 ± 8.5, 58.9% female). CVD was present in 80% of the participants (ischemic heart disease: 49.7%, heart failure: 60.0%, stroke 25.7%). Participants with CVD had significantly higher prevalence of geriatric syndromes compared to those without CVD (Table 1). During 6-month follow-up, 48.6% of the participants had at least one hospitalization. In multivariable logistic regression model, the presence of CVD increased the risk of hospitalization (adjusted OR 4.70, 95%CI 1.72 – 12.85), allowing for age, sex, frailty, ADL impairment, IADL impairment, fall risk, malnutrition, polypharmacy (Table 2).

Conclusion

In this study, there was a very high prevalence of CVD in older patients with end-stage renal disease and chronic dialysis. Participants with CVD had higher burden of geriatric syndromes and their risk of 6-month hospitalization increased by approximately 5 times.

Contrast induced nephropathy in older Vietnamese patients undergoing coronary angiography and intervention

Funding Acknowledgements

Type of funding sources: None.

Background

The prevalence of coronary heart disease increases with age and older people accounted for a large proportion of patients presenting with coronary heart disease. Advancement in percutaneous coronary intervention (PCI) has contributed to reduced mortality in patients with coronary artery disease. However, coronary angiography and percutaneous intervention have also increased the risk of developing contrast induced nephropathy (CIN), especially in older patients. More than ten risk assessment tools have been developed to predict CIN. Among these, the Mehran risk score has been the most commonly used in Vietnam. In recent years, new simple risk prediction models have been proposed, including the contrast volume-to-glomerular filtration rate ratio (CV/GFR ratio). The CV/GFR ratio is calculated as the ratio of contrast medium quantity to glomerular filtration rate.

Purpose

The aim of this study was to (1) examine the incidence of CIN in a cohort of older patients undergoing coronary angiography and/or PCI at a tertiary hospital in Vietnam, (2) compare the validity of the CV/GFR ratio and the Mehran score in predicting CIN, and (3) to identify optimal cut-off points of these scales by which can help identify older patients with high risk of developing CIN in this population.

Methods

A prospective observational study was conducted in patients aged ≥ 60 years at a tertiary hospital in Vietnam from September 2019 to May 2020. CIN was defined as 25% increase in serum creatinine from baseline or 0.5mg/dL absolute increase in serum creatinine occurring within 48 hours post IV contrast administration. The CV/GFR ratio and the Mehran score were applied for predicting risk of CIN. Previous studies suggest Mehran score >5 or CV/GFR ratio >3.7 as a predictor of an early abnormal increase in serum creatinine after PCI. Receiver Operator Characteristic (ROC) was applied to evaluate area under the curve (AUC) of the CV/GFR ratio and Mehran score in predicting CIN, and the sensitivity, specificity for common cut-off points that were suggested in previous studies.

Results

A total of 170 participants were included in this study. They had a mean age of 70 years, 33.1% were women. The incidence of CIN was 9.4%. Participants with CIN had higher prevalence of chronic kidney disease, heart failure and anaemia at admission. The AUC of the CV/GFR ratio against CIN was 0.79 (95%CI 0.65-0.92), and of the Mehran score against CIN was 0.65 (95%CI 0.51-0.82) (Figure 1). The sensitivity and specificity for common cut-off points of the CV/GFR ratio and Mehran score are presented in Figure 2.

Conclusions

Our study found that CIN was common in older patients after PCI. Both CV/GFR ratio and Mehran score had good diagnostic value for predicting CIN in the study participants.

Ultrasonographic features of the endometrium following successful medical termination of early pregnancy

OBJECTIVE

Ultrasonographic features of the endometrium are often assessed when deciding the necessity of surgical intervention following early medical abortion. Knowledge is therefore needed on the ultrasonographic appearance of the endometrium following successful medical abortion in order to avoid unnecessary surgical interventions. We aimed to assess endometrial thickness and echogenicity at multiple time points following successful early medical abortion.

STUDY DESIGN

We conducted a retrospective study in the largest office-based abortion providing clinic in Denmark. Using archived ultrasonographic images, we assessed endometrial thickness and echogenicity following all early medical abortions that did not need surgical intervention or repeated medication for completion during the years 2014-2017.

