β-Cell-Specific E2f1 Deficiency Impairs Glucose Homeostasis, β-Cell Identity, and Insulin Secretion

The loss of pancreatic β-cell identity has emerged as an important feature of type 2 diabetes development, but the molecular mechanisms are still elusive. Here, we explore the cell-autonomous role of the cell-cycle regulator and transcription factor E2F1 in the maintenance of β-cell identity, insulin secretion, and glucose homeostasis. We show that the β-cell-specific loss of E2f1 function in mice triggers glucose intolerance associated with defective insulin secretion, altered endocrine cell mass, downregulation of many β-cell genes, and concomitant increase of non-β-cell markers. Mechanistically, epigenomic profiling of the promoters of these non-β-cell upregulated genes identified an enrichment of bivalent H3K4me3/H3K27me3 or H3K27me3 marks. Conversely, promoters of downregulated genes were enriched in active chromatin H3K4me3 and H3K27ac histone marks. We find that specific E2f1 transcriptional, cistromic, and epigenomic signatures are associated with these β-cell dysfunctions, with E2F1 directly regulating several β-cell genes at the chromatin level. Finally, the pharmacological inhibition of E2F transcriptional activity in human islets also impairs insulin secretion and the expression of β-cell identity genes. Our data suggest that E2F1 is critical for maintaining β-cell identity and function through sustained control of β-cell and non-β-cell transcriptional programs.

ARTICLE HIGHLIGHTS

β-Cell-specific E2f1 deficiency in mice impairs glucose tolerance. Loss of E2f1 function alters the ratio of α- to β-cells but does not trigger β-cell conversion into α-cells. Pharmacological inhibition of E2F activity inhibits glucose-stimulated insulin secretion and alters β- and α-cell gene expression in human islets. E2F1 maintains β-cell function and identity through control of transcriptomic and epigenetic programs.

Pharmacological HDAC inhibition impairs pancreatic β-cell function through an epigenome-wide reprogramming

Histone deacetylases enzymes (HDACs) are chromatin modifiers that regulate gene expression through deacetylation of lysine residues within specific histone and non-histone proteins. A cell-specific gene expression pattern defines the identity of insulin-producing pancreatic β cells, yet molecular networks driving this transcriptional specificity are not fully understood. Here, we investigated the HDAC-dependent molecular mechanisms controlling pancreatic β-cell identity and function using the pan-HDAC inhibitor trichostatin A through chromatin immunoprecipitation assays and RNA sequencing experiments. We observed that TSA alters insulin secretion associated with β-cell specific transcriptome programming in both mouse and human β-cell lines, as well as on human pancreatic islets. We also demonstrated that this alternative β-cell transcriptional program in response to HDAC inhibition is related to an epigenome-wide remodeling at both promoters and enhancers. Our data indicate that HDAC activity could be required to protect against loss of β-cell identity with unsuitable expression of genes associated with alternative cell fates.

Aortic valve replacement for aortic stenosis in France – influence of centers' volumes on TAVR adoption rate and outcomes

Aims

Over the last decade, transcatheter aortic valve replacement (TAVR) became extensively used, now being the recommended as first line procedure for aortic valve replacement (AVR) in selected patients' populations. It is unknown whether TAVR adoption rate and variability in outcomes is influenced by centers' volume.

Methods

From a French administrative hospital-discharge database, we collected all AVR performed in France between 2007 and 2019. Centers were stratified to terciles based on their annual SAVR per year per center during 2007–2009 (“pre TAVR era”).

Results

There was 218,489 AVRs (153,747 SAVR and 74,732 TAVR) performed in 46 centers between 2007–2019. Number of total AVR and even more so number of number of TAVR significantly and linearly increased from 2007 to 2019 in all terciles but faster in the high volume tercile (+17, +17 and +31 AVR/center/year in the low, middle and high terciles respectively, P [ANCOVA]<0.001; +11, + 19 and +33 TAVR/center/year in the low, medium and high tercile respectively, P [ANCOVA] <0.00, Figure 1). The age of patients underwent TAVR remained grossly unchanged in all three terciles, however, the Charlson index declined from 2010 to 2019 (from 1.35±1.42 to 0.65±1.04, from 1.21±1.40 to 0.65±1.05 and from 1.53±1.58 to 0.81±1.21, in the low, middle and high terciles, P for trend <0.001, 0.021, and <0.001, respectively). Charlson score in the years 2017–2019, was higher in the high than middle and low terciles (0.87±1.22, 0.76±1.11 and 0.65±1.04, respectively, P<0.0001). The in-hospital mortality rate for TAVR significantly declined from 2010 to 2019 for TAVR in all terciles (from 8.3% to 2.1%, from 7.5% to 2.5% and from 8.2% to 2.1% for low, middle and high TAVR terciles, respectively; p for trend = 0.002, 0.001 and <0.001, respectively, Figure 2). Average mortality in 2017–2019 was similar in all terciles (2.3%, 2.5% and 2.2% for low, middle and high terciles, respectively, P=0.47). After adjusting for age, sex and Charlson score, mortality was higher in the low tercile compared with middle and high terciles (OR 1.15, P<0.001, confidence interval [CI] 1.0–1.2, and OR 1.18, P<0.001, CI 1.1–1.2, respectively).

