Variation in protein metabolism biomarkers during the transition period and associations with health, colostrum quality, reproduction, and milk production traits in Holstein cows

The aims of this study were to assess (1) the variation of protein metabolism biomarkers and factors affecting them during the transition period, (2) the association of each biomarker with skeletal muscle reserves and their changes, and (3) the association of these biomarkers with postpartum health, colostrum quality, reproduction, and milk production. For this purpose, 238 multiparous Holstein cows from 6 herds were used in a prospective cohort study. Plasma concentrations of 3-methylhistidine (3-MH) and 1-methylhistidine (1-MH) and serum concentrations of total protein (TP), albumin (ALB), urea nitrogen (BUN), and creatinine (SCR) were determined for each cow at -21, -7, 7, 21, and 28 d relative to calving. Clinical diseases were recorded during the first 28 d postcalving, and presence of subclinical ketosis (scKET) was investigated at 7 and 21 d. Colostrum quality was estimated by Brix refractometry. Reproduction data by 150 d in milk (DIM) and milk production records were also available. Linear mixed models including the fixed effects of time point, herd, parity, body condition score (-21 d), duration of dry period and postparturient diseases were fitted to assess the variation in each biomarker's concentration. The association between the biomarkers' concentration during the prepartum period with the odds for each postparturient disease and for a combined trait (CD_1-28), defined as the presence of at least one clinical condition during the first 28 d after calving, were assessed with separate binary logistic models for time points -21 d and -7 d. The relationship of each biomarker's concentration with longissimus dorsi thickness (LDT) and the changes in LDT (ΔLDT) was assessed with pairwise correlations. Separate general linear models were used to assess the association of each biomarker with colostrum Brix values and milk production traits. Finally, the associated hazard for first artificial insemination (AI) and for pregnancy by 150 DIM (PREG_150DIM) was assessed with Cox proportional hazard models, whereas odds for pregnancy to the first AI (PREG_1stAI) were assessed with binary logistic models. The level of 3-MH was affected mainly by herd, time points, and their interaction. Higher 3-MH was associated with increased odds for metritis and CD_1-28, increased hazard for PREG_150 DIM and with increased milk production. 1-Methylhistidine was affected mainly by herd, scKET and occurrence of displaced abomasum. Higher 1-MH was associated with better colostrum quality, increased odds for scKET, increased hazard for first AI by 150 DIM and with decreased milk production. Both 3-MH and 1-MH were weakly to moderately negatively correlated with LDT and moderately to strongly negatively correlated with ΔLDT at the corresponding time periods. Additionally, higher TP was associated with increased odds for metritis and CD_1-28 and increased milk production, while higher ALB was associated with increased odds for scKET and increased milk production. Moreover, higher BUN was associated with decreased odds for scKET, increased odds for PREG_1stAI and increased milk production. Higher SCR was associated with decreased odds for retained fetal membranes, metritis, and CD_1-28. Periparturient protein metabolism is significantly associated with postpartum health, colostrum quality, reproduction, and milk production; mechanisms involved require further investigation.

Development and validation of a fully automated 2-dimensional imaging system generating body condition scores for dairy cows using machine learning

Monitoring body condition score (BCS) is a useful management tool to estimate the energy reserves of an individual cow or a group of cows. The aim of this study was to develop and evaluate the performance of a fully automated 2-dimensional imaging system using a machine learning algorithm to generate real-time BCS for dairy cows. Two separate datasets were used for training and testing. The training dataset included 34,150 manual BCS (MAN_BCS) assigned by 5 experienced veterinarians during 35 visits at 7 dairy farms. Ordinal regression methods and deep learning architecture were used when developing the algorithm. Subsequently, the testing dataset was used to evaluate the developed BCS prediction algorithm on 4 of the participating farms. An experienced human assessor (HA1) visited these farms and performed 8 whole-milking-herd BCS sessions. Each farm was visited twice, allowing for 30 d (±2 d) to pass between visits. The MAN_BCS assigned by HA1 were considered the ground truth data. At the end of the validation study, MAN_BCS were merged with the stored automated BCS (AI_BCS), resulting in a testing dataset of 9,657 single BCS. A total of 3,817 cows in the testing dataset were scored twice 30 d (±2 d) apart, and the change in their BCS (ΔBCS) was calculated. A subset of cows at one farm were scored twice on consecutive days to evaluate the within-observer agreement of both the human assessor and the system. The manual BCS of 2 more assessors (HA2 and HA3) were used to assess the interobserver agreement between humans. Finally, we also collected ultrasound measurements of backfat thickness (BFT) from 111 randomly selected cows with available MAN_BCS and AI_BCS. Using the testing dataset, intra- and interobserver agreement for single BCS and ΔBCS were estimated by calculating the simple percentage agreement (PA) at 3 error levels and the weighted kappa (κw) for the exact agreement. A Bland-Altman plot was constructed to visualize the systematic and proportional bias. The association between MAN_BCS and AI_BCS and the BFT was assessed with Passing-Bablok regressions. The system had an almost perfect repeatability with a κw of 0.99. The agreement between MAN_BCS and AI_BCS was substantial, with an overall κw of 0.69. The overall PA at the exact, ± 0.25-unit, and ± 0.50-unit BCS error range between MAN_BCS and AI_BCS was 44.4%, 84.6%, and 94.8%, respectively, and greater than the PA obtained between HA1 and HA3. The Bland-Altman plot revealed a minimal systematic bias of -0.09 with a proportional bias at the extreme scores. Furthermore, despite the low κw of 0.20, the overall PA at the exact and ± 0.25-unit of BCS error range between MAN_BCS and AI_BCS regarding the ΔBCS was 45.7 and 88.2%, respectively. A strong linear relationship was observed between BFT and AI_BCS (ρ = 0.75), although weaker than that between BFT and MAN_BCS (ρ = 0.91). The system was able to predict single BCS and ΔBCS with satisfactory accuracy, comparable to that obtained between trained human scorers.

New robotic platform for transoral robotic surgery: an IDEAL stage 0 study

Objectives

This study aims to assess the feasibility to perform transoral robotic surgery (TORS) with a new robotic platform, the Versius Surgical System (CMR Surgical, UK) in a preclinical cadaveric setting in accordance to stage 0 of the IDEAL-D framework.

Design

IDEAL stage 0 preclinical assessment of the Versius Robotic System in TORS in human cadavers.

Setting

All procedures were performed in a simulated operating theatre environment at a UK surgical training centre.

Participants

11 consultant head and neck surgeons from the UK, mainland Europe and the USA took part in TORS procedures on six human cadavers.

Interventions

3 key index procedures were assessed that represent the core surgical workload of TORS: lateral oropharyngectomy, tongue base resection and partial supraglottic laryngectomy.

Main outcome measures

The primary outcome was the successful completion of each surgical procedure. Secondary outcomes included the optimisation of system setup, instrumentation and surgeon-reported outcomes for feasibility of each component procedural step.

Results

33 cadaveric procedures were performed and 32 were successfully completed. One supraglottic laryngectomy was not fully completed due to issues dividing the epiglottic cartilage with available instrumentation. Surgeon-reported outcomes met the minimal level of feasibility in all procedures and a consensus that it is feasible to perform TORS with Versius was reached. Available instrumentation was not representative of other robotic platforms used in TORS and further instrument optimisation is recommended before wider dissemination.

Conclusions

It is feasible to perform TORS with the Versius Surgical System (CMR Surgical) within a pre-clinical cadaveric setting. Clinical evaluation is needed and appropriate with the system. Further instrument development and optimisation is desirable.