RESULTS

Ultrasonographic endometrial features were assessed 1854 times following 1074 early medical abortions. Median endometrial thickness in the 1st week from induction was 13 milimeters (mm; lower-upper quartile 11-17 mm). For the 2nd, 3rd, 4th, and >4th week, the median endometrial thickness was found to be 11 mm (9-15 mm), 11 mm (8-14 mm), 12 mm (9-16 mm), and 11 mm (8-14 mm), respectively. Of the ultrasonographic examinations performed in the 1st week from medical induction, 24.7 % showed a heterogenous endometrium. For 2nd, 3rd, 4th, >4th week, the frequency of heterogeneity was 23.9 %, 16.3 %, 21.3 %, 18.9 %, respectively. A total of 151 abortions (14.1 %) were each examined three times, median time of examination being day 7, 15, and 26 following induction. Among these abortions, the three most common patterns of change in endometrial thickness were "decreasing" (37.7 %), "increasing-decreasing" (23.2 %), and "decreasing-increasing" (21.9 %). Further, 49.7 % of the 151 abortions showed a homogenous endometrium at all three examinations, 17.2 % showed a heterogenous endometrium at first examination and a homogenous endometrium the following two examinations, and 9.9 % showed a heterogenous endometrium at the first two examinations followed by a homogenous endometrium.

CONCLUSION

In early medical abortions completed without secondary intervention, endometrial thickness and echogenicity varied clinically significantly for weeks following the medical induction. Every possible pattern of change in endometrial thickness and echogenicity was observed.

Green Fabrication of Heterostructured CoTiO3/TiO2 Nanocatalysts for Efficient Photocatalytic Degradation of Cinnamic Acid

In this work, CoTiO₃/TiO₂ (CTO/Ti) heterostructures were prepared by a hydrothermal procedure in a neutral medium using perovskite CoTiO₃ and tetraisopropyl titanate. Characteristics of the synthesized catalysts were analyzed by various techniques including X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller adsorption-desorption, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and point of zero charges. The activity in the photodegradation of cinnamic acid (CA) under UV-A irradiation of the CTO/Ti heterostructure was investigated and compared with individual materials TiO₂ (Ti-w) and CoTiO₃ (CTO). The investigation showed that the heterostructured CoTiO₃/TiO₂ catalyst with optimal composition (5% CTO) exhibited much higher photocatalytic activity for degradation of cinnamic acid than individual CoTiO₃ and TiO₂. Under the optimal conditions (C _cat = 0.75 g/L, Q _air = 0.3 L/min, and pH = 3.8) the 90 min conversion of cinnamic acid reached 80.9% on 5CTO/Ti, much higher than those of CTO (4.6%) and Ti-w (75.2%). It was found that the enhancement in activity for the CA removal of the CTO/Ti heterostructure was due to the construction of a heterojunction structure between TiO₂(Ti-w) and CoTiO₃ that resulted in an increase in the specific surface area and porosity, reduction of the band gap energy, and higher efficient separation of charge carriers on the surface to prevent recombination. Alternatively, a comparison of the recyclability of 5CTO/Ti and Ti-w was made for CA degradation. The results showed a decrease in the CA conversion by 38% on 5CTO/Ti and 48% on Ti-w after six reaction cycles.

Multipolar Ablation Using Mapping Electrodes: A Novel Approach to Intramural Arrhythmia Substrates

Intramural ventricular arrhythmias are challenging to treat. Adjunctive techniques such as bipolar ablation, ethanol injection, use of a needle catheter, or surgery have been described. These are often not readily available. This is a case report of a patient with refractory intramural ventricular arrhythmia that was ablated by incorporating electrodes of a mapping catheter into the ablation circuit. The results of ex vivo experiments to determine the characteristics of multipolar ablation lesions using different ablation settings are reported. The feasibility of generating transmural lesions with multipolar ablation in vivo in a porcine model was tested.

