Impact of different antiplatelet therapy cessation modes on outcomes in patients treated with ticagrelor with or without aspirin after PCI: the twilight-antiplatelet cessation study

Background

The Ticagrelor With Aspirin or Alone in High-Risk Patients After Coronary Intervention (TWILIGHT) trial showed that a regimen consisting of a 3-month dual antiplatelet therapy (DAPT) followed by ticagrelor monotherapy reduces the rate of bleeding events without increasing ischemic complications compared with standard DAPT [1]. Previous studies, such as Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients (PARIS) demonstrated how deviation or cessation of the prescribed antiplatelet regimen might negatively affect clinical outcomes [2].

Purpose

The proposed analysis aims to assess the impact of different antiplatelet therapy cessation patterns on ischemic and bleeding outcomes in patients treated with ticagrelor with or without aspirin after percutaneous coronary intervention (PCI).

Methods

All 7,119 patients randomized at 3 months post-PCI in the TWILIGHT study will be included. The analyses will be conducted separately in the two treatment arms (ticagrelor plus placebo and ticagrelor plus aspirin). According to the PARIS study definitions and as prespecified in the TWILIGHT trial protocol, the occurrence of the three following antiplatelet cessation modes will be assessed: 1) discontinuation (e.g., caused by intolerable side effects or because of a safety concern); 2) interruption (temporary, <14 days, because of surgical or other invasive procedures); 3) disruption (due to non-compliance or bleeding).

The primary endpoint will be the composite of all-cause death, myocardial infarction (MI), or stroke at 12 months after randomization. The key secondary endpoint will be BARC type 2, 3 or 5 bleeding. Other secondary endpoints will include the components of the primary endpoint, cardiovascular death, definite or probable stent thrombosis and BARC types 3 or 5 bleeding. The number of events will be estimated according to the antiplatelet cessation status before the clinical event. Hazard ratios and 95% confidence intervals will be generated using Cox proportional hazards models including antiplatelet therapy cessation as a time-updated variable. If more than one cessation event occurred during follow-up, the antiplatelet therapy cessation category will change only if the more recent mode is worse than the previous: disruption will have priority over interruption, which in turn will have priority over discontinuation. Patients without cessation events will represent the reference group. All adverse events and episodes of antiplatelet cessation were independently adjudicated.

Results

The results of this analysis will be presented for the first time at ESC 2022.

Conclusion

This prespecified analysis of the TWILIGHT study will show for the first time the impact on clinical outcomes of different antiplatelet therapy cessation modes when a regimen of Ticagrelor with our without aspirin is prescribed after PCI.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Astra Zeneca, United Kingdom

Effect of aspirin discontinuation according to individualised patient bleeding and ischemic risks after PCI: a TWILIGHT trial sub-analysis

Background

The TWILIGHT trial demonstrated a reduction in BARC 2, 3 or 5 (BARC-235) bleeding without an increase in ischemic events at 1-year in high-risk PCI patients randomized to placebo or aspirin (ASA) on a background of ticagrelor 3-months after PCI. However, the effect of ASA discontinuation according to baseline risk of bleeding and ischemic events remain unclear.

Purpose

To a) develop separate models to predict the risk of bleeding and ischemic events, and b) to assess treatment effect of ASA discontinuation across the risk strata.

Methods

Using the TWILIGHT patient database (N=7,119), two multivariable models, one for BARC-235 bleeding and one for CV death, nonfatal MI or nonfatal ischemic stroke (ischemic endpoint) were developed, and their predictive capacity was assessed. The effect of randomized treatment on bleeding and ischemic events across different patient risk-group categories as determined by the risk scores was investigated.

Results

At 1-year, 350 (5.4%) patients experienced a BARC-235 bleeding event and 258 (3.6%) experienced an ischemic event. Independent predictors of BARC-235 included haemoglobin levels at index PCI, proton-pump inhibitor non-use at discharge, age, liver disease and active smoking (c-statistic 0.64). Independent predictors of the ischemic outcome included a positive troponin ACS, prior CABG, diabetes, age, peripheral artery disease, prior PCI, a history of congestive heart failure, active smoking, the level of index PCI complexity, and prior MI (c-statistic 0.71). The risk of a BARC-235 almost doubled between patients in lower versus higher bleeding risk categories (4.3% versus 7.9%) and ischemic risk more than tripled between patients in lower versus higher ischemic risk categories (2.0% versus 7.0%) (see Figure 1). There was no evidence of a differential treatment effect for dual antiplatelet therapy versus ticagrelor monotherapy across the different risk categories of bleeding (interaction P=0.54) and ischemic risk (interaction P=0.95) (Table 1).

