Early appearance of radiolucent lines around total knee arthroplasty in rheumatoid arthritis patients. How does it impact the aseptic failure rate and functional outcomes at 13 years of follow-up?

INTRODUCTION

Aseptic total knee arthroplasty (TKA) failure has been associated with radiolucent lines. This study aimed to determine the impact of the early appearance of radiolucent lines (linear images of 1, 2, or >2mm at the cement-bone interface) around the TKA on prosthetic survival and functional outcomes in rheumatoid arthritis (RA) patients during a 2-20 years follow-up.

METHODS

We retrospectively analyzed a consecutive series of RA patients treated with TKA between 2000 and 2011. We comparatively analyzed patients with and without radiolucent lines around implants. Clinical outcomes were assessed with the knee society score (KSS) collected before surgery, at years 2, 5, and 10, and at the last postoperative follow-up. The knee society roentgenographic evaluation system was used to analyze the impact of radiolucent lines around the implants at 1, 2, 5, and more than ten years of follow-up. The reoperation and prosthetic survival rates were calculated at the end of the follow-up.

RESULTS

The study series included 72 TKAs with a median follow-up of 13.2 years (range: 4.0-21.0), of which 16 (22.2%) had radiolucent lines. We did not observe aseptic failure, and prosthetic survival at the end of the study was 94.4% (n=68). The KSS improved significantly (p<0.001) between preoperative values at 2, 5, and 10 years and the end of follow-up, with no differences between patients with and without radiolucent lines.

CONCLUSIONS

Our study demonstrates that the early appearance of radiolucent lines around a TKA in RA patients does not significantly impact prosthetic survival or long-term functional outcomes at 13 years of follow-up.

Total hip arthroplasty in patients under 50 years old: Does cementless fixation have better results?

BACKGROUND

Cementless fixation for hip arthroplasties has increased in the last decades, particularly in younger patients. The purpose of this study was to compare the long-term results three different types of fixations in patients under 50years old.

METHODS

Cemented, hybrid and cementless fixations were assessed in patients under 50years old with a minimum follow-up of 8years. Loosening, demarcation, complications, and prosthesis survival were assessed. Functional analysis was performed with the modified Harris Hip Score and Visual analogue scale was collected.

RESULTS

Final series consisted in 222 patients. Significant improvement was observed regarding mHHS and VAS score in each group. We observed statistically significant difference regarding demarcation between the groups (P<.001). The higher rate of acetabular and femoral stem loosening was observed in the cemented (20.0%) and hybrid (18.9%) group. The lowest prosthesis survival rate after 16 years was observed in hybrid group (P<.001).

CONCLUSION

Total hip replacement has good long-term clinical and functional outcomes. The lowest rate of prosthesis survival was observed in hybrid group with 84.2% after 16years.

Multi-Modal Digital Impressions For Palatal Defects

INTRODUCTION

This in-vitro study investigated limitations of intra-oral scanners (IOS) in capturing palatal defects at decreased mouth openings. The trueness and precision of composite 3D-printed models from Cone-Beam Computed Tomography (CBCT) and IOS were measured.

METHODS

A partially dentate palatal defect model was scanned with IOS (3M™TrueDefinition) at various simulated mouth openings. Five silicone impressions were poured in gypsum. Scans were taken using 3M™TrueDefinition; Planmeca Planscan®, n=5 each. Model was scanned on two CBCT (PlanmecaProFace®; Accuitomo170®CBCT, n=5 each). Geomagic®Control2014™ was used to create composite-models merging CBCT with IOS. Thirty composite-models were 3D-printed. Trueness and precision were measured. Pearson Correlation Coefficients measured correlation between mouth opening and data capture. Data analysed using Kruskal-Wallis, Wilcoxon rank-sum, and ANOVA. Statistical significance inferred when p⟨0.05.

RESULTS

Mouth openings ⟨20mm, IOS didn't capture information of soft tissue. Increased mouth opening positively correlated with increased data capture(r=0.93, p=0.001). AccuitomoCBCT and TrueDefinition IOS composite-models had the highest (trueness) and [precision](median (IQR) 0.172 mm(0.062-0.426)); [mean [SD] 0.080 mm [0.008]]. Casts had the lowest results (median (IQR) 0.289 mm(0.119-1.565));[mean [SD] 0.338 mm [0.089]](p⟨0.001).

