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Résumé Objectifs La survenue d’une thrombose de la valve ou des cusps après TAVI est mal connue, alors qu’elle impacte négativement la durabilité de la prothèse et que son incidence est plus fréquente qu’initialement supposé. Épidémiologie L’incidence de thromboses infracliniques survenant entre le premier et le troisième mois après implantation de TAVI est comprise entre 10 et 15 %. Toutes les valves implantées sont concernées. Diagnostic La reprise de symptômes ou une augmentation des gradients transvalvulaires sont les deux modes d’expressions classiques de thrombose. Les facteurs favorisants sont nombreux : l’âge avancé des patients, l’armature métallique des prothèses, l’expansion parfois incomplète de la prothèse, son apposition incomplète, la création de zones de stagnation de sang. Certains facteurs de risques sont rapportés : les valves larges, l’altération de la FEVG, les valve in valve, le sexe masculin, les sinus de grand diamètre, l’absence de traitement anticoagulant. Traitement Le traitement post-TAVI reste empirique et retient 1 à 6 mois de monothérapie ou de bithérapie anti-agrégante, prolongé d’un traitement par aspirine à vie. En cas de thrombose avérée, une anticoagulation orale par AVKs ou par anticoagulants oraux directs permet à 3 mois une restauration du jeu valvulaire normal, avec un délai moyen de réduction du gradient transvalvulaire de 14 jours. Goals Transcatheter aortic valve or leaflets thrombosis are mainly misapprehended. It negatively impacts the long-term efficiency of such prosthesis. Moreover, its incidence is presumably higher than previously described. Epidemiology Recently reported subclinical leaflet thrombosis, occurring between first to third months after implantation, is about 10to 15%. All prosthesis are concerned by potential thrombosis. Diagnosis Transcatheter aortic valve thrombosis is usually detected on the basis of increased transvalvular pressure gradients or symptoms at routine follow-up. Main causes of post-TAVI thrombosis are: elderly patients, incomplete TAVI expansion, incomplete TAVI apposition to the aortic wall, areas of diminished blood flow and stagnation around the prosthesis. Main risk-factors of thrombosis are: large valves, patients with ejection fraction lower than 35%, valve-in-valve implantation, males, patients with large sinus of Valsalva, patients without anticoagulants. Treatment Post-TAVI anti thrombotic regimen remains empirical. It is based on aspirin alone or dual antiplatelet therapy for 1–6 months, followed by aspirin for life. Symptomatic patients with thrombus-based valve dysfunction are to be treated by oral anticoagulation (i.e., VKA or new oral anticoagulants NOAC). This treatment allows the restoration of normal leaflet motion in patients with a median time of 14 days. [ABSTRACT FROM AUTHOR]

Résumé Rechercher une ischémie myocardique consiste à utiliser un ou plusieurs tests permettant le diagnostic de coronaropathie avec le double objectif de rapidité et d’à-propos diagnostique. Chez les femmes en comparaison aux hommes, la puissance diagnostique des différents tests est généralement plus faible. Ainsi, pour s’affranchir de cette pénalisation liée au sexe, il faut définir une stratégie diagnostique basée sur la stratification du niveau de risque a priori, et identifier avec précision les patientes relevant d’une exploration invasive. Cette mise au point reprend les performances des différents tests diagnostiques non invasifs au travers d’une approche volontairement féminine et définit en fonction du niveau de risque de coronaropathie et du caractère symptomatique ou non les outils de l’arsenal thérapeutique. Screening of myocardial ischemia refers to the use of one or more diagnostic tests for coronary heart disease with a dual objective of appropriateness and promptness. In women, as compared to men, the accuracy of the different tests is worse. Thus, to overcome this sex-related penalty, we must define a diagnosis strategy based on risk stratification, enabling the identification of patients requiring invasive investigations. This review discusses various non-invasive diagnostic tests focusing on a female-specific approach and defines the use of numerous diagnostic tests with respect to both risk stratification and symptoms. [ABSTRACT FROM AUTHOR]

