Prevalence of LAA thrombus in patients undergoing percutaneous ablation of atrial fibrillation

Introduction

Computed tomography (CT) is often performed before atrial fibrillation (AF) ablation to assess the anatomy of the pulmonary veins and exclude left atrial (LA) and left atrial appendage (LAA) thrombus. With the growing use of new oral anticoagulants (NOACs), a reassessment of the need for systematic thrombus exclusion in this context seems warranted.

Objective

To evaluate the prevalence of thrombus in LA/LAA in pre-ablation CT in a contemporary cohort of patients predominantly anticoagulated with NOACs.

Methods

We evaluated 789 consecutive patients (mean age 61±12 years; 38% female; 84% with paroxysmal AF) who underwent pre-ablation CT between Oct/2015 and Oct/2019. ECG-gated CT-angiography was performed using a dual-source 64-slice CT after iodinated contrast injection. Whenever necessary, a second dedicated acquisition was made 60 seconds after the first set of images. Presence of thrombus was defined as a persistent opacification defect. For each patient, thromboembolic risk was assessed with the CHA2DS2-VASc score.

Results

The median interval between CT and AF ablation was 1 day (IQR 1 – 2 days). The median CHA2DS2-VASc was 2 points (IQR 0 – 3 points), with 590 patients (75%) having CHA2DS2-VASc ≥1. Among the 199 patients (25%) with CHA2DS2-VASc = 0, 118 (59,3%) were anticoagulated with a NOAC and 14 (7%) with a vitamin K antagonist; 67 (34%) were not anticoagulated. Conversely, amongst the 590 patients with CHA2DS2-VASc ≥1, 84% were anticoagulated with a NOAC (n=494), 11% used vitamin K antagonists (n=62), and 34 patients were not anticoagulated (23 with CHA2DS2-VASc = 1). On cardiac CT, 521 (66%) patients were in sinus rhythm. Overall, only one LAA thrombus was found (0.12% [1/789]; 95% CI: 0.0–0.7%) – in a patient with CHA2DS2-VASc = 0, anticoagulated with a NOAC. The median effective radiation dose was 3.2 mSv (IQR 2.1–4.8 mSv). There were 5 minor allergic reactions to iodinated contrast. No strokes were documented within the first 24 hours after ablation.

Conclusion

In this contemporary cohort of patients with predominantly paroxysmal AF and anticoagulated with NOAC, the prevalence of intracavitary thrombus was extremely low (0.12%). While these findings do not compromise the multipurpose role of pre-ablation CT, they should nevertheless inform future discussions on the risk/benefit and cost/benefit of performing systematic exclusion of LA/LAA thrombi prior to AF ablation.

Funding Acknowledgement

Type of funding source: None

Lung water quantification by cardiac magnetic resonance imaging: a novel prognostic tool in hf

Background

Cardiac magnetic resonance (CMR) imaging has recently been proposed to quantify lung water density (LWD, %) non-invasively. Given that pulmonary congestion plays a key role in the pathophysiology of Heart Failure (HF), we designed a study to assess the prognostic significance of a simplified LWD measure in patients with HF and reduced left ventricular ejection fraction (LVEF).

Methods

We conducted a single-center retrospective study of consecutive patients with HF and LVEF <50% who underwent CMR on a 1.5T scanner. Those with severe interstitial lung disease or chronic liver disease were excluded. All measurements were performed in a parasagittal plane at the right midclavicular line on a standard HASTE sequence, which is widely available in all CMR studies. As previously reported, LWD was determined by the lung-to-liver signal ratio multiplied by 0.7. A cohort of 102 healthy controls was used to derive the upper limit of normal (mean ± 2SD) of the LWD (21.2%). The primary endpoint was a composite of all-cause death or HF hospitalization.