Magnetic-field-synchronized wireless modulation of neural activity by magnetoelectric nanoparticles

The in vitro study demonstrates wirelessly controlled modulation of neural activity using magnetoelectric nanoparticles (MENPs), synchronized to magnetic field application with a sub-25-msec temporal response. Herein, MENPs are sub-30-nm CoFe₂O₄@BaTiO₃ core-shell nanostructures. MENPs were added to E18 rat hippocampal cell cultures (0.5 μg of MENPs per 100,000 neurons) tagged with fluorescent Ca²⁺ sensitive indicator cal520. MENPs were shown to wirelessly induce calcium transients which were synchronized with application of 1200-Oe bipolar 25-msec magnetic pulses at a rate of 20 pulses/sec. The observed calcium transients were similar, in shape and magnitude, to those generated through the control electric field stimulation with a 50-μA current, and they were inhibited by the sodium channel blocker tetrodotoxin. The observed MENP-based magnetic excitation of neural activity is in agreement with the non-linear M - H hysteresis loop of the MENPs, wherein the MENPs' coercivity value sets the threshold for the externally applied magnetic field.

Evaluating the Oncology Research Internship (ORIoN) during the COVID-19 Pandemic: A Comparison of Virtual and In-Person Iterations

Purpose/Objective(s)

The Oncology Research Internship (ORIoN), a novel resident-supervised initiative for medical students (MS), was first established in 2018 and found to be mutually beneficial to both residents and MS. The COVID-19 pandemic halted many scholarly programs, including ORIoN, which relied heavily on mentorship through in-person interactions. We report results of the first virtual program, adapted to the COVID-19 pandemic, and compare participant feedback to previous in-person iterations.

Materials/Methods

ORIoN application details were published online and emailed to first- and second-year MS. A panel of 3 physicians reviewed and scored applications independently. Successful MS applicants were paired with volunteer resident supervisors; each pair supervised by a staff oncologist. Compared to previous years, all meetings, correspondences and presentations between MS, residents, and supervising oncologists were conducted exclusively remotely. Only chart reviews were conducted on-site by MS. At the program's conclusion, each MS delivered a live virtual oral presentation of their completed case report, previously done in-person. Resident and MS participants completed questionnaires pre-/post program. Responses were collected on a 5-point Likert scale with open-ended free-text responses. Survey results from this virtual and the previous in-person programs were compared.

Results

Of 54 applications (previously 32 in 2018), 9 MS (three first-year, six second-year) were accepted and assigned to 9 volunteer residents (6 radiation oncology, 2 medical oncology, 1 pathology). To date, 9 manuscripts have been completed with 2 submitted for publication (1 published, 1 under review). Survey response rates were 100% (9/9) for residents and 89% (8/9) for MS. In the post-program surveys comparing the virtual and prior in-person programs, 87.5% (7/8) MS felt comfortable completing a clinical research project (22% strongly agree (SA), 62.5% agree (A), previously 25% and 75% respectively) and 100% (8/8) felt comfortable writing a case report (50% SA, 50% A, previously 75%, 25% respectively). All MS felt comfortable giving an oral research presentation (37.5% SA, 62.5% A) and teaching another MS to complete a case report (37.5% SA, 50% A). Similar to the in-person program, MS unanimously agreed that ORIoN was a beneficial experience (100%) and felt the program contributed to their career goals (100%, previously 88%). Post-program, all residents felt comfortable as a supervisor (67% SA, 22% A, previously 33%, 67% respectively), reviewing manuscripts (56% SA, 33% A, previously 33%, 50% respectively) and providing constructive feedback to trainees (67% SA, 33% A, previously 17%, 67% respectively).

Conclusion

Compared to the previous in-person program, the virtual ORIoN retained strongly favorable ratings from MS and residents alike. These findings support adapting similar scholarly and mentorship programs to a virtual setting when in-person interactions are not feasible.

Delivering actionable infodemic insights and recommendations for the COVID-19 pandemic response

Issue

The COVID-19 pandemic and current recovery efforts have been complicated by a parallel infodemic. The infodemic has manifested itself in the rapid spread of questions, concerns and misinformation that can affect population attitudes and behavior harmful to health -promoting stigma and discrediting science, non-recommended treatments and cures, politicizing health programs and eroding trust in health workers and health systems.

Description

WHO's COVID-19 Pillar 2 (risk communication, community engagement and infodemic management) developed an integrated public health infodemic insights methodology for weekly analysis of social media, traditional media and other data sources to identify, categorize, and understand the key concerns and narratives expressed, and inform risk communication and response activities.