Résumé La thromboaspiration, lors de la prise en charge invasive d’un infarctus du myocarde de type ST+, paraît intuitivement légitime. Les premiers registres rapportaient des résultats discordants, mais l’idée que les cardiologues interventionnels s’en faisaient plaidait pour son utilisation. Si les premières études étaient concordantes pour rattacher à la thromboaspiration une amélioration significative du segment ST et moins d’embolisations distales, seule TAPAS s’accompagnait d’une réduction de la mortalité. Les études ultérieures n’ont pas confirmé ces résultats encourageants, concluant que l’utilisation systématique de la thromboaspiration avant angioplastie primaire ne diminue pas la mortalité cardiovasculaire, le risque de récidive d’infarctus ou l’insuffisance cardiaque sévère, mais majore le risque d’accident vasculaire cérébral. Faut-il pour autant abandonner la thromboaspiration ? Il faut probablement continuer à travailler pour définir qui est éligible à une thromboaspiration, comment pratiquer une thromboaspiration de « bonne » qualité, préciser la technique d’approche, l’environnement pharmacologique, le nombre de passages, les critères d’arrêts ou de répétitions d’aspirations, cette technique « scientifiquement » déclassée gardant un potentiel non négligeable pour nombre de cardiologues interventionnels. Routine manual thrombectomy during primary percutaneous coronary intervention might be intuitively justified. While older registers reported contradictory results, interventional cardiologists remained interested in using such devices during the mechanical treatment of acute myocardial infarction. The first studies were congruent to demonstrate a significant relationship between thromboaspiration and significant improvement of ST-segment elevation, lower distal embolization, despite TAPAS was the only to significantly reduce the mortality. Later studies were unable to confirm these promising data, avoiding routine manual thrombectomy prior to primary angioplasty to decrease cardiovascular mortality, recurrent myocardial infarction, cardiogenic shock or severe heart failure. Moreover, thrombectomy was associated with an increased rate of stroke. Should thrombectomy therefore be conclusively overlooked? It is presumably required to define which patient is eligible for thrombectomy, to define how to perfectly perform manual thrombectomy, to specify how to gently move towards the thrombus, the optimal pharmacological environment, the number of aspirations and the criterion to stop or to repeat aspiration. Indeed, while thrombectomy is nowadays scientifically downgraded, it remains of potential interest in numerous interventional cardiologists. [ABSTRACT FROM AUTHOR]

Abstract: New oral anticoagulants constitute an important breakthrough for cardiologists and their patients. After reviewing their mechanism of action, their role in the context of interventional cardiology, particularly for patients with acute coronary syndromes, is discussed. [Copyright &y& Elsevier]

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Abstract: Patent Foramen Ovale (PFO) is a normal fetal communication between right and left atria that persists after birth by about 30% in adults. It is discussed to be associated to potential clinical events, asking rational of such closure. Its correction throughout venous access can be attempted on four different indications: (1) secondary prevention of stroke or transient ischemic attack, (2) decompression illness, (3) migraine with aura, and (4) platypnea-orthodeoxia. The PFO closure procedure implies the double control of X-rays and ultrasound, and is relatively simple to perform, using various prostheses. In France, the place of percutaneous closure procedure is nowadays unclear since the Haute Autorité de santé currently suspended recommendations about the management after stroke. [Copyright &y& Elsevier]

Objectives: We sought to examine the use and impact of standard medical therapies in patients with end-stage renal disease (ESRD) faced with an acute myocardial infarction (AMI).Background: The poor prognosis of patients in this high-risk population has become increasingly well recognized.Methods: Using the ESRD database and the Cooperative Cardiovascular Project (CCP) database, we identified AMI patients who were receiving either peritoneal dialysis or hemodialysis before admission. The early administration of aspirin and beta-blockers was compared between ESRD and non-ESRD patients and the effect of these therapies on 30-day mortality was evaluated with logistic regression models.Results: The cohort consisted of 145,740 patients without ESRD and 1,025 patients with ESRD. Aspirin (67.0% vs. 82.4%, p < 0.001), beta-blockers (43.2% vs. 50.8%, p < 0.001), and angiotensin-converting enzyme (ACE) inhibitors (38.5% vs. 60.3%, p < 0.001) were less likely to be administered to ESRD patients than to non-ESRD patients. The benefit of these therapies on 30-day mortality was similar among ESRD patients (aspirin: relative risk [RR] 0.64; 95% confidence interval [CI] 0.50 to 0.80; beta-blocker: RR 0.78; 95% CI 0.60 to 0.99; ACE inhibitor: RR 0.58; 95% CI 0.42 to 0.77) and non-ESRD patients (aspirin: RR 0.57; 95% CI 0.55 to 0.58; beta-blocker: RR 0.70; 95% CI 0.68 to 0.72; ACE inhibitor: RR 0.64; 95% CI 0.63 to 0.66).Conclusions: End-stage renal disease patients are far less likely than non-ESRD patients to be treated with aspirin, beta-blockers, and ACE inhibitors during an admission for AMI. The lower rates of usage for these medications, particularly aspirin, may contribute to the increased 30-day mortality. These findings demonstrate a marked opportunity to improve care in this population. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of exogenous amylase supplementation on gas production and on in vitro rumen starch degradability (IVSD) of different sized particles of corn and barley meals (Cm and Bm, respectively). An aqueous liquid amylase formulation from Bacillus licheniformis was tested at 3 enzyme doses (EnzD; 0, 300 and 1,500 kilo novo units/kg of dry matter) on small (<750 μm) and large (≥750 μm) particle size (PS) of Cm and Bm. Data were analyzed according to a randomized complete block design with a factorial arrangement of treatments; the main tested effects were PS, EnzD, and their interaction. Fermentation run entered in the model as random effect. The mixed rumen fluid was collected from 2 rumen-fistulated Holstein dry dairy cows fed at maintenance (forage:concentrate ratio of 80:20; 12% crude protein; 55% amylase-treated neutral detergent fiber). Small particles of both Cm and Bm had a greater rate of fermentation and shorter lag time than large particles. The rate of starch degradation was greater for small than for large particles of Bm, being 0.187 and 0.125 1/h, respectively. Conversely, the rate of starch degradation of Cm averaged 0.063 1/h and was similar among treatments. Enzyme supplementation tended to reduce lag time and to increase rate of fermentation for both PS of Cm and Bm, with a more pronounced effect for small PS. A limited EnzD effect was measured for IVSD data and rate of starch degradation; PS influenced fermentation parameters and the magnitude of starch degradation more than EnzD. Supplementation with exogenous amylase influenced the rumen fermentation pattern of small and large PS of Cm and Bm, even if the effect of the enzyme supplementation differed according to the PS of cereal meals. [ABSTRACT FROM AUTHOR]

