Short-term outcome after transcatheter aortic valve replacement with a novel balloon-expandable valve

OBJECTIVES

Transcatheter aortic valve replacement (TAVR) has been expanding rapidly with numerous transcatheter heart valve (THV) systems currently available. The Myval balloon-expandable (BE) valve (Meril Life Sciences Pvt. Ltd., India) is a novel THV system indicated for the treatment of patients with severe aortic stenosis. The primary objective of this study is to assess the safety and performance of the Myval BE valve.

METHODS

In this prospective single-centre study, 120 consecutive patients who underwent TAVR with the Myval BE valve were included. Clinical outcomes were evaluated at 30 days and 6 months using Valve Academic Research Consortium‑2 criteria. All-cause mortality, stroke, acute kidney injury, major vascular complications, moderate or severe paravalvular leakage (PVL) and need for a permanent pacemaker implantation (PPI) were investigated.

RESULTS

At 6‑month follow-up, all-cause death and cardiac death were seen in 5.8% and 0.8% of the patients respectively. Periprocedural stroke and need for PPI were both seen in 3.3% of the patients. Access-site-related vascular and bleeding complications were absent. Improved valve haemodynamics and no moderate to severe PVL could be seen at 30 days. An intermediate valve size was selected in 51% of the patients.

CONCLUSIONS

The Myval BE valve demonstrates improved valve haemodynamics, absence of moderate to severe PVL and good safety outcomes at 6‑month follow-up with low cardiac death rate and acceptable rates of permanent pacemaker implantation and periprocedural stroke. Future randomised controlled trials will further establish the clinical utility of the Myval BE valve.

Prognostic Value of Histopathological Thrombus Age in Large Vessel Occlusion-Related Stroke

INTRODUCTION

Acute mechanical thrombectomy (MT) is the preferred treatment for large vessel occlusion-related stroke. Histopathological research on the obtained occlusive embolic thrombus may provide information regarding the aetiology and pathology of the lesion to predict prognosis and propose possible future acute ischaemic stroke therapy.

METHODS

A total of 75 consecutive patients who presented to the Amphia Hospital with acute large vessel occlusion-related stroke and underwent MT were included in the study. The obtained thrombus materials were subjected to standard histopathological examination. Based on histological criteria, they were considered fresh (<1 day old) or old (>1 day old). Patients were followed for 2 years for documentation of all-cause mortality.

RESULTS

Thrombi were classified as fresh in 40 patients (53%) and as older in 35 patients (47%). Univariate Cox regression analysis showed that thrombus age, National Institutes of Health Stroke Scale at hospital admission, and patient age were associated with long-term mortality (p < 0.1). Multivariable Cox hazards and Kaplan-Meier analysis demonstrated that after extensive adjustment for clinical and procedural variables, thrombus age persisted in being independently associated with higher long-term mortality (hazard ratio: 3.34; p = 0.038, log-rank p = 0.013).

CONCLUSION

In this study, older thromboemboli are responsible for almost half of acute large ischaemic strokes. Moreover, the presence of an old thrombus is an independent predictor of mortality in acute large vessel occlusion-related stroke. More research is warranted regarding future therapies based on thrombus composition.

Comparison of Supraflex Cruz 60 μm Versus Ultimaster Tansei 80 μm Stent Struts in High Bleeding Risk PCI Patients: Study design and Rational of Compare 60/80 HBR trial

Up to 45% of patients who underwent percutaneous coronary intervention (PCI) may have a high bleeding risk (HBR), depending on the bleeding risk definition.1 This condition is often associated with an enhanced risk of thrombotic events with a negative impact on short- and long-term outcomes,2-8 making the choice of an appropriate antithrombotic regimen after PCI particularly challenging. Advances in stent technologies, in which the introduction of newer generations of thinner strut drug-eluting stents (DES), have significantly reduced the rate of thrombotic complications and may justify a shorter dual antiplatelet therapy (DAPT) duration. Both in vitro and in vivo studies have shown that local hemodynamic factors may critically affect the natural history of atherosclerosis. Strut thickness correlates with flow disturbances and endothelial shear stress. Flow separation within struts determines areas of recirculation with low endothelial shear stress which promotes local concentration of activated platelets.9 By mitigating inflammation, vessel injury, and neointimal proliferation, thin and streamlined struts have been associated with faster vascular healing and re-endothelization and have resulted in lower rates of thrombotic events after PCI.10,11 The use of thin strut and ultra-thin strut stents may lead to a favorable trade-off in bleeding and ischemic events in patients with HBR. However, dedicated studies evaluating the performance of thin strut versus ultrathin strut stents in patients with HBR are lacking.

Assessing the Novel Myval Balloon-Expandable Valve with the Evolut Valve: A Propensity-Matched Study

BACKGROUND

The Myval balloon-expandable (BE) valve has shown encouraging early clinical data in terms of safety and efficacy. Comparative data with other well-established contemporary valves are nonetheless still scarce. This study aims to compare the performance of the Myval BE valve with the Evolut self-expanding (SE) valve.

METHODS

In this retrospective single-center study, 223 patients with symptomatic severe aortic stenosis (AS) were included and treated with the Myval BE valve (n = 120) or with the Evolut SE valve (n = 103). Then, 91 pairs were compared after matching. Clinical outcomes were evaluated at 30 days and 1 year. Echocardiographic follow-up was performed at 30 days.

RESULTS

Procedural complications were rare in both groups. At the 30-day follow-up, no significant difference in cardiac death (Myval: 1% vs. Evolut: 2%, p = 0.56), stroke (2% vs. 4%, p = 0.41) and myocardial infarction (1% vs. 3%, p = 0.31) was observed. A permanent pacemaker implantation (PPI) was significantly less needed in the Myval group (4% vs. 15%, p = 0.01). At 1 year, cardiac death (2% vs. 4%, p = 0.41) and the stroke rate (7% vs. 5%, p = 0.76) were similar. Moderate-severe paravalvular leakage (PVL) was also comparable in both groups (1% vs. 4%, p = 0.17).

