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.

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.

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.

[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.

[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.

Sonotherapy, antirestenotic therapeutic ultrasound in coronary arteries: the first clinical experience

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty-seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in-stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 +/- 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6-month follow-up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 +/- 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% +/- 11%. IST can be applied safely and with high acute procedural success. Sonotherapy-related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies.

Reduced impact of migraine in everyday life: an observational study in the Dutch Society of Headache Patients

OBJECTIVE

To explore the percentage of patients who report a reduced impact of migraine on their life, and to which factors this improvement can be attributed.

METHODS

Four hundred forty-eight members of the Dutch Society of Headache Patients answered a set of structured questionnaires, including the Migraine-Specific Quality of Life instrument (MSQOL).

RESULTS

Of this group, 70% reported a reduced impact of migraine. The most frequently reported reason for this reduction was a change in medication (77%); in particular, change to a triptan. Other favorable factors included a change in life-style (56%): 42% of patients reported more relaxed coping with migraine, a reduction of stress in general (28%) and of stress related to work (24%), and leading a more regular life-style (21%). In addition, social support was frequently mentioned, particularly that offered by the Dutch Society of Headache Patients (58%), family (46%), and their general practitioner (28%). The patients who reported a reduced impact of migraine had less migraine attacks and a higher quality of life than those who did not report such a reduction.

CONCLUSION

The results confirm that factors that are proven effective in clinical trials on migraine also have these effects outside a formal experimental environment.