Abstract: One focus of current ruminant research is identification of feed supplementation strategies for mitigating enteric CH4 production that do not impair rumen fermentation. Previous in vitro studies have indicated a potential anti-methanogenic activity of garlic (Allium sativum), garlic oil (GO), and its main compound diallyl disulfide (DADS). In our study, effects of supplementation of a standard hay and concentrate diet with 5g GO or 2g DADS/kg dietary dry matter (DM) were tested in sheep in a duplicated 3×3 Latin square design experiment with three 23d periods. Respiratory measurements were on d 17 and 18. Dietary supplementation with GO or DADS had no influence on the amount of CH4 produced (27g/d). When rates of CH4 production/kg OM digested were compared, DADS, but not GO, tended (P=0.09) to decrease CH4 production compared to control. DM intake was not affected by GO or DADS, although concentrate intake was slightly decreased (P=0.10) with GO compared to control. DADS increased (P=0.02) digestibility of OM and aNDFom (P=0.03), as well as energy utilization (P=0.03) compared to control. Low palatability and lack of effect on either CH4 mitigation or energy use efficiency indicate that a GO supplemented concentrate is of little relevance in practice. As DADS supplementation only tended to decrease CH4 formation relative to OM digested, it too is limited use as a means of CH4 mitigation. However, DADS supplementation improved digestibility and energy use efficiency. This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson. [Copyright &y& Elsevier]

This study examined the effect of 3-nitrooxypropanol (3-NOP), an investigational substance, on enteric methane emission, milk production, and composition in Holstein dairy cows. Following a 3-wk covariate period, 48 multi- and primiparous cows averaging (± standard deviation) 118 ± 28 d in milk, 43.4 ± 8 kg/d milk yield, and 594 ± 57 kg of body weight were blocked based on days in milk, milk yield, and enteric methane emission and randomly assigned to 1 of 2 treatment groups: (1) control, no 3-NOP, and (2) 3-NOP applied at 60 mg/kg feed dry matter. Inclusion of 3-NOP was through the total mixed ration and fed for 15 consecutive weeks. Cows were housed in a freestall barn equipped with a Calan Broadbent Feeding System (American Calan Inc., Northwood, NH) for monitoring individual dry matter intake and fed ad libitum once daily. Enteric gaseous emissions (methane, carbon dioxide, and hydrogen) were measured using 3 GreenFeed (C-Lock Inc., Rapid City, SD) units. Dry matter intake, cow body weight, and body weight change were not affected by 3-NOP. Compared with the control group, 3-NOP applied at 60 mg/kg feed dry matter decreased daily methane emission, emission yield, and emission intensity by 26, 27, and 29%, respectively. Enteric emission of carbon dioxide was not affected, and hydrogen emission was increased 6-fold by 3-NOP. Administration of 3-NOP had no effect on milk and energy-corrected milk yields and feed efficiency, increased milk fat and milk urea nitrogen concentrations, and increased milk fat yield but had no other effects on milk components. Concentration of C6:0 and C8:0 and the sum of saturated fatty acids in milk fat were increased by 3-NOP. Total trans fatty acids and the sum of polyunsaturated fatty acids were decreased by 3-NOP. In this experiment, 3-NOP decreased enteric methane daily emission, yield, and intensity without affecting dry matter intake and milk yield, but increased milk fat in high-producing dairy cows. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of 3-nitrooxypropanol (3-NOP), an enteric methane inhibitor under investigation, on short-term dry matter intake (DMI) in lactating dairy cows. Following a 1-wk adaptation period, 12 multiparous Holstein cows were fed a basal total mixed ration (TMR) containing increasing levels of 3-NOP during 5 consecutive, 6-d periods. The experiment was conducted in a tiestall barn. Feed bins were split in half by a solid divider, and cows simultaneously received the basal TMR supplemented with the following: (1) a placebo without 3-NOP or (2) 3-NOP included in the TMR at 30, 60, 90, or 120 mg/kg of feed dry matter (experimental periods 2, 3, 4, and 5, respectively). Cows received the control diet (basal TMR plus placebo premix) during experimental period 1. A premix containing ground corn grain, soybean oil, and dry molasses was used to incorporate 3-NOP in the ration. Cows were fed twice daily as follows: 60% of the daily feed allowance at 0800 h and 40% at 1800 h. Feed offered and refused was recorded at each feeding. During the morning feedings, each cow was offered either control or 3-NOP-treated TMR at 150% of her average intake during the previous 3 d. After collection of the evening refusals, cows received only the basal TMR without the premix until the next morning feeding. The test period for the short-term DMI data collection was defined from morning feeding to afternoon refusals collection during each day of each experimental period. Location (left or right) of the control and 3-NOP diets within a feed bin was switched every day during each period to avoid feed location bias. Dry matter intake of TMR during the test period was quadratically increased by 3-NOP compared with the control. Inclusion of 3-NOP at 120 mg/kg of feed dry matter resulted in decreased 10-h DMI compared with the lower 3-NOP doses, but was similar to the control. There was no effect of feed location (left or right) within feed bin on DMI. Data from this short-term study suggests that 3-NOP does not have a negative effect on DMI in lactating dairy cows. [ABSTRACT FROM AUTHOR]