CONCLUSION

Safety and efficacy outcomes were comparable between the two valves, except for a higher PPI rate for the Evolut SE valve. Up to 1-year follow-up, clinical outcomes showed acceptable rates of stroke and cardiac death with both valves. Valve hemodynamics were excellent with a low rate of moderate-severe PVL in both groups.

Assessment of the Level of Physical Activity and Mood in Students after a Year of Study in a Mixed Mode in the Conditions of Restrictions Resulting from the Pandemic

The COVID-19 pandemic has forced social isolation affecting all areas of life. It also affected the functioning of schools and universities. Many countries have introduced full or partial distance learning. The aim of the study was to assess the level of physical activity and student mood of the Faculty of Physiotherapy of the Academy of Physical Education in Wrocław (Poland) and students of the Faculty of Health of the ODISSE University in Brussels (Belgium) after a year of the study conducted in a mixed mode due to contact restrictions resulting from the COVID-19 pandemic and checking which of the analyzed factors increases the risk of depression to the greatest extent.

MATERIAL AND METHODS

297 students from the 2nd to 4th year of full-time studies took part in the observation. The academic year 2020/2021 was assessed. Physical activity was assessed using the Global Physical Activity Questionnaire (GPAQ) recommended for this type of analysis by WHO. The GPAQ questionnaire enables the assessment of activity performed at work, movement, and leisure time and assesses the time of sitting or resting in a supine position. The Beck Depression Inventory was used to assess mental health. The subjects also completed a questionnaire concerning selected somatic features and describing their living conditions in the previous year.

RESULTS

In the group of Polish students, classes conducted in a completely remote mode accounted for about 50%, while in the group of Belgian students, about 75%. In the described period, 19% of students from Poland and 22% of students from Belgium were infected with COVID-19. The median of the results of the Beck Depression Scale in both groups was lower than 12 points (7 points in the AWF group and 8 points in the ODISSE group, respectively). A detailed analysis showed that in both study groups, more than 30% of students received results showing a depressed mood. A total of 19% of the surveyed students of the University of Physical Education and 27% of the ODISSE students were characterized by a result indicating mild depression. The results of the GPAQ questionnaire show that the total physical activity, including work/study, recreation, and mobility was 16.5 h a week for students from Poland and 7.4 h a week for students from Belgium.

CONCLUSIONS

Both groups of subjects reached all the thresholds recommended by the WHO as a sufficient level of weekly physical activity. A group of students of the Faculty of Physiotherapy of the University of Physical Education in Wrocław was characterized by more than twice as high (statistically significant) level of weekly physical activity as compared to the group of participants from the ODISSE University in Brussels. In both study groups, more than 30% of students experienced a lowered mood of varying intensity. It is necessary to monitor the mental state of students and, in the event of obtaining control results at a similar level, to implement psychological assistance for willing participants.

Bio-distribution and longevity of mesenchymal stromal cell derived membrane particles

Vesicle-based medicines hold great promise for therapy development but essential knowledge on the bio-distribution and longevity of vesicles after administration is lacking. We generated vesicles from the membranes of human mesenchymal stromal cells (MSC) and we demonstrated earlier that these so-called membrane particles (MP) mediate immunomodulatory and regenerative responses in target cells. In the present study we examined the bio-distribution and longevity of MP after intravenous administration in mice. While most vesicle tracking methods are based on imaging techniques, which require labeling of vesicles and can only detect dense accumulations of vesicles, we used proteomics analysis to detect the presence of MP-derived proteins in multiple organs and tissues. MP proteins were mainly present in plasma and leukocytes at 1 h after injection, indicating that MP - in contrast to whole MSC - do not accumulate in the lungs upon first passage but remain in circulation. After 24 h, MP proteins were still present in plasma but were most abundant in the liver. RNA sequencing of livers demonstrated that MP impact liver function and in particular induce metabolic pathways. These data provide a clear view of the bio-distribution and longevity of MP, which is likely extrapolatable to other types of vesicles, and demonstrate that MP circulate for up to 24 h and may be a tool for targeting the liver.

A Case Of Disseminated Histoplasmosis In A Patient With Sarcoidosis

Introduction/Objective

Sarcoidosis is a syndrome of unknown cause that may manifest with clinical, radiographic and pathological findings similar to those seen with histoplasmosis. We present a case of disseminated histoplasmosis in an immunocompetent patient previously diagnosed with sarcoidosis.

Methods/Case Report

A 69-year-old obese male with a history of hypertension, diabetes mellitus and long-standing sarcoidosis was admitted to the hospital for several months of intermittent fevers and pancytopenia. His sarcoidosis was diagnosed 21 years prior, initially involving the lungs and eventually showing cardiac involvement, requiring a pacemaker. He had been treated with methotrexate and prednisone. His recent medical history was also significant for COVID-19 infection, diagnosed 3 months before admission. His fevers were initially attributed to sarcoidosis and his pancytopenia to methotrexate. However, his symptoms continued despite discontinuation of his medications, and further workup was initiated.

Computed tomography showed hepatomegaly, splenomegaly, and lymphadenopathy, concerning for a lymphoproliferative disorder. The patient underwent a bone marrow biopsy that showed noncaseating granulomas and microorganisms consistent with histoplasmosis on fungal stain. Bone marrow cultures were not possible as the marrow was inaspirable. The patient subsequently underwent a lymph node biopsy with both morphology and culture identifying histoplasmosis. Urine and serum histoplasma antigen also returned positive. The patient’s overall clinical picture was consistent with disseminated histoplasmosis and he was administered intravenous Amphotericin B for 3 weeks followed by oral itraconazole for 1 year. One month follow-up after discharge showed significant improvement in the patient’s condition.