Conclusions

From 2007 to 2019 total AVR linearly increased, mostly due to increase in TAVR, irrespective of centers' volume, but increase rate was higher in high volume centers. A constant decline in patients risk profile, with a striking decrease in mortality rate, was observed in all volume terciles. High-volume centers patients' have higher risk profile, with adjusted mortality slightly lower than medium and low volume centers.

Funding Acknowledgement

Type of funding sources: None.

Epigenetic and Transcriptomic Programming of HSC Quiescence Signaling in Large for Gestational Age Neonates

Excessive fetal growth is associated with DNA methylation alterations in human hematopoietic stem and progenitor cells (HSPC), but their functional impact remains elusive. We implemented an integrative analysis combining single-cell epigenomics, single-cell transcriptomics, and in vitro analyses to functionally link DNA methylation changes to putative alterations of HSPC functions. We showed in hematopoietic stem cells (HSC) from large for gestational age neonates that both DNA hypermethylation and chromatin rearrangements target a specific network of transcription factors known to sustain stem cell quiescence. In parallel, we found a decreased expression of key genes regulating HSC differentiation including EGR1, KLF2, SOCS3, and JUNB. Our functional analyses showed that this epigenetic programming was associated with a decreased ability for HSCs to remain quiescent. Taken together, our multimodal approach using single-cell (epi)genomics showed that human fetal overgrowth affects hematopoietic stem cells' quiescence signaling via epigenetic programming.

Rare Variant Analysis of Obesity-Associated Genes in Young Adults With Severe Obesity From a Consanguineous Population of Pakistan

Recent advances in genetic analysis have significantly helped in progressively attenuating the heritability gap of obesity and have brought into focus monogenic variants that disrupt the melanocortin signaling. In a previous study, next-generation sequencing revealed a monogenic etiology in ∼50% of the children with severe obesity from a consanguineous population in Pakistan. Here we assess rare variants in obesity-causing genes in young adults with severe obesity from the same region. Genomic DNA from 126 randomly selected young adult obese subjects (BMI 37.2 ± 0.3 kg/m2; age 18.4 ± 0.3 years) was screened by conventional or augmented whole-exome analysis for point mutations and copy number variants (CNVs). Leptin, insulin, and cortisol levels were measured by ELISA. We identified 13 subjects carrying 13 different pathogenic or likely pathogenic variants in LEPR, PCSK1, MC4R, NTRK2, POMC, SH2B1, and SIM1. We also identified for the first time in the human, two homozygous stop-gain mutations in ASNSD1 and IFI16 genes. Inactivation of these genes in mouse models has been shown to result in obesity. Additionally, we describe nine homozygous mutations (seven missense, one stop-gain, and one stop-loss) and four copy-loss CNVs in genes or genomic regions previously linked to obesity-associated traits by genome-wide association studies. Unexpectedly, in contrast to obese children, pathogenic mutations in LEP and LEPR were either absent or rare in this cohort of young adults. High morbidity and mortality risks and social disadvantage of children with LEP or LEPR deficiency may in part explain this difference between the two cohorts.

Compound genetic etiology in a patient with a syndrome including diabetes, intellectual deficiency and distichiasis

BACKGROUND

We studied a young woman with atypical diabetes associated with mild intellectual disability, lymphedema distichiasis syndrome (LDS) and polymalformative syndrome including distichiasis. We used different genetic tools to identify causative pathogenic mutations and/or copy number variations.