This experiment was designed to test the effect of inclusion rate of 3-nitrooxypropanol (3-NOP), a methane inhibitor, on enteric methane emissions in dairy cows. The study was conducted with 49 multiparous Holstein cows in a randomized complete block design in 2 phases; phase 1 was with 28 cows, and phase 2 with 21 cows. Cows were fed a basal total mixed ration ad libitum and were blocked based on days in milk, milk yield, and enteric methane emissions during a 14-d covariate period. Treatments were control (no 3-NOP) and 40, 60, 80, 100, 150, and 200 mg of 3-NOP/kg of feed dry matter. Following a 14-d adaptation period, enteric gaseous emissions (methane, carbon dioxide, and hydrogen) were measured using the GreenFeed system (C-Lock Inc., Rapid City, SD) over a 3-d period. Compared with the control, inclusion rate of 3-NOP quadratically decreased daily enteric methane emissions from 22 to 40%. Maximum mitigation effect was achieved with the 3 highest 3-NOP doses (with no statistical difference among 100, 150, and 200 mg/kg). The decrease in methane emission yield and emission intensity ranged from 16 to 36% and from 25 to 45%, respectively. Emissions of hydrogen quadratically increased 6- to 10-fold, compared with the control; the maximum increase was with 150 mg/kg 3-NOP. Treatment did not affect daily emissions of carbon dioxide, but a linear increase in carbon dioxide emission yield was observed with increasing 3-NOP doses. Dry matter intake and milk yield of the cows was not affected by 3-NOP. Milk fat concentration and yield were increased by 3-NOP due to increased concentration of de novo synthetized short-chain fatty acids in milk. Inclusion of 3-NOP also tended to increase milk urea nitrogen but had no other effects on milk components. In this short-term experiment, 3-NOP decreased enteric methane emissions without affecting dry matter intake or milk yield and increased milk fat in dairy cows. Maximum mitigation effect was achieved at 100 to 200 mg/kg of feed dry matter. [ABSTRACT FROM AUTHOR]