Conclusion

Individual patient bleeding and ischemic risks after PCI can both be readily characterised with good discrimination. The effect of ASA discontinuation in preventing bleeding in ticagrelor-treated patients was consistent regardless of baseline bleeding risk. There was no evidence for increased ischemic events with ASA discontinuation according to baseline ischemic risk.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): AstraZenecaIcahn School of Medicine at Mount Sinai

Ticagrelor monotherapy after percutaneous coronary intervention in patients with concomitant diabetes mellitus and chronic kidney disease: a TWILIGHT substudy

Background

Diabetes mellitus (DM) and chronic kidney disease (CKD) are established risk factors for cardiovascular events, with patients presenting both conditions being at extremely high risk. P2Y12 inhibitor monotherapy with ticagrelor after a short course of dual antiplatelet therapy has emerged as a bleeding avoidance strategy for high-risk patients undergoing percutaneous coronary intervention (PCI).

Purpose

To investigate ischemic and bleeding outcomes associated with ticagrelor monotherapy versus ticagrelor plus aspirin according to the presence or absence of CKD and DM.

Methods

The TWILIGHT trial enrolled patients undergoing PCI with a drug-eluting stent who fulfilled at least one clinical and one angiographic high-risk criterion. Both DM and CKD (estimated glomerular filtration rate <60 mL/min/1.73m2) were clinical study entry criteria. Following 3 months of ticagrelor plus aspirin, patients who had been adherent to treatment and free from major adverse events were randomly assigned to either aspirin or placebo in addition to ticagrelor for 1 year. The primary endpoint was Bleeding Academic Research Consortium (BARC) type 2, 3 or 5 bleeding. The key secondary endpoint was the composite of all-cause death, myocardial infarction, or stroke. Net adverse clinical events (NACE) were defined as BARC type 3 or 5 bleeding, all-cause death, myocardial infarction, or stroke.

Results

Of the 6273 patients included in the analysis, 8.0% had both CKD and DM (DM+/CKD+), 8.9% had CKD only (DM-/CKD+), 29.0% had DM only (DM+/CKD-), and 52.1% had neither CKD nor DM (DM-/CKD-). At 1-year follow-up, there was a progressive increase in the rates of bleeding and ischemic events according to DM and CKD status (Figure 1). Ticagrelor plus placebo reduced the primary bleeding endpoint as compared with ticagrelor plus aspirin across all study groups, including DM+/CKD+ patients (4.7% vs. 8.7%; HR 0.52, 95% CI 0.25–1.07), with no evidence of heterogeneity (p-interaction=0.68). Similar treatment effects of ticagrelor monotherapy were observed for major BARC type 3 or 5 bleeding (p-interaction=0.17), with DM+/CKD+ patients showing the greatest absolute risk reduction (0.9% vs. 5.1%; HR 0.16, 95% CI 0.04–0.72). The key secondary endpoint was not significantly different between treatment arms across study groups, with the exception of a reduced risk in DM+/CKD- patients receiving ticagrelor monotherapy (p-interaction=0.033). A similar pattern in the DM+/CKD- group was observed for NACE (p-interaction=0.030) (Figure 2).

Conclusions

Among high-risk patients undergoing PCI, ticagrelor monotherapy reduced the risk of clinically relevant and major bleeding without a significant increase in ischemic events as compared with ticagrelor plus aspirin, irrespective of the presence of DM and CKD. Furthermore, ticagrelor monotherapy seemed to be associated with a more favourable net benefit in patients with DM without CKD.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Investigator-initiated grant from AstraZeneca Figure 1. Event rates according to DM/CKD statusFigure 2. Effects of ticagrelor monotherapy

Preoperative anaemia management in patients undergoing vascular surgery

CAVIAR is a multicentre prospective stepped observational study encompassing 160 patients undergoing vascular intervention. The aim was to identify whether it was feasible to establish a preoperative anaemia pathway and, if so, the efficacy of intravenous iron for treatment of preoperative anaemia. Large barriers prevented implementation of an intravenous iron pathway, with only ten patients receiving intravenous iron and a small increase in haemoglobin level (mean 5·7 (95 per cent c.i. 4·5 to 6·9) g/l). Preoperative anaemia was associated with a longer hospital stay and greater transfusion requirement. Anaemia common and dedicated pathway difficult to instigate.

The uptake of the hip fracture core outcome set: analysis of 20 years of hip fracture trials

BACKGROUND

clinical trials test the effectiveness or efficacy of treatments. It is important that researchers evaluate interventions with the most meaningful outcome measures. The 2014 hip fracture core outcome set recommended that mortality, mobility, pain, activities of daily living and health-related quality of life (HRQOL) should be assessed in all trials of patient with hip fracture. The purpose of this analysis was to determine the uptake of these recommendation.

METHODS

all trials registered from 1997 to 2018 recruiting participants following hip fracture were identified from the ClinicalTrials.gov trials registry. The frequency of each core domain adopted annually were assessed.