RESULTS

Although proband's, diabetes mellitus occurred during childhood, type 1 diabetes was unlikely due to the absence of detectable autoimmunity. DNA microarray analysis first identified a de novo, heterozygous deletion at the chr16q24.2 locus. Previously, thirty-three pathogenic or likely pathogenic deletions encompassing this locus have been reported in patients presenting with intellectual deficiency, obesity and/or lymphedema but not with diabetes. Of note, the deletion encompassed two topological association domains, whose one included FOXC2 that is known to be linked with LDS. Via whole-exome sequencing, we found a heterozygous, likely pathogenic variant in WFS1 (encoding wolframin endoplasmic reticulum [ER] transmembrane glycoprotein) which was inherited from her father who also had diabetes. WFS1 is known to be involved in monogenic diabetes. We also found a likely pathogenic variant in USP9X (encoding ubiquitin specific peptidase 9 X-linked) that is involved in X-linked intellectual disability, which was inherited from her mother who had dyscalculia and dyspraxia.

CONCLUSIONS

Our comprehensive genetic analysis suggested that the peculiar phenotypes of our patient were possibly due to the combination of multiple genetic causes including chr16q24.2 deletion, and two likely pathogenic variants in WFS1 and USP9X.

Dominant negative mutation in oxalate transporter SLC26A6 associated with enteric hyperoxaluria and nephrolithiasis

Background

Nephrolithiasis (NL) is a complex multifactorial disease affecting up to 10%–20% of the human population and causing a significant burden on public health systems worldwide. It results from a combination of environmental and genetic factors. Hyperoxaluria is a major risk factor for NL.

Methods

We used a whole exome-based approach in a patient with calcium oxalate NL. The effects of the mutation were characterised using cell culture and in silico analyses.

Results

We identified a rare heterozygous missense mutation (c.1519C>T/p.R507W) in the SLC26A6 gene that encodes a secretory oxalate transporter. This mutation cosegregated with hyperoxaluria in the family. In vitro characterisation of mutant SLC26A6 demonstrated that Cl⁻-dependent oxalate transport was dramatically reduced because the mutation affects both SLC26A6 transport activity and membrane surface expression. Cotransfection studies demonstrated strong dominant-negative effects of the mutant on the wild-type protein indicating that the phenotype of patients heterozygous for this mutation may be more severe than predicted by haploinsufficiency alone.

Conclusion

Our study is in line with previous observations made in the mouse showing that SLC26A6 inactivation can cause inherited enteric hyperoxaluria with calcium oxalate NL. Consistent with an enteric form of hyperoxaluria, we observed a beneficial effect of increasing calcium in the patient’s diet to reduce urinary oxalate excretion.

[stent thrombosis : A won battle ? (data from the France PCI registry)]

GOAL

The aim of the study is to assess the incidence, risk factors and prognosis of definite stent thrombosis (ST) at 1 year in the France PCI multicenter prospective registry.

PATIENTS AND METHODS

Only patients who underwent coronary angioplasty with at least one stent implantation between 1^st January 2014 and 31 December 2019 were included. The population was separated into 2 groups: the "ST" group with stent thrombosis and the "control" group without stent thrombosis.

RESULTS

35,435 patients were included. 256 patients (0.72%) presented a ST at 1 year. The rate of ST decreased significantly in acute coronary syndrome (1.5% in 2014 vs. 0.73% in 2019; p = 0.05) but not in chronic coronary syndrome (0.46% in 2014 vs 0.40%; p = 0.98). The risk factors are young age (65.8 years vs 68.2; p = 0.002), clinical context (35.27% vs 16.68%; p = 0.0001), diabetes (35.2 % vs 26.4%; p = 0.002), renal failure (11.7% vs 8%; p = 0.009) and history of coronary angioplasty (28.63% vs 21.86%; p = 0.009) and peripheral arterial disease (14.5% vs 10.1%; p = 0.021), LV dysfunction (37% vs 27.5%; p = 0.003), mean length (39.6 mm vs 31, 7mm; p <0.0001) and the mean number of stents per procedure (1.9 vs 1.6; p <0.0001), a TIMI flow ≤1 pre procedure (21.5% vs 12.4%; p <0.0001) and an intrastent restenosis (11% vs 6%; p <0.0001). The 1-year mortality of the ST group was significantly higher than that of the control group (19.14% vs 5.82%; p <0.0001).

CONCLUSION

Since 2014, the incidence of ST at 1 year has been decreasing but remains stuck at a floor level of 0.54% in 2019. The battle for ST seems to have been partly won and its risk factors well identified, but its mortality is still high.

Right ventricular dysfunction before transcatheter aortic valve implantation: incidence, predictive factors and prognostic impact

Background

Right ventricular dysfunction (RVD) is considered to be a late marker of advanced aortic stenosis (AS) and is associated with poor prognosis. Currently. there are conflicting data on the impact of RVD on clinical outcomes in patients with severe AS treated with TAVI. Moreover, few studies have studied the evolution (recovery or persistence) of RVD and its prognostic impact.