Results

A total of 290 HF patients (mean age 64±12 years, 74.8% male, 56.2% of ischemic etiology) with a mean LVEF of 34±10% were included. LWD measurement took on average 35±4 seconds and showed excellent inter-observer agreement (intra-class correlation coefficient >0.90). LWD was increased in 65 (22.4%) patients. Compared to those with normal LWD, the former were more symptomatic (NYHA ≥III: 29.2% vs. 1.8%; p=0.017) and had higher median NT-proBNP [1973 (IQR: 809–3766) vs 802 (IQR: 355–2157pg/mL); p<0.001]. During a median followup of 21 months (IQR: 13–29), 20 (6.9%) patients died and 40 (13.8%) had at least one HF hospitalization. In multivariate analysis, LVEF (HR per 1%: 0.96; CI-95%: 0.93–0.99; p=0.024), creatinine (HR per 1mg/dL: 2.43; CI-95%: 1.25–4.71; p=0.009) and LWD (HR per 1%: 1.06; CI-95%: 1.01–1.12; p=0.013) were independent predictors of the primary endpoint. The findings were mainly driven by an association between LWD and HF hospitalization (HR per 1%: 1.08; CI-95%: 1.03–1.13; p=0.002).

Conclusions

A CMR-derived method for LWD quantification independently predicts an increased risk of death or HF hospitalization in HF patients with LVEF <50%. Our results support LWD measurement as a simple, reproducible and widely available method, further adding to the prognostic role of CMR in this population.

Funding Acknowledgement

Type of funding source: None

A machine-learning algorithm to predict atrial fibrillation recurrence after a pulmonary vein isolation procedure

Background

Contemporary risk models to predict the recurrence of atrial fibrillation (AF) after pulmonary vein isolation have limited predictive ability. Models with high specificity seem particularly suited for the setting of AF ablation, where they could be used as gatekeepers to withhold intervention in patients with low likelihood of success. Machine learning (ML) has the potential to identify complex nonlinear patterns within datasets, improving the predictive power of models. This study sought to determine whether ML can be used to better identify patients who will relapse within one year of an AF ablation procedure.

Methods

We assessed 484 patients (294 men, mean age 61±12 years, 76% with paroxysmal AF) who underwent radiofrequency pulmonary vein isolation (PVI) for symptomatic drug-refractory AF. Using this dataset, a machine-learning model based on Support Vector Machines (SVM) was developed to predict AF recurrence within one year of the procedure. The following variables were used to feed the model: type of AF (paroxysmal vs. non-paroxysmal), previous ablation procedure, left atrium (LA) volume, and epicardial fat volume (both derived from pre-ablation cardiac CT). The algorithm was trained in a random sample of 70% of the study population (n=339) and tested in the remainder 30% (n=145).

Results

A total of 130 patients (27%) suffered AF recurrence within one year of the procedure. The ML model predicted AF recurrence with 75% accuracy (95% CI 67–82%), yielding a sensitivity and specificity of 25% (95% CI 13–41%) and 94% (95% CI 88–98%), respectively. The corresponding positive and negative predictive values were 62% (95% CI 39–81%) and 77% (95% CI 67–82%), respectively. The relative weight of the variables in the ML model was: epicardial fat 56%, type of AF 23%, previous ablation 14%, and LA volume 7%. A high-risk subgroup representing 10.8% of patients was identified with the ML algorithm. In this subgroup, one-year recurrence was 62%, representing 24% of the total number of recurrences.

Conclusion

A machine-learning model showed high specificity in the identification of patients who relapse during the first year after AF ablation. In the future, these tools may be useful to improve patient selection.

Funding Acknowledgement

Type of funding source: None

Relationship between epicardial fat and left atrium fibrosis in patients with atrial fibrillation

Background

Epicardial adipose tissue (EAT) has recently been shown to be associated with the presence, severity, and recurrence of atrial fibrillation (AF). Although the pathophysiological mechanisms underlying this association remain to be established, several hypotheses have been put forward, including direct adipocyte infiltration, oxidative stress, and the secretion of adipokines causing inflammation and fibrosis of atrial tissue. We hypothesized that the volume of EAT and the amount of left atrium (LA) fibrosis assessed by non-invasive imaging would be significantly correlated in patients with AF, and that both would predict time to relapse after pulmonary vein isolation (PVI).