Results

The infodemic characterization, integrated analysis and insights generation consisted of a 3-step mixed-methods approach. First, data was collected from publicly available social and news media and categorized into categories of conversations by a COVID-19 public health taxonomy. Second, the dataset was analyzed and compared week-on-week to identify changes in narratives and conversation sentiment. Third, the digital infodemic intelligence was reviewed by a group of subject matter experts and triangulated with other data sources to derive infodemic insights and provide recommendations for action for the week. The methodology has been applied to inform COVID-19 response, COVID-19 vaccine demand promotion, and preparing for mass gatherings or mass immunization campaigns.

Lessons

The methodology for infodemic intelligence generation and integration has introduced evidence-based analytical practices for generation of infodemic insights and recommendations for action into the work of WHO. It must be further adapted for use by different health programmes and preparedness functions, and is described WHO Field Infodemiology Manual.

Key messages

• Health authorities can use infodemic insights to respond to people’s concerns, questions and information deficits in a timely and effective manner.

• An evidence-based methodology has been developed and validated to generate infodemic insights and recommendations for action during an acute health event or emergency.

The WHO initiative to measure the effectiveness and impact of PHSM – key activities in 2022

The presentation will focus on two main outcomes of the WHO initiative: a global research agenda to steer future evidence generation on PHSM, and a central monitoring system for PHSM research. In September 2021, a global technical consultation with over 60 global experts was organized to review the existing evidence on PHSM and identify the initiative's priorities. The consultation provided an opportunity to have an initial discussion on potential research priorities. This became the basis for an iterative online consultation process. The draft research agenda includes seven main research themes including effectiveness, unintended consequences, methodological challenges and implementation considerations affecting the uptake of and adherence to PHSM. Workshop participants will be invited to comment on the suggested themes and propose additional priority questions for the research agenda. The central research monitoring system will consist of a global repository of primary studies and reviews investigating the effectiveness and broader multisectoral impact of PHSM. Indexed studies will be mapped against the key themes of the research agenda, facilitating real-time monitoring and evaluation of its progress. An AI-based mechanism for automated updating of systematic reviews will complement the database. This one-stop shop will allow researchers and decision-makers worldwide to access the latest evidence on PHSM and keep track of the synthesized effectiveness and impact of different interventions and combinations. The platform will further provide a protected working interface. This monitoring system for PHSM research enables timely access to and utilization of evidence indecision-making processes during health emergencies and fosters international collaboration on the analysis and interpretation of data. Workshop participants will be invited to review the alpha version of the platform.

Infodemic management for public health practitioners: landscape analysis and practical tools

Issue

Infodemics (i.e., overflow of information in physical and digital spaces that makes it difficult for people to make good health decisions) can undermine emergency response, but capacity for infodemic management has been limited in countries thus far. Specifically, there is a need to build capacities in the field with practical and scalable tools.

Description of the problem

WHO has developed tools and trainings to quickly build and enhance infodemic management (IM) capacity at the country-level, such as tools for rapid generation of IM insights and a framework for conducting landscape analyses to establish sustainable IM capacities. These were developed in collaboration with multidisciplinary experts who provided feedback. We sought to create tools that can be a basis for introducing evidence-generation in health information systems to inform emergency preparedness and response, and mainstream methods into routine infodemic diagnostics activities.

Results

The tools and trainings provide a comprehensive framework for diagnosing and addressing infodemics, such as a public health taxonomy to guide digital intelligence analysis and integrated analysis methods for generation of actionable insights. Additionally, the landscape analysis framework outlines steps for assessing strategic needs and assets for routinizing IM functions as part of existing public health systems and programs.

Lessons

The tools and trainings will be deployed in the field to evaluate utility. Feedback from users in the global WHO infodemic manager community will be systematically captured.

Key messages

• Field responders need practical tools and trainings that guide quick infodemic response during health emergencies.

• These tools and trainings can be used to diagnose and intervene on infodemics, even in settings where infodemic insights units are not yet established.

Measuring the burden of infodemics on health outcomes through harmonized global metrics

Issue/problem

Infodemics happen when an excess of information makes it difficult for people to discern what they see and hear to make good health decisions. Several challenges limit the usefulness of applying infodemiology research to the practice of managing infodemics including inconsistency in how information exposure is measured and a lack of focus on assessing associations with health behaviors.

Description of the problem

In 2021, WHO partnered with the University of Sydney to develop a study toolkit. We sought to create novel tools for measuring information exposure that can be easily deployed, linked to surveys measuring health behaviors, and implements a standardized study protocol so that data can be directly synthesized into a global analysis of information risk factors associated with health behaviors.