Objectives

To assess the incidence and predictive factors of RVD before TAVI, its prognostic impact and its evolution after TAVI.

Methods

All patients treated with TAVI for severe AS were included in a prospective single center database. Only patients who had a quantitative assessment of RV including Tricuspid Annular Plane Systolic Excursion (TAPSE) and/or doppler tissue imaging-derived tricuspid lateral annular systolic velocity (S') measurements, were eligible to this study. RVD was defined by a TAPSE &lt;17 mm or S' &lt;9.5 cm/s if TAPSE was not available.

Results

Between May 2014 and April 2019, 503 patients with RV function evaluation were included. Incidence of RVD before TAVI was 18.7%. Predictors of RVD were diabetes (P=0.03), atrial fibrillation (P=0.001), altered left ventricular ejection fraction (P&lt;0.0001), left ventricular dilatation (P=0.007), and previous cardiac surgery (P=0.002). Long-term survival was altered in patients with RVD before TAVI as compared to those without RVD (HR 1.97, 95% CI: 1.1–3.4, P=0.01). One year after TAVI, 58.7% of patients with baseline RVD had a normal RV function and had similar outcome as compared to those without RVD at baseline. In contrast, patients with persistent RVD had the worst prognosis.

Conclusions

RVD is not rare and has a deleterious prognostic impact in patients treated by TAVI. Recovery of normal RV function is frequent after TAVI whereas persistence of RVD is associated with poor outcomes.

Funding Acknowledgement

Type of funding sources: None.

Monogenic diabetes characteristics in a transnational multicenter study from Mediterranean countries

BACKGROUND

Diagnosis of monogenic diabetes has important clinical implications for treatment and health expenditure. However, its prevalence remains to be specified in many countries, particularly from South Europe, North Africa and Middle-East, where non-autoimmune diabetes in young adults is increasing dramatically.

AIMS

To identify cases of monogenic diabetes in young adults from Mediterranean countries and assess the specificities between countries.

METHODS

We conducted a transnational multicenter study based on exome sequencing in 204 unrelated patients with diabetes (age-at-diagnosis: 26.1 ± 9.1 years). Rare coding variants in 35 targeted genes were evaluated for pathogenicity. Data were analyzed using one-way ANOVA, chi-squared test and factor analysis of mixed data.

RESULTS

Forty pathogenic or likely pathogenic variants, 14 of which novel, were identified in 36 patients yielding a genetic diagnosis rate of 17.6%. The majority of cases were due to GCK, HNF1A, ABCC8 and HNF4A variants. We observed highly variable diagnosis rates according to countries, with association to genetic ancestry. Lower body mass index and HbA1c at study inclusion, and less frequent insulin treatment were hallmarks of pathogenic variant carriers. Treatment changes following genetic diagnosis have been made in several patients.

CONCLUSIONS

Our data from patients in several Mediterranean countries highlight a broad clinical and genetic spectrum of diabetes, showing the relevance of wide genetic testing for personalized care of early-onset diabetes.

Assessment of long-term structural deterioration of transcatheter aortic bioprosthetic valves

Background

The durability of transcatheter aortic bioprosthetic valves is a crucial issue in the context of extension of indications in younger and lower-risk patients, but data are scarce, especially beyond 5 years of follow-up. This study sought to evaluate the incidence of structural valve degeneration (SVD) 5 to 10 years post-procedure.

Methods

Demographic, procedural, and in-hospital outcome data on patients who underwent transcatheter aortic valve implantation (TAVI) from 2002 to 2014 were obtained from our prospective institutional database. Patients in whom echocardiographic data were available both at baseline and 5 years post-TAVI were included. Clinical and echocardiographic follow-up were performed on site annually. Hemodynamic SVD was determined according to European task force committee guidelines.

Results

A total of 208 patients (82.5±7.6 years of age; 53% female) with paired post-procedure and late echocardiographic follow-up (median 5.3 years, range 5 to 11.4 years) were included. Eleven (5.3%) patients were treated with a self-expandable valve and 197 (94.7%) patients with a balloon-expandable valve. Mean aortic valve gradient and effective aortic valve area remained unchanged during follow-up. There were 2 cases (1.0%) of severe SVD 6 and 7 years after implantation requiring redo-TAVI. There were 4 cases (1.9%) of moderate SVD (mean 6.0 years post-implantation; range 5 to 7 years).

Conclusions

Our data do not demonstrate any alarm on transcatheter aortic valve durability. Careful prospective assessment in younger and lower risk patients and comparison with surgical bioprosthetic valves are required to further assess long-term durability of transcatheter valves.