RESULTS

311 trials were identified and analysed. On analysing trial registries for years which presented a minimum of 10 registrations, full core outcome set adoption ranged from 0% (2017; 2018) to 24% (2009). Mortality and mobility were the most consistently reported domains (mortality: 27% (2017) to 56% (2011); mobility: 36% (2015) to 60% (2004)). In contrast, pain and HRQOL were least reported (pain: 14% (2017) to 61% (2015); HRQOL: 10% (2010) to 11% (2008)). There was no clear change in core outcome domain set adoption following the publication of Hayward et al.'s (2014) core outcome set.

CONCLUSIONS

there has been limited adoption of the hip fracture core outcome set from its publication in 2014. Further consideration to improve implementation is required to improved uptake.

The effect of high-flow nasal oxygen on hospital length of stay in cardiac surgical patients at high risk for respiratory complications: a randomised controlled trial

There has been increased interest in the prophylactic and therapeutic use of high‐flow nasal oxygen in patients with, or at risk of, non‐hypercapnic respiratory failure. There are no randomised trials examining the efficacy of high‐flow nasal oxygen in high‐risk cardiac surgical patients. We sought to determine whether routine administration of high‐flow nasal oxygen, compared with standard oxygen therapy, leads to reduced hospital length of stay after cardiac surgery in patients with pre‐existing respiratory disease at high risk for postoperative pulmonary complications. Adult patients with pre‐existing respiratory disease undergoing elective cardiac surgery were randomly allocated to receive high‐flow nasal oxygen (n = 51) or standard oxygen therapy (n = 49). The primary outcome was hospital length of stay and all analyses were carried out on an intention‐to‐treat basis. Median (IQR [range]) hospital length of stay was 7 (6–9 [4–30]) days in the high‐flow nasal oxygen group and 9 (7–16 [4–120]) days in the standard oxygen group (p=0.012). Geometric mean hospital length of stay was 29% lower in the high‐flow nasal group (95%CI 11–44%, p = 0.004). High‐flow nasal oxygen was also associated with fewer intensive care unit re‐admissions (1/49 vs. 7/45; p = 0.026). When compared with standard care, prophylactic postoperative high‐flow nasal oxygen reduced hospital length of stay and intensive care unit re‐admission. This is the first randomised controlled trial examining the effect of prophylactic high‐flow nasal oxygen use on patient‐centred outcomes in cardiac surgical patients at high risk for postoperative respiratory complications.

Modafinil and cognitive enhancement in schizophrenia and healthy volunteers: the effects of test battery in a randomised controlled trial

BACKGROUND

Cognitive deficits in schizophrenia have major functional impacts. Modafinil is a cognitive enhancer whose effect in healthy volunteers is well-described, but whose effects on the cognitive deficits of schizophrenia appear to be inconsistent. Two possible reasons for this are that cognitive test batteries vary in their sensitivity, or that the phase of illness may be important, with patients early in their illness responding better.

METHODS

A double-blind, randomised, placebo-controlled single-dose crossover study of modafinil 200 mg examined this with two cognitive batteries [MATRICS Consensus Cognitive Battery (MCCB) and Cambridge Neuropsychological Test Automated Battery (CANTAB)] in 46 participants with under 3 years' duration of DSM-IV schizophrenia, on stable antipsychotic medication. In parallel, the same design was used in 28 age-, sex-, and education-matched healthy volunteers. Uncorrected p values were calculated using mixed effects models.

RESULTS

In patients, modafinil significantly improved CANTAB Paired Associate Learning, non-significantly improved efficiency and significantly slowed performance of the CANTAB Stockings of Cambridge spatial planning task. There was no significant effect on any MCCB domain. In healthy volunteers, modafinil significantly increased CANTAB Rapid Visual Processing, Intra-Extra Dimensional Set Shifting and verbal recall accuracy, and MCCB social cognition performance. The only significant differences between groups were in MCCB visual learning.

CONCLUSIONS

As in earlier chronic schizophrenia studies, modafinil failed to produce changes in cognition in early psychosis as measured by MCCB. CANTAB proved more sensitive to the effects of modafinil in participants with early schizophrenia and in healthy volunteers. This confirms the importance of selecting the appropriate test battery in treatment studies of cognition in schizophrenia.

Validation of viscoelastic coagulation tests during cardiopulmonary bypass

BACKGROUND

Viscoelastic point-of-care tests such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are increasingly used to guide hemostatic therapy after cardiac surgery. The aim of this study was to assess their clinical utility during cardiopulmonary bypass to predict postbypass coagulation status and to guide therapy.

METHODS

In this prospective study, TEG and ROTEM tests were performed in 52 adult patients undergoing elective cardiac surgery at two time points: near the end of cardiopulmonary bypass and after heparin reversal with protamine. The 95% confidence intervals of the mean difference were compared with a prespecified clinically relevant limit of ± 20% of the value after protamine.