This study examined the effect of 3-nitrooxypropanol (3-NOP), a substance under investigation, on enteric methane (CH 4) emission, rumen fermentation, lactational performance, sensory properties of milk, and the resumption of ovarian cyclicity in early-lactation dairy cows. Fifty-six multi- and primiparous Holstein cows, including 8 that were rumen cannulated, were used in a 15-wk randomized complete block design experiment. Cows were blocked based on parity and previous lactation milk yield (MY) or predicted MY, and within each block were randomly assigned to one of 2 treatments: (1) control (CON), administered no 3-NOP, or (2) 3-NOP applied at 60 mg/kg of feed dry matter (3-NOP). Enteric CH 4 emission was measured during experimental wk 2, 6, 9, and 15, using the GreenFeed system. Dry matter intake (DMI) and MY data were collected daily throughout the experiment, and milk composition samples were collected 7 times during the experiment. Milk samples were collected from 14 to 60 (±2) d after calving, 3 d per week, and assayed for progesterone concentration to determine resumption of ovarian activity. Compared with CON, 3-NOP decreased daily CH 4 emission by 26%, CH 4 yield (CH 4 per kg of DMI) by 21%, and CH 4 emission intensity [CH 4 per kg of MY or energy-corrected milk (ECM)] by 25%. Enteric emission of carbon dioxide was decreased by 5%, and hydrogen emission was increased 48-fold by 3-NOP. Inclusion of 3-NOP decreased concentration of total volatile fatty acids (by 9.3%) and acetate but increased butyrate molar proportion, ethanol, and formate concentrations in ruminal fluid. Dry matter intake was lower for 3-NOP compared with CON, but DMI expressed as a percentage of body weight was not different between treatments. Treatment had no effect on milk and ECM, body weight change, or body condition score. Milk composition and milk fat and protein yields were not affected by treatment, except that concentrations of short-chain fatty acids in milk were increased by 3-NOP. Nutrient digestibility and blood metabolites and hormones were not affected by 3-NOP, except that insulin was decreased by 3-NOP. There was no effect of 3-NOP on postpartum resumption of ovarian activity, including days to first and second luteal phases, length of first and second luteal phases, and interval from first to second luteal phase. Sensory properties of milk from cows fed 3-NOP and cheese made from that milk were not affected by treatment. In this experiment, 3-NOP decreased daily enteric CH 4 emission, emission yield, and emission intensity, improved feed efficiency, and did not affect lactational performance or onset of ovarian activity in early-lactation dairy cows. [ABSTRACT FROM AUTHOR]

The aim of this work was to determine the effect of 3-nitrooxypropanol (3-NOP) on the enteric methane (CH4) emissions and performance of lactating dairy cows when mixed in with roughage or incorporated into a concentrate pellet. After 2 pretreatment weeks without 3-NOP supplementation, 30 Holstein Friesian cows were divided into 3 homogeneous treatment groups: no additive, 3-NOP mixed in with the basal diet (roughage; NOPbas), and 3-NOP incorporated into a concentrate pellet (NOPconc). The pretreatment period was followed by a 10-wk treatment period in which the NOPbas and NOPconc cows were fed 1.6 g of 3-NOP/cow per day. After the treatment period, a 2-wk washout period followed without 3-NOP supplementation. The CH4 emissions were measured using a GreenFeed unit (C-Lock Inc., Rapid City, SD) installed in a freestall with cubicles during the entire experimental period. On average for the total treatment period and compared with the no-additive group, CH4 production (g/d) was 28 and 23% lower for NOPbas and NOPconc, respectively. Methane yield (g/kg of dry matter intake) and methane intensity (g/kg of milk) were 23 and 24% lower for NOPbas, respectively, and 21 and 22% lower for NOPconc, respectively. No differences were found between NOPbas and NOPconc. Moreover, supplying 3-NOP did not affect total dry matter intake, milk production, or milk composition. The results of this experiment show that 3-NOP can reduce enteric CH4 emissions of dairy cattle when incorporated into a concentrate pellet and that this reduction is not different from the effect of mixing in 3-NOP with the basal diet (roughage). This broadens the possibilities for using 3-NOP in the dairy sector worldwide, as it is not always feasible to provide an additive mixed in with the basal diet. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare 2 commonly used techniques for measuring methane emissions from ruminant animals: the GreenFeed (GF) system and the sulfur hexafluoride (SF6) technique. The study was part of a larger experiment in which a methane inhibitor, 3-nitrooxypropanol, fed at 4 application rates (0, 40, 60, and 80 mg/kg of feed dry matter) decreased enteric methane emission by an average of 30% (measured by both GF and SF6) in a 12-wk experiment with 48 lactating Holstein cows fed a total mixed ration. The larger experiment used a randomized block design and was conducted in 2 phases (February to May, phase 1, and June to August, phase 2), with 2 sets of 24 cows in each phase. Using both GF and SF6 techniques, methane emission data were collected simultaneously during experimental wk 2, 6, and 12 (phase 1) and 2, 9, and 12 (phase 2), which corresponded to a total of 6 sampling periods. During each sampling period, 8 spot samples of gas emissions (staggered over a 3-d period) were collected from each cow using GF, as well as 3 × 24-h collections using the SF6 technique. Methane emission data were averaged per cow for the statistical analysis. The mean methane emission was 373 (standard deviation = 96.3) and 405 (standard deviation = 156) g/ cow per day for GF and SF6, respectively. Coefficients of variation for the 2 methods were 25.8 and 38.6%, respectively; correlation and concordance between the 2 methods were 0.40 and 0.34, respectively. The difference in methane emission between the 2 methods (SF6 - GF) within treatment was from 46 to 144 and 24 to 27 g/d for phases 1 and 2, respectively. In the conditions of this experiment, the SF6 technique produced larger variability in methane emissions than the GF method. The overall difference between the 2 methods was on average about 8%, but was not consistent over time, likely influenced by barn ventilation and background methane and SF6 concentrations. [ABSTRACT FROM AUTHOR]