Funding Acknowledgement

Type of funding source: None

Pathogenic variants in actionable MODY genes are associated with type 2 diabetes

Genome-wide association studies have identified 240 independent loci associated with type 2 diabetes (T2D) risk, but this knowledge has not advanced precision medicine. In contrast, the genetic diagnosis of monogenic forms of diabetes (including maturity-onset diabetes of the young (MODY)) are textbook cases of genomic medicine. Recent studies trying to bridge the gap between monogenic diabetes and T2D have been inconclusive. Here, we show a significant burden of pathogenic variants in genes linked with monogenic diabetes among people with common T2D, particularly in actionable MODY genes, thus implying that there should be a substantial change in care for carriers with T2D. We show that, among 74,629 individuals, this burden is probably driven by the pathogenic variants found in GCK, and to a lesser extent in HNF4A, KCNJ11, HNF1B and ABCC8. The carriers with T2D are leaner, which evidences a functional metabolic effect of these mutations. Pathogenic variants in actionable MODY genes are more frequent than was previously expected in common T2D. These results open avenues for future interventions assessing the clinical interest of these pathogenic mutations in precision medicine.

Dry heat and microwave-generated steam protocols for the rapid decontamination of respiratory personal protective equipment in response to COVID-19-related shortages

BACKGROUND

In the wake of the SARS-CoV-2 pandemic and unprecedented global demand, clinicians are struggling to source adequate access to personal protective equipment. Respirators can be in short supply, though are necessary to protect workers from SARS-CoV-2 exposure. Rapid decontamination and reuse of respirators may provide relief for the strained procurement situation.

METHOD

In this study, we investigated the suitability of 70°C dry heat and microwave-generated steam (MGS) for reprocessing of FFP2/N95-type respirators, and Type-II surgical face masks. Staphylococcus aureus was used as a surrogate as it is less susceptible than enveloped viruses to chemical and physical processes.

RESULTS

We observed >4 log10 reductions in the viability of dry S. aureus treated by dry heat for 90 min at 70°C and >6 log10 reductions by MGS for 90 s. After 3 reprocessing cycles, neither process was found to negatively impact the bacterial or NaCl filtration efficiency of the respirators that were tested. However, MGS was incompatible with Type-II surgical masks tested, as we confirmed that bacterial filtration capacity was completely lost following reprocessing. MGS was observed to be incompatible with some respirator types due to arcing observed around some types of metal nose clips and by loss of adhesion of clips to the mask.

CONCLUSION

Considering the advantages and disadvantages of each approach, we propose a reprocessing personal protective equipment/face mask workflow for use in medical areas.

Genetic Causes of Severe Childhood Obesity: A Remarkably High Prevalence in an Inbred Population of Pakistan

Monogenic forms of obesity have been identified in ≤10% of severely obese European patients. However, the overall spectrum of deleterious variants (point mutations and structural variants) responsible for childhood severe obesity remains elusive. In this study, we genetically screened 225 severely obese children from consanguineous Pakistani families through a combination of techniques, including an in-house-developed augmented whole-exome sequencing method (CoDE-seq) that enables simultaneous detection of whole-exome copy number variations (CNVs) and point mutations in coding regions. We identified 110 (49%) probands carrying 55 different pathogenic point mutations and CNVs in 13 genes/loci responsible for nonsyndromic and syndromic monofactorial obesity. CoDE-seq also identified 28 rare or novel CNVs associated with intellectual disability in 22 additional obese subjects (10%). Additionally, we highlight variants in candidate genes for obesity warranting further investigation. Altogether, 59% of cases in the studied cohort are likely to have a discrete genetic cause, with 13% of these as a result of CNVs, demonstrating a remarkably higher prevalence of monofactorial obesity than hitherto reported and a plausible overlapping of obesity and intellectual disabilities in several cases. Finally, inbred populations with a high prevalence of obesity provide unique, genetically enriched material in the quest of new genes/variants influencing energy balance.

Predictive Value for Outcome and Evolution of Geriatric Parameters after Transcatheter Aortic Valve Implantation

OBJECTIVES

To identify parameters of comprehensive geriatric assessment (CGA) CGA including ABCDEF score, a multidomain frailty assessment, associated with poor outcome after TAVI and to assess the evolution of CGA parameters at 6-months follow-up.

DESIGN

one-year monocentric prospective cohort study.

SETTING

Departments of geriatric medicine and cardiology in Rouen University Hospital, Normandy, France.

PARTICIPANTS

all patients over 70, selected for TAVI by a multidisciplinary "heart team".