Methods

Sixty-eight patients with AF being studied for a first PVI procedure underwent both cardiac computerized tomography (CT) and cardiac magnetic resonance (CMR) within less than 48h. EAT was quantified on contrast-enhanced CT images. LA fibrosis was quantified on isotropic 1.5mm 3D delayed enhancement CMR for image intensity ratio values >1.20. Radiofrequency PVI was performed using an irrigated contact force-sensing ablation catheter, guided by electroanatomical mapping. After PVI, patients were followed for AF recurrence, defined as symptomatic or documented AF after a 3-month blanking period. Pearson's correlation coefficient was used for gauging the correlation between EATLM volume and LA fibrosis. The relationship between these two variables and time to AF recurrence was assessed by Cox regression.

Results

Most of the 68 patients (46 men, mean age 61±12 years) had paroxysmal AF (71%, n=48). The mean body mass index (BMI) was 28.0±4.0 kg/m2. Patients had a median EATLM volume of 2.4 cm3/m2 [interquartile range (IQR) 1.6–3.2 cm3/m2], and a median estimated amount of LA fibrosis of 8.9 g (IQR 5–15 g), corresponding to 8% (IQR 5–11%) of the total LA wall mass. The correlation between EATLM and LA fibrosis was statistically significant but weak (Pearson's R = 0.38, P=0.001) – Figure 1. During a median follow-up of 22 months (IQR 12–31), 31 patients (46%) suffered AF recurrence. Four predictors of relapse were identified in univariate Cox regression: EATLM (HR 2.19, 95% CI 1.65–2.91, P<0.001), LA fibrosis (HR 1.05, 95% CI 1.01–1.09, P=0.033), non-paroxysmal AF (HR 3.36, 95% CI 1.64–6.87, P=0.001), and LA volume (HR 1.03, 95% CI 1.01–1.06, P=0.006). Multivariate analysis yielded two independent predictors of time to AF relapse: EATLM (HR 2.05, 95% CI 1.51–2.79, P<0.001), and non-paroxysmal AF (HR 2.36, 95% CI 1.08–5.16, P=0.031).

Conclusion

The weak correlation between EAT and LA suggests that LA fibrosis is not the main mechanism by which EAT and AF are linked. EAT was more strongly associated with AF recurrence than LA fibrosis, which supports the existence of other, more important mediators between EAT and this arrhythmia.

Correlation between EAT and LA

Funding Acknowledgement

Type of funding source: None

Downstream testing after an halted coronary CT angiography due to high coronary artery calcium score

Background and aim

In many centers, coronary artery calcium score (CACS) is performed immediately before coronary CT angiography (CCTA) in order to exclude heavy calcification that could hamper test performance. When high CACS values are found, CCTA is usually aborted and other tests suggested. However, there are no recommendations on which test to pursue, and little data on their diagnostic yield in this setting. The aim of this study was to assess the type and results of downstream testing among patients whose CCTA study was halted due to high CACS.

Methods

Single-centre retrospective study of consecutive patients undergoing CCTA for suspected obstructive coronary artery disease (CAD). A CACS threshold of >400 was generally used to cancel CCTA. Downstream testing and its results were assessed using electronic medical records. A group of consecutive patients with CACS <400 who underwent CCTA was used for comparison.

Results

Of the 795 patients who performed CCTA for suspected CAD, 86 (10.8%), had their test halted due to high CACS (57 men, mean age 71±11 years). In this subgroup, the median pre-test probability for CAD was 27% (interquartile range 25) and the median CACS was 983 (interquartile range 930). Compared to patients who underwent CCTA, those who saw their tests cancelled were older, more frequently male, and had higher prevalence of cardiovascular risk factors and higher pre-test probability for CAD.