CONCLUSION

Mouth opening ⟨20mm resulted in insufficient data capture by IOS for clinical applications. Composite digital models showed promising trueness and precision results.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

The effect of fibre cell remodelling on the power and optical quality of the lens

Vertebrate eye lenses are uniquely adapted to form a refractive index gradient (GRIN) for improved acuity, and to grow slowly in size despite constant cell proliferation. The mechanisms behind these adaptations remain poorly understood. We hypothesize that cell compaction contributes to both. To test this notion, we examined the relationship between lens size and shape, refractive characteristics and the cross-sectional areas of constituent fibre cells in mice of different ages. We developed a block-face imaging method to visualize cellular cross sections and found that the cross-sectional areas of fibre cells rose and then decreased over time, with the most significant reduction occurring in denucleating cells in the adult lens cortex, followed by cells in the embryonic nucleus. These findings help reconcile differences between the predictions of lens growth models and empirical data. Biomechanical simulations suggested that compressive forces generated from continuous deposition of fibre cells could contribute to cellular compaction. However, optical measurements revealed that the GRIN did not mirror the pattern of cellular compaction, implying that compaction alone cannot account for GRIN formation and that additional mechanisms are likely to be involved.

Cost-Effectiveness Analysis of 68Ga-DOTATATE PET/MRI in Radiotherapy Planning in Patients with Intermediate-Risk Meningioma

BACKGROUND AND PURPOSE

While contrast-enhanced MR imaging is the criterion standard in meningioma diagnosis and treatment response assessment, gallium 68Ga-DOTATATE PET/MR imaging has increasingly demonstrated utility in meningioma diagnosis and management. Integrating 68Ga-DOTATATE PET/MR imaging in postsurgical radiation planning reduces the planning target volume and organ-at-risk dose. However, 68Ga-DOTATATE PET/MR imaging is not widely implemented in clinical practice due to higher perceived costs. Our study analyzes the cost-effectiveness of 68Ga-DOTATATE PET/MR imaging for postresection radiation therapy planning in patients with intermediate-risk meningioma.

MATERIALS AND METHODS

We developed a decision-analytical model based on both recommended guidelines on meningioma management and our institutional experience. Markov models were implemented to estimate quality-adjusted life-years (QALY). Cost-effectiveness analyses with willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were performed from a societal perspective. Sensitivity analyses were conducted to validate the results. Model input values were based on published literature.

RESULTS

The cost-effectiveness results demonstrated that 68Ga-DOTATATE PET/MR imaging yields higher QALY (5.47 versus 5.05) at a higher cost ($404,260 versus $395,535) compared with MR imaging alone. The incremental cost-effectiveness ratio analysis determined that 68Ga-DOTATATE PET/MR imaging is cost-effective at a willingness to pay of $50,000/QALY and $100,000/QALY. Furthermore, sensitivity analyses showed that 68Ga-DOTATATE PET/MR imaging is cost-effective at $50,000/QALY ($100,000/QALY) for specificity and sensitivity values above 76% (58%) and 53% (44%), respectively.

CONCLUSIONS

68Ga-DOTATATE PET/MR imaging as an adjunct imaging technique is cost-effective in postoperative treatment planning in patients with meningiomas. Most important, the model results show that the sensitivity and specificity cost-effective thresholds of 68Ga-DOTATATE PET/MR imaging could be attained in clinical practice.

Risk factors for fixation failure in intertrochanteric fractures treated with cephalomedullary nailing: a retrospective study of 251 patients

This study aimed to identify the variables associated with fixation failure in intertrochanteric fractures treated with cephalomedullary nailing (CMN). We retrospectively analyzed 251 consecutive patients who underwent surgery between January 2016 and July 2019. In order to identify predictors of failure (cut-out, cut-through, and/or nonunion), we analyzed: gender, age, fracture stability (according to the AO/OTA Classification), femoral neck angle (FNA), FNA as compared to the contralateral hip, lag screw position, and tip-apex distance (TAD). The failure rate was 9.6%: there were 10 cut-outs (4%), 7 non-unions (2.8%), and 7 cut-throughs (2.8%). Univariate logistic regression analysis showed that the risk factors for fixation failure were: female sex (p= 0.018), FNA <125° (p= 0.003), a difference in FNA of 7.5° as compared to the contralateral hip on the lateral radiograph (p= <0.0001), superior (p= 0.0141) and anterior position (p= <0.0001) of the lag screw, and TAD >25mm (p= 0.016). According to the multivariate analysis, female gender (OR 12.92 ; p 0.0019), the difference in FNA on the lateral view (OR 1.36; p < 0.001), and the anterior position of the screw in the femoral head (OR14.01;p <0.001) were confirmed as independent predictors of failure. In order to avoid failures in intertrochanteric hip fractures treated with CMN, this study confirmed the importance of achieving an accurate reduction on the lateral plane and avoiding the anterior position of the screw on the femoral head.

Profile and prognosis of patients with heart failure with recovered ejection fraction

Background

Patients with heart failure (HF) and reduced ejection fraction (rEF) have a poor prognosis. Nevertheless, in the subgroup of patients with recovered ejection fraction (recEF) prognosis is unknown.

Purpose

To analyze characteristics and prognosis in patients with HFrEF (initial EF and at one year &lt;40%) and HFrecEF (initial EF &lt;40% and at one year ≥40% with ≥10% absolute improvement from the initial value).