RESULTS

Both viscoelastic fibrinogen assays were well within the prespecified clinically relevant limit (≥ 79% of patients). The laboratory Clauss fibrinogen was much lower during cardiopulmonary bypass than after protamine (mean difference 1.2 g L(-1) , 95% CI 1.03-1.4, which was outside a clinically acceptable difference. For intrinsically activated tests, clotting times (CT) were different and outside the prespecified limit on TEG (mean difference -1.2 min, 95% CI -1.8 to -0.6) but not on ROTEM (mean difference 2.3 sec, 95% CI -8.6 to 13.2), while clot strength was well within the clinical limit on both devices (≥ 94% of patients). For extrinsically activated tests, clot strength on both TEG and ROTEM was within the pre-specified limit in 98% of patients.

CONCLUSIONS

Results from TEG and ROTEM tests performed toward the end of cardiopulmonary bypass are similar to results after reversal of heparin. Amplitudes indicating clot strength were the most stable parameters across all tests, whereas CT showed more variability. In contrast, laboratory testing of fibrinogen using the Clauss assay was essentially invalid during cardiopulmonary bypass.

Nurse-coordinated multidisciplinary, family-based cardiovascular disease prevention programme (EUROACTION) for patients with coronary heart disease and asymptomatic individuals at high risk of cardiovascular disease: a paired, cluster-randomised controlled trial

BACKGROUND

Our aim was to investigate whether a nurse-coordinated multidisciplinary, family-based preventive cardiology programme could improve standards of preventive care in routine clinical practice.

METHODS

In a matched, cluster-randomised, controlled trial in eight European countries, six pairs of hospitals and six pairs of general practices were assigned to an intervention programme (INT) or usual care (UC) for patients with coronary heart disease or those at high risk of developing cardiovascular disease. The primary endpoints-measured at 1 year-were family-based lifestyle change; management of blood pressure, lipids, and blood glucose to target concentrations; and prescription of cardioprotective drugs. Analysis was by intention to treat. The trial is registered as ISRCTN 71715857.

FINDINGS

1589 and 1499 patients with coronary heart disease in hospitals and 1189 and 1128 at high risk were assigned to INT and UC, respectively. In patients with coronary heart disease who smoked in the month before the event, 136 (58%) in the INT and 154 (47%) in the UC groups did not smoke 1 year afterwards (difference in change 10.4%, 95% CI -0.3 to 21.2, p=0.06). Reduced consumption of saturated fat (196 [55%] vs 168 [40%]; 17.3%, 6.4 to 28.2, p=0.009), and increased consumption of fruit and vegetables (680 [72%] vs 349 [35%]; 37.3%, 18.1 to 56.5, p=0.004), and oily fish (156 [17%] vs 81 [8%]; 8.9%, 0.3 to 17.5, p=0.04) at 1 year were greatest in the INT group. High-risk individuals and partners showed changes only for fruit and vegetables (p=0.005). Blood-pressure target of less than 140/90 mm Hg was attained by both coronary (615 [65%] vs 547 [55%]; 10.4%, 0.6 to 20.2, p=0.04) and high-risk (586 [58%] vs 407 [41%]; 16.9%, 2.0 to 31.8, p=0.03) patients in the INT groups. Achievement of total cholesterol of less than 5 mmol/L did not differ between groups, but in high-risk patients the difference in change from baseline to 1 year was 12.7% (2.4 to 23.0, p=0.02) in favour of INT. In the hospital group, prescriptions for statins were higher in the INT group (810 [86%] vs 794 [80%]; 6.0%, -0.5 to 11.5, p=0.04). In general practices in the intervention groups, angiotensin-converting enzyme inhibitors (297 [29%] INT vs 196 [20%] UC; 8.5%, 1.8 to 15.2, p=0.02) and statins (381 [37%] INT vs 232 [22%] UC; 14.6%, 2.5 to 26.7, p=0.03) were more frequently prescribed.

INTERPRETATION

To achieve the potential for cardiovascular prevention, we need local preventive cardiology programmes adapted to individual countries, which are accessible by all hospitals and general practices caring for coronary and high-risk patients.

Brain natriuretic peptide testing for angina in a rapid-access chest pain clinic

BACKGROUND

Patients complaining of chest pain are frequently referred to secondary care, although the majority have pain of non-cardiac origin.

AIM

To investigate whether B-type natriuretic peptide (BNP) levels are predictive of a diagnosis of non-cardiac pain.

DESIGN

Cross-sectional study.

METHODS

Consecutive patients (n = 296) presenting to a rapid-access chest pain clinic (RACPC) received the usual clinical assessment plus near-patient BNP testing, with the assessor blinded to the result. After clinical assessment (including exercise stress testing if clinically indicated), pain was diagnosed likely/definitely cardiac or non-cardiac.

RESULTS

Median BNP was higher in those diagnosed with likely/definite cardiac chest pain (26.5 vs. 8 pg/ml) (p < 0.0001, Wilcoxon rank sum test). The odds ratio for cardiac pain in those with BNP <20 pg/ml was 0.25 (95%CI 0.14-0.47) (p < 0.0005); adjusting for age and sex reduced this to 0.41 (95%CI 0.20-0.83) (p = 0.01). The area under the curve (AUC) for the model including BNP, age and sex was 0.70. With BNP as a continuous variable, the AUC for the same model was 0.72.