The objective of this crossover experiment was to investigate the effect of a methane inhibitor, 3-nitrooxypropanol (3NOP), on enteric methane emission, methane isotopic composition, and rumen fermentation and microbial profile in lactating dairy cows. The experiment involved 6 ruminally cannulated late-lactation Holstein cows assigned to 2 treatments: control and 3NOP (60 mg/kg of feed dry matter). Compared with the control, 3NOP decreased methane emission by 31% and increased hydrogen emission from undetectable to 1.33 g/d. Methane emissions per kilogram of dry matter intake and milk yield were also decreased 34% by 3NOP. Milk production and composition were not affected by 3NOP, except milk fat concentration was increased compared with the control. Concentrations of total VFA and propionate in ruminal fluid were not affected by treatment, but acetate concentration tended to be lower and acetate-to-propionate ratio was lower for 3NOP compared with the control. The 3NOP decreased the molar proportion of acetate and increase those of propionate, butyrate, valerate, and isovalerate. Deuterium-to-hydrogen ratios of methane and the abundance of 13CH3D were similar between treatments. Compared with the control, minor (4‰) depletion in the 13C/12C ratio was observed for 3NOP. Genus composition of methanogenic archaea (Methanobrevibacter, Methanosphaera, and Methanomicrobium) was not affected by 3NOP, but the proportion of methanogens in the total cell counts tended to be decreased by 3NOP. Prevotella spp., the predominant bacterial genus in ruminal contents in this experiment, was also not affected by 3NOP. Compared with the control, Ruminococcus and Clostridium spp. were decreased and Butyrivibrio spp. was increased by 3NOP. This experiment demonstrated that a substantial inhibition of enteric methane emission by 3NOP in dairy cows was accompanied with increased hydrogen emission and decreased acetate-topropionate ratio; however, neither an effect on rumen archaeal community composition nor a significant change in the isotope composition of methane was observed. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the effect of feeding ethyl-3-nitrooxy propionate (E3NP) and 3-nitrooxypropanol (3NP), 2 recently developed compounds with potential antimethanogenic activity, in vitro and in vivo in nonlactating sheep on ruminal methane production, fermentation pattern, the abundance of major microbial groups, and feed degradability. Three experiments were conducted, 1 in vitro and 2 in vivo. The in vitro batch culture trial (experiment 1) tested 2 doses of E3NP and 3NP (40 and 80 μL/L), which showed a substantial reduction of methane production (up to 95%) without affecting concentration of volatile fatty acids (VFA). The 2 in vivo trials were conducted over 16 d (experiment 2) and 30 d (experiment 3) to study their effects in sheep. In experiment 2, 6 adult nonpregnant sheep, with permanent rumen cannula and fed alfalfa hay and oats (60:40), were treated with E3NP at 2 doses (50 and 500 mg/animal per day). After 7, 14, and 15 d of treatment, methane emissions were recorded in respiration chambers and rumen fluid samples were collected for VFA analysis and quantification of bacterial, protozoal, and archaeal numbers by real-time PCR. Methane production decreased by 29% compared with the control with the higher dose of E3NP on d 14 to 15. A decrease in the acetate:propionate ratio was observed without detrimental effects on dry matter intake. In experiment 3, 9 adult nonpregnant sheep, with permanent rumen cannula and fed with alfalfa hay and oats (60:40), were treated with E3NP or 3NP at one dose (100 mg/animal per day) over 30 d. On d 14 and d 29 to 30, methane emissions were recorded in respiration chambers. Rumen fluid samples were collected on d 29 and 30 for VFA analysis and quantification of bacterial, protozoal, and archaeal numbers by real-time PCR. In addition, on d 22 and 23, samples of oats and alfalfa hay were incubated in the rumen of sheep to determine dry matter ruminal degradation over 24 and 48 h, respectively; no effect was observed (78.6, 78.3, and 78.8% of alfalfa and 74.2, 74.0, and 70.6% of oats in control, E3NP, and 3NP groups, respectively). A reduction in methane production was observed for both additives at d 14 and d 29 to 30. In both treatments, the acetate:propionate ratio was significantly decreased. Likewise, total concentrations of the analyzed microbial groups in the rumen showed no difference among treatments and doses for both experiments. Both tested compounds showed promise as methane inhibitors in the rumen, with no detrimental effects on fermentation or intake, which would need to be confirmed in lactating animals. [ABSTRACT FROM AUTHOR]