Methods

Retrospective observational study of outpatients referred to the HF unit within March/2006 and November/2021. Baseline characteristics, ecocardiographic data and follow-up were collected, discerning between patients with HFrEF and HFrecEF.

Results

A total of 346 patients (76.0% men) were analyzed with a mean of age 66.3 (IQR 57.8–74.4) years, of which 50.6% remained with rEF and 49.4% recEF. Median follow-up was 4.6 (2.8–7.9) years. Both groups had a similar risk profile albeit less prevalence of dyslipidemia in the group with recEF (43.5% vs 56.7%, p=0.015). Ischemic etiology predominated in those with rEF (41.7% vs 25.7%, p=0.002) and enolic in recEF (10.5% vs 3.4%, p=0.009). The incidence of combined event (readmission for HF or death) was lower in HFrecEF (33.6% vs 66.4%, p&lt;0.001), as well as death (33.9% vs 66.1%, p&lt;0.001) and readmission for HF (24.4% vs 75.6%, p&lt;0.001). Prevalence of cardiovascular death was lower in the group with recEF (37.8% vs 61.1%, p=0.021). In the multivariate analysis, rEF was an independent predictor for the combined event (HR 2.17; 95% IC [1.45–3.25], p&lt;0.001), as well as for global mortality and readmission for HF.

Conclusion

Patients with HFrecEF have a similar risk profile than patients with HFrEF although with better long-term prognosis.

Funding Acknowledgement

Type of funding sources: None.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Affective States and Virtual Reality to Improve Gait Rehabilitation: A Preliminary Study

Over seven million people suffer from an impairment in Mexico; 64.1% are gait-related, and 36.2% are children aged 0 to 14 years. Furthermore, many suffer from neurological disorders, which limits their verbal skills to provide accurate feedback. Robot-assisted gait therapy has shown significant benefits, but the users must make an active effort to accomplish muscular memory, which usually is only around 30% of the time. Moreover, during therapy, the patients' affective state is mostly unsatisfied, wide-awake, and powerless. This paper proposes a method for increasing the efficiency by combining affective data from an Emotiv Insight, an Oculus Go headset displaying an immersive interaction, and a feedback system. Our preliminary study had eight patients during therapy and eight students analyzing the footage using the self-assessment Manikin. It showed that it is possible to use an EEG headset and identify the affective state with a weighted average precision of 97.5%, recall of 87.9%, and F1-score of 92.3% in general. Furthermore, using a VR device could boost efficiency by 16% more. In conclusion, this method allows providing feedback to the therapist in real-time even if the patient is non-verbal and has a limited amount of facial and body expressions.

Clinical Correlates of Cardiac Conduction in Bipolar Disorder

Introduction

Patients with bipolar disorder (BD) have an increased risk for cardiovascular morbimortality. Clinical risk factors, specifically for arrhythmias and sudden cardiac death remain understudied.

Objectives

This study was conducted to assess differences in cardiac conduction among BD patients.

Methods

We included patients with BD in a cross-sectional design, confirmed by structured interview, age 18 through 80. Clinical characteristics were obtained using a structured questionnaire or medical records review. ECG intervals duration and morphology were manually assessed by cardiologists and compared among clinical subgroups using Chi-square, Mann-Whitney, and Kruskall-Wallis tests. Exploratory multivariable linear and logistic regression models were fitted to adjust for potential confounders.

Results

We included 117 patients (60.7% women, 76.9% bipolar I, 50% history of psychosis, 22.6% suicide attempts). We found a significantly longer QTc interval in BD patients with hypertension (difference: 9.5 ms, p=0.006), obesity (difference: 25 ms, p=0.001), and metabolic syndrome (difference: 13 ms, p=0.007). Hypertension remained a significant predictor of longer QTc after adjusting for age, gender, and antipsychotic use (estimate 17.718, p=0.018). We observed a significantly shorter PR interval in women (difference: 6 ms, p=0.029), early age of onset (difference 6 ms, p=0.025), non-users of lithium (difference 4 ms, p=0.002), and early trauma (difference 4 ms, p=0.038). Finally, we identified significant correlations between symptom severity, blood glucose and PR interval (r=0.298, p=0.001; r=0.278, p=0.003; respectively).

Conclusions

Patients with BD and hypertension may have an increased risk for QTc prolongation. Careful cardiovascular monitoring may be warranted.

Disclosure

No significant relationships.