Results

A web-based study platform was developed, comprising tools for capturing information exposures within studies that link to health behavior surveys. The first tool is a smartphone application that asks users to actively record relevant information they see or hear in diary. The second application is a web browser plugin that passively tracks webpages with relevant keywords. Because localized studies follow a standardized protocol and de-identified participant data are recorded in a common format, local study investigators can opt-in to contributing study data to support global surveillance efforts.

Lessons

Through standardization of measurement tools and relevant study protocols, the toolkit can be used to quickly collect and synthesize data for global or regional analysis of infodemics, including in Europe. Validation of the toolkit in the field is needed to inform its open-source release.

Key messages

• A toolkit for measuring information risk factors associated with behavioral outcomes was developed.

• Global collaboration using the toolkit can improve synthesisability of studies investigating infodemic burden of disease.

Hydroxyapatite Derived from Salmon Bone As Green Ecoefficient Support for Ceria-Doped Nickel Catalyst for CO2 Methanation

Hydroxyapatite (HA) derived from salmon bone byproducts is used as a green support for the nanostructured nickel catalysts applied in the methanation of carbon dioxide (CO₂). Undoped nickel catalysts and various ceria-doped nickel supported on hydroxyapatite (HA) were prepared by coimpregnation. Characteristics of the as-prepared catalysts were investigated by the various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H₂-TPR), carbon dioxide temperature-programmed desorption (CO₂-TPD), and energy-dispersive X-ray spectroscopy (EDX). The catalyst activity was assessed throughout CO₂ methanation in the low-temperature range of 225-350 °C with the molar ratio of H₂/CO₂ = 4/1. The function of HA and ceria provided a high dispersity of nickel particles over the catalyst surface with the size range of 24.5-25.8 nm, leading to improvement in the reduction and CO₂ adsorption capacity of the catalysts as well as enhancing the catalytic efficiency in CO₂ methanation. The 10Ni/HA catalyst reduced at suitable conditions of 400 °C for 2 h showed the highest catalytic performance among the tested catalysts. CO₂ conversion and CH₄ selectivity reached 76.6 and 100% at a reaction temperature of 350 °C, respectively. The results show that the Ni/HA sample doped with 6.0 wt % ceria was the best, with the CO₂ conversion and the CH₄ selectivity reaching 92.5% and 100%, respectively, at a reaction temperature of 325 °C.

Green Orange Peel-Mediated Bioinspired Synthesis of Nanoselenium and Its Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus

In this study, green orange peel (GOP) was feasibly evidenced in preparing selenium nanoparticles (SeNPs). Acting as reducing agents, polyphenolic compounds were extracted from GOP at the optimal extraction conditions (at 70 °C for 1.5 h, mass ratio of dried orange peel/distilled water of 5/100). The formation of SeNPs was observed at the wavelength range of 250-300 nm by ultraviolet-visible spectroscopy (UV-vis), and their highest yield could be reached at the following conditions: volume ratio of extract/selenious acid solution (V _Ext/V _Se) of 40/10, synthesis duration of 4 h, selenious acid concentration (C _Se) of 80 mM, and reaction temperature of 120 °C. The highly crystalline structure of SeNPs in the hexagonal phase was characterized by powder X-ray diffraction (XRD) with a lattice parameter of 4.3 Å; meanwhile, their spheres with an average crystal size of 18.3 nm were estimated by high-resolution transmission electron microscope (HR-TEM). The rationale of bioreducing agents extracted from green orange peel for the formation of SeNPs was also recognized by Fourier-transform infrared spectroscopy (FT-IR). The antibacterial investigation of the SeNP sample was assessed against antibiotic-resistant bacteria, typically methicillin-resistant Staphylococcus aureus (MRSA), by executing the zone of inhibition and the minimum inhibitory concentration (MIC) tests. The SeNP sample demonstrated excellent antibacterial activity with an average diameter of inhibition zones of 20.0 ± 0.7 mm and an MIC of 4.94 μg/L. A comparison of the physicochemical properties of SeNPs synthesized from GOP extract by the hydrothermal method with SeNP products from other green reducing agents and other methods as well as its antibacterial activity compared with other nanoparticles and some antibiotics was conducted to highlight the superiority of GOP-mediated green-synthesized SeNPs.

