P-082 Microfluidic-based device selects sperm with less DNA damage and higher motility, what else?

Study question

Does the microfluidic-based sperm selection device ZyMōt improve sperm parameters and other laboratory key performance indicator (KPI) values compared to the conventional swim-up method?

Summary answer

The microfluidic-based sperm selection device ZyMōt selects sperm with lower DNA fragmentation and higher motility than conventional swim-up method in intracytoplasmic sperm injection (ICSI) cycles.

What is known already

Elevated levels of sperm DNA fragmentation (SDF) in semen samples have been associated with poor embryo development and low pregnancy rates. SDF refers to breaks in the sperm's genetic material, mainly due to defects during spermatogenesis and other factors such as reactive oxygen species that are favored by centrifugation. Conventional sperm selection methods, by integrating centrifugation into their protocols, have become ineffective in selecting sperm with low SDF. In order to solve this problem and improve reproductive outcomes, microfluidic-based devices such as ZyMōt have been designed to avoid centrifugation and select spermatozoa with low SDF.

Study design, size, duration

Prospective, experimental, single-center study conducted from June to December 2021. A total of 14 couples with ≥ 10 retrieved oocytes were recruited for an intra-patient comparison. Semen sample was split and processed for ICSI by the conventional swim-up method or by the microfluidic-based device ZyMōt. Each fraction was used to fertilize half of the total number of oocytes retrieved. SDF index, semen parameters, useful blastocyst rate, fertilization rate and morphokinetic variables were observed.

Participants/materials, setting, methods

Oocytes retrieved were from own (n = 96) and donation cycles (n = 93). From each patient, the cohort of oocytes was divided into two groups: 1) inseminated with spermatozoa selected by swim-up and 2) inseminated with spermatozoa selected by ZyMōt 850 µL device. Embryo evaluation and development were then followed by time-lapse monitoring using EmbryoScope. Sperm chromatin dispersion (SCD) assay was used to measure SDF, analyzed by ImageJ. Each treatment followed routine protocol established in the clinical practice.

Main results and the role of chance

SDF index was significantly lower in ZyMōt group in comparison with swim-up group (10% vs 20%), indicating a better selection by the ZyMōt of sperm with less DNA breaks. Additionally, ZyMōt group also presented a significantly greater number of spermatozoa with progressive motility (96.9% vs 95.4%). In contrast, useful blastocyst rate showed a slightly, but not significantly, increment in ZyMōt group compared to swim-up group (53.2% vs 46.6%). No significant differences in fertilization rate or sperm recovery rate were observed between groups. Regarding morphokinetic parameters, timing variables from first cell division to blastocyst stage (t2-tB) showed no significant correlation with ZyMōt group contrasted with swim-up. Blastocysts were evaluated and a value was assigned with respect to their quality (A to D). There was a higher number of embryos with A grade in ZyMōt group and a higher number of embryos with D grade in swim-up group. The annotated variables were assessed using paired t-test and P value <0.05 was considered statistically significant.

Limitations, reasons for caution

The impact on reproductive outcomes may vary depending on whether the breakage is single- or double-stranded, however, SCD is not able to distinguish between them. These, together with the oocyte's ability to repair sperm damage, lead us to the explanation for the non-significance on embryo quality.

Wider implications of the findings

This study provides further insights into the use of ZyMōt for the selection of low SDF spermatozoa in a simple manner. Its use could be indicated in patients with a high SDF value in their semen samples. Benefits on reproductive outcome will be confirmed with larger sample size.

Trial registration number

2102-VLC-007-MD

O-145 Limitations of designing carrier screening panels based on estimated frequencies. Concordance between recommendations and observed frequencies

Study question

Are recommended carrier screening (CS) panels suitable worldwide or should they be designed taking into account observed carrier frequencies (CF)?

Summary answer

Limitations of carrier screening panel recommendations based on estimated frequencies could be avoided with a worldwide-database of observed carrier frequencies.