OP0223 DISTINGUISHING OSTEOARTHRITIS AND RHEUMATOID ARTHRITIS SYNOVIUM WITH MACHINE LEARNING USING AUTOMATED CELL DENSITY AND PATHOLOGIST SCORES

Background

Joint damage in the knee can be severe in both rheumatoid arthritis (RA) and osteoarthritis (OA) such that total knee replacement (TKR) is often the only management option. Pathological assessment of the extent or type of synovial tissue inflammation from joint explants or biopsies can be useful. However, an ongoing challenge in using semi-quantitative assessments of synovitis is the disagreement between human pathologist scores of the same sample. We previously developed and validated a computer vision algorithm to automatically count each cell nucleus in an H&E-stained synovial whole slide image and yield a value of cell density, defined as mean nuclei count per mm2 of tissue1.

Objectives

We sought to develop methods to distinguish OA from RA based on machine learning analysis of histologic features on H&E-stained synovial tissue samples.

Methods

We measured 14 pathologist-scored histology features (137 RA and 152 OA patients) and computer vision quantified cell density (60 RA and 147 OA patients) in H&E stained synovial tissue samples from total knee replacement arthroplasty explants. A random forest model was trained using disease state (OA vs RA) as classifier and histology features and/or cell density as inputs, and feature importance scores for the model were calculated.

Results

Synovium from patients with RA exhibited increased lymphocytic inflammation, lining hyperplasia, neutrophils, detritus, plasma cells, Russell bodies, binucleate plasma cells, sub-lining giant cells, synovial lining giant cells, and fibrin (all p<0.001), while synovium from patients with OA had increased mast cells and fibrosis (both p<0.001). Fourteen pathologist-scored features allowed for discrimination between RA and OA samples, producing a macro-averaged area under the receiver operating curve (AUC) of 0.85. This discriminatory ability was comparable to that of the computer vision score of cell density alone (AUC = 0.88). Combining the pathologist scores with the cell density metric improved the discriminatory power of the model (AUC = 0.91). The three most important features in this combined model were mast cells followed by cell density and fibrosis (Figure 1). AUC values for each individual feature are provided in Table 1. The optimal cell density threshold to distinguish RA from OA synovium was 3,400 cells per mm2, which yielded a sensitivity of 0.82 and specificity of 0.82.

Table 1.

Area under receiver operating characteristic curves (AUC) of the synovial features in distinguishing RA and OA patients

FeatureAUCAutomated Cell Density0.88Fibrosis0.84Mast cells0.80Lining hyperplasia0.78Lymphocytic inflammation0.69Fibrin0.68Plasma cells0.66Detritus0.64Binucleate plasma cells0.60Neutrophils0.60Synovial giant cells0.58Sub-lining giant cells0.57Russell bodies0.56Germinal centers0.51Mucoid change0.50Figure 1.

Importance of synovial features in distinguishing RA and OA synovium

Feature importance scores for supervised machine learning model including all 14 pathology scores and the computer vision-generated cell density.

Conclusion

H&E-stained images of RA and OA TKR explant synovium are distinct. We identified cell density, mast cells and fibrosis as the three most important features for making this distinction, with RA being characterized by increased cell density, low mast cells, and low fibrosis. Cell density greater than 3400 per mm2 of tissue yields a sensitivity of 0.82 and a specificity of 0.82 for distinguishing RA from OA. In the future, this can have clinical and research applications as this technique removes the requirement for subjective selection of a certain field of interest, is reproducible, and is scalable as it does not require technical expertise of a pathologist.

References

[1]Guan S, Mehta B…Orange DE. Rheumatoid Arthritis Synovial Inflammation Quantification Using Computer Vision. ACR Open Rheumatology. 2022 Jan 10;acr2.11381.

Acknowledgements

This work was supported by the C. Ronald MacKenzie Young Scientist Endowment Award, the Leon Lowenstein Foundation, and the Kellen Scholar Award supported by the Anna Marie and Stephen Kellen Foundation Total Knee Improvement Program.

Disclosure of Interests

Bella Mehta Paid instructor for: Novartis, Susan Goodman Consultant of: UCB, Grant/research support from: Novartis, Edward DiCarlo: None declared, Deanna Jannat-Khah Shareholder of: AstraZeneca, Cytodyn, and Walgreens, J. Alex Gibbons: None declared, Miguel Otero Consultant of: Regeneron Pharmaceuticals, Grant/research support from: Tissue Genesis, Laura Donlin Speakers bureau: Stryker, Consultant of: Stryker, Grant/research support from: Karius, Inc, Tania Pannellini: None declared, William Robinson: None declared, Peter Sculco Consultant of: Intellijoint Surgical, DePuy Synthes, Lima Corporate, Zimmer Biomet, and EOS Imaging, Grant/research support from: Intellijoint Surgical and Zimmer Biomet, Mark Figgie Shareholder of: HS2, Mekanika, and Wishbone, Consultant of: Lima and Wishbone, Jose Rodriguez Consultant of: ConforMIS, Medacta, Exactech, Inc, and Smith & Nephew, Grant/research support from: DePuy, Exactech, Inc, and Smith & Nephew, Jessica Kirschmann: None declared, James Thompson: None declared, David Slater: None declared, Damon Frezza: None declared, Zhenxing Xu: None declared, Fei Wang: None declared, Dana Orange: None declared

Left atrial appendage perimeter ostium evaluation by cardiac CT utilizing 3mensio technology for watchman implantation

Background

Left atrial appendage occlusion (LAAO) with Watchman device traditionally relies on accurate left atrial appendage ostium diameter measurement by 2D or 3D transesophageal echocardiogram (TEE). Alternate methods of ostium measurement including area-derived diameter and perimeter-derived diameter using cardiac computed tomography (CT) have been proposed.