Patient's downstream testing is illustrated in Figure. From the 86 patients enrolled, 12 are currently waiting for downstream tests and were excluded from further analysis. Overall, 35 patients ended up performing invasive coronary angiography (ICA, 47.3%) of whom 19 (54.3%) had significant CAD. Among those who underwent non-invasive testing (N=19, 25.7%), 10 (52.6%) had significant ischemia and 4 (21%) underwent additional testing with ICA. In 24 patients (32.4%), no downstream testing was pursued. Finally, 17 (22.3%) patients underwent coronary revascularization, either percutaneous (N=10, 13.5%) or surgical (N=7, 10.8%).

Conclusion

Invasive coronary angiography is the most frequently used downstream test when CCTA is halted due to high CACS values, and shows significant CAD in roughly half of the cases. Considering the high prevalence of significant CAD, direct referral for ICA (with the possibility of invasive functional testing) seems a reasonable approach.

Funding Acknowledgement

Type of funding source: None

Pre-test probability of obstructive coronary artery disease in the new guidelines: too much, too little or just enough?

Background

Previous 2013 ESC guidelines recommended the use of the Modified Diamond-Forrester method to assess the pre-test probability (PTP) of obstructive coronary artery disease (CAD). The 2019 ESC Chronic Coronary Syndrome guidelines updated this recommendation with a major downgrade in PTP. The aim of this study was to compare the performance of these two methods in patients with stable chest pain undergoing coronary computed tomography angiography (CCTA) for suspected CAD.

Methods

We performed a retrospective analysis on prospectively collected data from a cohort of consecutive patients undergoing CCTA for suspected CAD from October 2016 to 2019. Key exclusion criteria were age <30 years-old, known CAD, suspected acute coronary syndrome or symptoms other than chest pain. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. Whenever invasive coronary angiography (ICA) was subsequently performed, patients were reclassified if luminal stenosis was <50%. The two PTP prediction models were assessed for calibration and discrimination.

Results

A total of 320 patients (median age 63 years [IQR 53–70], 59% women) were included. Chest pain characteristics were: 48% atypical angina, 38% non-anginal chest pain, 14% typical angina. The observed prevalence of obstructive CAD was 16.3% (n=52). Patients with obstructive CAD were more often male, were significantly older and had a higher prevalence of typical angina and cardiovascular risk factors (except for family history of CAD). On average, individual PTP was 22.1% lower in the new guidelines. The 2013 prediction model significantly overestimated the likelihood of obstructive CAD (mean PTP 37.3% vs 16.3%; relative overestimation of 130%, p-value for miscalibration 0.005). The updated 2019 method showed good calibration for predicting the likelihood of obstructive CAD (mean PTP 15.2% vs 16.3%; relative underestimation of 6.5%, p-value for miscalibration 0.712). The two approaches showed similar discriminative power, with a C-statistics of 0.730 and 0.735 for the 2013 and 2019 methods, respectively (p-value for comparison 0.933). Stratification by gender produced similar results.

Conclusions

In patients with stable chest pain undergoing CCTA, the updated 2019 prediction model allows for a more precise estimation of pre-test probabilities of obstructive CAD than the previous model. Adoption of this new score may improve disease prediction and change the downstream diagnostic pathway in a significant proportion of cases.

Graph 1

Funding Acknowledgement

Type of funding source: None

LV replacement fibrosis in aortic stenosis: prevalence and relation to LV remodelling and function

Background

Progressive myocardial fibrosis takes part in left ventricular (LV) remodeling in aortic stenosis (AS) and drives the transition from hypertrophy to heart failure. Replacement fibrosis may be characterized by late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR).

Aim

To assess the prevalence and association between LGE and indexes of LV function in patients with severe aortic stenosis.

Methods

We prospectively studied 53 consecutive patients (age: 71±8 years [min. 51–max. 84], 54.7% men) with severe symptomatic AS, referred for surgical aortic valve replacement with no previous history of ischemic cardiomyopathy. Aortic valve mean gradient was 54.6 mmHg [IQR 46.6–63.2] and aortic valve area 0.74cm2 [IQR 0.61–0.89]; all patients with high gradient, 4 with low-flow. CMR with tissue characterization (T1 mapping, LGE and extracellular volume by ECV quantification – using 5SD from remote myocardium as signal intensity cut-off), was performed before surgery. AS severity indexes, LV mass, systolic and diastolic LV function indexes including global longitudinal strain (GLS) and torsion were compared in both groups of patients, with and without LGE.