DISCUSSION

In typical patients presenting to a RACPC, those with a BNP < or =20 pg/ml were significantly less likely to be diagnosed with cardiac pain. Near-patient BNP testing may have a role as a 'rule out test' for angina in patients presenting to a RACPC.

Molecular imaging of carcinogenesis with immuno-targeted nanoparticles

Molecular characterization of cancer could have important clinical benefits such as earlier cancer detection based on molecular characterization, the ability to predict the risk of cancer progression, real time margin detection, the ability to rationally select molecular therapy and to monitor response to the therapy. We present a new class of molecular specific contrast agents for optical imaging of carcinogenesis in vivo - gold nanoparticles conjugated with monoclonal antibodies specific for cancer biomarkers.

Contemporary mortality due to acute myocardial infarction, unstable angina and exertional angina in a population in South East London

BACKGROUND

Data on the contemporary mortality of coronary heart disease (CHD) are surprisingly sparse.

AIM

To describe the contemporary mortality of all manifestations of CHD.

DESIGN

Prospective follow-up of patients with a first presentation of CHD in a defined population.

METHODS

We studied 537 patients with a first presentation of acute myocardial infarction, unstable angina or new exertional angina in Bromley Health Authority, London (population 295,000). Patients were prospectively monitored for cardiac and non-cardiac mortality for a median of 6 years.

RESULTS

During a median 6 years follow-up, there were 88 (16%) deaths. Survival free from cardiac death was not significantly different between unstable angina (92%) and new exertional angina (94%), but was lower for acute myocardial infarction (84%).

DISCUSSION

Mortality from CHD appears to be falling. However, efforts to prevent myocardial infarction should continue to be a priority, because on-going early mortality remains high. New exertional angina should be diagnosed and managed promptly, as its mortality is similar to that of unstable angina.

European Nicotinamide Diabetes Intervention Trial (ENDIT): a randomised controlled trial of intervention before the onset of type 1 diabetes

BACKGROUND

Results of studies in animals and human beings suggest that type 1 diabetes is preventable. Nicotinamide prevents autoimmune diabetes in animal models, possibly through inhibition of the DNA repair enzyme poly-ADP-ribose polymerase and prevention of beta-cell NAD depletion. We aimed to assess whether high dose nicotinamide prevents or delays clinical onset of diabetes in people with a first-degree family history of type 1 diabetes.

METHOD

We did a randomised double-blind placebo-controlled trial of nicotinamide in 552 relatives with confirmed islet cell antibody (ICA) levels of 20 Juvenile Diabetes Federation (JDF) units or more, and a non-diabetic oral glucose tolerance test. Participants were recruited from 18 European countries, Canada, and the USA, and were randomly allocated oral modified release nicotinamide (1.2 g/m2) or placebo for 5 years. Random allocation was done with a pseudorandom number generator and we used size balanced blocks of four and stratified by age and national group. Primary outcome was development of diabetes, as defined by WHO criteria. Analysis was done on an intention-to-treat basis.

FINDINGS

There was no difference in the development of diabetes between the treatment groups. Of 159 participants who developed diabetes in the course of the trial, 82 were taking nicotinamide and 77 were on placebo. The unadjusted hazard ratio for development of diabetes was 1.07 (95% CI 0.78-1.45; p=0.69), and the hazard ratio adjusted for age-at-entry, baseline glucose tolerance, and number of islet autoantibodies detected was 1.01 (0.73-1.38; p=0.97). Of 168 (30.4%) participants who withdrew from the trial, 83 were on placebo. The number of serious adverse events did not differ between treatment groups. Nicotinamide treatment did not affect growth in children or first-phase insulin secretion.

INTERPRETATION

Large-scale controlled trials of interventions designed to prevent the onset of type 1 diabetes are feasible, but nicotinamide was ineffective at the dose we used.

Traffic calming for the prevention of road traffic injuries: systematic review and meta-analysis

OBJECTIVE

To assess whether area-wide traffic calming schemes can reduce road crash related deaths and injuries.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials, Medline, EMBASE, Sociological Abstracts Science (and social science) citation index, National Technical Information service, Psychlit, Transport Research Information Service, International Road Research Documentation, and Transdoc, and web sites of road safety organisation were searched; experts were contacted, conference proceedings were handsearched, and relevant reference lists were checked.

INCLUSION CRITERIA

Randomised controlled trials, and controlled before/after studies of area-wide traffic calming schemes designed to discourage and slow down through traffic on residential roads.

METHODS

Data were collected on road user deaths, injuries, and traffic crashes. For each study rate ratios were calculated, the ratio of event rates before and after intervention in the traffic calmed area divided by the corresponding ratio of event rates in the control area, which were pooled to give an overall estimate using a random effects model.