Association between a genetic index for digital dermatitis resistance and the presence of digital dermatitis, heel horn erosion and interdigital hyperplasia in Holstein cows

Digital dermatitis (DD) is a polybacterial disease endemic to most UK dairy farms. It poses a major financial and welfare threat and is characterized by high incidence and recurrence rates. We aimed to investigate the association between the UK estimated breeding value for resistance to digital dermatitis, the Digital Dermatitis Index (DDI) and the frequency of DD, heel horn erosion (HHE), and interdigital hyperplasia (IH) in a population of Holstein dairy cows. We enrolled and genotyped 2,352 cows from 4 farms in a prospective cohort study. Foot lesion records were recorded by veterinary surgeons for each animal at 4 time points during a production cycle, starting at approximately 2 mo before calving and ending in late lactation. Importantly, these records were not used in the calculation of the DDI. Lesion records were matched to the animal's own DDI (n = 2,101) and their sire's DDI (n = 1,812). Digital Dermatitis Index values in our study population ranged from -1.41 to +1.2 and were transformed to represent distance from the mean expressed in standard deviations. The relationship between the DDI and the presence of DD was investigated using a logistic regression model, with farm, parity, and a farm-parity interaction fitted as covariates. A multivariable logistic regression model was fitted to evaluate the relationship between HHE and DDI with farm fitted as a covariate. Finally, a univariable logistic regression model with DDI as explanatory variable was used to investigate the relationship between IH and DDI. The odds ratio of an animal being affected by DD was 0.69 for one standard deviation (SD) increase in the animal's DDI (95% confidence interval (CI) = 0.63-0.76). The odds of HHE and IH were 0.69 (95%CI = 0.62-0.76) and 0.58 (95%CI = 0.49-0.68) respectively for one SD increase in DDI. The adjusted probability of DD was 32% (95% CI = 27-36%) for cows with mean DDI value of 0 while it was 24% (95% CI = 20-29%) in cows with a DDI value of +1. Sire DDI breeding values were standardized in the same way and then binned into terciles creating an ordinal variable representing bulls of high, medium, and low genetic merit for DD resistance. The daughters of low genetic merit bulls were at 2.05 (95% CI = 1.60-2.64), 1.96 (95% CI = 1.53-2.50), and 2.85 (95% CI = 1.64-5.16) times greater odds of being affected by DD, HHE, and IH respectively compared with the daughters of high genetic merit bulls. The results of this study highlight the potential of digital dermatitis genetic indexes to aid herd management of DD, and suggest that breeding for resistance to DD, alongside environmental and management control practices, could reduce the prevalence of the disease.

Specific pathway abundances in the neonatal calf faecal microbiome are associated with susceptibility to Cryptosporidium parvum infection: a metagenomic analysis

BACKGROUND

Cryptosporidium parvum is the main cause of calf scour worldwide. With limited therapeutic options and research compared to other Apicomplexa, it is important to understand the parasites' biology and interactions with the host and microbiome in order to develop novel strategies against this infection. The age-dependent nature of symptomatic cryptosporidiosis suggests a link to the undeveloped immune response, the immature intestinal epithelium, and its associated microbiota. This led us to hypothesise that specific features of the early life microbiome could predict calf susceptibility to C. parvum infection.

RESULTS

In this study, a single faecal swab sample was collected from each calf within the first week of life in a cohort of 346 animals. All 346 calves were subsequently monitored for clinical signs of cryptosporidiosis, and calves that developed diarrhoea were tested for Rotavirus, Coronavirus, E. coli F5 (K99) and C. parvum by lateral flow test (LFT). A retrospective case-control approach was taken whereby a subset of healthy calves (Control group; n = 33) and calves that went on to develop clinical signs of infectious diarrhoea and test positive for C. parvum infection via LFT (Cryptosporidium-positive group; n = 32) were selected from this cohort, five of which were excluded due to low DNA quality. A metagenomic analysis was conducted on the faecal microbiomes of the control group (n = 30) and the Cryptosporidium-positive group (n = 30) prior to infection, to determine features predictive of cryptosporidiosis. Taxonomic analysis showed no significant differences in alpha diversity, beta diversity, and taxa relative abundance between controls and Cryptosporidium-positive groups. Analysis of functional potential showed pathways related to isoprenoid precursor, haem and purine biosynthesis were significantly higher in abundance in calves that later tested positive for C. parvum (q ≤ 0.25). These pathways are either absent or streamlined in the C. parvum parasites. Though the de novo production of isoprenoid precursors, haem and purines are absent, C. parvum has been shown to encode enzymes that catalyse the downstream reactions of these pathway metabolites, indicating that C. parvum may scavenge those products from an external source.

CONCLUSIONS

The host has previously been put forward as the source of essential metabolites, but our study suggests that C. parvum may also be able to harness specific metabolic pathways of the microbiota in order to survive and replicate. This finding is important as components of these microbial pathways could be exploited as potential therapeutic targets for the prevention or mitigation of cryptosporidiosis in bovine neonates.

The bovine foot skin microbiota is associated with host genotype and the development of infectious digital dermatitis lesions

BACKGROUND

Bovine Digital Dermatitis (BDD) is a prevalent infectious disease, causing painful foot skin lesions and lameness in cattle. We describe herein the bovine foot skin microbiota and its associations with BDD using 16S rRNA gene amplicon and shotgun metagenomic sequencing on samples from 259 dairy cows from three UK dairy farms.

RESULTS

We show evidence of dysbiosis, and differences in taxonomy and functional profiles in the bovine foot skin microbiome of clinically healthy animals that subsequently develop BDD lesions, compared to those that do not. Our results suggest that taxonomical and functional differences together with alterations in ecological interactions between bacteria in the normal foot skin microbiome may predispose an animal to develop BDD lesions. Using genome-wide association and regional heritability mapping approaches, we provide first evidence for interactions between host genotype and certain members of the foot skin microbiota. We show the existence of significant genetic variation in the relative abundance of Treponema spp. and Peptoclostridium spp. and identify regions in the bovine genome that explain a significant proportion of this variation.

CONCLUSIONS

Collectively this work shows early changes in taxonomic and functional profiles of the bovine foot-skin microbiota in clinically healthy animals which are associated with subsequent development of BDD and could be relevant to prevention of disease. The description of host genetic control of members of the foot skin microbiota, combined with the association of the latter with BDD development offer new insights into a complex relationship that can be exploited in selective breeding programmes. Video Abstract.

Skeletal muscle and adipose tissue reserves and mobilisation in transition Holstein cows: Part 1 Biological variation and affecting factors

Nutrient deficit during the periparturient period leads to mobilisation of body energy and protein reserves. Research regarding fat reserves and mobilisation is extensive, while, on the contrary, investigation of muscle mobilisation during the periparturient period is limited. The aim of this cohort study was to simultaneously investigate the biological variation of skeletal muscle and subcutaneous fat reserves together with their mobilisation in transition Holstein cows of different herds, using ultrasonography, and to assess potential affecting factors. For this purpose, ultrasound measurements of longissimus dorsi muscle thickness (LDT) and backfat thickness (BFT) from 238 multiparous cows of six dairy farms were obtained at six time points across the transition period (from 21 days pre- to 28 days postpartum). Concentrations of serum creatinine and non-esterified fatty acids were determined in order to confirm the loss of muscle mass and adipose tissue, respectively. Cases of clinical postparturient diseases and subclinical ketosis (scKET) during the first 28 days postcalving were recorded. Cows mobilised on average 32.8% and 37.3% of LDT and BFT reserves, respectively. Large between-cow variation was observed for both the onset and the degree of mobilisation. Time point, initial body condition score and parity were the most important predictors of LDT variation. Cows diagnosed with metritis (MET) had lower LDT postpartum and mobilised more muscle depth compared to cows not diagnosed with MET. Initial BCS, time point, initial BW (estimated by heart girth measurement) and parity were the most important predictors of BFT variation. Cows diagnosed with MET mobilised more backfat between -7d and 7d compared to cows not diagnosed with MET. Cows with scKET mobilised more backfat between 7- and 21 days postpartum compared to healthy ones. Variation of subcutaneous fat and skeletal muscle reserves during the transition period was large and affected by herd and several cow-level factors.