Great Safety and Efficacy of a New Drug-eluting-stent manufactured in a developing country at minimal cost: the VSTENT at 3 years follow-up

Background

In the care patients with coronary artery disease, a new drug-eluting stent, the VSTENT, covered with sirolimus was designed and manufactured in a developing country at minimal cost. Beside the clinical concern, from an engineering perspective, the questions were: Was this stent flexible? What was its radial strength? Did this stent brace itself against the wall with a strong strut network? What was the cell size and design?

Methods

From 6.2019 to 8.2020, 150 patients from 5 hospitals underwent PCI with a new VSTENT in 212 lesions. At the index PCI (D1), a subgroup of 61 patients (40%) was preselected to undergo additional imaging procedures including intravascular ultrasound (IVUS=41) or optical coherence tomography (OCT=20). All patients were followed-up clinically every month for one year. At 6 months (D180) they underwent digital subtraction angiography (DSA=143) or a second IVUS or OCT for the intravascular subgroup. The rate of invasive imaging follow-up was 95% for DSA, 92% for IVUS and 95% for OCT. The rate of major adverse cardiovascular events (MACE: mortality, in-stent restenosis (ISR), Target lesion revascularization (TLR) and data on radial strength, longitudinal flexibility, expansion and coverage were calculated.

Results

In all patients, the technical success was 100% (successful balloon inflation, complete stent expansion, uneventful balloon removal). The VSTENTs were deployed in arteries of all sizes: small with diameter (D) = 2.5mm in 11.3%, D= 2.75mm in 24.1%, and in large arteries D= or >3mm in 66.6% of patients. The stent length varied from 15–38mm with 80% >20mm. 92% had good apposition as evidenced by OCT or IVUS. There was no acute in-stent thrombus, no loss of side branch and no perforation. There was one cardiac arrest with successful resuscitation. The bench and angiographic data on radial strength, longitudinal flexibility, expansion and coverage were excellent

In Figure 1, The VSTENT design has open cells in the middle and closed cell at both distal segments. This design of mixed closed and open cell increases the radial strength at both ends while preventing the diametric difference (dog-boning effect)

In Figure 2, after deployment of a VSTENT, the size of the open cell design in the middle of the stent is approximately 3.40 mm2 while the size of the distal closed cells design is 1.7 mm2.

At 6 months, the rate of angiographic ISR inside the stent and within the 5 mm from the two ends was 3.5%. The rate of late lumen loss was 0.8mm in the in-stent segment and 0.07mm within 5mm of the two ends. The composite MACE was 4.7% with 1 mortality (0.7%) and 4 TLRs. At 36 months follow-up, only one TLR was reported.

Conclusions

At 3 years follow-up, the rate of angiographic ISR and TLR of the VSTENT was low. The data on radial strength, longitudinal flexibility, expansion and coverage were excellent. The VSTENT could be an affordable choice for interventional cardiology service in developing countries.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): United Healthcare

What are the ideal systolic and diastolic blood pressure which do not injure the intima of iliac and coronary arteries?

 

For patients with coronary artery disease, hypertension (HTN) is a major risk factor. How could uncontrolled HTN start atherosclerosis? In our prior research, laminar flow in coronary arteries prevented the formation of plaques while turbulent flow injured the intima and triggered atherosclerosis. In this present study our question was: Which blood pressure (BP) level is optimal in not producing turbulence and so not injuring the intima?

Methods

At first, a systolic BP<120mmHg and diastolic BP<75mmHg) were arbitrarily set as controlled (group A) while a BP of >160/105mmHg as uncontrolled (group B). All patients underwent a dynamic coronary angiogram recorded at 15 images/second or 0.06 seconds per image. The first image was of the index artery completely filled with contrast. In subsequent images the blood in white color moved in over a background of black contrast (Figure 1A). In 1B, 0.06 seconds later, the blood arrived at the mid segment (white arrow). In 1C, the flood moved forward, however there was darker contrast hanging at the mid segment, marking the location of collision from the retrograde against the antegrade flow (white arrow). The reason was that in uncontrolled BP the contraction of the left ventricle was stronger so in systole, the coronary blood could reverse its course, run on a retrograde direction, collide against the antegrade flow and create turbulence (1C).