MEASUREMENTS

8-areas CGA was performed before TAVI and at 6-months follow-up. Poor outcome was defined as decrease in 1 BADL or unplanned readmission at 6 months or death within the first year after TAVI. Geriatric characteristics associated with poor outcome were assessed by logistic regression with surgical scores as bivariable. Geriatric characteristics were compared between baseline and 6-months follow-up.

RESULTS

114 patients (mean age 85.8±5.3 years) were included. Mean EuroSCORE was 19.1±10.6%. Poor outcome occurred in 57(50.0%) patients. Loss of one BADL (OR:1.66, 95CI[1.11-2.48]), decrease in IADL (OR:1.41, 95CI[1.14-1.74]), in plasmatic albumin (OR:1.10, 95CI[1.01-1.20]), in MMSe (OR:1.13, 95CI[1.02-1.26]), low walking speed (OR:1.53, 95CI[1.01-2.33]) and ABCDEF score ≥2 (OR:1.63, 95CI[1.09-2.42]) were independently associated with poor outcome. In survivors with complete follow-up (n=80), most geriatric parameters were maintained 6 months after TAVI, but IADL decreased (5.6±1.9 to 4.9±2.2, p<0.001). MMSe increased in patients with previous cognitive impairments whereas it decreased in those without (p<0.001).

CONCLUSION

CGA parameters are independently associated with poor outcome after TAVI. These parameters, but IADL, are maintained at 6 months and course of the MMSe depends on previous cognitive status.

Loss-of-function mutations in MRAP2 are pathogenic in hyperphagic obesity with hyperglycemia and hypertension

The G-protein-coupled receptor (GPCR) accessory protein MRAP2 is implicated in energy control in rodents, notably via melanocortin-4 receptor (MC4R)¹. Although some MRAP2 mutations have been described in people with obesity^1–3, their functional consequences on adiposity remain elusive. Using large-scale sequencing of MRAP2 in 9,418 people, we identified 23 rare heterozygous variants associated with increased obesity risk in both adults and children. Functional assessment of each variant shows that loss-of-function MRAP2 variants are pathogenic for monogenic hyperphagic obesity, with hyperglycemia and hypertension. This contrasts with other monogenic forms of obesity characterized by excessive hunger, including MC4R deficiency, that present with low blood pressure and normal glucose tolerance⁴. The pleiotropic metabolic effect of loss-of-function mutations in MRAP2 might be due to the failure of different MRAP2-regulated GPCRs in various tissues including pancreatic islets.

P3664Infective endocarditis after transcatheter aortic valve implantation, a comparison with endocarditis occurring in surgical aortic prosthesis and native aortic valve patients

Background

Infective endocarditis is rare but serious. Epidemiology is well known in standard population and surgical valve patients (Pts). The recent development of Transcatheter Aortic Valve Implantation (TAVI) raises new questions about endocarditis in this population.

Purpose

The aim of this study was to assess outcomes of endocarditis in TAVI Pts and to compare the results to surgical aortic valve (SV) owners and native aortic valve (NV) patients.

Methods

We included all patients hospitalized in our institution and presenting with endocarditis after TAVI between 2012 and 2018. We compared these patients to those discussed within the “endocarditis team” and presenting with endocarditis located on SV or on NV.

Results

A total of 34 TAVI Pts were included and compared to a population of 45 SV and 68 NV Pts. TAVI Pts were older (83.1±1.1 yrs, vs 73.3±1.7 and 66.0±1.7, respectively; p<0.001) and had a higher Charlson score (6.2±0.4, vs 5.6±0.4 and 4.1±0.3; p<0.001). TAVI Pts underwent more frequently invasive procedures during the 6 months prior to the diagnosis of endocarditis (38.2%, vs 11.4 and 8.8%; p<0.001). They had less incidence of a new valvular murmur (0%, vs 28.9 and 33.8%; p=0.001) and less heart failure symptoms (26.5%, vs 28.9 and 33.8%; p=0.007). Clinical complications were similar between the 3 groups and mortality was high and comparable at 1 year (29.2%, vs 36.4 and 29.7% p=0.730). However, TAVI Pts were more frequently re-hospitalized (41.2% vs 26.7% and 16.2%, p=0.02) and were treated less invasively (surgery or pacemaker extraction in 14.7% vs 35.6% and 42.6%, p=0.019). Only one TAVI Pt needed surgical aortic valve replacement.

Conclusion

Despite more frequent comorbidities, TAVI patients affected by infective endocarditis have the same mortality during the first year after diagnosis compared to SV and NV patients but are more often rehospitalized.