What is known already

Currently, there is no consensus for specific gene panel for CS, but some scientific societies, based on estimated carrier frequencies, recommend to analyze a narrow panel rather than exome. The American College of Medical Genetics and Genomics (ACMG) recently recommended a 4-tiered system, encouraging to analyze genes in tier 3, genes with less carrier frequency (tier 4) are only recommended to be analyzed on specific cases. Similarly, Sociedad Española de Fertilidad (SEF) recommends in absence of genetic matching (GM) a 6 gene basic panel for donor screening and in a GM context suggests a 50-diseases panel.

Study design, size, duration

This study includes 8542 patients analyzed with an expanded carrier screening panel of 300 genes, including autosomal recessive (AR) and X-linked (XL) disorders by next-generation sequencing (NGS). ACMG guidelines were followed for variant interpretation and only pathogenic and likely pathogenic variants were reported. The study has been conducted between August 2018 and December 2021.

Participants/materials, setting, methods

DNA was extracted and sequenced. Obtained data was processed by bioinformatic tools. CF for diseases analyzed was stablished. Genes were categorized according to tier-3 of the ACMG recommendations (112 genes, only 80 included on this study) and also by 50-disease panel of SEF recommendations (49 genes, 40 included on this study). Likewise, analyzed diseases were divided in two groups according to the obtained CF: A (CF ≤ 1/200 - 56 genes); B (CF > 1/200 - 244 genes).

Main results and the role of chance

The analysis of the 8542 patients showed that 2582 (30.23%) of them were not carriers of any disease analyzed, 2205 (25.81%) of them were only carriers of one or more of the diseases included in the ACMG tier3 panel and 3755 (43.96%) were carriers of at least one disease not included this category. 

When diseases analyzed were categorized by SEF 50-disease panel, 2280 (26.69%) patients were only carriers of one or more of the diseases included in this panel and 3680 (43.08%) were carriers of at least one disease that would not be analyzed by this panel.  

On the other hand, when diseases were divided by observed carrier frequency, a total of 3476 patients (40.69%) were carriers only of a disease(s) included in A group. With this panel, only 2484 (29.08%) of the 8542 patients would not have been correctly diagnosed. Moreover, the variants undetected would affect less frequent diseases (B group).

It is important to notice that group A has been created regarding the data of a 300 gene panel. If another panel would have been analyzed, the group of genes may have changed, but the data collected highlights the importance of observed CF on panel design.

Limitations, reasons for caution

Not all Tier3 ACMG and 50-disease SEF genes are included due to original panel limitations. Observed CF may vary depending on the population analyzed. NGS panel design does not cover variants in regulatory or deep intronic regions. Pseudogenes can interfere. Not all structural variants can be detected by NGS.

Wider implications of the findings

These data highlight the importance of reviewing the genes included in carrier screening panels by their frequency. Furthermore, it points out the need to have updated databases with observed CF available so an universal panel can be designed or adapted to patient’s needs.

Trial registration number

Not applicable

Mother and father depression symptoms and child emotional difficulties: a network model

Introduction

Enhancing understanding of depression symptom interactions between parents and associations with subsequent child emotional difficulties will inform targeted treatment of depression to prevent transmission within families.

Objectives

To use a network approach to identify ‘bridge’ symptoms that reinforce mother and father depression, and whether bridge symptoms, as well as other symptoms, impact subsequent child emotional difficulties.

Methods

Symptoms were examined using two unregularized partial correlation network models. The study included 4,492 mother-father-child trios from a prospective, population-based cohort in the United Kingdom. Mother and father reports of depression symptoms were assessed when the child was twenty-one months old. Child emotional difficulties were reported by the mother at ages nine, eleven and thirteen years.