Skeletal muscle and adipose tissue reserves and mobilisation in transition Holstein cows: Part 2 association with postpartum health, reproductive performance and milk production

The aim of this study was, for the first time, to simultaneously assess the association of skeletal muscle and subcutaneous fat reserves and their mobilisation, measured by ultrasonography, with the incidence of specific postparturient health, reproduction, and milk production traits. For this purpose, ultrasound measurements of longissimus dorsi thickness (LDT) and backfat thickness (BFT) from 238 multiparous cows from 6 dairy farms were obtained at 6 time points during the transition period (from 21 days pre- to 28 days postpartum). In each case, LDT and BFT measurements at each time point and LDT and BFT mobilisation variables at each study period were assessed simultaneously. Cases of specific clinical postparturient diseases and subclinical ketosis were recorded. An additional disease trait was used, defined as the presence or absence of at least one clinical condition after calving (CD_1-28). The associated disease odds with LDT/BFT variables were assessed with binary logistic regression models. The associated hazard for 1st artificial insemination (AI) and for pregnancy by 150 days-in-milk (PREG_150DIM) was assessed with Cox proportional hazard models. Moreover, binary logistic models were used to assess the associated odds for pregnancy to 1^stAI (PREG_1^stAI). Finally, association with 30d, 100d and 305d milk yield was assessed with linear regression models. Increased muscle depth during transition was negatively associated with odds for metritis and CD_1-28, while associations with odds for subclinical ketosis were inconclusive. Moreover, increased LDT reserves were associated with greater hazard for 1st AI by 150 days-in-milk, but results were inconclusive regarding odds for PREG_1^stAI. Increased LDT mobilisation was associated with increased odds for metritis. Increased BFT reserves were positively associated with odds for metritis, CD_1-28 and subclinical ketosis and with decreased hazard for PREG_150DIM. Increased BFT mobilisation was associated with increased odds for subclinical ketosis and with decreased odds for PREG_1^stAI and decreased hazard for PREG_150DIM. Cows with moderate BFT reserves performed better. Finally, increased BFT mobilisation during -21d to -7d from parturition was associated with less milk by 30d and 100d. On the contrary, increased BFT mobilisation during -7d to 7d was associated with more milk by 305d. Metabolism of muscle and fat tissue during transition period was differently associated with different postparturient health, reproduction and milk production traits. In general, greater muscle mass and moderate fat reserves with limited muscle and fat mobilisation were associated with better performance.

TAVI for low-flow, low-gradient severe aortic stenosis: impact on outcome

Background

Several factors have been identified as predictors of events after transcatheter aortic valve implantation (TAVI) but the impact of transaortic flow (F) and mean transaortic gradient (MG) upon outcomes is controversial. This study aimed to clarify the prognostic role of low FL and low MG after TAVI.

Methods

Patients with severe and symptomatic aortic stenosis [effective orifice area (EOA) ≤1cm2], referred for TAVR at our institution were consecutively enrolled. Given the aim of this analysis, patients were divided according to F and MG into four groups: 1) LF-LG Patients with low flow (SVi <35ml/m2) and low mean gradient (MG <40mmHg), 2) NF-LG Patients with normal flow (SVi ≥35ml/m2) and low mean gradient (MG <40mmHg), 3) LF-HG Patients with low flow (SVi <35ml/m2) and high mean gradient (MG ≥40mmHg) and 4) NF-HG patients with normal flow (SVi ≥35ml/m2) and high mean gradient (MG ≥40mmHg). Prospectively collected demographic, laboratory and echocardiographic data were retrospectively analyzed. One-year outcomes were compared between the 4 groups of patients. Primary clinical endpoint was all-cause mortality at long term follow up, as defined by the criteria proposed by the Valve Academic Research Consortium2.

Results

In total 255 patients undergoing TAVI at our institution were included in our study: 35 (13.7%) patients with LF-LG, 17 (6.7%) with NF-LG, 108 (42.4%) with LF-HG and 95 (37.3%) with NF-HG. There was a statistically significant difference in gender distribution between the groups with most females being represented in the NF-HG group (64.2%) vs the LF-LG (31.4%), the NF-LG (47.1%) or the LF-HG group (50.9%) (p=0.008). Moreover, LF-LG patients were younger than NF-LG, LF-HG or NF-HG patients (ANOVA, p=0.037). There was a greater prevalence of prior myocardial infarction (MI) in the LF-LG group (34.5%) vs 20% in the NF-LG, 16.1% in the LF-HG and 20.2% in the NF-HG group (p=0.005). At 1 year follow up there were no statistically significant differences in major vascular complication, major bleeding complication or permanent pacemaker implantation rates between the groups, (all p>0.05). At a median follow up of 36 months IQR (17, 56) all-cause mortality was significantly higher in the LF-LG group as opposed to the NF-LG, LF-HG and NF-HG groups (77.41% vs 60% vs 55.67% vs 46.15% respectively, p=0.005). These results were confirmed by multivariate logistic regression analysis, as the combination of low flow and low mean gradient emerged as the strongest long term all cause mortality predictor (HR: 5.39, 95% confidence intervals: 1.72–16.83; p=0.004)

Conclusion

Combination of low flow and low mean transaortic gradient portends a worse prognosis after TAVI.

Funding Acknowledgement

Type of funding sources: None.

Impact of significant preprocedural mitral regurgitation on mortality after transcatheter aortic valve implantation

Background

Mitral regurgitation (MR) is commonly encountered in patients with severe aortic stenosis scheduled for transcatheter aortic valve implantation (TAVI). The presence of significant pre-procedural MR, however, has not been accounted in pivotal trials of TAVI and data regarding its independent impact on outcome are contradictory.

Methods

Patients with severe and symptomatic aortic stenosis [effective orifice area (EOA) ≤1cm2] referred for TAVI at our institution were consecutively enrolled. Prospectively collected demographic, laboratory and echocardiographic data were retrospectively analysed. Patients were stratified into two groups according to MR severity: ≤ grade 1 were defined as non-significant and ≥ grade 2 as significant. Change in MR was determined by comparison between baseline and 30-day echocardiogram. Primary clinical endpoint was all-cause mortality, as defined by the criteria proposed by the Valve Academic Research Consortium2.

Results

A total of 331 consecutive patients were enrolled in the study: 247 (74.6%) had non-significant MR and 84 (25.4%) patients had significant MR at baseline. Patients with significant pre-procedural MR had lower baseline ejection fraction (47.7±10.4% versus 51.2±8.4%, p=0.002), higher pulmonary artery systolic pressure (52±14.3mmHg versus 42.5±11.1mmHg, p<0.0001) and higher rates of moderate or severe tricuspid regurgitation (TR) (50% versus 19.4%) compared to patients with non-significant MR. Of all patients, mitral regurgitation improved in 9.5%, remained the same in 83.9%, and worsened in 6.6% 30 days after TAVR. In a multivariable analysis, pre-procedural TR severity was predictor of improved mitral regurgitation [OR 3.003,(95% CI 1.216–7.417, p=0.017)].

The primary clinical end point occurred in 44.7% of all patients during a follow-up period of 36.6.±25.9 months. Patients with significant pre-procedural MR had significantly higher rates of all-cause mortality compared to patients with non-significant (54.7% and 41.3%, respectively; log rank p=0.015). Performing a multivariable analysis demonstrated that preprocedural MR severity could independently predict cumulative mortality [OR 0.480, (95% CI 0.247–0.932, p=0.03)].

Conclusion

Significant pre-procedural MR is common in patients undergoing TAVI and is associated with increased all-cause mortality. TAVI is associated with a significant improvement in MR, especially in severe types. These data provide new insights in the crucial role of mitral regurgitation in the risk assessment of TAVI candidates.

Funding Acknowledgement

Type of funding sources: None.

Effect of concomitant atrioventricular valve regurgitation on the outcome after transcatheter aortic-valve implantation

Background

Many patients undergoing transcatheter aortic valve implantation (TAVI) have concomitant mitral regurgitation (MR) of moderate grade or more. The impact of coexistent tricuspid regurgitation (TR) remains to be determined.

Methods

Patients with severe and symptomatic aortic stenosis [effective orifice area (EOA)≤1cm2] referred for TAVI at our institution were consecutively enrolled. Prospectively collected demographic, laboratory and echocardiographic data were retrospectively analysed. Patients were divided into 4 groups according to MR and TR severity pre-procedurally: no/mild MR and TR, moderate/severe MR, moderate/severe TR, moderate/severe MR and TR. Primary clinical endpoint was all-cause mortality, as defined by the criteria proposed by the Valve Academic Research Consortium2.

Results

A total of 244 consecutive patients were enrolled in the study: 148 (60.7%) patients no/mild MR and TR, 32 (13.1%) moderate/severe MR, 35 (14.3%) moderate/severe TR, 29 (11.9%) moderate/severe MR and TR pre-procedurally. There was significant difference in pre-procedural pulmonary artery systolic pressure (PASP) among groups (no/mild MR and TR: 40.8±10 mmHg, moderate/severe MR: 46.6±11.2 mmHg, moderate/severe TR: 49.9±13mmHg, moderate/severe MR and TR: 59.8±15.2mmHg, p<0.0001). The Kaplan–Meier curves for 2 year mortality showed that the severity of TR was associated with poor survival. Interestingly, patients with moderate/severe MR and TR had the worse survival (no/mild MR and TR (91.2%), moderate/severe MR (78.1%), moderate/severe TR (62.9%), moderate/severe MR and TR (62.1%), p<0.0001).