Results (if a Case Study enter NA)

N/A

Conclusion

Sarcoidosis reduces T-cell activity, and treatment with steroids causes further immunosuppression and vulnerability for development of a disseminated infection. COVID-19 also presumably increases the predisposition to acquire bacterial or fungal co-infections. Clinicians and pathologists should be aware of the overlap in clinical, radiologic and pathological presentations of sarcoidosis and histoplasmosis to make the correct diagnosis and administer the appropriate treatment.

Institutional challenges and stakeholder perception towards planned water reuse in peri-urban agriculture of the Bengal delta

The indirect, unplanned use of urban wastewater by peri-urban farmers in developing countries poses a severe risk to the environment and the farmers. Planned water reuse could contribute substantially to the irrigation water demand in peri-urban agriculture and minimize the risk. However, implementing such practice requires a thorough evaluation of stakeholder's perception and the scope within the existing organizational structures. This paper aims to assess the level of awareness, perception, and willingness of different stakeholders toward current practices and the prospect of urban water reuse in Khulna City - one of the most vulnerable cities located in the southwest of Bangladesh due to the consequences of rapid climate changes in the Bengal delta. Also, institutional arrangements and their functioning were analyzed to understand the current sectoral performance. One questionnaire with 385 respondents from the urban area, 32 in-depth interviews and one focus group discussion with farmers in the peri-urban area, and ten interviews with key informants from the government and non-government organization was conducted. Results indicate an overall positive attitude among major stakeholder groups toward planned water reuse for peri-urban agriculture. More than half of the citizens (53%) are willing to pay for the treatment of wastewater and majority of the farmers (66%) are willing to pay for the supply of better-quality irrigation water. However, the public sector responsible for wastewater collection and treatment requires adjustment in rules and regulations to implement planned water reuse. Interrelated factors such as lack of transparency and coordination, shifting responsibilities to other organizations, lack of required resources need to be addressed in the updated rules and regulations. Strategies to enforce current regulations and align all stakeholders are also crucial for collection and treatment of wastewater and its subsequent use for crop production.

Update and, internal and temporal-validation of the FRANCE-2 and ACC-TAVI early-mortality prediction models for Transcatheter Aortic Valve Implantation (TAVI) using data from the Netherlands heart registration (NHR)

Background

The predictive performance of the models FRANCE-2 and ACC-TAVI for early-mortality after Transcatheter Aortic Valve Implantation (TAVI) can decline over time and can be enhanced by updating them on new populations. We aim to update and internally and temporally validate these models using a recent TAVI-cohort from the Netherlands Heart Registration (NHR).

Methods

We used data of TAVI-patients treated in 2013-2017. For each original-model, the best update-method (model-intercept, model-recalibration, or model-revision) was selected by a closed-testing procedure. We internally validated both updated models with 1000 bootstrap samples. We also updated the models on the 2013-2016 dataset and temporally validated them on the 2017-dataset. Performance measures were the Area-Under ROC-curve (AU-ROC), Brier-score, and calibration graphs.

Results

We included 6177 TAVI-patients, with 4.5% observed early-mortality. The selected update-method for FRANCE-2 was model-intercept-update. Internal validation showed an AU-ROC of 0.63 (95%CI 0.62-0.66) and Brier-score of 0.04 (0.04-0.05). Calibration graphs show that it overestimates early-mortality. In temporal-validation, the AU-ROC was 0.61 (0.53-0.67).The selected update-method for ACC-TAVI was model-revision. In internal-validation, the AU-ROC was 0.63 (0.63-0.66) and Brier-score was 0.04 (0.04-0.05). The updated ACC-TAVI calibrates well up to a probability of 20%, and subsequently underestimates early-mortality. In temporal-validation the AU-ROC was 0.65 (0.58-0.72).

Conclusion

Internal-validation of the updated models FRANCE-2 and ACC-TAVI with data from the NHR demonstrated improved performance, which was better than in external-validation studies and comparable to the original studies. In temporal-validation, ACC-TAVI outperformed FRANCE-2 because it suffered less from changes over time.

CMR markers for early right ventricular dysfunction in precapillary pulmonary hypertension

Introduction

Precapillary pulmonary hypertension (pPH) causes right ventricular (RV) pressure overload inducing RV remodeling, often resulting in dysfunction and dilatation, heart failure, and ultimately death. The ability of the right ventricle to adequately adapt to increased pressure loading is key for patients' prognosis. RV ejection fraction (RVEF) by cardiac magnetic resonance (CMR) is related to outcome in pPH patients, but this global measurement is not ideal for detecting early changes in RV function. Strain analysis on CMR using feature tracking (FT) software provides a more detailed assessment, and might therefore detect early changes in RV function.

Aim

1) To compare RV strain parameters in pPH patients and healthy controls, and 2) to compare strain parameters in a subgroup of pPH patients with preserved RVEF (pRVEF) and healthy controls.

Methods

In this prospective study, a CMR was performed in pPH patients and healthy controls. Using FT-software on standard cine images, the following RV strain parameters were analyzed: global, septal, and free wall longitudinal strain (GLS, sept-LS, free wall-LS), time to peak strain (TTP, as a % of the whole cardiac cycle), the fractional area change (FAC), global circumferential strain (GCS), global longitudinal and global circumferential strain rate (GLSR and GCSR, respectively). A pRVEF is defined as a RVEF &gt;50%. To compare RV strain parameters in pPH patients to healthy controls, the Mann-Whitney U test was used.