Results

Bridge symptoms mutually reinforcing mother and father depression symptoms were feelings of guilt and self-harm ideation, whereas anhedonia acted as a bridge from the father to the mother, but not vice-versa (fig.1, network 1). The symptom of feelings of guilt in mothers was the only bridge symptom which directly associated with child emotional difficulties. Other symptoms that directly associated with child emotional difficulties were feeling overwhelmed for fathers and anhedonia, sadness, and panic in mothers (fig.1, network 2).

Conclusions

Specific symptom interactions are central to the co-occurrence of depression symptoms between parents. Of interest, only one of the bridge symptoms associated with later child emotional difficulties. In addition, specific symptom-to-child outcomes were identified, suggesting that different symptoms in mothers and fathers are central for increased vulnerability in children.

Disclosure

No significant relationships.

Nature-Based Early Childhood Education and Children's Physical Activity, Sedentary Behavior, Motor Competence, and Other Physical Health Outcomes: A Mixed-Methods Systematic Review

BACKGROUND

The purpose was to synthesize evidence on the association between nature-based Early Childhood Education (ECE) and children's physical activity (PA) and motor competence (MC).

METHODS

A literature search of 9 databases was concluded in August 2020. Studies were eligible if (1) children were aged 2-7 years old and attending ECE, (2) ECE settings integrated nature, and (3) assessed physical outcomes. Two reviewers independently screened full-text articles and assessed study quality. Synthesis was conducted using effect direction (quantitative), thematic analysis (qualitative), and combined using a results-based convergent synthesis.

RESULTS

1370 full-text articles were screened and 39 (31 quantitative and 8 qualitative) studies were eligible; 20 quantitative studies assessed PA and 6 assessed MC. Findings indicated inconsistent associations between nature-based ECE and increased moderate to vigorous PA, and improved speed/agility and object control skills. There were positive associations between nature-based ECE and reduced sedentary time and improved balance. From the qualitative analysis, nature-based ECE affords higher intensity PA and risky play, which could improve some MC domains. The quality of 28/31 studies was weak.

CONCLUSIONS

More controlled experimental designs that describe the dose and quality of nature are needed to better inform the effectiveness of nature-based ECE on PA and MC.

Fetoscopic Laser Ablation for Twin-to-Twin Transfusion Syndrome: A 15-year Review of Perinatal Survival

Objective Twin to twin transfusion syndrome (TTTS) complicates 5-15% of monochorionic twin pregnancies and untreated is associated with a 90% mortality rate. The aim was to present the perinatal survival of patients with TTTS treated with laser ablation, by a national fetal medicine team. Methods This was a review of all cases of TTTS treated with fetoscopic laser ablation performed from March 2006 through to December 2020. All patients treated with fetoscopic laser were identified from the hospital database. The perinatal outcomes for the overall cohort and the individual Quintero stages were determined. Results A total of 155 cases of TTTS underwent fetoscopic laser ablation during the study period. The median gestational age at diagnosis was 19+1 weeks, with a mean growth discordance of 23.6%. The Quintero stage at diagnosis was: Stage 1 6.5% (10/155), Stage 2 49% (76/155), Stage 3 38.7% (60/155), Stage 4 5.8% (9/155). There was at least one survivor in 83.2% (129/155) of pregnancies, with dual survival in 52.9% (82/155). An increase in the rate of any survivor was observed from 75% (2006-2014) to 94% (2014-2020) (p<0.05). Dual survival decreased with increasing Quintero Stage (p<0.05). 80.6% (125/155) of pregnancies delivered prior to 34+6 weeks gestation. Conclusion Fetoscopic laser ablation is the recommended first line treatment for severe TTTS. We observed a survival rate of at least one twin in 83.2% pregnancies which is comparable to internationally published data on single-centre outcomes.

A taxonomy of occupational and organisational stressors and protectors of mental health reported by veterinary professionals in Australasia

AIM

To develop a taxonomy of positive and negative occupational and organisational factors reported that impact the mental health of veterinary professionals.