FINDINGS

Sixteen controlled before/after studies met our inclusion criteria. Eight studies reported the number of road user deaths: pooled rate ratio 0.63 (95% confidence interval (CI) 0.14 to 2.59). Sixteen studies reported the number of injuries (fatal and non-fatal): pooled rate ratio 0.89 (95% CI 0.80 to 1.00). All studies were in high income countries.

CONCLUSION

Area-wide traffic calming in towns and cities has the potential to reduce road traffic injuries. However, further rigorous evaluations of this intervention are needed, especially in low and middle income countries.

Post-licence driver education for the prevention of road traffic crashes

BACKGROUND

Worldwide, each year over a million people are killed and some ten million people are permanently disabled in road traffic crashes. Post-licence driver education is used by many as a strategy to reduce traffic crashes. However, the effectiveness of post-licence driver education has yet to be ascertained.

OBJECTIVES

To quantify the effectiveness of post-licence driver education in reducing road traffic crashes.

SEARCH STRATEGY

We searched the following electronic databases: the Cochrane Injuries Group's Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, TRANSPORT (NTIS, TRIS, TRANSDOC, IRRD), Road Res (ARRB), ATRI, National Research Register, PsycInfo, ERIC, SPECTR, Zetoc, SIGLE, Science (and Social Science) Citation Index. We searched the Internet, checked reference lists of relevant papers and contacted appropriate organisations. The search was not restricted by language or publication status.

SELECTION CRITERIA

Randomised controlled trials comparing post-licence driver education versus no education, or one form of post-licence driver education versus another.

DATA COLLECTION AND ANALYSIS

Two reviewers independently screened search results, extracted data and assessed methodological trial quality.

MAIN RESULTS

We found 24 trials of driver education, 23 conducted in the USA and one in Sweden. Twenty trials studied remedial driver education. The methodological quality of the trials was poor and three reported data unsuitable for meta-analysis. Nineteen trials reported traffic offences: pooled relative risk (RR) = 0.96, 95% confidence interval (95% CI) = 0.94, 0.98); trial heterogeneity was significant (p=<0.00001). Fifteen trials reported traffic crashes: pooled RR = 0.98 (95% CI 0.96, 1.01), trial heterogeneity was not significant (p=0.75). Four trials reported injury crashes: pooled RR = 1.12 (95% CI 0.88, 1.41), trial heterogeneity was significant (p=<0.00001). No one form of education (correspondence, group or individual) was found to be substantially more effective than another, nor was a significant difference found between advanced driver education and remedial driver education. Funnel plots indicated the presence of publication bias affecting the traffic offence and crash outcomes.

REVIEWER'S CONCLUSIONS

This systematic review provides no evidence that post-licence driver education is effective in preventing road traffic injuries or crashes. Although the results are compatible with a small reduction in the occurrence of traffic offences, this may be due to selection biases or bias in the included trials. Because of the large number of participants included in the meta-analysis (close to 300,000 for some outcomes) we can exclude, with reasonable precision, the possibility of even modest benefits.

Area-wide traffic calming for preventing traffic related injuries

BACKGROUND

It is estimated that by 2020 road traffic crashes will have moved from ninth to third in the world disease burden ranking, as measured in disability adjusted life years, and second in developing countries. The identification of effective strategies for the prevention of traffic related injuries is of global health importance. Area-wide traffic calming schemes that discourage through traffic on residential roads is one such strategy.

OBJECTIVES

To evaluate the effectiveness of area-wide traffic calming in preventing traffic related crashes, injuries, and deaths.

SEARCH STRATEGY

We searched the following electronic databases: Cochrane Injuries Group's Specialised Register, Cochrane Controlled Trials Register, MEDLINE, EMBASE and TRANSPORT (NTIS, TRIS, TRANSDOC). We searched the web sites of road safety organisations, handsearched conference proceedings, checked reference lists of relevant papers and contacted experts in the area. The search was not restricted by language or publication status.

SELECTION CRITERIA

Randomised controlled trials, and controlled before-after studies of area-wide traffic calming schemes.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data on type of study, characteristics of intervention and control areas, and length of data collection periods. Before and after data were collected on the total number of road traffic crashes, all road user deaths and injuries, pedestrian-motor vehicle collisions and road user deaths. The statistical package STATA was used to calculate rate ratios for each study, which were then pooled to give an overall estimate using a random effects model.

MAIN RESULTS

We found no randomised controlled trials, but 16 controlled before-after trials met our inclusion criteria. Seven studies were done in Germany, six in the UK, two in Australia and one in the Netherlands. There were no studies in low or middle income countries. Eight trials reported the number of road traffic crashes resulting in deaths. The pooled rate ratio was 0.63 (0.14, 2.59 95% CI). Sixteen studies reported the number of road traffic crashes resulting in injuries (fatal and non fatal). The pooled rate ratio was 0.89 (0.80, 1.00 95% CI). Nine studies reported the total number of road traffic crashes. The pooled rate ratio was 0.95 (0.81, 1.11 95% CI). Thirteen trials reported the number of pedestrian-motor vehicle collisions. The pooled rate ratio was 1.00 (0.84, 1.18). There was significant heterogeneity for the total number of crashes and deaths and injuries.