Results

33 pPH-patients (55 [45–63] yrs; 10 (30%) male) and 22 healthy controls (40 [36–48] yrs; 15 (68%) male) were included. All RV strain parameters were significantly reduced in pPH patients compared to healthy controls (see table), except for GCS and GCSR. Most importantly, in pPH patients with pRVEF (n=8) GLS (−26.6% [−22.6 to −27.3] vs. −28.1% [−26.2 to −30.6], p=0.04), sept-LS (−21.2% [−19.8 to −23.2] vs. −26.0% [−24.0 to −27.9], p=0.005), and FAC (39% [35–44] vs. 44% [42–47], p=0.02) were still significantly impaired compared to healthy controls. The RV TTP was significantly increased in pPH patients compared to healthy controls (47% [44–57] vs. 40% [33–43], p≤0.001).

Conclusions

Several CMR-FT strain parameters of the right ventricle are impaired in pPH patients when compared to healthy controls. Moreover, even in pPH patients with a preserved RVEF multiple RV strain parameters (GLS, sept-LS, and FAC) remained significantly impaired, and TTP significantly prolonged, in comparison to healthy controls. This suggests that RV strain parameters may be used as an early marker of RV dysfunction in pPH patients.

Funding Acknowledgement

Type of funding source: None

Use of Lithotripsy in a Calcified Saphenous Vein Graft

Percutaneous coronary interventions in saphenous vein grafts can pose a variety of challenges, such as severely calcified lesions. If these lesions are nondilatable, lithotripsy can arguably be a proper tool for lesion preparation. We present a case in which a nondilatable, calcified saphenous vein graft was successfully treated using Shockwave lithotripsy. (Level of Difficulty: Intermediate.)

The rationale of using cerebral embolic protection devices during transcatheter aortic valve implantation

Aortic valve stenosis is one of the most common valvular abnormalities, which can manifest as angina, syncope, dyspnoea and sudden cardiac death. Transcatheter aortic valve implantation (TAVI) has been introduced as an alternative to surgical valve replacement in patients with severe aortic valve stenosis, resulting in less morbidity, shorter time to recovery and similar mortality rates. Progress in this field has reduced complication rates. However, the incidence of peri-procedural stroke remains relatively high (around 4%). To fully utilise the potential of TAVI, cerebral embolic protection devices (CEPD) have been developed and introduced. In this position paper, we aim to summarise the available data on several CEPD.

Analysis of the Prevalence and Causes of Ultrafiltration Failure during Long-Term Peritoneal Dialysis: A Cross-Sectional Study

Background

Ultrafiltration failure (UFF) is a major complication of peritoneal dialysis (PD). It can occur at any stage of PD, but develops in time and is, therefore, especially important in long-term treatment. To investigate its prevalence and to identify possible causes, we performed a multicenter study in The Netherlands, where patients treated with PD for more than 4 years were studied using a peritoneal function test (standard peritoneal permeability analysis) with 3.86% glucose. UFF was defined as net UF < 400 mL after a 4-hour dwell.

Results

55 patients unselected for the presence or absence of UFF were analyzed. Mean age was 48 years (range 18 – 74 years); duration of PD ranged from 48 to 144 months (median 61 months); UFF was present in 20 patients (36%). Patients with and without UFF did not differ in age or duration of PD. Median values for patients with normal UF compared to patients with UFF were, for net UF 659 mL versus 120 mL ( p < 0.01), transcapillary UF rate 3.8 versus 2.1 mL/minute ( p < 0.01), effective lymphatic absorption 1.0 versus 1.6 mL/min ( p < 0.05), mass transfer area coefficient (MTAC) for creatinine 9.0 versus 12.9 mL/min ( p < 0.01), dialysate-to-plasma ratio (D/P) for creatinine 0.71 versus 0.86 ( p < 0.01), glucose absorption 60% versus 73% ( p < 0.01), maximum dip in D/P sodium (as a measure of free water transport) 0.109 versus 0.032 ( p < 0.01), and osmotic conductance to glucose 3.0 versus 2.1 μL/min/mmHg ( p < 0.05). As causes for UFF, high MTAC creatinine, defined as > 12.5 mL/min, or a glucose absorption > 72%, both reflecting a large vascular surface, a lymphatic absorption rate (LAR) of > 2.14 mL/min, and a decreased dip in D/P sodium of < 0.046 were identified. Most patients had a combination of causes (12 patients), whereas there was only a decreased dip in D/P sodium in 3 patients, only high MTAC creatinine in 1 patient, and only high LAR in 2 patients. We could not identify a cause in 2 patients. Both groups had similar clearances of serum proteins and peritoneal restriction coefficients. However, dialysate cancer antigen 125 concentrations, reflecting mesothelial cell mass, were lower in the UFF patients (2.79 vs 5.38 U/L).

Conclusion

The prevalence of UFF is high in long-term PD. It is caused mainly by a large vascular surface area and by impaired channel-mediated water transport. In addition, these patients also had signs of a reduced mesothelial cell mass, indicating damage of the peritoneum on both vascular and mesothelial sites.

Coronary Artery Perforation After Shockwave Intravascular Lithotripsy

Severely calcified coronary lesions remain a challenge in current percutaneous coronary interventions. Shockwave intravascular lithotripsy (Shockwave Medical, Inc., Santa Clara, California) is an alternative for rotational atherectomy in such lesions that supports stent deliverability and achieves optimal results. We describe a case of coronary artery perforation after use of this lithotripsy device. (Level of Difficulty: Advanced.)

Nurses as a source of system-level resilience: Secondary analysis of qualitative data from a study of intravenous infusion safety in English hospitals

Background

Deviations from local policy and national recommended best practice are common in the administration of intravenous infusions, but not all result in negative consequences. Some are the result of nurses’ clinical judgement. However, little is known about such practices and their effects on the safety of intravenous infusions. Our objective was to explore ways in which nurses contribute to system-level resilience when administering intravenous infusions.

Methods

We conducted a secondary analysis of qualitative data from debriefs and focus groups from a mixed methods study of errors and policy deviations in intravenous infusion administration across 16 English hospitals. Analysis focused on nurses’ contributions to system-level resilience, drawing on Larcos’s et al. framework of types of resilience.