METHODS

Veterinary professionals working in Australasia were surveyed between February and June of 2021. The survey comprised two questions related to participants' perceptions of the positive and negative aspects of their job role that impact their mental health and wellbeing. Reflexive thematic analysis was employed to analyse the responses and generate two taxonomies of occupational and organisation stressors and protectors reported by participants.

RESULTS

Fifty-three responses from veterinary professionals were analysed. The final stressor taxonomy generated contained 9 overarching themes and 36 subthemes. The most common of these were negative work conditions, challenging relationships with clients, and adverse events and patient outcomes. The taxonomy of protectors contained 11 overarching themes and 32 subthemes, with the most common including fulfillment and satisfaction, positive work conditions, and relationships with colleagues.

CONCLUSION

This study is the first to examine both positive and negative factors in the veterinary industry reported by veterinary professionals in Australasia. The results highlighted stressors that can be addressed on both an individual and organisational level to promote the mental and health well-being of professionals working in the animal care industry.

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

744 3 YEAR FOLLOW-UP OF SEDATIVE PRESCRIBING FOR RESPONSIVE BEHAVIOURS IN NURSING HOME RESIDENTS, AN IRISH STUDY

Introduction

Sedative medications are commonly prescribed for older adults; these include neuroleptics, benzodiazepines, opioids, ‘z’ drugs and trazadone. The prevalence of sedative drug prescriptions is increasing (1). Nursing home residents are three times more likely to be prescribed benzodiazepines (2). Regular medication review and education have been shown to reduce rates of sedative use in nursing homes (3). We previously demonstrated a significant reduction in prescription of these target medications at an Irish nursing home with specific focus, within scheduled medication reviews, on reduction or discontinuation of the target drugs in combination with education on management of Behavioural and Psychological symptoms (BPSD). This audit examines the prescribing patterns 3 years on from the initial audit.

Methods

Point prevalence study of sedative prescriptions and BPSD of all 95 nursing home residents on 6/5/21. Comparison with data from two previous audits in the same unit. All data was anonymised. Data analysed with SPSS statistical software.

Results

Sustained significant drop in quetiapine use from 30% of residents to 14% post-intervention in 2018 and three-year follow-up (p = 0.06). Borderline significant reduction in overall neuroleptics (from 39% to 25%, p = 0.06). Significant rise in ‘z’ drug prescription (from 8% to 17%, p = 0.03). BPSD reported in 33%, compared to 49% pre-intervention.

Conclusion

Regularly scheduled medication reviews can effectively rationalise sedative prescription rates in nursing home residents. Increasing ‘z’ drug prescription likely represents the appropriate replacement of neuroleptics. Reduced BPSD may be due to reporting bias of staff since regular education has been introduced or changing cohort of residents. References numbered above not included given limited word count.

A121 QUANTIFYING INTER-OBSERVER VARIABILITY IN THE SEGMENTATION OF RECTAL TUMORS IN ENDOSCOPY IMAGES AND ITS EFFECTS ON DEEP LEARNING

Background

Tumor delineation in endoscopy images is a crucial part of clinical diagnoses and treatment planning for rectal cancer patients. However, it is challenging to detect and adequately determine the size of tumors in these images, especially for inexperienced clinicians. This motivates the need for a standardized, automated segmentation method. While deep learning has proven to be a powerful tool for medical image segmentation, it requires a large quantity of high-quality annotated training data. Since the annotation of endoscopy images is prone to high inter-observer variability, creating a robust unbiased deep learning model for this task is challenging.

Aims

To quantify the inter-observer variability in the manual segmentation of tumors in endoscopy images of rectal cancer patients and investigate an automated approach using deep learning.

Methods

Three gastrointestinal physicians and radiation oncologists (G1, G2, and G3) segmented 2833 endoscopy images into tumor and non-tumor regions. The whole image classifications and the pixelwise classifications into tumor and non-tumor were compared to quantify the inter-observer variability. Each manual annotator is from a different institution.

Three different deep learning architectures (FCN32, U-Net, and SegNet) were trained on the binary contours created by G2. This naive approach investigates the effectiveness of neglecting any information about the uncertainty associated with the task of tumor delineation.