Conclusion

The presence of concomitant moderate or severe mitral and tricuspid valve regurgitation was associated with the higher mortality. This suggests that a thorough evaluation of the mechanisms underlying concomitant mitral and tricuspid valve regurgitation should be performed to determine the best strategy for avoiding TAVI-related futility.

Funding Acknowledgement

Type of funding sources: None.

Novel computed-tomography derived prognostic markers in patients undergoing TAVI with a self-expanding valve

Introduction

Transcatheter aortic valve implantation is the treatment of choice in a consistently expanding group of patients with severe aortic valve stenosis. Tricuspid and mitral annular dilatation with consequent valvular regurgitation are associated with adverse outcome. Computed tomography angiography (CTA) is routinely performed for preprocedural evaluation of vascular access and prosthesis sizing.

Purpose

To evaluate the impact of mitral and tricuspid annular dimensions in preprocedural CTA on prognosis of patients undergoing TAVI with a self-expanding valve.

Methods

CTAs of consecutive patients undergoing TAVI in a single high-volume center between 2016 and 2019 were retrospectively evaluated. Maximal septolateral tricuspid annular diameters (TAD) and mitral annular diameters (MAD) were obtained and measured from properly angulated three dimensional CTA datasets. Moreover, maximal pulmonary artery diameter perpendicular to the long axis was measured in every patient. Patients were followed up by clinical visits or telephone contacts. As clinical events were defined all-cause mortality, stroke and heart failure hospitalization.

Results

In total 123 patients were included in the study. The mean follow-up duration was 875±383 days and 21 clinical events were recorded. There was a moderate but statistical significant correlation between TAD and both pulmonary artery diameter (r=0.39, p<0.001) and pulmonary artery systolic pressure by echocardiography (r=0.23, p=0.015). In univariate logistic regression analysis pulmonary artery diameter and TAD were both associated with heart failure hospitalization (p=0.03 and 0.02 respectively). In addition, MAD was associated with total events (OR: 0.43, 95% CI 0.19–0.99, p=0.048). The relationship of MAD with events remained significant after adjustment for sex, age and tricuspid annular dimensions (OR: 0.28, 95% CI 0.1–0.79, p=0.02).

Conclusions

TAD and MAD were associated with heart failure rehospitalization and clinical events respectively in patients undergoing TAVI with a self-expanding valve. Further larger prospective studies are warranted to evaluate the prognostic value of these CTA markers.

Funding Acknowledgement

Type of funding sources: None.

Percutaneous access versus surgical cutdown in TAVI: vascular and bleeding complications

Background

Access options for transcatheter aortic valve implantation (TAVI) are vital, since use of large sheaths may lead to access-related complications and bleeding.

Purpose

To determine the access-related vascular and bleeding complications of patients undergoing transfemoral TAVI.

Methods

Consecutive patients scheduled for transfemoral TAVI were retrospectively grouped according to vascular access [percutaneous access (p-TAVI) and surgical cutdown (sc-TAVI)]. Primary end points were vascular and bleeding complications, based on the VARC-II criteria.

Results

Totally, 187 patients were included in the analysis (p-TAVI: 124 patients; sc-TAVI: 63 patients). Mean procedure time was shorter in the p-TAVI group compared to the sc-TAVI group (45.65±6.17 min versus 64.05±15.73 min, p<0.001). Contrast use was lower in the p-TAVI group compared to the sc-TAVI group (81.18±15.96 ml versus 106.75±25.67 ml, p<0.001), which resulted in higher rates of acute kidney injury in the sc-TAVI group (13% versus 1%, p=0.01). Vascular access complications occurred numerically but not statistically more often in the p-TAVI group compared to the sc-TAVI group (11% versus 5% for minor complications and 6% versus 3% for major complications respectively, p=0.10). Patients in the p-TAVI group had the same minor and major bleeding complications compared to the sc-TAVI group (11% versus 8% for minor, 10% versus 6% for major bleeding complications respectively, p=0.49), but no life-threatening bleeding (0% versus 1.5%).

Conclusions

Transfemoral access options in TAVI (surgical cutdown or percutaneous) have similar efficacy and should be offered in TAVI patients if and when appropriate.

Funding Acknowledgement

Type of funding sources: None.

Impact of severe mitral annular calcification on paravalvular leak after transcatheter aortic valve implantation

Aims

Paravalvular leak (PVL) remains a frequent complication after transcatheter aortic valve implantation (TAVI) and seems to affect short- and long-term survival.

Purpose

The aim of this study was: 1) to identify anatomical predictors of PVL after TAVI and 2) assess the impact of PVL on cumulative survival.

Methods and results

Patients with severe and symptomatic aortic stenosis [effective orifice area (EOA) ≤1cm2] referred for TAVI at our institution were consecutively enrolled. Prospectively collected demographic, laboratory and echocardiographic data were retrospectively analyzed. Patients were stratified into two groups according to the presence of PVL after TAVI and were followed up postoperatively with clinical and echocardiographic assessment. Primary clinical endpoint was all-cause mortality, as defined by the criteria proposed by the Valve Academic Research Consortium 2. In total, 291 patients were included (male: 50.2%, mean age: 80±7.6 years) in our study. Of these, 165 (56,8%) presented at least mild PVL after TAVI (mild: 85,5%, moderate: 13.3% and severe: 1.2%). The median follow-up period was 27.3 [min. 0, max 113 months. Two patients with severe PVL were excluded from the analysis. In the follow up period, there was no significant difference regarding all-cause mortality between patients with and those without PVL after TAVI, independently from the degree of PVL (log rank: 0.991 - Figure 1). Severe aortic annulus calcification, the presence of a bicuspid aortic valve and aortic root angulation, as assessed by computed tomography (CT), were found to associate with PVL after TAVI in univariate analysis. In the multivariate analysis, severe aortic annulus calcification was found to be the only independent predictor of mild or moderate PVL after TAVI [Exp(B): 1.540, 95% Confidence Interval: 1.067–2.224, B=0.432, p=0.021].

Conclusion

The presence of mild or moderate PVL after TAVI was not found to affect cumulative survival in the 27 months of follow up period. Severe annulus calcification assessed by CT-scan, was found to be the only independent predictor of PVL after TAVI.

Funding Acknowledgement

Type of funding sources: None.

A study on the use of thermal imaging as a diagnostic tool for the detection of digital dermatitis in dairy cattle

Our aims were to (1) determine how interdigital skin temperature (IST), measured using infrared thermography, was associated with different stages of digital dermatitis (DD) lesions and (2) develop and validate models that can use IST measurements to identify cows with an active DD lesion. Between March 2019 and March 2020, infrared thermographic images of hind feet were taken from 2,334 Holstein cows across 4 farms. We recorded the maximum temperature reading from infrared thermographic images of the interdigital skin between the heel bulbs on the hind feet. Pregnant animals were enrolled approximately 1 to 2 mo precalving, reassessed 1 wk after calving, and again at approximately 50 to 100 d postpartum. At these time points, IST and the clinical stage of DD (M-stage scoring system: M1-M4.1) were recorded in addition to other data such as the ambient environmental temperature, height, body condition score, parity, and the presence of other foot lesions. A mixed effect linear regression model with IST as the dependent variable was fitted. Interdigital skin temperature was associated with DD lesions; compared to healthy feet, IST was highest in feet with M2 lesions, followed by M1 and M4.1 lesions. Subsequently, the capacity of IST measurements to detect the presence or absence of an active DD lesion (M1, M2, or M4.1) was explored by fitting logistic regression models, which were tested using 10-fold validation. A mixed effect logistic regression model with the presence of active DD as the dependent variable was fitted first. The average area under the curve for this model was 0.80 when its ability to detect presence of active DD was tested on 10% of the data that were not used for the model's training; an average sensitivity of 0.77 and an average specificity of 0.67 was achieved. This model was then restricted so that only explanatory variables that could be practically recorded in a nonresearch, external setting were included. Validation of this model demonstrated an average area under the curve of 0.78, a sensitivity of 0.88, and a specificity of 0.66 for 1 of the time points (precalving). Lower sensitivity and specificity were achieved for the other 2 time points. Our study adds further evidence to the relationship between DD and foot skin temperature using a large data set with multiple measurements per animal. Additionally, we highlight the potential for infrared thermography to be used for routine on-farm diagnosis of active DD lesions.