Results

Mid-wall LGE was present in 36 patients (67.9%) with a median fraction of 6.0% [IQR 4.9–12.7%] of LV mass. Native T1 value and ECV were within normal ranges (median values: 1047ms [IQR 1028–1084]; 22% [IQR 18–25], respectively). Median CMR LV ejection fraction and mass were 64.5% [IQR 51.3–70.8%] (11 patients with reduced EF) and 76.5g/m2 [IQR 57.4–94.8g/m2], respectively. Median GLS was −13.9% [IQR −11.4 to −17.0%] and torsion was 24.2° [IQR 19.8–32.5°]. Patients with LGE had significantly higher LV mass (87.1g/m2 vs 63.3 g/m2, p=0.001), worse GLS (−14.4% vs −16.9%, p=0.041) and higher NT-proBNP values (1333.7ng/mL vs 559.9ng/mL, p=0.004) (Figure).

Conclusions

Non-ischemic LGE is common in this group of patients with severe symptomatic high gradient aortic stenosis. As it is more prevalent in patients with more pronounced LVH, lower longitudinal deformation and higher NT-proBNP values, it probably represents a more advanced stage of the disease.

Funding Acknowledgement

Type of funding source: None

Contribution of Different Patient Information Sources to Create the Best Possible Medication History

INTRODUCTION

Obtaining the best possible medication history is the crucial step in medication reconciliation. Our aim was to evaluate the potential contributions of the main data sources available - patient/caregiver, hospital medical records, and shared electronic health records - to obtain an accurate 'best possible medication history'.

MATERIAL AND METHODS

An observational cross-sectional study was conducted. Adult patients taking at least one medicine were included. Patient interview was performed upon admission and this information was reconciled with hospital medical records and shared electronic health records, assessed retrospectively. Concordance between sources was assessed. In the shared electronic health records, information was collected for four time-periods: the preceding three, six, nine and 12-months. The proportion of omitted data between time-periods was analysed.

RESULTS

A total of 148 patients were admitted, with a mean age of 54.6 ± 16.3 years. A total of 1639 medicines were retrieved. Only 29% were collected simultaneously in the three sources of information, 40% were only obtained in shared electronic health records and only 5% were obtained exclusively from patients. The total number of medicines gathered in shared electronic health records considering the different time frames were 778 (three-months), 1397 (six-months), 1748 (nine-months), and 1933 (12-months).

DISCUSSION

The use of shared electronic health records provides data that were omitted in the other data sources available and retrieving the information at six months is the most efficient procedure to establish the basis of the best possible medication history.

CONCLUSION

Shared electronic health records should be the preferred source of information to supplement the patient or caregiver interview in order to increase the accuracy of best possible medication history of the patient, particularly if collected within the prior six months.

P3382Vascular calcium Index: an imaging tool to predict vascular complications and major bleeding in TF-TAVI

Introduction

Vascular calcification has been associated with worse outcomes in transfemoral TAVI (TF-TAVI). However, there is currently no simple method to assess it and identify different patterns of calcification in an objective and quantitative manner. The purpose of this study was to develop a quantitative score of aortic (Ao) and ileofemural (IF) calcification and to assess its ability to predict life-threatening bleeding (LTB) and major vascular complications during TF-TAVI.

Methods

Case-control single center retrospective study of patients undergoing TF-TAVI between Nov2015 and Aug2018 including 183 consecutive patients (99 women, mean age 83±3 years, mean Euroscore II - ESII - 6.0±4.1). The Vascular Calcium Score was calculated for the entire Ao and IF vessels using a modified Agatston score derived from contrast-enhanced CT images, with calcium threshold locally adjusted for luminal attenuation (mean attenuation + 5x SD). A luminal attenuation threshold >600UH impaired vascular calcium evaluation and patients were excluded. LTB and major vascular complications were adjudicated according to the VARC-2 classification and identified by chart review by and independent team.