Finally, segmentations from G2 and the deep learning models’ predictions were compared against ground truth labels from G1 and G3, and accuracy, sensitivity, specificity, precision, and F1 scores were computed for images where both segmentations contained tumors.

Results

The deep-learning segmentation took less than 1 second, while manual segmentation took approximately 10 seconds per image. There was significant inter-observer variability for the whole-image classifications made by the manual annotators (Figure 1A). The segmentation scores achieved by the deep learning models (SegNet F1:0.80±0.08) were comparable to the inter-observer variability for the pixel-wise image classification (Figure 1B).

Conclusions

The large inter-observer variability observed in this study indicates a need for an automated segmentation tool for tumors in endoscopy images of rectal cancer patients. While deep learning models trained on a single observer’s labels can segment tumors with an accuracy similar to the inter-observer variability, these models do not accurately reflect the intrinsic uncertainty associated with tumor delineation. In our ongoing studies, we investigate training a model with all observers’ contours to reflect the uncertainty associated with the tumor segmentations.

Funding Agencies

CIHRNSERC

COVID-19 reinfection after pregnancy

Background

There have been reports of COVID-19 reinfections, but the immunological characterization of these cases is partial. We report a case of reinfection with SARS-CoV-2, where the first infection occurred in the course of late pregnancy.

Case presentation

On May 27, 2020, a 37-year-old woman gave birth at full term, 3 hours after full dilatation. She developed fever (38.3 °C) after delivery. Mild biological anomalies compatible with COVID-19 were observed: lymphopenia, thrombocytopenia, elevated D-Dimers, CRP, and LDH. At 6-month follow-up, she reported having contracted COVID-19 with high fever, rhinorrhea, hand frostbites, cough, headache, dysgeusia and anosmia.

Conclusions

We report a case of COVID-19 reinfection with a first mild infection during late pregnancy and a more aggressive second infection 5 months later.

Low dose thioguanine guided by therapeutic drug monitoring is a safe and effective alternative in inflammatory bowel disease patients intolerant to conventional thiopurines

BACKGROUND AND AIMS

Thioguanine is an alternative thiopurine for IBD patients. We evaluated the short-term efficacy and safety of low dose therapeutic drug monitored (TDM) thioguanine.

METHODS

A retrospective evaluation of IBD patients intolerant to conventional thiopurines started on thioguanine from 2017-2019 with dosing guided by TDM was conducted. Clinical response was defined for Ulcerative colitis (UC) as a reduction of partial MAYO score ≥ 3 with reduction in rectal bleeding score of at least 1 and a final rectal bleeding sub score of 0-1 at week 12 of therapy. Crohn's disease (CD) response was defined as a reduction of Harvey-Bradshaw index ≥ 3 (HBI) at week 12 of therapy. Remission was defined in UC as partial MAYO score of < 2 and in CD as HBI score of < 5.

RESULTS

46 patients were included in the study. The median thioguanine dose was 20 mg/day (SD 7.3, range: 10-40 mg/day) with a median 6-TGN level of 564 pmol/8×108 (IQR 517) for CD and 672 pmol/8×108 (IQR 349) for UC. The overall clinical response rate was 62% (13/21), intention to treat (ITT). Maintenance of remission was 76% (19/25, ITT). 37% (17/46) of patients experienced an adverse effect. No early cases of NRH were seen.

CONCLUSION

Thioguanine was tolerated well in 63% of patients. Clinical response was seen in 62 % of and maintenance of remission was high at 76 %. No cases of early NRH were seen. Longer-term follow-up is required to ensure safety and to assess durability of response. This article is protected by copyright. All rights reserved.