The dysbiosis of ovine foot microbiome during the development and treatment of contagious ovine digital dermatitis

BACKGROUND

Contagious Ovine Digital Dermatitis (CODD) is an emerging and common infectious foot disease of sheep which causes severe welfare and economic problems for the sheep industry. The aetiology of the disease is not fully understood and control of the disease is problematic. The aim of this study was to investigate the polybacterial aetiopathogenesis of CODD and the effects of antibiotic treatment, in a longitudinal study of an experimentally induced disease outbreak using a 16S rRNA gene amplicon sequencing approach.

RESULTS

CODD was induced in 15/30 experimental sheep. During the development of CODD three distinct phenotypic lesion stages were observed. These were an initial interdigital dermatitis (ID) lesion, followed by a footrot (FR) lesion, then finally a CODD lesion. Distinct microbiota were observed for each lesion in terms of microbial diversity, clustering and composition. Porphyromonadaceae, Family XI, Veillonellaceae and Fusobacteriaceae were significantly associated with the diseased feet. Veillonellaceae and Fusobacteriaceae were most associated with the earlier stages of ID and footrot rather than CODD. Following antibiotic treatment of the sheep, the foot microbiota showed a strong tendency to return to the composition of the healthy state. The microbiota composition of CODD lesions collected by swab and biopsy methods were different. In particular, the Spirochaetaceae family were more abundant in samples collected by the biopsy method, suggesting that these bacteria are present in deeper tissues of the diseased foot.

CONCLUSION

In this study, CODD presented as part of a spectrum of poly-bacterial foot disease strongly associated with bacterial families Porphyromonadaceae, Family XI (a family in Clostridiales also known as Clostridium cluster XI), Veillonellaceae and Fusobacteriaceae which are predominately Gram-negative anaerobes. Following antibiotic treatment, the microbiome showed a strong tendency to return to the composition of the healthy state. The composition of the healthy foot microbiome does not influence susceptibility to CODD. Based on the data presented here and that CODD appears to be the severest end stage of sheep infectious foot disease lesions, better control of the initial ID and FR lesions would enable better control of CODD and enable better animal welfare.

The effect of permanent pacemaker implantation following transcatheter aortic valve implantation upon survival

Purpose

Transcatheter aortic valve implantation (TAVI) is often followed by conduction abnormalities, leading to a permanent pacemaker implantation (PPI). Data regarding the clinical impact of PPI following TAVI is yet to be established.

Methods

Patients with severe and symptomatic aortic stenosis [effective orifice area (EOA) ≤1cm2] referred for TAVI at our institution were consecutively enrolled. Prospectively collected demographic, laboratory and echocardiographic data were retrospectively analyzed. Patients were stratified into two groups according to the need for PPI after TAVI and were followed up postoperatively with clinical and echocardiographic assessment. Primary clinical endpoint was all-cause mortality, as defined by the criteria proposed by the Valve Academic Research Consortium 2.

Results

In total, 292 patients were included (male: 50.2%, mean age: 80±7.6 years) in our study. Of these, 109 (37.5%) underwent PPI simultaneously or shortly after TAVI. The median follow-up period was 27.3 In this period, all-cause mortality showed no significant difference between patients with and those without PPI after TAVI (log-rank p=0.756), even after excluding patients with a pre-existing pacemaker from the analysis. Subgroup analysis also showed no difference in survival between patients with low ejection fraction (<50%) and those with preserved (≥50%) receiving a permanent pacemaker after TAVR (log-rank p=0.269). Taking into consideration factors that were found to associate to PPI in univariate analysis (pre TAVI - ejection fraction, pulmonary artery systolic pressure and New York Heart Association functional class) in a multivariate model, pre TAVI pulmonary artery systolic pressure was found to be an independent predictor of peri-procedural PPI [Exp(B): 0.977, 95% Confidence Interval: 0.957–0.998, B=−0.023, p=0.029]. Pre-TAVI conduction abnormalities and the degree of aortic annulus calcification, as assessed by computed-tomography, were not found to predict PPI after TAVI.

Conclusion

PPI following TAVI was not associated with survival at 27 months of follow-up, independently from the pre TAVI ejection fraction.

Figure 1

Funding Acknowledgement

Type of funding source: None

Carotid artery temperature reduction with statin therapy in patients with familial hyperlipidemia syndromes

Background

Familial hypercholesterolemia (FH) syndromes constitute an important risk factor for premature atherosclerosis. Microwave radiometry (MWR) assess non-invasively carotid artery temperatures reflecting inflammation. Recent data support that statin therapy, that constitutes the cornerstone for the treatment of FH, reduces systemic inflammation.

Purpose

To investigate the impact of statin therapy either with simvastatin or with combination simvastatin plus ezetimibe on carotid artery temperatures.

Methods

Consecutive patients with diagnosis of either heterozygous hypercholesterolemia (hFH) or combined hyperlipidemia (FCH) not under statin therapy for at least 6 months were included in the study. FH pts were assigned to either simvastatin 40 mg or simvastatin 40 mg plus ezetimibe 10mg according to the discretion of the physician. FH patients who refused statin therapy were used as control group for the assessment of statins effect. In all subjects, common carotid intima-media thickness (ccIMT) was measured in the last 2 cm of the far wall of both common carotids close to the carotid bifurcation and ΔT (maximum-minimum) temperature measurements were performed across each carotid during MWR evaluation. Examinations were performed at baseline and after 6 months. Blood's lipid profile was also obtained in all patients.

Results

In total 115 patients were included in the study. Of them 40 patients received simvastatin (19 hFH and 11 FCH), 41 simvastatin + ezetimibe (31hFH and 10 FCH) and 34 (21 hFH and 13 FCH) no statin. There was no difference at baseline in ccIMT and ΔT measurements between hFH and FCH patients (0.10±0.03 vs 0.10±0.02, p=0.74 and 0.88±0.38 vs 0.84±0.32, p=0.52, respectively). Patients who refused statin therapy did not show any reduction in ccIMT and ΔT measurements between baseline and follow up (ccIMT: 0.10±0.02 vs 0.09±0.02, p=0.06 and ΔT: 0.72±0.26 vs 0.70±0.26). In contrast, there was a significant reduction in ccIMT and ΔT for patients under both simvastatin (0.10±0.03 vs 0.09±0.01, p=0.004 for ccIMT and 0.83±0.34 vs 0.63±0.24, p=0.04 for ΔT) and simvastatin + ezetimibe therapy (0.11±0.03 vs 0.09±0.02, p<0.001 and 1.00±0.38 vs 0.69±0.23, p<0.001 for ΔT). Patients under combination therapy reduced more significantly their carotid artery temperatures compared to patients under simvastatin monotherapy or patients without statin (−0.31±0.46 vs −0.2±0.40 vs −0.01±0.37, ANOVA p=0.04, Figure 1).

Conclusions

Both simvastatin and simvastatin + ezetimibe therapy among the beneficial effect on IMT, reduced carotid wall inflammation in FH pts.

Figure 1

Funding Acknowledgement

Type of funding source: None

Long-term outcomes after transcatheter aortic valve implantation. An analysis of 5-year survival and beyond

Background

Transcatheter aortic valve implantation (TAVI) has seen an unprecedented rise in the past decade and has become the gold-standard therapy for inoperable, high- and intermediate-risk patients with aortic valve stenosis.

Purpose

To investigate the long-term clinical outcomes (5-year survival and beyond) of patients undergoing TAVI.

Methods

Consecutive patients who underwent TAVI with a self-expanding valve between 2012 - 2015 were included in the study. Patients with bicuspid valves and valve-in-valve procedures were excluded. Clinical follow-up was performed at specified time intervals (30-day post TAVI and yearly thereafter). The primary endpoint of this study was to evaluate survival rates in the long-term (≥5 years). Secondary endpoints were echocardiographic findings and clinical status at 5 years. All endpoints were considered as per the VARC-2 criteria and the latest consensus documents.