Results

Five types of system-level resilience were identified in nurses’ behaviour: anticipatory resilience, responsive resilience, resilience based on past experience, workarounds and nurses performing informal ‘risk assessments’ in relation to how best to treat individual patients. Examples of practices contributing to infusion safety were found for each of these types of resilience.

Conclusion

Our findings suggest nurses are a key source of system-level resilience. Some behaviours that may be considered deviations from policy or best practice are the result of reasoned clinical judgement to improve infusion safety in response to the specific situation at hand. Adaptive behaviour is necessary to cope with the complexity of practice. There is a tension between standardisation and supporting flexibility in safety management.

Spontaneous Platelet Aggregation in Cerebrovascular Disease

50 patients from a group of 130 patients with transient ischaemic attacks or cerebral infarction were found to demonstrate in vitro spontaneous platelet aggregation (SPA) while 80 normal subjects tested never showed this phenomenon.

The following additional findings point towards a possible platelet abnormality:

1. Platelets from 10 patients with SPA when isolated and resuspended in normal plasma still demonstrated SPA while isolated normal platelets resuspended in patient’s plasma did not.

2. Platelets demonstrating SPA showed an increased aggregation tendency upon incubation with ADP while normal platelets developed the expected refractory state.

SPA was found to be dependant upon the presence of divalent cations and could further be inhibited by phentolamine and adenosine. Aspirin effectively abolished SPA in 50 patients and relieved the clinical symptoms of patients with recurrent complaints of transient blindness and paraesthesia.

Spontaneous Platelet Aggregation in Cerebrovascular Disease II

A group of 186 patients with Transient Ischaemic Attacks (TIA) or cerebral Infarction (Cl) was found to demonstrate in vitro Spontaneous Platelet Aggregation (SPA) in 39% of those studied. Of the 176 normal subjects studied the incidence of in vitro SPA was found to be 5%. Further investigation of the phenomenon of SPA revealed that:

1. it is associated with ADP-hyperaggregability, i. e. the threshold concentration to induce second wave aggregation is decreased;

2. it is dependant on the increase in pH which occurs in platelet-rich plasma stirring in an aggregometer while concurrent ADP-hyperaggregability is independant of this change in pH;

3. it is associated with malondialdehyde production and the release of endogenous 5- hydroxytryptamine; and that

4. in addition Km and Vmax values for [14C]-5HT incorporation are normal; and that

5. no gross abnormalities of the platelet membrane glycoproteins were apparent although occasionally glycoprotein III was found to be increased.

This study demonstrates abnormal platelet behaviour in patients with TIA and Cl where the enzyme system involved in thromboxane production is sufficiently stimulated, by stirring alone, to induce aggregation of platelets and the release reaction.

Acetylsalicylic acid abolishes SPA and prolongs the bleeding time with similar characteristics as has been described for normal individuals. Plasma (3-thromboglobulin levels are significantly increased in the patients studied. However, no correlation was established with the incidence of in vitro SPA.

Orientation-dependent stereo Wigner time delay and electron localization in a small molecule

Attosecond metrology of atoms has accessed the time scale of the most fundamental processes in quantum mechanics. Transferring the time-resolved photoelectric effect from atoms to molecules considerably increases experimental and theoretical challenges. Here we show that orientation- and energy-resolved measurements characterize the molecular stereo Wigner time delay. This observable provides direct information on the localization of the excited electron wave packet within the molecular potential. Furthermore, we demonstrate that photoelectrons resulting from the dissociative ionization process of the CO molecule are preferentially emitted from the carbon end for dissociative ²Σ states and from the center and oxygen end for the ²Π states of the molecular ion. Supported by comprehensive theoretical calculations, this work constitutes a complete spatially and temporally resolved reconstruction of the molecular photoelectric effect.

Defining and Measuring a Standard Set of Patient-Relevant Outcomes in Coronary Artery Disease

Systematic outcome measurement enables to continuously improve treatment results and stimulates dissemination of best practices. For patients with coronary artery disease, no examples yet exist of standard sets of patient-relevant outcome measures that have already been fully implemented at a large scale in clinical care. The aim of this paper is twofold: (1) to share the standard set of outcome measures as developed by Meetbaar Beter, and (2) to show how the standard set is presented and published to support improvement of cardiac care. A step-wise approach was followed by an expert panel to construct a standard set of outcome measures. This resulted in a comprehensive set of relevant outcome measures, comprising 4 generic and 11 treatment-specific outcomes. Both short-term and long-term outcomes measures up to 5 years of follow-up were included. Relevant initial conditions were selected to enable case-mix adjustment. The standard set has been implemented in 21 hospitals across the Netherlands. The results and experiences have been used to fine-tune the set in 4 reporting cycles in 2012 to 2016, using an annual maintenance cycle. Currently about 83,000 percutaneous coronary interventions and 30,000 coronary artery bypass graftings are included in the dataset, covering the majority of all percutaneous coronary interventions and coronary artery bypass graftings in the Netherlands. In conclusion, Meetbaar Beter has defined and implemented a comprehensive set of patient-relevant outcome measures for coronary artery disease, and the variation of the results among the centers indicates that there are sufficient opportunities to further improve cardiac care in the Netherlands.

Comparison of attosecond streaking and RABBITT

Recent progress in the generation of ultra-short laser pulses has enabled the measurement of photoionization time delays with attosecond precision. For single photoemission time delays the most common techniques are based on attosecond streaking and the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT). These are pump-probe techniques employing an extreme-ultraviolet (XUV) single attosecond pump pulse for streaking or an attosecond pump pulse train for RABBITT, and a phase-locked infrared (IR) probe pulse. These techniques can only extract relative timing information between electrons originating from different initial states within the same atom or different atoms. Here we address the question whether the two techniques give identical timing information. We present a complete study, supported by both experiments and simulations, comparing these two techniques for the measurement of the photoemission time delay difference between valence electrons emitted from the Ne 2p and Ar 3p ground states. We highlight not only the differences and similarities between the two techniques, but also critically investigate the reliability of the methods used to extract the timing information.