P907Respective pronostic value of the valvular aortic calcifications and the thoracic aorta calcifications in patients with and without low gradient aortic stenosis after TAVI

Background

Both the valvular aortic calcifications (VAC) and the thoracic aorta calcifications (TAC) have a prognostic impact in patients with aortic stenosis. Their respective prognostic values in patients with and without low gradient aortic stenosis (LGAS) remain unknown after TAVI.

Objectives

To assess the prognostic significance of VAC and TAC in patients with and without LGAS regarding cardiovascular mortality after 3 years follow-up.

Methods

The CAPRI-LGAS is an ancillary study of the C4CAPRI trial (NCT02935491) including 1282 consecutive TAVI patients. Calcifications were measured on pre-TAVI CT. The primary outcome was defined as cardiovascular mortality 3 years after TAVI.

Results

Among the 1282 patients, 397 (31%) had a LGAS. Compared to the other patients, LGAS patients were more prone to be men, younger, with atrial fibrillation, and lower left ventricular ejection fraction (LVEF), p<0.05 for all. No statistically significant difference was noticed for pulmonary systolic pressures, history of diabetes, chronic respiratory disease, renal insufficiency or peripheral vascular disease. VAC was lower in LGAS compared to non-LGAS patients (1.05 cm3±0.7 vs 0.75 cm3±0.5), p<0.001, the contrary was noticed for TAC, (3.1 cm3±3 vs 3.7 cm3±3.7), p=0.011. After 3 years follow-up, 227 (17.7%) patients died from cardiovascular causes; respectively 85 (21.4%) and 142 (16.1%) patients with and without LGAS, p=0.02. In univariate analysis, in LGAS patients each increase of 1cm3 TAC was associated with cardiovascular mortality while VAC was not, respectively Hazard Ratio (HR) 1.07 and confidence interval (CI) (1.023–1.119) p=0.003, and HR 0.822 CI (0.523–1.292), p=0.39. In patients without LGAS both TAC and VAC were associated with mortality, respectively HR 1.054 CI (1.006–1.104), p=0.028 and HR 1.363 CI (1.092–1.701), p=0.006. Multivariate analysis was adjusted for TAC, VAC, age, gender, atrial fibrillation, and LVEF. In LGAS patients TAC but not VAC was still a predictor of cardiovascular mortality, respectively HR 1.092 CI (1.031–1.158), p=0.003, and HR 0.743 CI (0.464–1.191), p=0.21. In patients without LGAS TAC was no more associated with cardiovascular mortality while VAC was, respectively HR 1.306 CI (1.024–1.666), p=0.031, and HR 1.038 CI (0.985–1.094), p=0.161. When further adjusting on pulmonary systolic pressures, history of diabetes, chronic respiratory disease, renal insufficiency and peripheral vascular disease, the results remained similar ie in LGAS patients, TAC HR 1.090 CI (1.022–1.162), p=0.009 while in patients without LGAS VAC HR 1.377 CI (1.049–1.809), p=0.021.

Conclusions

The present study shows that VAC and TAC involve different prognostic information in patients with and without LGAS after TAVI. While VAC may be a marker of early and periprocedural mortality and aortic regurgitation in non-LGAS patients, TAC may continue to be harmful and increase afterload in patients with LGAS whom LVEF is often impaired.

4069From first in man transcatheter aortic valve implantation, a 15-year experience

Background

Since the first-in-man transcatheter aortic valve implantation (TAVI) performed in 2002, the number of procedures has dramatically increased. However, long-term data regarding outcome and valve durability remain poor.

Purpose

We aimed to evaluate the evolution of 30-day outcomes over years and long-term mortality and valve durability after TAVI.

Methods

All consecutive patients presenting with severe symptomatic aortic stenosis treated by TAVI in our center were included prospectively. Clinical and echocardiographic follow-up was performed at 30 days and annually thereafter. Survival curves were constructed using Kaplan-Meier analysis. We also evaluated valve durability according to the European standardized definition of structural valve deterioration.