Results

In total, 267 patients were included in the study. Complete follow-up was complete in 189 (70%) patients. The mean age at implantation was 80.71±6.81 years, 129 (48%) were female, mean logistic EuroSCORE was 24.28±8.64% and 73% of patients were at NYHA Class III. The median follow-up was 4.0±1.5 years.

Before the procedure, ejection fraction (EF) was 49.92±9.37%, mean gradient was 48.83±14.68mmHg, pulmonary artery systolic pressure (PASP) was 44.31±12.72mmHg and aortic valve area was 0.98±5.02cm2.

All patients received the self-expanding valve (mean valve size was 27.60±2.12mm), with the majority of them undergoing transfemoral TAVI (71%). Predilation was performed in 77% of the population and post TAVI dilation was performed in 20%.

Compared to pre TAVI values, EF was higher at 50.66±9.37% (p=0.041), mean gradient was lower at 9.41±4.65mmHg (p<0.001), PASP was lower at 41.55±9.93mmHg (p=0.005) and aortic valve area was higher at 1.69±0.81cm2 (p<0.001) post TAVI.

At the end of the fifth year, 160 (60%) patients were alive. Mean survival post TAVI was 32 months (median: 32.2 months, range: 0–91.2 months) and the majority of deaths were non-cardiac in nature (78%). Also, 43% patients of patients were at NYHA Class I, 50% were at NYHA Class II and 7% were at NYHA Class III. At multivariate analysis, sole independent predictor of death at 5 years was baseline PASP levels (OR 1.027, 95% CI: 1–1.054, p=0.049).

Conclusion

Transcatheter aortic valve implantation offers a viable solution for aortic stenosis patients and long-term results beyond 5 years are reassuring. Further studies are necessary in order to shed a light for very long-term outcomes.

Funding Acknowledgement

Type of funding source: None

Prognostic implication of electrocardiographic left ventricular strain in patients undergoing Transcatheter Aortic Valve Implantation

Background

Electrocardiographic (ECG) strain has been linked to excess cardiovascular morbidity and mortality in asymptomatic patients with aortic stenosis.

Purpose

We aim to determine the differential impact of baseline ECG-strain on long-term mortality after transcatheter aortic valve implantation (TAVI).

Methods

Patients with severe and symptomatic aortic stenosis (effective orifice area [EOA]≤1cm2), who were scheduled for TAVI with a self-expanding valve between May 2015 and May 2018 were consecutively enrolled. Left ventricular strain was defined as the presence of ≥1mm convex ST-segment depression with asymmetrical T-wave inversion in leads V5 to V6 on baseline ECG. Patients were excluded, if they had bundle branch block or a permanent pacemaker at baseline. Baseline parameters were compared, and multivariate Cox proportional hazard regression models were generated to assess outcome difference. The primary clinical endpoint was cumulative mortality defined according to the criteria proposed by the Valve Academic Research Consortium-2.

Results

Of the 171 patients screened, 56 patients were excluded due to left bundle branch block or paced rhythm. In the 115 included patients (mean age: 81.4±7), 36 patients (31.3%) had strain pattern on pre-TAVI ECG. There were no differences in baseline characteristics between the two groups. During a median follow-up of 2.32 years (IQR 1.62 to 3), 11 patients (9.6%) reached the primary clinical endpoint. Patients in the strain group had higher incidence of all-cause mortality compared to patients without left ventricular strain (25% vs 2.5%, χ2=14.4, p<0.001). Kaplan-Meier survival analysis showed a significantly decreased cumulative probability of survival at 3 years in patients with LV-strain compared with patients without LV-strain (log-rank p=0.002, Figure 1). In the multivariate analysis, left ventricular strain [Exp(B): 8.952, 95% Confidence Interval (CI): 1.215–65.938, B=2.192, p=0.031] and QRS duration [Exp(B): 1.058, 95% CI: 1.022–1.095, B=0.056, p<0.001] were found to be independent predictors of all-cause mortality after TAVI.

Conclusion

Baseline ECG left ventricular strain was an independent predictor of long-term mortality post TAVI. Systematic strain measurements might aid in risk-stratifying patients scheduled for TAVI.

Figure 1

Funding Acknowledgement

Type of funding source: None

The role of transoral fine needle aspiration in expediting diagnosis and reducing risk in head and neck cancer patients in the coronavirus disease 2019 (COVID-19) era: a single-institution experience

OBJECTIVE

The global coronavirus disease 2019 (COVID-19) pandemic has necessitated rapid alterations to diagnostic pathways for head and neck cancer patients that aim to reduce risk to patients (exposure to the hospital environment) and staff (aerosol-generating procedures). Transoral fine needle aspiration cytology offers a low-risk means of rapidly diagnosing patients with oral cavity or oropharyngeal lesions. The technique was utilised in selected patients at our institution during the pandemic. The outcomes are considered in this study.

METHOD

Diagnostic outcomes were retrospectively evaluated for a series of patients undergoing transoral fine needle aspiration cytology of oral cavity and oropharyngeal lesions during the COVID-19 pandemic.

RESULTS

Five patients underwent transoral fine needle aspiration cytology, yielding lesional material in 100 per cent, with cell blocks providing additional information. In one case, excision biopsy of a lymphoproliferative lesion was required for final diagnosis.

CONCLUSION

Transoral fine needle aspiration cytology can provide rapid diagnosis in patients with oral cavity and oropharyngeal lesions. Whilst limitations exist (including tolerability and lesion location), the technique offers significant advantages pertinent to the COVID-19 era, and could be employed in the future to obviate diagnostic surgery in selected patients.

Age at first calving in UK Jersey cattle and its associations with first lactation 305-day milk yield, lifetime daily milk yield, calving interval and survival to second lactation

BACKGROUND

The association between age at fist calving (AFC) and production, fertility and survivability in Jersey heifers requires evaluation and comparison with published literature on Holstein heifers.

METHOD

Lactation records from 7256 pedigree Jersey heifers were grouped by AFC. Analysis comprised mixed effects multivariable regression modelling and binary logistic regression modelling.

RESULTS

Increased lifetime daily yield (LDY) was significantly associated with a reduced AFC; calving UK Jersey heifers at 24 months or below is optimal. Heifers calving at 25-26 months had a significantly lower mean calving interval (391 days; 95 per cent CI 386 to 397) than those calving over 30 months (399; 95 per cent CI 394 to 405) (P=0.03). Heifers with an AFC over 30 months were less likely to survive to second lactation than those with an AFC 18-24 months. Spring calving heifers produced significantly less milk per day (9.87 kg; 95 per cent CI 9.64 to 10.1) than autumn (10.18; 95 per cent CI 9.94 to 10.41) or winter calvers (10.07; 95 per cent CI 9.84 to 10.3) (P≤0.01). Heifers that calved in the winter had a significantly shorter calving interval (389 days; 95 per cent CI 394 to 383) (P≤0.01) than heifers calved in other seasons.

CONCLUSION

The impact of AFC on Jersey production, fertility and longevity traits shows a similar trend to that seen in the Holstein, potentially on a lesser scale.

P1491 Aneurysm of the membranous septum after spontaneous closure of ventricular septal defect combined with bicuspid aortic valve

An 18-year-old asymptomatic patient with a cardiac background of ventricular septal defect (VSD) and bicuspid aortic valve diagnosed in early childhood, was referred to our Adult Congenital Heart Disease (ACHD) outpatient clinic for routine assessment. Imaging by transthoracic echocardiography and Cardiac Magnetic Resonance (CMR) showed a well-developed multilobulated appendiform saccular formation (34x20mm) arising from the right ventricular side of the membranous septum inferior to the anterior aortic cusp and just beneath the septal leaflet of the tricuspid valve, protruding into the right ventricular outflow tract and the body of right ventricle. The fibrous quality and the absence of myocardium in this structure led to the formation of an aneurysm of the membranous septum (AMS) with the characteristic outpouching or ‘windsock’ appearance from its distention during ventricular systole (Figure). There was no shunt between the ventricles. The aortic valve was true bicuspid with severe aortic regurgitation and an eccentric jet towards the anterior leaflet of the mitral valve. The left ventricle was dilated with preserved systolic function. On the basis of the above information the Heart Team decided for surgical management.Both the presence of a true bicuspid valve (embryologically linked to VSD) as well as the pre-existing left-to-right shunting (until the spontaneous VSD closure) seem to have contributed to aortic valve dysfunction in this case. An interesting physical phenomenon concerning fluid dynamics, known as the ‘Venturi effect’, occurs in patients with ‘aneurysmal transformation’ of the ventricular septum, where the VSD becomes smaller creating thus a low-pressure zone that affects the adjacent aortic valve cusp, causing prolapse and, hence, aortic valve regurgitation.