The objective was to measure effects of 3-nitrooxypropanol (3NP) on methane production of lactating dairy cows and any associated changes in digestion and energy and N metabolism. Six Holstein-Friesian dairy cows in mid-lactation were fed twice daily a total mixed ration with maize silage as the primary forage source. Cows received 1 of 3 treatments using an experimental design based on two 3 x 3 Latin squares with 5-wk periods. Treatments were a control placebo or 500 or 2,500 mg/d of 3NP delivered directly into the rumen, via the rumen fistula, in equal doses before each feeding. Measurements of methane production and energy and N balance were obtained during wk 5 of each period using respiration calorimeters and digestion trials. Measurements of rumen pH (48 h) and postprandial volatile fatty acid and ammonia concentrations were made at the end of wk 4. Daily methane production was reduced by 3NP, but the effects were not dose dependent (reductions of 6.6 and 9.8% for 500 and 2,500 mg/d, respectively). Dosing 3NP had a transitory inhibitory effect on methane production, which may have been due to the product leaving the rumen in liquid outflow or through absorption or metabolism. Changes in rumen concentrations of volatile fatty acids indicated that the pattern of rumen fermentation was affected by both doses of the product, with a decrease in acetate:propionate ratio observed, but that acetate production was inhibited by the higher dose. Dry matter, organic matter, acid detergent fiber, N, and energy digestibility were reduced at the higher dose of the product. The decrease in digestible energy supply was not completely countered by the decrease in methane excretion such that metabolizable energy supply, metabolizable energy concentration of the diet, and net energy balance (milk plus tissue energy) were reduced by the highest dose of 3NP. Similarly, the decrease in N digestibility at the higher dose of the product was associated with a decrease in body N balance that was not observed for the lower dose. Milk yield and milk fat concentration and fatty acid composition were not affected but milk protein concentration was greater for the higher dose of 3NP. Twice-daily rumen dosing of 3NP reduced methane production by lactating dairy cows, but the dose of 2,500 mg/d reduced rumen acetate concentration, diet digestibility, and energy supply. Further research is warranted to determine the optimal dose and delivery method of the product. [ABSTRACT FROM AUTHOR]

The objective of the current study was to determine the effects of adding 3-nitrooxypropanol to the diet of lactating Holstein cows on methane emissions, rumen fermentation, ruminal microbial profile, and milk production. Twelve ruminally cannulated Holstein cows in midlactation were used in a crossover design study with 28-d periods. Cows were fed a diet containing 38% forage on a dry matter basis with either 2,500 mg/d of 3-nitrooxypropanol (fed as 25 g of 10% 3-nitrooxypropanol on silicon dioxide) or 25 g/d of silicon dioxide (control). After a 21-d diet adaptation period, dry matter intake (DMI) and milk yield were recorded daily. Rumen fluid and digesta were collected on d 22 and 28 for volatile fatty acid analysis and microbial profiling. Enteric methane emissions were measured on d 23 to 27 using the sulfur hexafluoride tracer gas technique. Feeding 3-nitrooxypropanol did not affect DMI; however, methane production was reduced from 17.8 to 7.18 g/kg of DMI. No change in milk or milk component yields was observed, but cows fed 3-nitrooxypropanol gained more body weight than control cows (1.06 vs. 0.39 kg/d). Concentrations of total volatile fatty acids in ruminal fluid were not affected by treatment, but a reduction in acetate proportion and a tendency for an increase in propionate proportion was noted. As such, a reduction in the acetate-to-propionate ratio was observed (2.02 vs. 2.36). Protozoa counts were not affected by treatment; however, a reduction in methanogen copy count number was observed when 3-nitrooxypropanol was fed (0.95 vs. 2.69 x 108/g of rumen digesta). The data showed that feeding 3-nitrooxypropanol to lactating dairy cows at 2,500 mg/d can reduce methane emissions without compromising DMI or milk production. [ABSTRACT FROM AUTHOR]

Abstract: A new technique for medical imaging, “3γ imaging”, is studied by our group at SUBATECH for few years. A small liquid xenon time projection chamber prototype has been built in order to demonstrate the feasibility of this technique. With an ultra-low-noise front-end electronics, the energy deposit and resolution of 511keV γ-ray as a function of drift electric field (E) is measured with high precision. 500μm of z resolution is estimated by measuring the charge carriers drift velocity and time resolution. [Copyright &y& Elsevier]