Methods

We performed a retrospective analysis of 92 patients with atrial fibrillation (Afib) who underwent LAAO with WATCHMAN implantation with pre-procedural TEE and CT between May 2015 and December 2018. LAA characteristics including ostial or landing zone perimeter, minimum and maximum diameters were acquired utilizing 3mensio Structural Heart Imaging Program. Proposed device size was estimated utilizing ostium perimeter by CT and compared to the current standard utilizing ostium diameter by 2D-TEE. Both measurements were then compared to actual final device size that satisfying release criteria.

Results

CT had a very high correlation with the actual implanted device size (Pearson coefficient r=0.94, p&lt;0.001), while TEE based sizing had a lower correlation (Pearson coefficient r=0.66, p&lt;0.001). CT predicted size had a significantly higher agreement compared to standard TEE based sizing (93.4% vs 47.8%), and higher interrater agreement (Cohen's kappa = 0.91 vs Cohen's kappa = 0.32, p&lt;0.001, p&lt;0.001 respectively). Bland-Altman analysis also showed better correlation with CT-based sizing. Procedural complications were 0, and 0 patients had a leak recorded at 45-days post implant.

Conclusion

CCT LAA perimeter sizing is superior to the current standard TEE based Watchman sizing. Larger, multi-center studies may be necessary to further validate results.

Funding Acknowledgement

Type of funding sources: None. 3mensio after CT upload

Latent-transforming growth factor beta-binding protein-2 (LTBP-2) is required for longevity but not for development of zonular fibers

Latent-transforming growth factor beta-binding protein 2 (LTBP-2) is a major component of arterial and lung tissue and of the ciliary zonule, the system of extracellular fibers that centers and suspends the lens in the eye. LTBP-2 has been implicated previously in the development of extracellular microfibrils, although its exact role remains unclear. Here, we analyzed the three-dimensional structure of the ciliary zonule in wild type mice and used a knockout model to test the contribution of LTBP-2 to zonule structure and mechanical properties. In wild types, zonular fibers had diameters of 0.5-1.0 micrometers, with an outer layer of fibrillin-1-rich microfibrils and a core of fibrillin-2-rich microfibrils. LTBP-2 was present in both layers. The absence of LTBP-2 did not affect the number of fibers, their diameters, nor their coaxial organization. However, by two months of age, LTBP-2-depleted fibers began to rupture, and by six months, a fully penetrant ectopia lentis phenotype was present, as confirmed by in vivo imaging. To determine whether the seemingly normal fibers of young mice were compromised mechanically, we compared zonule stress/strain relationships of wild type and LTBP-2-deficient mice and developed a quasi-linear viscoelastic engineering model to analyze the resulting data. In the absence of LTBP-2, the ultimate tensile strength of the zonule was reduced by about 50%, and the viscoelastic behavior of the fibers was altered significantly. We developed a harmonic oscillator model to calculate the forces generated during saccadic eye movement. Model simulations suggested that mutant fibers are prone to failure during rapid rotation of the eyeball. Together, these data indicate that LTBP-2 is necessary for the strength and longevity of zonular fibers, but not necessarily for their formation.

Autogenous transfer of intracytoplasmic sperm injection-produced equine embryos into the uterus of the oocyte donor during the same oestrous cycle

The clinical use of intracytoplasmic sperm injection (ICSI) in horses usually involves the transfer of embryos into recipient mares, resulting in substantial cost increases. This is essential when subfertile mares are oocyte donors; but some donors are fertile, with ICSI compensating for limited or poor-quality spermatozoa. Fertile oocyte donors could carry pregnancies, eliminating the need for a recipient. We assessed the potential of using oocyte donors as recipients for their own ICSI-produced embryos during the same cycle. Donors in oestrus and with large dominant follicles were administered ovulation-inducing compounds to cause follicle and oocyte maturation. Maturing oocytes were collected, cultured and fertilised using ICSI. At 6 or 7 days after ICSI, developing blastocysts were transferred into respective donors' uteri, and pregnancy rates were determined. Twenty follicles were aspirated from nine mares and 12 oocytes were collected. After ICSI, 10 of the 12 oocytes (83%) cleaved, and eight (67% of injected oocytes) developed into blastocysts for transfer. Five pregnancies resulted from the eight transferred embryos (pregnancy rate 62% per embryo and 42% per sperm-injected oocyte). Following this synchronisation regime, ICSI-produced embryos can be transferred into oocyte donors' uteri during the same cycle, allowing donors to carry pregnancies after assisted fertilisation.