Prophylactic intraoperative antithrombotics in open infrainguinal arterial bypass surgery: a systematic review

Unfractionated heparin (UFH) is used intraoperatively as antithrombotic by most vascular surgeons worldwide during infrainguinal bypass surgery (IABS) to reduce the risk of peroperative and early graft thrombosis. To reduce the harmful side effects of UFH (bleeding complications, HIT) and to reduce peroperative and early graft failure, other pharmaceuticals have been suggested for IABS. A systematic review was performed using MEDLINE, EMBASE and Cochrane databases. Only 9 studies on IABS and intraoperative antithrombotic use were eligible for review. Between studies heterogeneity was high and investigated study populations were often of small size. No study was retrieved comparing UFH to no-UFH. Dextran, human antithrombin and iloprost showed no beneficial effect compared to UFH alone for patency, mortality and morbidity. Low molecular weight heparin (LMWH) has potential benefits compared to UFH, but a statistically significant effect could not be demonstrated from the current review. The use of UFH during IABS to prevent intraoperative graft thrombosis has not been proven in randomized clinical trials. Dextran, human antithrombin and iloprost showed to be of no added beneficial effect for the patient compared to UFH alone. Data on the use of LMWH instead of UFH are promising, but no statistically significant benefit could be reproduced from literature. Results from a recent Cochrane review were favourable for LMWH, but it appeared that included data were not complete in that review. Randomized controlled trials are required for intra-operative use of antithrombotics and to improve peroperative and early patency after IABS.

Perioperative prophylactic antithrombotic strategies in vascular surgery: current practice in the Netherlands

AIM

The aim of this study was to evaluate the current practice of the use of perioperative antithrombotic drugs to prevent arterial thrombo-embolic complications during arterial vascular surgery by Dutch vascular surgeons. Aim was also to compare the results with the literature and to evaluate the effect of guidelines.

METHODS

A comprehensive questionnaire was sent to all Dutch vascular surgeons performing arterial reconstructive surgery.

RESULTS

The response rate was 84%. Acetylsalicylic acid (ASA) was continued perioperatively by most surgeons (91%). Clopidogrel was discontinued by the majority of respondents (65%). During operation 97% of surgeons administered unfractionated heparin (UFH) before arterial clamping. A minority (11%) measures peroperatively anticoagulant activity in patients' blood. After infrainguinal venous bypass most surgeons (81%) preferred monotherapy with vitamin K antagonists (VKA), in agreement with the Dutch guideline in this respect. Before the introduction of the guideline in 2005, a survey was performed in 2004. Results of our 2011 survey showed more respondents (6% to 11%) prescribed ASA or VKA according to these guidelines.

CONCLUSION

This survey showed a recognizable pattern of variation for perioperative arterial thrombosis prophylaxis amongst Dutch vascular surgeons, in agreement with reports from other countries over the past 20 years. Although a higher percentage of surgeons complied in 2011 with existing guidelines than in 2004, guidelines were not completely met. Possibly because current guidelines are not fully supported by evidence and do not cover all aspects of perioperative arterial thrombosis prophylaxis. Clearly there is need for (more) convincing data based on RCT's concerning the various aspects of perioperative arterial thrombosis prophylaxis.

Long term effects of epoetin alfa in patients with ST- elevation myocardial infarction

PURPOSE

The HEBE III trial showed that epoetin alfa administration in patients with a first ST-elevation myocardial infarction (STEMI) did not improve left ventricular function at 6 weeks after primary percutaneous coronary intervention (PCI). The long term effects of erythropoiesis- stimulating agents on cardiovascular morbidity and mortality are unknown, therefore we evaluated clinical events at 1 year after PCI.

METHODS

A total of 529 patients with a first STEMI and successful primary PCI were randomized to standard optimal medical treatment (N = 266) or an additional bolus of 60,000 IU epoetin alfa administered intravenously (N = 263) within 3 h after PCI. Analyses were performed by intention to treat.

RESULTS

At 1 year after STEMI, 485 patients had complete follow-up. The rate of the composite end point of all-cause mortality, re-infarction, target vessel revascularization, stroke and/or heart failure was 6.4 % (N = 15) in the epoetin alfa group and 9.6 % (N = 24) in the control group (p = 0.18). Thromboembolic events were present in 1.3 % (N = 3) of patients in the epoetin alfa group and 2.4 % (N = 6) in the control group. There was no evidence of benefit from epoetin alfa administration in subgroups of patients.

CONCLUSIONS

Administration of a single bolus of epoetin alfa in patients with STEMI does not result in a reduction of cardiovascular events at 1 year after primary PCI. There was a comparable incidence of thromboembolic complications in both treatment groups, suggesting that epoetin alfa administration is safe at long term.

Leaf photosynthesis and respiration of three bioenergy crops in relation to temperature and leaf nitrogen: how conserved are biochemical model parameters among crop species?

Given the need for parallel increases in food and energy production from crops in the context of global change, crop simulation models and data sets to feed these models with photosynthesis and respiration parameters are increasingly important. This study provides information on photosynthesis and respiration for three energy crops (sunflower, kenaf, and cynara), reviews relevant information for five other crops (wheat, barley, cotton, tobacco, and grape), and assesses how conserved photosynthesis parameters are among crops. Using large data sets and optimization techniques, the C(3) leaf photosynthesis model of Farquhar, von Caemmerer, and Berry (FvCB) and an empirical night respiration model for tested energy crops accounting for effects of temperature and leaf nitrogen were parameterized. Instead of the common approach of using information on net photosynthesis response to CO(2) at the stomatal cavity (A(n)-C(i)), the model was parameterized by analysing the photosynthesis response to incident light intensity (A(n)-I(inc)). Convincing evidence is provided that the maximum Rubisco carboxylation rate or the maximum electron transport rate was very similar whether derived from A(n)-C(i) or from A(n)-I(inc) data sets. Parameters characterizing Rubisco limitation, electron transport limitation, the degree to which light inhibits leaf respiration, night respiration, and the minimum leaf nitrogen required for photosynthesis were then determined. Model predictions were validated against independent sets. Only a few FvCB parameters were conserved among crop species, thus species-specific FvCB model parameters are needed for crop modelling. Therefore, information from readily available but underexplored A(n)-I(inc) data should be re-analysed, thereby expanding the potential of combining classical photosynthetic data and the biochemical model.