Results

Between 2002 and 2018, 1530 consecutive patients underwent TAVI including 1285 (84.0%) patients via a femoral approach. A balloon-expandable transcatheter heart valve was predominantly used (1421 patients; 92.9%). The annual transfemoral approach rate increased progressively to reach 93.3%. Age of patients remained stable over time with a global mean age of 83.7±6.5 years old. Logistic EuroSCORE decreased from 49.2±8.2% to 14.3±8.6% (p<0.0001). Thirty-day mortality dramatically decreased below 3% since 2015 and was 0% in 2018. Similarly, major vascular complications decreased from 50.0% in the first year to less than 1% since 2017 (p=0.001). The length of hospital-stay progressively shortened up to a median of 2 days in 2018. The Kaplan-Meier survival estimation was 82.3%, 60.3%, 33.0%; 11.7% and 8.9% respectively at 1, 3, 5, 8 and 10 years. On long-term follow-up the mean aortic gradient remained unchanged (Figure), and only five patients presented a severe prosthetic valve deterioration. Among them, four patients successfully benefited from a valve in valve TAVI procedure. The competing risk analysis at 10 years estimates risk for severe and moderate-or-severe valve deterioration of 1.9±0.9% and 4.3±1.3% respectively.

TEE mean transaortic gradient

Conclusions

Long-term (up to 10 years) follow-up of our large pioneer series of patients treated by TAVI shows a dramatic improvement of outcomes and no warning signs of valve deterioration suggesting very encouraging valve durability, using predominantly, a balloon expandable prosthesis. Further studies are warranted to study valve durability after TAVI before extension to lower risk patients.

CoDE-seq, an augmented whole-exome sequencing, enables the accurate detection of CNVs and mutations in Mendelian obesity and intellectual disability

Objective

The molecular diagnosis of extreme forms of obesity, in which accurate detection of both copy number variations (CNVs) and point mutations, is crucial for an optimal care of the patients and genetic counseling for their families. Whole-exome sequencing (WES) has benefited considerably this molecular diagnosis, but its poor ability to detect CNVs remains a major limitation. We aimed to develop a method (CoDE-seq) enabling the accurate detection of both CNVs and point mutations in one step.

Methods

CoDE-seq is based on an augmented WES method, using probes distributed uniformly throughout the genome. CoDE-seq was validated in 40 patients for whom chromosomal DNA microarray was available. CNVs and mutations were assessed in 82 children/young adults with suspected Mendelian obesity and/or intellectual disability and in their parents when available (n_total = 145).

Results

CoDE-seq not only detected all of the 97 CNVs identified by chromosomal DNA microarrays but also found 84 additional CNVs, due to a better resolution. When compared to CoDE-seq and chromosomal DNA microarrays, WES failed to detect 37% and 14% of CNVs, respectively. In the 82 patients, a likely molecular diagnosis was achieved in >30% of the patients. Half of the genetic diagnoses were explained by CNVs while the other half by mutations.

Conclusions

CoDE-seq has proven cost-efficient and highly effective as it avoids the sequential genetic screening approaches currently used in clinical practice for the accurate detection of CNVs and point mutations.

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Whole-exome sequencing (WES) poorly detects CNVs.

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Whole-genome sequencing remains expensive and hard to handle in clinical practice.

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CoDE-seq (based on an augmented WES protocol) accurately detect CNVs.

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CoDE-seq is highly effective for the diagnosis of obesity & intellectual disability.

High Prevalence of Rare Monogenic Forms of Obesity in Obese Guadeloupean Afro-Caribbean Children

CONTEXT

The population of Guadeloupe Island exhibits a high prevalence of obesity.

OBJECTIVE

We aimed to investigate whether rare genetic mutations in genes involved in monogenic obesity (or diabetes) might be causal in this population of Afro-Caribbean ancestry.

DESIGN AND SETTING

This was a secondary analysis of a study on obesity conducted in schoolchildren from Guadeloupe in 2013 that aimed to assess changes in children's profiles after a lifestyle intervention program. Through next-generation sequencing, we sequenced coding regions of 59 genes involved in monogenic obesity or diabetes in participants from this study.

PARTICIPANTS AND INTERVENTIONS

A total of 25 obese schoolchildren from Guadeloupe were screened for rare mutations (nonsynonymous, splice-site, or insertion/deletion) in 59 genes.

MAIN OUTCOME MEASURES

Correlation between phenotypes and mutations of interest.

RESULTS

We detected five rare heterozygous mutations in five different children with obesity: MC4R p.Ile301Thr and SIM1 p.Val326Thrfs*43 mutations that were pathogenic; SIM1 p.Ser343Pro and SH2B1 p.Pro90His mutations that were likely pathogenic; and NTRK2 p.Leu140Phe that was of uncertain significance. In parallel, we identified seven carriers of mutations in ABCC8 (p.Lys1521Asn and p.Ala625Val) or KCNJ11 (p.Val13Met and p.Val151Met) that were of uncertain significance.

CONCLUSIONS

We were able to detect pathogenic or likely pathogenic mutations linked to severe obesity in >15% of this population, which is much higher than what we observed in Europeans (∼5%).