AB0594 EFFECTIVENESS OF RITUXIMAB IN CSDMARDS-RESISTANT ACTIVE MIXED CONNECTIVE TISSUE DISEASE

Background:

Objectives:

To evaluate rituximab (RTX) effectiveness and safety in treating patients with refractory mixed connective tissue disease (MCTD).

Methods:

Open observational study including patients with refractory MCTD (active disease despite treatment with glucocorticoids and csDMARDs) from two third-level hospitals who had been treated with RTX (off-label use) from January 2001 to December 2019.

Results:

Thirteen patients (all women) were included, with a mean age of 32 years (SD: 10, range 17-50) and a median time of evolution of the disease of 55 months (SD: 34.3; range 5-98 months). The main indication for initiating treatment with RTX was refractory arthritis (100%), most of the times accompanied by other features of the disease including shrinking lung syndrome (2), fibrosing progressive non-specific interstitial pneumonia (FP-NSIP) (1), recurrent serositis (2), glomerulonephritis (GMN) (2), lymphadenitis (1) and immune thrombocytopenic purpura (ITP) (1). All patients were treated with RTX at rheumatoid arthritis dosage while the baseline immunosuppressive treatment (methotrexate, azathioprine, mycophenolate, leflunomide or tacrolimus) remained unchanged. Hydroxychloroquine was also associated in 8 of the patients. The follow-up time (median) after starting RTX was 118 months (range, 65-177 months, with a total of 132.6 patient-years of follow-up) and the mean number of cycles of treatment was 4.2 (range, 1-15), with a variable interval (from 6 to 12 months). After the first RTX cycle, a partial or complete response was achieved in 92% of the patients. A significant improvement in the mean DAS28-ESR was observed (initial: 4.56 ± 1.6 / final: 2.21 ± 0.85; p=0.008). In all but one patient, who had previously failed to 2 anti-TNFα DAS28-ESR clinical remission or low activity was achieved, generally from week 16 to 20, although relapses were frequent and all cases need retreatment after 6-9 months. In 4 patients, RTX retreatment dosage was optimized to 1 g/cycle. The 3 patients with pulmonary involvement showed stabilization (2 cases) or improvement (1) of the lung function(as defined by the American Thoracic Society). In patients with GMN, renal response to RTX treatment was complete in a patient and partial in the other. The patient with ITP entered remission after the first RTX cycle and no more cycles were needed. Response in patients with serositis and lymphadenitis was also complete and maintained. Moreover, the glucocorticoid doses were reduced to less than half of the initial dose in all cases. At the end of the follow-up, 7 out of the 13 patients (54%) were still being treated with RTX. For the remaining 6 patients, RTX was withdrawn because of primary failure (1), recurrent bacterial infections (2), gestational desire (2) sustained remission (1).

Conclusion:

According to our preliminary results, RTX seems to be effective and relatively safe in patients with csDMARDs-resistant active MCTD.

Disclosure of Interests:

L Montolio-Chiva: None declared, J. Narváez: None declared, Juanjo J Alegre-Sancho Consultant of: UCB, Roche, Sanofi, Boehringer, Celltrion, Paid instructor for: GSK, Speakers bureau: MSD, GSK, Lilly, Sanofi, Roche, UCB, Actelion, Pfizer, Abbvie, Novartis, J Lluch Pons: None declared, Ana V Orenes Vera: None declared, I Vázquez-Gómez: None declared, Maribel Mora: None declared, Xavier González: None declared, Carla Marco: None declared, Jesús Rodriguez: None declared, Montserrat Romera: None declared, Joan Miquel Nolla: None declared

Natural History of Perianal Fistulising Lesions in Patients With Elderly-onset Crohn's Disease: A Population-based Study

INTRODUCTION

Most studies of elderly-onset Crohn's disease [CD; diagnosed in patients aged 60 or over] have described a mild course. However, data on the natural history of perianal fistulising CD [pfCD] in this population are scarce. In a population-based cohort study, we described the prevalence, natural history, and treatment of pfCD in patients with elderly-onset CD vs patients with paediatric-onset CD.

METHOD

All patients diagnosed with CD at or after the age of 60 between 1988 and 2006, were included [n = 372]. Logistic regression, Cox models, and a nested case-control method were used to identify factors associated with pfCD.