Ultrasound-accelerated thrombolysis for lower extremity ischemia: multicenter experience and literature review

AIM

This study evaluates the short-term outcome of ultrasound-accelerated thrombolysis in patients with lower extremity ischemia caused by thromboembolic occlusions.

METHODS

A retrospective cohort study was conducted from December 2008 to May 2011 of 57 patients (42 men; median age, 66 ± 11 years) undergoing 62 episodes of ultrasound-accelerated thrombolysis for thromboembolic arterial occlusions of the lower extremities. The EKOS EndoWave System (EKOS Corporation, Bothell, WA, USA) was combined with urokinase (100000 IU/hour). Thirty-day and 6-month follow-up consisted of clinical evaluation, and Duplex scan or magnetic resonance angiography of the treated extremity.

RESULTS

Initial technical success was 97%, radiologic success was 82%, and overall clinical success was 77%. Median thrombolysis time was 21 hours (IQR, 15-24). In 38 of 51 procedures with successful lysis (75%) complete lysis was achieved within 24 hours. Major hemorrhage occurred in 2 procedures (3%), and distal embolization in 2 procedures (3%). During the initial hospitalization, the major amputation rate was 8% (N.=5) and the mortality rate was 2% (N.=1). The 30-day patency rate was 81%, without additional mortality. During a median 6-month (range, 2-14) follow-up, 9 reinterventions were performed. Two patients underwent major amputation and 3 patients died; because of malignancy (N.=2) and stroke (N.=1).

CONCLUSION

Initial success rates of ultrasound-accelerated thrombolysis are high and complication rate is low. However, reintervention rate during short-term follow-up for recurrent ischemia is substantial. Results from a randomized controlled trial comparing ultrasound-accelerated thrombolysis with standard thrombolysis for lower extremity ischemia (DUET, Current Controlled Trials, ISRCTN72676102) are eagerly awaited.

A single dose of erythropoietin in ST-elevation myocardial infarction

AIMS

Cardioprotective effects of erythropoietin (EPO) have been shown in experimental and smaller clinical studies. We performed a prospective, multicentre, randomized trial to assess the effects of a single high dose of EPO after primary coronary intervention (PCI) for an ST-elevation myocardial infarction (STEMI). Methods and results Patients with a successful PCI for a first STEMI were randomized to receive either standard medical care alone, or in combination with a single bolus with 60,000 IU i.v. of epoetin alfa within 3 h after PCI. Primary endpoint was left ventricular ejection fraction (LVEF) after 6 weeks, assessed by planar radionuclide ventriculography. Pre-specified secondary endpoints included enzymatic infarct size and major adverse cardiovascular events. A total of 529 patients were enrolled (EPO n = 263, control n = 266). At baseline (before EPO administration), groups were well-matched for all relevant characteristics. After a mean of 6.5 (± 2.0) weeks, LVEF was 0.53 (± 0.10) in the EPO group and 0.52 (± 0.11) in the control group (P = 0.41). Median area under the curve (inter-quartile range) after 72 h for creatinine kinase was 50 136 (28 212-76 664)U/L per 72 h in the EPO group and 53 510 (33 973-90 486)U/L per 72 h in the control group (P = 0.058). More major adverse cardiac events occurred in the control than in the EPO group (19 vs. 8; P = 0.032). Conclusion A single high dose of EPO after a successful PCI for a STEMI did not improve LVEF after 6 weeks. However, the use of EPO was related to less major adverse cardiovascular events and a favourable clinical safety profile.

CLINICAL TRIAL REGISTRATION INFORMATION

NCT00449488; http://www.clinicaltrials.gov/ct2/show/NCT00449488?term=voors&rank=2.

Simulation of wheat growth and development based on organ-level photosynthesis and assimilate allocation

Intimate relationships exist between form and function of plants, determining many processes governing their growth and development. However, in most crop simulation models that have been created to simulate plant growth and, for example, predict biomass production, plant structure has been neglected. In this study, a detailed simulation model of growth and development of spring wheat (Triticum aestivum) is presented, which integrates degree of tillering and canopy architecture with organ-level light interception, photosynthesis, and dry-matter partitioning. An existing spatially explicit 3D architectural model of wheat development was extended with routines for organ-level microclimate, photosynthesis, assimilate distribution within the plant structure according to organ demands, and organ growth and development. Outgrowth of tiller buds was made dependent on the ratio between assimilate supply and demand of the plants. Organ-level photosynthesis, biomass production, and bud outgrowth were simulated satisfactorily. However, to improve crop simulation results more efforts are needed mechanistically to model other major plant physiological processes such as nitrogen uptake and distribution, tiller death, and leaf senescence. Nevertheless, the work presented here is a significant step forwards towards a mechanistic functional-structural plant model, which integrates plant architecture with key plant processes.