Evolution of COVID-19 mortality over time: results from the Swiss hospital surveillance system (CH-SUR)

BACKGROUND

When the periods of time during and after the first wave of the ongoing SARS-CoV-2/COVID-19 pandemic in Europe are compared, the associated COVID-19 mortality seems to have decreased substantially. Various factors could explain this trend, including changes in demographic characteristics of infected persons and the improvement of case management. To date, no study has been performed to investigate the evolution of COVID-19 in-hospital mortality in Switzerland, while also accounting for risk factors.

METHODS

We investigated the trends in COVID-19-related mortality (in-hospital and in-intermediate/intensive-care) over time in Switzerland, from February 2020 to June 2021, comparing in particular the first and the second wave. We used data from the COVID-19 Hospital-based Surveillance (CH-SUR) database. We performed survival analyses adjusting for well-known risk factors of COVID-19 mortality (age, sex and comorbidities) and accounting for competing risk.

RESULTS

Our analysis included 16,984 patients recorded in CH-SUR, with 2201 reported deaths due to COVID-19 (13.0%). We found that overall in-hospital mortality was lower during the second wave of COVID-19 than in the first wave (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.63- 0.78; p <0.001), a decrease apparently not explained by changes in demographic characteristics of patients. In contrast, mortality in intermediate and intensive care significantly increased in the second wave compared with the first wave (HR 1.25, 95% CI 1.05-1.49; p = 0.029), with significant changes in the course of hospitalisation between the first and the second wave.

CONCLUSION

We found that, in Switzerland, COVID-19 mortality decreased among hospitalised persons, whereas it increased among patients admitted to intermediate or intensive care, when comparing the second wave to the first wave. We put our findings in perspective with changes over time in case management, treatment strategy, hospital burden and non-pharmaceutical interventions. Further analyses of the potential effect of virus variants and of vaccination on mortality would be crucial to have a complete overview of COVID-19 mortality trends throughout the different phases of the pandemic.

98 SCHEDULED MEDICATION REVIEWS AND EDUCATION ON SEDATIVE PRESCRIBING FOR RESPONSIVE BEHAVIOURS IN NURSING HOME RESIDENTS, A 3 YEAR FOLLOW-UP STUDY

Background

Sedative medications including neuroleptics, benzodiazepines, opioids, ‘z’ drugs and trazadone are commonly prescribed for older adults. Nursing home residents are three times more likely to be prescribed benzodiazepines. Sedative medications are associated with significant risks including falls and delirium in older adults. Neuroleptics also increase risk of cerebrovascular disease and functional decline. Regular medication review and education have been shown to reduce rates of sedative use in nursing homes. Scheduled medication reviews were introduced in an Irish nursing home with a specific focus on reduction or discontinuation of these target medications in combination with education of management of Behavioural and Psychological symptoms (BPSD). We demonstrated previously a significant reduction in prescribing following these interventions. This audit examines the prescribing patterns 3 years on from the initial audit.

Methods

Point prevalence study of sedative prescriptions and BPSD on 6/5/21 of all 95 nursing home residents. Data compared with two preceding audits in 2018 in the same unit. All data anonymised. Data analysed with SPSS statistical software.

Results

Significant reduction in quetiapine use sustained from 30% of residents pre-intervention to 14% post-intervention in 2018 and 2021 (p = 0.06).

Neuroleptic prescription reduced from 39% to 25% (p = 0.06).

‘Z’ drug prescribing increased from 8% to 17% (p = 0.03).

33% of residents had BPSD reported compared to 49% pre-intervention.

Conclusion

3 year follow-up showed regularly scheduled medication reviews and education in a nursing home can effectively rationalise sedative prescription rates. Sustained reduction in neuroleptics and increased ‘z’ drug prescriptions may represent appropriate replacement. Reduced BPSD may be due to changing nursing home resident cohort or reporting bias of staff since the introduction of regular education.

Novel cryoballoon to isolate pulmonary veins in patients with paroxysmal atrial fibrillation: one-year outcomes in a multicenter study

Background

Recently, a novel cryoballoon (CB; POLARx) has been developed with increased steerability which maintains size and pressure throughout the ablation. Initial clinical data has demonstrated acute procedural safety and efficacy in de novo pulmonary vein isolation (PVI) procedures in patients with paroxysmal atrial fibrillation (AF). However, there are limited studies demonstrating the long-term efficacy of the CB.