RESULTS

A total of 34 elderly patients [9% of the 372] had pfCD at diagnosis. After a median follow-up of 6 years (interquartile range [IQR]: 3; 10), 59 patients [16%] had pfCD; the same prevalence [16%] was observed in paediatric-onset patients. At last follow-up, anal incontinence was more frequent in elderly patients with pfCD than in elderly patients without pfCD [22% vs 4%, respectively; p < 10-4]. Rectal CD at diagnosis was associated with pfCD: hazard ratio (95% confidence interval [CI] = 2.8 [1.6-5.0]). Although 37% of the patients received immunosuppressants and 17% received anti-tumour necrosis factor agents, 24% [14 out of 59] had a definitive stoma at last follow-up.

CONCLUSION

During the first 6 years of disease, the prevalence of pfCD was similar in elderly and paediatric patients. Rectal involvement was associated with the appearance of pfCD in elderly-onset patients. Around a quarter of patients with elderly-onset CD will have a stoma. Our results suggest that treatment with biologics should be evaluated in these patients.

The FiberTAG project: Tagging dietary fibre intake by measuring biomarkers related to the gut microbiota and their interest for health

The scientific rationale for dietary fibre intake recommendations comes from the recognition of their benefits for health based on studies first published many years ago. It remains unclear which are the key physiological effects generated by dietary fibre in view of the diversity of the food components considered as dietary fibre, of the relevance of their classification (soluble and insoluble) and from the recent discoveries putting forward their interactions with the gut microbiota. The project FiberTAG (Joint Programming Initiative 'A Healthy Diet for a Healthy Life' 2017-2020 https://www.fibertag.eu/) aims to establish a set of biomarkers (markers of gut barrier function and bacterial co-metabolites including volatile compounds and lipid derivatives), measured in different biological compartments (faeces, blood or breath) linking dietary fibre intake and gut microbiota-related health effects. The FiberTAG consortium brings together academic and industrial partners from Belgium, France, Germany and Canada to share data and samples obtained from existing as well as new intervention studies in order to evaluate the relevance of such biomarkers. The FiberTAG consortium is currently working on five existing cohorts (prospective observational or nutritional interventions in healthy or obese patients), and a number of new intervention studies to analyse the effect of insoluble dietary fibre (wheat bran and chitin-glucan, provided by the industrial partners) in healthy individuals or in obese patients at high cardiometabolic risk.

SuperCam Calibration Targets: Design and Development

SuperCam is a highly integrated remote-sensing instrumental suite for NASA's Mars 2020 mission. It consists of a co-aligned combination of Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), Visible and Infrared Spectroscopy (VISIR), together with sound recording (MIC) and high-magnification imaging techniques (RMI). They provide information on the mineralogy, geochemistry and mineral context around the Perseverance Rover. The calibration of this complex suite is a major challenge. Not only does each technique require its own standards or references, their combination also introduces new requirements to obtain optimal scientific output. Elemental composition, molecular vibrational features, fluorescence, morphology and texture provide a full picture of the sample with spectral information that needs to be co-aligned, correlated, and individually calibrated. The resulting hardware includes different kinds of targets, each one covering different needs of the instrument. Standards for imaging calibration, geological samples for mineral identification and chemometric calculations or spectral references to calibrate and evaluate the health of the instrument, are all included in the SuperCam Calibration Target (SCCT). The system also includes a specifically designed assembly in which the samples are mounted. This hardware allows the targets to survive the harsh environmental conditions of the launch, cruise, landing and operation on Mars during the whole mission. Here we summarize the design, development, integration, verification and functional testing of the SCCT. This work includes some key results obtained to verify the scientific outcome of the SuperCam system.

Mueller matrix of the particle-free atmospheric enhanced backscatter

The spatially resolved Mueller matrix of a mono-static optical system with the corner-cube retro-reflector operating in the presence of clear-air atmospheric turbulence is measured for the first time, to the best of our knowledge. The changes in the polarization properties of the beam are caused by the combination of deterministic polarimetric modulation by the retro-reflector and random scalar modulation of the return beam by atmospheric turbulence. In particular, the spatial structure of the Mueller matrix within the enhanced backscatter area is revealed.

P1475Risk stratification after STEMI. Ejection fraction by echocardiography as the gatekeeper for a selective use of cardiac magnetic resonance

Introduction

Cardiac magnetic resonance (CMR) has emerged as the most potent non-invasive imaging technique for risk stratification after ST-segment elevation myocardial infarction (STEMI) but an indiscriminate use in all patients is unfeasible. Echocardiography (Echo) has been universally used for prognostication in this scenario. We hypothesized that left ventricular ejection fraction (LVEF) by Echo can represent the gatekeeper for selecting those patients who benefit most from CMR for prognostic purposes.