REVIEWER'S CONCLUSIONS

The results from this review suggest that area-wide traffic calming in towns and cities may be a promising intervention for reducing the number of road traffic injuries, and deaths. However, further rigorous evaluations of this intervention are needed.

PCR-ELISA detection of Escherichia coli in milk

AIMS

The purpose of this study was to develop a reliable molecular procedure for the detection of Escherichia coli in milk.

METHODS AND RESULTS

Robust and expeditious DNA extraction and PCR techniques were evaluated using Enzyme-Linked Immunosorbent Assay (ELISA) detection of biotin-labelled amplicons to facilitate optimal detection of E. coli DNA.

CONCLUSIONS

It was found that 5 E. coli colony-forming units (cfu) could be detected per PCR reaction using the PCR-ELISA system, equating to a sensitivity of detection of 100 E. coli cfu ml(-1) pasteurized milk.

SIGNIFICANCE AND IMPACT OF THE STUDY

This approach should facilitate evaluation of milk contamination and enable rapid detection of E. coli mastitis, leading to correct deployment of relevant antibiotic therapy and improved animal welfare.

Near real time in vivo fibre optic confocal microscopy: sub-cellular structure resolved

We have built a fibre optic confocal reflectance microscope capable of imaging biological tissue in near real time. The measured lateral resolution is 3 micro m and axial resolution is 6 micro m. Images of epithelial cells, excised tissue biopsies, and the human lip in vivo have been obtained at 15 frames s-1. Both cell morphology and tissue architecture can be appreciated from images obtained with this microscope. This device has the potential to enable reflected light confocal imaging of internal organs for in situ detection of pathology.

Laser scanning confocal microscopy of cervical tissue before and after application of acetic acid

OBJECTIVES

The use of high-resolution in vivo confocal imaging may offer a clinically useful adjunct to standard methods for the diagnosis and screening of epithelial precancers. This study assesses the feasibility of real-time confocal reflectance imaging of cervical tissue and the use of acetic acid as a contrast agent to increase visualization of cell nuclei.

STUDY DESIGN

A confocal microscope was used to image cervical cells and colposcopically normal and abnormal cervical biopsy specimens. Images were obtained before and after the application of 6% acetic acid.

RESULTS

The confocal imaging system resolved subcellular detail throughout the entire epithelial thickness. Normal and abnormal tissues were clearly able to be differentiated. Addition of acetic acid enhanced nuclear signal in all acquired images.

CONCLUSION

High-contrast reflected light images of cervical tissue are attainable in near real time. Acetic acid significantly increases light scattering from cell nuclei, which may partially explain why acetowhitening occurs.

Near real time confocal microscopy of amelanotic tissue: dynamics of aceto-whitening enable nuclear segmentation

High resolution, in vivo confocal imaging of amelanotic epithelial tissue may offer a clinically useful adjunct to standard histopathologic techniques. Application of acetic acid has been shown to enhance contrast in confocal images of these tissues. In this study, we record the time course of aceto-whitening at the cellular level and determine whether the contrast provided enables quantitative feature analysis. Confocal images and videos of cervical specimens were obtained throughout the epithelium before, during and post-acetic acid after the application of 6% acetic acid. Aceto-whitening occurs within seconds after the application. The confocal imaging system resolved sub-cellular detail throughout the entire epithelial thickness and provided sufficient contrast to enable quantitative feature analysis.

Monocyte, macrophage and foreign body giant cell interactions with molecularly engineered surfaces

To elucidate the mechanisms involved in monocyte/macrophage adhesion and fusion to form foreign body giant cells on molecularly engineered surfaces, we have utilized our in vitro culture system to examine surface chemistry effects, cytoskeletal reorganization and adhesive structure development, and cell receptor-ligand interactions in in vitro foreign body giant cell formation. Utilizing silane-modified surfaces, monocyte/macrophage adhesion was essentially unaffected by surface chemistry, however the density of foreign body giant cells (FBGCs) was correlated with surface carbon content. An exception to the surface-independent macrophage adhesion were the alkyl-silane modified surfaces which exhibited reduced adhesion and FBGC formation. Utilizing confocal immunofluorescent techniques, cytoskeletal reorganization and adhesive structure development in in vitro FBGC formation was studied. Podosomes were identified as the adhesive structures in macrophages and FBGCs based on the presence of characteristic cytoplasmic proteins and F-actin at the ventral cell surface. Focal adhesion kinase (FAK) and focal adhesions were not identified as the adhesive structures in macrophages and FBGCs. In studying the effect of preadsorbed proteins on FBGC formation, fibronectin or vitronectin do not play major roles in initial monocyte/macrophage adhesion, whereas polystyrene surfaces modified with RGD exhibited significant FBGC formation. These studies identify the potential importance of surface chemistry-dependent conformational alterations which may occur in proteins adsorbed to surfaces and their potential involvement in receptor-ligand interactions. Significantly, preadsorption of alpha2-macroglobulin facilitated macrophage fusion and FBGC formation readily on the RGD surface in the absence of any additional serum proteins. As alpha2-macroglobulin receptors are not found on blood monocytes but are expressed only with macrophage development, these results point to a potential interaction between adsorbed 2-macroglobulin and its receptors on macrophages during macrophage development and fusion. These studies identify important surface independent and dependent effects in foreign body reaction development that may be important in the identification of biological design criteria for molecularly engineered surfaces and tissue engineered devices.

Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast

The use of high resolution, in vivo confocal imaging for noninvasive assessment of tissue pathology may offer a clinically important adjunct to standard histopathological techniques. To augment the present understanding of both the capabilities and limitations of in vivo confocal imaging, we investigated cellular sources of image contrast in amelanotic tissues, how contrast can be enhanced with external agents and how contrast is degraded by the scattering of overlying cells. A high-resolution reflected light confocal microscope was constructed and used to obtain images of various types of unstained amelanotic cells in suspension in real time before and after the addition of contrast agents. Reflectance images were compared to phase contrast images and electron micrographs to identify morphology visible with real time reflected light confocal microscopy. Mechanisms which decrease image contrast, including interference effects and scattering in overlying layers of cells, were considered. In amelanotic epithelial cells, fluctuations in the nuclear index of refraction provide signal which can be imaged even under several overlying cell layers. Acetic acid is an external contrast agent which can enhance this nuclear backscattering. Image contrast is degraded by the presence of multiple scattering in overlying cell layers. The degradation of image contrast by cell scattering depends on the scattering phase function; in vitro models which use polystyrene microspheres to approximate tissue underestimate the actual degradation caused by cell scattering. The loss in contrast can be explained using a finite difference time domain model of cellular scattering. We conclude that near real time reflected light confocal microscopy can be used to study cell morphology in vivo. Contrast degradation due to overlying tissue is a concern and cannot adequately be modeled using conventional tissue phantoms; however, acetic acid may be used to substantially increase intrinsic contrast, allowing imaging at significant depths despite distortion from overlying layers. © 1998 Society of Photo-Optical Instrumentation Engineers.

Biocompatibility of poly(etherurethane urea) containing dehydroepiandrosterone

Poly(etherurethane urea) (PEUU) elastomers, with their broad range of mechanical properties and high biocompatibility, are used clinically for medical applications. However, the possibility exists for the ether soft segment of PEUU to degrade in long-term uses. To retard degradation, antioxidants that scavenge reactive oxygen intermediates are added. In this study, we incorporated dehydroepiandrosterone (DHEA), which functions by the alternate mechanism of modulating or down-regulating adherent macrophage activity, to retard the biodegradation of PEUUs. Biocompatibility of PEUU samples containing 1% DHEA, 5% DHEA, and 5% vitamin E (alpha-tocopherol) by weight were studied in vivo and in vitro. The biocompatibility was initially evaluated by examination of the inflammatory cellular exudate. Compared to PEUU without additives and PEUU with 5% vitamin E, the addition of 5% DHEA to PEUU caused a decrease in the total leukocyte exudate concentration at 4 days. The addition of 5% DHEA also caused lower macrophage adhesion and FBGC formation compared to the other materials at 7 days. Despite these short-term effects, the biocompatibility at later time points (14, 21, and 70 days) was similar for all materials. Transmission infrared analysis of the materials revealed that more than 70% of the DHEA had leached out of the samples by 3 days implantation. Furthermore, through attenuated total reflectance Fourier transform analysis and scanning electron microscopy, it was determined that unlike vitamin E, DHEA did not enhance long-term PEUU biostability. The effect of DHEA on inflammatory cell activity appeared to be dose dependent, with improved biocompatibility in vivo for higher loading levels of DHEA, but the overall effect was limited owing to the rapid diffusion of the water-soluble DHEA from the PEUU.

Aphagia and adipsia after preferential destruction of nerve cell bodies in hypothalamus

Microinjections of the excitatory neurotoxin kainic acid into the lateral hypothalamus of rats produced a period aphagia and adipsia. Kainate-treated rats displayed transient motor effects during the first hours after the injection but did not show the persisting sensory-motor and arousal disturbances typically observed in animals with electrolytic lesions in this part of the hypothalamus. Histological examination revealed a significant reduction in the number of nerve cell bodies in the lateral hypothalamus. Silver-stained material indicated no evidence of damage to fiber systems passing through the affected region. Assays of dopamine in hypothalamus, striatum, and telencephalon did not indicate significant differences between experimental and control animals. These results are in agreement with recent reports of the anatomical and biochemical effects of intracerebral kainic acid injections and suggest that the observed effect on feeding behavior is related to the destruction of neurons in the lateral hypothalamus.