Non-invasive imaging evaluation of patients with AMS is required for optimal diagnosis and treatment as well as for follow-up examinations. Echocardiography is an effective tool for diagnosing AMS, mainly as an incidental finding in asymptomatic subjects whereas CMR is capable of three-dimensional anatomical assessment and provides functional data about the blood flow into the aneurysm and integrity of the ventricular membranous septum.

Abstract P1491 Figure

P1817 The effect of permanent pacemaker implantation following transcatheter aortic valve replacement upon survival

Background

Transcatheter aortic valve replacement (TAVR) is often followed by conduction abnormalities, leading to a permanent pacemaker implantation (PPI). Data regarding the clinical impact of PPI following TAVR is yet to be established.

Purpose

To determine the effect of PPI after TAVR on long-term survival.

Methods : Patients with severe and symptomatic aortic stenosis [effective orifice area (EOA)≤1cm2] referred for TAVI at our institution were consecutively enrolled. Prospectively collected demographic, laboratory and echocardiographic data were retrospectively analyzed. Patients were stratified into two groups according to the need for PPI after TAVR and were followed up postoperatively with clinical and echocardiographic assessment. Primary clinical endpoint was all-cause mortality, as defined by the criteria proposed by the Valve Academic Research Consortium2.

Results : In total, 276 patients were included (male : 48.9%, mean age : 80 ± 7.5years) in our study . Of these, 107 (38.8%) underwent PPI simultaneously or shortly after TAVR. The median follow-up period was 26.6 [min. 0, max 116] months. In this period, all-cause mortality showed no significant difference between patients with and those without PPI after TAVR (log-rank p = 0.862). Subgroup analysis also showed no difference in survival between patients with low ejection fraction (<50%) and those with preserved (≥50%) receiving a permanent pacemaker after TAVR (log-rank p = 0.360). Including factors that were found to associate to PPI in univariate analysis (pre TAVR - ejection fraction, pulmonary artery systolic pressure and New York Heart Association functional class) in a multivariate model, pre TAVR pulmonary artery systolic pressure was found to be an independent predictor of peri-procedural PPI [Exp(B) : 0.974, 95% Confidence Interval : 0.953- 0.995, B= - 0.027, p= 0.015].

Conclusion : PPI following TAVR was not associated with survival at 26 months of follow-up, independently from the pre TAVR ejection fraction.

Abstract P1817 Figure.

P298 The long-term impact of persistent pulmonary hypertension in patients undergoing TAVR with a self-expanding valve

Background

Persistent severe pulmonary hypertension (PH) is considered to negatively affect early and late outcomes of patients undergoing aortic valve surgery. There is limited data however, cincerning the incidence of persistent PH after transcatheter aortic valve replacement (TAVR) and its impact on outcome is limited.

Purpose

We sought to investigate the impact of persistent PH on clinical outcomes of patients undergoing TAVR with a self-expanding valve.

Methods

Consecutive patients with severe symptomatic aortic stenosis scheduled for TAVR in our tertiary center were included in the study. Prospectively collected data before and after TAVR were retrospectively analyzed in all patients. Severe PH was defined as systolic pulmonary arterial pressure (sPAP) ≥45mmHg as assessed by echocardiography. For analysis purposes, patients with a sPAP decrease after TAVR to below 45mmHg were compared to patients with persistent PH following TAVR. All outcomes were evaluated according to the VARC-2 criteria.

Results

In total, 258 patients were included in this study (mean age 80.06 ± 7.50 years old, logEuroscore 24.50 ± 9.70%, NYHA III/IV Class 98.6%). Of these, 149 (57.8%) had sPAP less than 45mmHg and 109 (42.2%) had sPAP above or equal to 45mmHg at baseline. Patients with severe PH were older (81.1 ± 7.0 vs 79.1 ± 7.7, p = 0.034), presented with higher logEuroscore (26.9 ± 9.3% vs 22.5 ± 9.9%, p< 0.001), lower ejection fraction (47.9 ± 9.3% vs 52.2 ± 8.5%, p< 0.001) and higher rates of at least moderate mitral regurgitation (36.7% vs 16.2%, p = 0.002) compared to the group without PH. After TAVR, 161 (62.4%) patients had sPAP less than 45mmHg and 97 (37.6%) had sPAP above 45mmHg. There was a significant decrease of 2.4 ± 12.2mmHg in sPAP post TAVR (p < 0.01). Multivariable analysis (univariate analysis: age, logEuroscore, pre TAVR mitral regurgitation, pre TAVR ejection fraction below 40%) identified pre TAVR ejection fraction below 40% to be the most powerful predictor for persistent PH after TAVR (odds ratio 2.4, 95% confidence interval 1.0.9 – 5.26, p = 0.028). During a mean follow up period of 26.6 ± 26.8, the presence of pre TAVR severe PH was not found to be predictive of cumulative mortality[Hazard Ratio(HR) : 1.57, 95% Confidence Intervals (CI) 0.92 – 2.66, p = 0.09). However, in the same follow up period, patients with persistent PH after TAVR had higher cumulative risk of death compared to patients with sPAP < 45mmHg after TAVR (Hazard Ratio 0.49, 95% Confidence Intervals 0.29-0.82, p = 0.007) (Figure).

Conclusions

Our data suggest that TAVR is associated with a significant reduction in sPAP. Persistent PH post TAVR seems to be a predictor of higher cumulative mortality post TAVR.

Abstract P298 Figure.

P1320 Percutaneous mitral valve leaflet plication to reduce systolic anterior motion and mitral regurgitation using the transcatheter mitral clip system

A 72-year-old female patient with a past medical history of severe mitral regurgitation, atrial fibrillation and embolic cerebrovascular events was admitted to our institution. The patient was under optimal medical therapy and complained for progressive worsening of activity-related dyspnea with limitation of physical activity (NYHA III).

Transthoracic echocardiography showed the presence of severe mitral regurgitation with a central jet. There was prolapse of both mitral valve leaflets and interestingly the anterior leaflet presented systolic anterior motion (SAM) at the same time. There was no significant left ventricular outflow tract obstruction (LVOT). Further evaluation of the regurgitant mitral valve with a transesophageal echocardiography (TOE) confirmed the above findings and the mechanism of MV regurgitation was attributed to prolapse in addition to SAM of an elongated anterior leaflet. Laboratory test showed elevated NT-pro-BNP levels. A coronary angiography was performed and excluded significant coronary artery disease.

The findings were assessed by our institution’s HEART TEAM and, in the presence of high surgical risk (LogEuroscore 32,76%), a decision for transcatheter mitral valve repair with a Mitral Clip implantation was taken. The Mitral Clip was succesfully implanted with immediate significant reduction of the regurgitant jet and no signs of stenotic behavior of the repaired valve. There was only mild mitral valve regurgitation. Notably, after the procedure there was elimination of the SAM and no LVOT obstruction (Figure). In accordance to the echocardiography findings, the patient demonstrated a significant clinical improvement and was discharged home 1 day after the procedure. Mitral clip implantation in this case showed improvement of the MR by reducing the SAM of the mitral valve.

Abstract P1320 Figure.

P1812 The effect of pre-procedural significant mitral regurgitation upon mortality after transcatheter aortic valve implantation

Background

The presence of concomitant mitral regurgitation (MR) is a common issue in patients with severe aortic stenosis and negatively affects patient outcome. Available data regarding MR reduction due to aortic gradient reduction and left ventricular reverse remodeling after transcatheter aortic valve implantation (TAVI) are contradictory.

Purpose

To investigate the prognostic impact of both pre- and post-procedural MR in patients undergoing TAVI.