Results

Thirty patients (16%) suffered major bleeding and 13 (7%) experienced LTB. Major vascular injury occurred in 11 patients (6%). The median total vascular calcium score (TCS) was 11752 AU (IQR: 6388–19844) and median IF score (IFS) was 2210AU (IQR: 865–4170). TCS indexed for body surface area (TCSi) was predictor of LTB (AUC: 0.78±0.07, p<0.05) and of major vascular complications (AUC: 0.85±0.05, p<0.05). After multivariate analysis, iTCS and glomerular filtration rate (GFR) remained as predictors of LTB with an HR of 1.11 for each increase in 1000UA/m2 of TCSi (95% CI: 1.03–1.18) and 0.94 (95% CI: 0.88–0.985) respectively, independently of the ESII. iTCS and GFR were also independently associated with major vascular complications (p<0.05). Patients with an iTCS above 9750AU/m2 have an odds ratio of 7.7 (95% CI: 2.0 - 29.2) for LTB. This cut-off has a sensitivity of 77% and a specificity of 70% for LTB. Similarly, patients with an iTCS above 9750AU/m2 have an odds ratio of 10.3 (95% CI: 22 - 49.3) for major vascular injury.

Conclusions

A quantitative score for vascular calcification in contrast-enhanced CT images was developed. iTCS was independently associated with life-threatening bleeding and major vascular complications.

1204Pericardial fat volume outperforms classic risk markers in the prediction of relapse after pulmonary vein isolation

Introduction

Pericardial adipose tissue has been implicated in the pathophysiology of atrial fibrillation (AF), but its relevance to clinical practice remains uncertain. The aim of this study was to assess the relative importance of pericardial fat as predictor of recurrence after pulmonary vein isolation (PVI).

Methods

We assessed 453 patients (278 men, age 61±13 years, 348 paroxysmal AF) with symptomatic AF undergoing cardiac CT prior to a PVI procedure. Pericardial fat was quantified on contrast-enhanced images using a new simplified semi-automated method. The study endpoint was symptomatic and/or documented AF recurrence.

Results

Over a median follow-up of 14 months (IQR 7–23), 170 patients (38%) relapsed. Survival analysis showed significant differences in AF-free survival across tertiles of pericardial fat (Figure). Pericardial fat volume was weakly correlated to body mass index [(BMI), Pearson's R=0.34]. After adjustment for BMI and other univariate predictors of relapse, three variables emerged independently associated with time to AF recurrence: non-paroxysmal AF (HR 2.08, 95% CI: 1.51–2.87, p<0.001), indexed left atrial (LA) volume (HR 1.02 per mL/m2, 95% CI: 1.01–1.02, p<0.001), and indexed pericardial fat volume (HR 1.50 per mL/m2, 95% CI: 1.37–1.64, p<0.001). Based on the Wald test, indexed pericardial fat volume was the strongest of these predictors of relapse (X2 values of 20, 13, and 77, respectively). The population attributable risk (PAF) was higher for pericardial fat (PAF=37% for 1st vs 4th quartile) vs LA volume (PAF=11% for 1st quartile vs 4th quartile) and non-paroxysmal AF (PAF=23%). Pericardial fat volume also showed greater discriminate power than indexed LA volume, with a C-statistic of 0.80 (95% CI 0.76–0.85) vs. 0.61 (95% CI 0.55–0.66), p for difference <0.001. The method for quantifying pericardial fat showed high inter-observer reproducibility (Pearson's R=0.90) and was quick to perform (38±3 seconds).

Conclusion

Pericardial fat volume is a strong independent predictor of AF relapse after PVI, outperforming classic risk markers such as LA volume and type of AF. The underlying mechanisms of this association deserve further study. Meanwhile, this simple parameter may help select patients who are more likely to derive sustained benefit from AF ablation.