Methods

Data were obtained from a large prospective registry of reperfused STEMI patients (n=516) in whom Echo (2D and Doppler variables) and CMR (cine images, microvascular obstruction and infarct size) were simultaneously recorded at pre-discharge (7±2 days). Major adverse cardiac events (MACE) were defined as a combined clinical end-point: death or re-admission for acute heart failure (whichever occurred first). Patients were categorized in reduced LVEF (r-LVEF, <40%), mid-range LVEF (mr-LVEF, 40–49%) and preserved LVEF (p-LVEF, ≥50%). Hierarchical multivariate Cox regression analyses including first clinical+Echo variables and then CMR variables where carried out. C-statistics, “net reclassification” (NRI) and “integrated discrimination” (IDI) indexes were obtained.

Results

During a mean and median follow-up of 4 years, 86 first MACE (17%) were registered (39 deaths and 47 re-admissions for acute heart failure). In the whole study group (n=516), the independent predictors of MACE were time to revascularization (min), GRACE score, CMR-LVEF (%) and CMR-microvascular obstruction (% of LV mass); C-statistic 0.82 (p<0.001). The MACE rate in patients with r-LVEF, mr-LVEF and p-LVEF was 47%, 23% and 11% by Echo-LVEF and 45%, 17% and 8% by CMR-LVEF. LVEF was lower by CMR than by Echo (51±13 vs. 54±10, p<0.001) and r-LVEF was more frequently detected by CMR (n=94, 18%) than by Echo (n=48, 9%), p<0.001. CMR significantly improved clinical+Echo stratification in those 112 patients (22%) with mr-Echo-LVEF (C-statistitics 0.74 vs 0.82; NRI and IDI: p<0.05) but it did not in those 355 patients (69%) with p-Echo-LVEF (C-statistitics 0.75 vs 0.76; NRI and IDI: non-significant) and in those 49 patients (9%) with r-Echo-LVEF (C-statistitics 0.77 vs 0.77; NRI and IDI: non-significant).

Figure 1. Risk stratification after STEMI

Conclusions

Applied in an individualized manner, Echo-LVEF appears as a useful gatekeeper for a selective use of CMR soon after STEMI for prognostic purposes. The event rate is high in patients with reduced Echo-LVEF and low in those with preserved Echo-LVEF; CMR does not seem to significantly improve risk stratification in these scenarios. Nevertheless, the occurrence of mid-range Echo-LVEF permits discriminating the specific subset of STEMI patients (less than a quarter) who really benefit from pre-discharge CMR in terms of risk assessment.

Acknowledgement/Funding

Funded by “Instituto de Salud Carlos III”/FEDER (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and Generalitat Valenciana (GV/2018/116).

P6397Ejection fraction by cardiac magnetic resonance 6 months after STEMI: impact on risk stratification in chronic phase

Background

Left ventricular ejection fraction (LVEF) has traditionally been used as the cornerstone for risk stratification after STEMI and it can be accurately quantified by cine cardiovascular magnetic resonance (CMR). In recent years, the additional prognostic value of contrast CMR-derived infarct size (IS) and microvascular obstruction (MVO) soon after infarction has been demonstrated. The usefulness of CMR-derived LVEF in chronic phase for risk stratification late after STEMI is unclear.

Purpose

We hypothesized that 6-month CMR-derived LVEF can contribute in the prediction of clinical events late after STEMI beyond pre-discharge LVEF, IS and MVO.

Methods

Data were obtained from a prospective registry of reperfused STEMI patients (n=456) who were stable 6 months after infarction and in whom 1-week and 6-month CMR-derived LVEF, IS and MVO were sequentially quantified. Major adverse cardiac events (MACE) were defined as a combined clinical end-point that included death or re-admission for acute decompensated heart failure (r-ADHF), whichever occurred first, occurring after the 6-month CMR.

Results

During a mean and median follow-up of 6 years, 56 late MACE (12%, 32 deaths and 24 r-ADHF) were registered. From 1-week to 6-month, CMR parameters exhibited significant dynamic changes (p<0.001): LVEF improved (52±12 vs. 56±13%), IS decreased (21±14 vs. 18±12% of LV mass) and MVO vanished (2±4 vs. 0±1% of LV mass). At 6-month CMR, 60 patients (13%) displayed reduced LVEF (<40%), 69 (15%) mid-range LVEF (40–50%) and 327 (72%) preserved LVEF (≥50%). Late MACE rates were 28% in patients with reduced LVEF, 14% in those with mid-range LVEF and 9% in those with preserved LVEF at 6-month CMR (p<0.001 for the trend). After adjustment for baseline characteristics and for 1-week and 6-month CMR parameters, more preserved LVEF at 6 months independently associated with a lower risk of MACE late after STEMI (hazard ratio 0.96 [0.94–0.98] per 1% increase).

Conclusions

Dramatic dynamic changes occur in CMR parameters within the first months after STEMI. Reassessment of CMR-derived LVEF in chronic phase in those patients who remain stable provides relevant prognostic information for long-term risk stratification.

Acknowledgement/Funding

Funded by “Instituto de Salud Carlos III”/FEDER (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants) and Generalitat Valenciana (GV/2018/116).