Right ventricular failure (RVF) after LVAD implantation remains difficult to predict. RV-PA coupling assessed by echocardiographic assessment of the ratio of tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) has shown to be prognostic in pulmonary hypertension and HFpEF. However, its utility in predicting RV failure after LVAD implantation has not been studied. We hypothesized that a low TAPSE/PASP ratio would be predictive of RV failure after LVAD. This was a single center retrospective observational study of patients who had first-time continuous flow LVAD implantation between 2012-2018. Pre-implant transthoracic echocardiograms were reviewed for each patient to obtain TAPSE and PASP. The primary outcome was early right ventricular failure defined as need for RVAD, inotrope duration >14 days, and/or pulmonary vasodilator use >48 hours. Differences between definition groups were assessed with two sample t-test. Results are reported as means with standard deviations. 254 patients were initially included in the LVAD cohort. Of those, 159 patients had complete echocardiogram data to calculate a TAPSE/PASP ratio. 40 patients (25%) had postoperative RV failure after LVAD implantation, of which 8 (25%) required RVAD. There was no difference in the TAPSE/PASP ratio in the RV failure cohort compared to the non-RV failure cohort (0.36 ± 0.14 versus 0.38 ± 0.18, respectively). However, there was a significant difference in pre-operative TAPSE/PASP ratio in patients who required RVAD compared to patients who did not require RVAD post-operatively (0.52 ± 0.17 versus 0.36 ± 0.14, respectively; p = 0.015). When restricting the definition of RV failure to need for RVAD or inotropes >14 days, there was no difference in the TASPE/PASP ratio between groups (p=0.77). In addition, a lower TAPSE/PASP ratio was associated with higher RA pressure (r= -0.27) and PVR (r= -0.28); however, there was no association between TAPSE/PASP and cardiac output. In a single center cohort of continuous flow LVAD patients, TAPSE/PASP as a surrogate for RV-PA coupling is not predictive of early RV failure post LVAD implantation. However, a higher ratio was associated with the need for RVAD. Further study is needed to determine if other metrics assessing RV/PA coupling are predictive of RV failure. [ABSTRACT FROM AUTHOR]

Cardiopulmonary stress test (CPX) is widely used to evaluate patients with end-stage heart failure who may benefit from advanced therapies, such as orthotopic heart transplantation (OHT). A hypotensive systolic blood pressure response on CPX may identify a subpopulation with the highest risk physiology. We sought to evaluate outcomes among OHT recipients with a pre-implantation hypotensive response. This retrospective single-center study evaluated consecutive patients undergoing OHT between 1/2011 and 6/2020 at our institution. Patients with CPX performed within 12 months before transplantation were included. Patients bridged with left ventricular assist devices (LVAD) were excluded. Hypotensive response was defined as a peak exercise systolic blood pressure lower than the resting systolic blood pressure. Hospital length of stay was right-skewed and thus log-transformed for analysis. Multivariable regression models were used to evaluate the relation between hypotensive exercise blood pressure response and hospital outcomes. Data for 211 patients were reviewed. 76 patients were identified to meet our inclusion criteria. The median age was 59.6 years. 26 patients had a hypotensive response on CPX (34%). Those with a normal blood pressure response on CPX had a 21% shorter length of stay (16 days vs 21 days, p=0.05). This remained unchanged when adjusting for age. There were no significant differences in postoperative complications or 1-year survival. Hypotensive blood pressure response on the CPX performed pre-OHT is independently associated with increased hospital length of stay. Additional studies are needed to further characterize this high-risk patient population and to identify strategies to optimize outcomes. [ABSTRACT FROM AUTHOR]

Elevated body mass index (BMI) is a well-established risk factor for post-operative adverse events. We hypothesized that patients with higher BMI are more likely to develop end stage renal failure (ESRD) after LVAD implantation, a complication regarded as a strong negative prognostic marker for survival. A single center continuous flow LVAD cohort (n=456) was queried for BMI at the time of LVAD implantation. To determine the relationship between BMI and the probability of ESRD, a multivariable Cox regression analysis was performed. Patients were stratified into 3 groups by BMI (<25, 25-30, >30 kg/m2) for analysis. The mean age of the cohort was 57±14 years. 80% were male, 54% had ischemic cardiomyopathy, 57% were designated as bridge to transplant and the median pre-implant creatinine was 1.2. The median follow-up time on LVAD support was 1.3 years. 25 of the 456 patients in our cohort (5.5%) developed ESRD. BMI >30 kg/m2 was associated with a significantly increased risk for renal failure (adjusted HR: 6.5, CI: 1.4-29.4; p=0.015). While there was a trend, the risk for the intermediate BMI group did not reach statistical significance (p=0.079) when compared to BMI<25 kg/m2. The model was adjusted for age, sex, INTERMACS profile, bridge to transplant status and pre-implant renal function. BMI above 30 kg/m2 at the time of LVAD implantation was associated with a significantly increased post-operative risk for renal failure in our cohort. Further studies are warranted to determine the pathophysiology and to develop strategies to mitigate this risk. [ABSTRACT FROM AUTHOR]