Efficacy of LISTEX P100 at Different Concentrations for Reduction of Listeria monocytogenes Inoculated in Sashimi

Sushi restaurants have become quite popular in Europe, with an increase in the consumption of the sashimi speciality. Pathogenic bacteria such as Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus have been reported in this kind of food. Controlling the presence and multiplication of L. monocytogenes is a challenge for food safety management systems owing to its ubiquitous presence and psychrotrophic growth. Bacteriophages have been used as pathogenic biocide agents for decades. The bacteriophage P100, present in LISTEX P100, was used in this study to understand the possibility of implementing a new critical control point for L. monocytogenes in sashimi preparation and sale. Different concentrations of LISTEX P100 were used for reduction of L. monocytogenes in inoculated samples at 3 and 22°C. The reduction in initial counts of 2 log CFU/g was effective in the first 24 h with the 8-log PFU/g inoculation. Promising results were obtained in assays with the 6-log CFU/g initial counts and the 8-log PFU/g inoculation, at 22°C, achieving a maximum reduction of 4.44 log CFU/g, compared with the control group. These results seem to confirm that bacteriophages can be an option in reducing the population of the L. monocytogenes pathogenic bacteria in sashimi, mainly in takeaway sales.

MicroRNA-124 loaded nanoparticles enhance brain repair in Parkinson's disease

Modulation of the subventricular zone (SVZ) neurogenic niche can enhance brain repair in several disorders including Parkinson's disease (PD). Herein, we used biocompatible and traceable polymeric nanoparticles (NPs) containing perfluoro-1,5-crown ether (PFCE) and coated with protamine sulfate to complex microRNA-124 (miR-124), a neuronal fate determinant. The ability of NPs to efficiently deliver miR-124 and prompt SVZ neurogenesis and brain repair in PD was evaluated. In vitro, miR-124 NPs were efficiently internalized by neural stem/progenitors cells and neuroblasts and promoted their neuronal commitment and maturation. The expression of Sox9 and Jagged1, two miR-124 targets and stemness-related genes, were also decreased upon miR-124 NP treatment. In vivo, the intracerebral administration of miR-124 NPs increased the number of migrating neuroblasts that reached the granule cell layer of the olfactory bulb, both in healthy and in a 6-hydroxydopamine (6-OHDA) mouse model for PD. MiR-124 NPs were also able to induce migration of neurons into the lesioned striatum of 6-OHDA-treated mice. Most importantly, miR-124 NPs proved to ameliorate motor symptoms of 6-OHDA mice, monitored by the apomorphine-induced rotation test. Altogether, we provide clear evidences to support the use of miR-124 NPs as a new therapeutic approach to boost endogenous brain repair mechanisms in a setting of neurodegeneration.

Feather conditions and clinical scores as indicators of broilers welfare at the slaughterhouse

The objective of this study was to evaluate the welfare of 64 different broiler farms on the basis of feather conditions and clinical scores measures collected at the slaughterhouse. A 3-point scale (0, 1 or 2) was used to classify dirty feathers, footpad dermatitis and hock burns measures, and a 2-point scale (present or absent) was used to classify breast burns, breast blisters and breast ulcer measures. Flocks were allocated into three body weight (BW) classes (A, B, C): class A (light) ≥1.43 and ≤1.68kg, class B (medium) ≥1.69 and ≤1.93kg; class C (heavy) ≥1.94 and ≤2.41kg. The absence of hock burns was more common in class A, while mild hock burns was more common in class B flocks. Breast ulcer was observed in class C flocks. The association observed for mild hock burns, breast burns and severe footpad dermatitis can indicate a simultaneous occurrence of these painful lesions. Very dirty feathers and severe footpad dermatitis relationship suggest litter humidity to be the common underlying cause. In conclusion, it was shown that clinical indicators can be used at the slaughterhouse to identify welfare problems. In the studied flocks, footpad dermatitis, feather conditions and hock burns were the main restrictions for good welfare and should be considered significant welfare indicators of the on-farm rearing conditions.