Analysing lodging of the panicle bearing cereal teff (Eragrostis tef)

Lodging, the permanent displacement of crop plants from their vertical because of root or shoot failure, is a major yield constraint of the gluten free, panicle bearing cereal teff. The objective of this paper was to analyse the causes of lodging of teff by using, modifying and validating conventional biomechanical models. The model parameters were obtained from a field trial with two contrasting teff cultivars, using novel in situ and laboratory measurements under wet and dry conditions. Cross-species model validation was done with rice (Oryza sativa). Teff is more susceptible to root lodging than to shoot lodging, although the data indicated that shoot strength is also insufficient. Hence, simultaneously breeding for both improved root anchorage and shoot strength is advocated. The study showed that the lodging model, derived for the spike-bearing cereal wheat, needed modifications in order to be able to deal with panicle-bearing plants such as teff and rice. Water adhering to plants owing to rain or dew increased calculated lodging susceptibility. To prevent underestimation of lodging susceptibility, future lodging research should be done under completely wet conditions (water saturated soil and wetted shoots).

Functional-structural plant modelling: a new versatile tool in crop science

Plants react to their environment and to management interventions by adjusting physiological functions and structure. Functional-structural plant models (FSPM), combine the representation of three-dimensional (3D) plant structure with selected physiological functions. An FSPM consists of an architectural part (plant structure) and a process part (plant functioning). The first deals with (i) the types of organs that are initiated and the way these are connected (topology), (ii) co-ordination in organ expansion dynamics, and (iii) geometrical variables (e.g. leaf angles, leaf curvature). The process part may include any physiological or physical process that affects plant growth and development (e.g. photosynthesis, carbon allocation). This paper addresses the following questions: (i) how are FSPM constructed, and (ii) for what purposes are they useful? Static, architectural models are distinguished from dynamic models. Static models are useful in order to study the significance of plant structure, such as light distribution in the canopy, gas exchange, remote sensing, pesticide spraying studies, and interactions between plants and biotic agents. Dynamic models serve quantitatively to integrate knowledge on plant functions and morphology as modulated by environment. Applications are in the domain of plant sciences, for example the study of plant plasticity as related to changes in the red:far red ratio of light in the canopy. With increasing availability of genetic information, FSPM will play a role in the assessment of the significance towards plant performance of variation in genetic traits across environments. In many crops, growers actively manipulate plant structure. FSPM is a promising tool to explore divergent management strategies.

Long-term effect of perindopril on coronary atherosclerosis progression (from the perindopril's prospective effect on coronary atherosclerosis by angiography and intravascular ultrasound evaluation [PERSPECTIVE] study)

The multicenter EUROPA trial of 12,218 patients showed that perindopril decreased adverse clinical events in patients with established coronary heart disease. The PERSPECTIVE study, a substudy of the EUROPA trial, evaluated the effect of perindopril on coronary plaque progression as assessed by quantitative coronary angiography and intravascular ultrasound (IVUS). In total 244 patients (mean age 57 years, 81% men) were included. Evaluable paired quantitative coronary angiograms were obtained from 96 patients randomized to perindopril and from 98 patients to placebo. Concomitant treatment at baseline consisted of aspirin (90%), lipid-lowering agents (70%), and beta blockers (60%). The primary and secondary end point was the difference of minimum and mean lumen diameters (quantitative coronary angiography) or mean plaque cross-sectional area (IVUS) measured at baseline and 3-year follow-up between the perindopril and placebo groups. After a median follow-up of 3.0 years (range 1.9 to 4.1), no differences in change in quantitative coronary angiographic or IVUS measurements were detected between the perindopril and placebo groups (minimum and mean luminal diameters -0.07 +/- 0.4 vs -0.02 +/- 0.4 mm, p = 0.34; mean luminal diameter -0.05 +/- 0.2 vs -0.05 +/- 0.3 mm, p = 0.89; mean plaque cross-sectional area -0.18 +/- 1.2 vs -0.02 +/- 1.2 mm(2), p = 0.48). In conclusion, we found no progression in coronary artery disease by quantitative coronary angiography and IVUS with long-term administration of perindopril or placebo, possibly because most patients were on concomitant treatment with a statin.

[High mortality in a herd with signs of jejunal hemorrhage syndrome]

Eleven cows from a herd of 80 dairy cows (14%) died over a 7-month period. Death occurred within 12-24 hours of the onset of the first clinical signs, namely, dullness and a decrease (mean 25%) in milk production. Within 12 hours the cows were unable to rise, felt cold, and were restless. Examined mucous membranes were pale. Two of three cows examined at necropsy had blood in the jejunum and high counts of Clostridium perfringens. Jejunal hemorrhage syndrome was diagnosed in these two cows on the basis of the clinical signs and postmortem findings.

Patient preferences for expectant management vs. surgical evacuation in first-trimester uncomplicated miscarriage

OBJECTIVE

Expectant and surgical management are widely accepted treatment options in case of a miscarriage. In the absence of differences in complications, the choice between both options can be based on patient preferences.

STUDY DESIGN AND SETTING

We studied treatment preferences for future miscarriages in women with a miscarriage randomized to expectant or surgical treatment or managed according to their own choice.

RESULTS

Data from 136 patients were analyzed. Women randomized either to expectant or surgical management opted for the allocated treatment in future in 55 and 74%, respectively. Of the women randomized to expectant management and with a successful spontaneous loss, 71% opted again for this treatment. Women who were managed according to their own treatment choice, held on to their initial treatment preference (expectant vs. surgical management; 84 and 88%, respectively). Preferences after treatment were strong.

CONCLUSION

A strong treatment preference should be taken into account in the counseling process. Women without a preference should be well informed on all medical aspects of the two options in order to facilitate informed-shared decision-making.

[Stillbirth/perinatal weak calf syndrome in dairy heifers: results of a pilot study]

A pilot study of 10 Dutch dairy herds was performed to investigate possible causes of stillbirth/perinatal weak calf syndrome in heifers. Possible causes and advice for further investigations on farms affected by this syndrome are discussed based on the results of investigations of blood and urine from pregnant young stock, postmortem examination of still-born calves, and a questionnaire held among farmers. Infections with Neospora caninum, Salmonella spp. or Leptospira hardjo, or a deficiency of iodine could be excluded.