Methods

Patients with severe and symptomatic aortic stenosis stenosis [effective orifice area (EOA)≤1cm2] referred for TAVI at our institution were consecutively enrolled. Prospectively collected demographic, laboratory and echocardiographic data were retrospectively analyzed. Patients were stratified into two groups according to MR severity : ≤ grade 1 were defined as non-significant and ≥ grade 2 as significant. Change in MR was determined by comparison between baseline and 30-day echocardiogram. Primary clinical endpoint was all-cause mortality, as defined by the criteria proposed by the Valve Academic Research Consortium2.

Results

263 consecutive patients (136 men, mean age : 80 ± 7.5 years) were included in the analysis. Significant (grade≥2) MR was present in 65 (24,7%) patients, while 198 (75,3%) patients had mild or no ( ≤ grade 1) MR. Comparing the two groups, patients with significant MR had higher systolic pulmonary pressure (51.3 ± 14.6mmHg versus 42.8 ± 11.2mmHg, p < 0.001), lower ejection fraction (47.4 ± 10.8% versus 51.2 ± 8.2%) and were more dyspnoic (New York Heart Association class IV 18.5% vesrus 2.5%, p < 0.001). The primary clinical end point occurred in 63 (24%) patients during a follow-up period of 26.6 ± 26.8 months. Patients with significant pre-procedural MR displayed greater cumulative mortality (40% versus 18.8%, p = 0.001). Perioperative risk assessed by logistic EuroScore, NYHA class and pre-procedural MR were found to significantly associate to cumulative mortality in a univariate analysis. Performing a multivariable analysis demonstrated that preprocedural MR severity could independently predict cumulative mortality [OR 2.38, B = 0.869 (95% CI 1.2 – 4.6, p = 0.01)] (Figure).

Conclusion

Significant MR is not infrequent in patients undergoing TAVI and appears to independently associate with high increased all-cause mortality.

Abstract P1812 Figure.

P3716Increased two-year cerebrovascular event rate in patients with bilateral high carotid tempratures

Introduction

The association of carotid plaque inflammation with cerebrovascular events is a matter of rigorous research. Microwave Radiometry (MWR) allows in vivo noninvasive measurement of the internal temperatures of tissues, reflecting inflammation.

Purpose

To investigate whether increased carotid temperatures in patients with documented coronary artery disease (CAD) are associated with cerebrovascular events.

Methods

Consecutive patients with significant CAD from three tertiary centers were included in the study. Maximum carotid plaque thickness was assessed in all carotids by ultrasound. ΔT by MWR was assigned as the temperature difference (maximal minus minimum) along the carotid artery. ΔT ≥0.90°C was assigned as high ΔT. All patients were followed-up clinically for two years and all strokes were adjudicated by an independent committee. Transient ischemic attacks were excluded.

Results

In total 300 patients were included in the study. High ΔT temperatures bilaterally were measured in 47 patients (15.7%). Three patients (1.0%) suffered a stroke, including one fatal. Stoke rate was 4.3% in the group with bilateral high ΔT and 0.4% in non-high ΔT group (p=0.02). In Kaplan-Meier plot patients with bilateral high ΔT showed higher stroke rate (log-rank p=0.004, figure)

Conclusions

Bilateral high carotid temperatures are associated with increased two-year stroke rate. The potential value of the present finding in risk stratification of intermediate carotid stenosis mandates further investigation.

Effect of feeding grape seed Proanthocyanidin extract on production performance, metabolic and anti-oxidative status of dairy cattle

ABSTRACT Aims to investigate the effects of grape seed proanthocyanidin extract (GSPE) on production performance, metabolism, and anti-oxidative status of Holstein dairy cattle in early lactation. Forty-eight multiparous Holstein dairy cattle were assigned to four groups (CON, G20, G40 and G80) and supplied with 0, 20, 40, and 80mg GSPE/kg of body weight/day. G20 significantly increased milk yield compared with other groups. Milk protein and non-fat-solids were increased in G20, G40 and G80 groups compared with the control group only at the 7th day during the experiment. No significant difference was observed in milk fat and somatic cell count, nor on parameters of energy metabolism in blood, liver function and kidney function between the four groups. There was no significant difference in glutathione peroxidase, superoxide dismutase, total antioxidant capacity, and hydrogen peroxide between the groups; but the malondialdehyde content of G20 significantly increased at day 14 in comparison with CON, and tended to increase at the 28th day. In conclusion, feeding 20mg GSPE/kg of body weight/day was associated with a significant increase in milk yield without detrimental effects on liver or kidney function and with substantial energy metabolism and antioxidant parameters improvement in early lactation dairy cattle.

16S rRNA amplicon sequencing reveals a polymicrobial nature of complicated claw horn disruption lesions and interdigital phlegmon in dairy cattle

Lameness represents an intractable problem for the dairy industry. Complicated claw horn disruption lesions, interdigital hyperplasia, and interdigital phlegmon are important lameness causing foot lesions. Their aetiology is multifactorial, but infectious processes are likely implicated in disease pathogenesis. Our aim was to investigate the bacterial profiles of these lesions using 16S rRNA gene sequencing of samples obtained from 51 cattle across ten farms in the UK. In this study, interdigital hyperplasia, interdigital hyperplasia with signs of interdigital dermatitis, interdigital phlegmon, complicated sole ulcers, complicated toe ulcers lesions, and complicated white line lesions were investigated; corresponding healthy skin control samples were also analysed. All diseased tissues displayed reduced microbial richness and diversity (as described by Chao1, Shannon, and Simpson alpha-diversity indices) compared to their healthy skin control samples. Our results confirm the association of Treponema spp with some of these disorders. Other anaerobic bacteria including Fusobacterium spp., Fastidiosipila spp. and Porphyromonas spp. were implicated in the aetiology of all these lesions with the exception of interdigital hyperplasia. Complicated claw horn disruption lesions, and interdigital phlegmon were found to have similar bacterial profiles. Such sharing of bacterial genera suggests many of the infectious agents detected in these foot lesions are acting opportunistically; this finding could contribute towards future treatment and control strategies.

The bovine milk microbiota: insights and perspectives from -omics studies

Recent findings and future perspectives of -omics studies on the bovine milk microbiota, focusing on its impact on animal health.

The effect of intrauterine infusion of dextrose on clinical endometritis cure rate and reproductive performance of dairy cows

The main objective of this study was to evaluate the intrauterine administration use of 200 mL of 50% dextrose solution as a treatment against clinical endometritis (CE); CE cure rate and reproductive performance were evaluated. Additionally, the association of several relevant risk factors, such as retained placenta (RP), metritis, CE, anovulation, hyperketonemia, and body condition score with reproductive performance, early embryonic mortality, and CE were evaluated. A total of 1,313 Holstein cows housed on 4 commercial dairy farms were enrolled in the study. At 7±3 DIM cows were examined for metritis and had blood collected to determine serum β-hydroxybutyrate concentration. To determine if cows had ovulated at least once before 44±3 DIM, the presence of a corpus luteum was evaluated by ovarian ultrasonography at 30±3 DIM and at 44±3 DIM. At 30±3 DIM, CE was diagnosed using the Metricheck device (SimcroTech, Hamilton, New Zealand); cows with purulent or mucopurulent vaginal discharge were diagnosed as having CE. Cows diagnosed with CE (n=175) were randomly allocated into 2 treatment groups: treatment (intrauterine infusion of 200 mL of 50% dextrose) or control (no infusion). Clinical endometritis cows were re-evaluated as described above at 44±3 DIM, and cows that were free of purulent or mucopurulent vaginal discharge were considered cured. Intrauterine infusion of dextrose tended to have a detrimental effect on CE cure rate, and treatment did not have an effect on first-service conception rate and early embryonic mortality. A multivariable Cox's proportional hazard model was performed to evaluate the effect of several variables on reproductive performance; the variables RP, CE, parity, anovulation, and the interaction term between parity and anovulation were associated with hazard of pregnancy. Cows that did not have RP or CE were more likely to conceive than cows that were diagnosed with RP or CE. Cows that had RP were at 3.36 times higher odds of losing their pregnancy than cows that did not have RP. In addition, cows diagnosed with CE were at 2.16 higher odds of losing their pregnancy than cows without CE. In conclusion, intrauterine infusion of 200 mL of 50% dextrose solution as a treatment for CE had a strong statistical tendency to decrease CE cure rate, did not improve first-service conception rate and early embryonic mortality, and did not decrease calving-to-conception interval.