Purpose

To evaluate the long-term safety and efficacy of the novel CB in treating paroxysmal AF.

Methods

This was a non-randomized, prospective, multi-center study. Fifty-eight consecutive patients with paroxysmal AF were enrolled at 4 centers for de novo PVI procedures. Cryoablation was delivered for 180s if time to isolation was ≤60s. Otherwise a 240s cryoablation was performed. PVI was confirmed with entrance and exit block testing. Patients were followed for 1 year with 24-hour Holter monitoring at 3, 6, and 12 months. After a 3-month blanking period, recurrence was defined as having any documented, symptomatic episode(s) of AF or atrial tachycardia.

Results

Acute isolation with the CB was achieved in 230 of 231 pulmonary veins (99.6%) with 5.2±1.5 cryoapplications per patient (1.3±0.6 cryoapplications per vein). There were 4 patients (6.9%) with phrenic nerve injury (3 resolved during the index procedure; 1 resolved at 6 months follow-up). One serious adverse device event was reported: femoral arterial embolism event occurring 2 weeks post index procedure (1.7%). Of the 56 patients that had complete 12-month follow-up, 43 (76.8%) were free from recurrent atrial arrhythmias.

Conclusion

Initial multicenter clinical experience with the novel CB has demonstrated long-term safety and efficacy of PVI in patients with paroxysmal AF. Further studies are underway to confirm these findings.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boston Scientific

Transcriptome-wide Gene Expression Analysis in Peri-implantitis Reveals Candidate Cellular Pathways

OBJECTIVE

Peri-implantitis is a condition resulting in destructive inflammation in the peri-implant soft tissue barrier. Clinically, it demonstrates vast clinical differences to periodontitis that suggest distinct inflammatory mechanisms. Implant-derived titanium particles (i-TiPs) frequently found around diseased implants appear to alter the microenvironment and confer resistance to antibiotic treatments. Studies in orthopedic implants have demonstrated potent inflammatory responses to i-TiPs involving a variety of cell types in aseptic conditions. Nonetheless, the genetic programs of cells surveilling and supporting the peri-implant soft tissue barrier in response to the combined challenges of biomaterial degradation products and oral bacteria are poorly defined. Thus, we studied gene expression specific to oral peri-implant inflammatory disease.

METHODS

Peri-implant tissues were collected from healthy or diseased implants (N = 10) according to the 2018 classification criteria. Following RNA extraction and purification, a gene-level view of the transcriptome was obtained via a next-generation transcriptome-wide microarray profiling workflow (Clariom S; Applied Biosystems) that covers >20,000 well-annotated genes. A discovery analysis assessed global differential expression of genes and identified pathways in peri-implant health versus disease.

RESULTS

Genes involved in the endosomal-lysosomal pathway, such as actin polymerization, were strongly upregulated in diseased tissues (P < .05), proposing increased intracellular activities in response to bacteria and i-TiPs. Cellular respiration pathways involved in oxidative stress were highly transcribed in all peri-implant samples, suggesting that implant-specific factors may trigger a constant state of oxidative stress.

CONCLUSION

Within the limitations of this discovery study, expressive upregulation of genes in the endosomal-lysosomal and oxidative stress pathway suggests that inflammation related to receptor-driven responses to extracellular signals, such as i-TiPs and pathogens, may have a crucial role in peri-implantitis. Results warrant external replication in validation cohorts.

KNOWLEDGE TRANSFER STATEMENT

Our findings regarding physiologic processes affected by peri-implantitis could advance knowledge of the mechanisms and consequences of the disease. Understanding the cellular programs that partake in peri-implant inflammation has the potential to translate to novel treatment strategies for patients with peri-implantitis.