At the end, before deploying a vascular closure device, an iliac angiogram was performed. In Figure 2, on a black background of contrast, the blood in white color moved forward with a pointed tip of laminar flow. 0.06 seconds later, the laminar tip was stopped abruptly with all the layers recoiling on each other like a falling stack of dominoes. In the next image. a large swirl of disorganized mixing of blood and contrast suggested the presence of turbulence caused by the collision.

The data to be collected were (1) the duration of the antegrade and retrograde flow, (2) duration of the collision (turbulence at the collision site)

Results

In the group A (BP <120/75 mmHg), 90% of 20 patients had no retrograde flow nor collision in the iliac and short collision in coronary arteries (<0.12 secs). In 30 patients of group B (BP >160/105 mmHg), the duration of retrograde flow and collision in the iliac artery were prolonged at >0.24 msecs. In the coronary arteries, the duration was prolonged at 0.18 msecs (all p<0.05 compared with group A). These locations of turbulence correlated with the location of plaques in our prior studies.

Conclusion

In patients with uncontrolled HTN, the retrograde flow was prolonged, and the turbulence was intense. In contrary, for patients with controlled BP, there was no retrograde flow and weaker collision in coronary arteries. The results suggest that a BP of <120/75 mmHg may not trigger the atherosclerotic process. New clinical trials with larger number of patients should be performed in search for the lowest ideal blood pressure.

Funding Acknowledgement

Type of funding sources: None.

NAV3 is a genetic determinant of myocardial recovery in dilated cardiomyopathy and attenuates cardiac fibrosis

Background

A genome-wide association study (GWAS) assessing change in left ventricular ejection fraction (LVEF) in dilated cardiomyopathy (DCM), a surrogate marker of morbidity and mortality in heart failure (HF), had not been performed previously and could provide insight into novel biological pathways that could lead to the development of new drugs that might target myocardial recovery. The presence and extent of cardiac fibrosis in DCM is independently associated with myocardial recovery and cardiovascular mortality.

Purpose

To identify the biological relevance of genetic targets that are associated with change in LVEF in patients with DCM.

Methods

A GWAS was performed using DNA from 686 patients with recent onset DCM who were on standard HF therapy using change in LVEF at a median of 6 months after initial diagnosis. Cultured human cardiac fibroblasts (HCFs) were used as an in vitro model to study the functional and biological relevance of the gene target identified in the GWAS. Specifically, HCFs were transfected with siRNA by using the Lipofectamine™ RNAiMAX Transfection Reagent for gene knockdown (KD). RNA-seq was performed using the Illumina TruSeq protocol with expression analysis conducted with the EdgeR package. Ingenuity Pathway Analysis was used.

Results

A single-nucleotide polymorphism, rs11105445(G>A), mapping to the neuron navigator 3 (NAV3) gene (rs11105445, p=2.37E-07; beta 2.74±0.53) was associated with improvement in LVEF. We performed a phenome-wide association study using data from the UK Biobank and demonstrated that genetic variation in NAV3 was significantly associated with HF mortality (p=3.2E-28), highlighting the potential importance of this gene in HF. Using GTEx data we demonstrated that in LV tissue the minor allele A was associated with ↓NAV3 expression (p=0.03) suggesting that ↓NAV3 expression might be associated with improvement in LVEF. We demonstrated that NAV3 KD significantly ↓TGF-β1 mediated HCF transdifferentiation into myofibroblasts, ↓α-smooth muscle actin (ACTA2) and ↓collagen I (COL1A1), therefore NAV3 KD was anti-fibrotic (see Figure 1), 1a. HCFs treated by vehicle/TGF-β1 after KD of NAV3/ctrl, and ACTA2 and COL1A1 were analyzed by qPCR; 1b. Representative immunofluorescence staining for α-SMA (in green), RNA-seq after NAV3 KD followed by pathway analysis suggested that NAV3 exerted its effect by regulating cell cycle related proteins (Figure 2), 2a. Volcano plot shows significant differentially expressed genes identified by RNA-seq analysis (down-regulated in blue, up-regulated in red); 2b. NAV3 KD significantly increased expression of cell cycle related proteins, which was validated by Western blot.

Conclusions

Decreased expression of NAV3 is associated with myocardial recovery in DCM, most likely due to its anti-fibrotic effect via direct regulation of cell cycle proteins. The role of NAV3 as a novel therapeutic target in DCM needs to be explored.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Mayo Clinic Center for Individualized MedicineMayo Clinic Department of Cardiovascular Medicine