Comparative Analysis of Coronary Artery Bypass Grafting Outcomes in Women Using Different Conduits in the National UK Data Set

BACKGROUND

There is limited report of outcomes in women undergoing isolated coronary artery bypass grafting (CABG) with left internal thoracic artery and different second conduits (saphenous vein graft [SVG], radial artery [RA], and right internal thoracic artery [RITA]).

METHODS

The National Adult Cardiac Surgery Audit database was queried for women undergoing isolated CABG with left internal thoracic artery graft in the United Kingdom from 1996 to 2019. Propensity score-based pairwise comparisons were performed between graft types. The primary outcome was in-hospital mortality.

RESULTS

The study included 58,063 women (SVG, n = 48,881 [84.2%]; RA, n = 6136 [10.6%]; RITA, n = 2445 [4.2%]). SVG use was stable over the years; RA and RITA use decreased. In-hospital mortality was similar between the RA and RITA grafts (2.3% vs 2.8%; odds ratio [OR], 0.80; 95% CI, 0.53-1.22; P = .39) and between the RA and SVG (2.3% vs 2.0%; OR, 1.20; 95% CI, 0.93-1.55; P = .17) but higher in the RITA group compared with the SVG (2.7% vs 1.4%; OR, 2.04; 95% CI, 1.27-3.36; P = .004). Women receiving the RITA graft were more likely to have sternal wound infection (SWI) compared with the RA (0.6% vs 0.06%; P = .004) and the SVG (0.6% vs 0.2%; P = .032). SWI was consistently associated with higher risk of in-hospital mortality.

CONCLUSIONS

Conduit selection may affect operative outcomes in women undergoing CABG. The RA shows similar mortality and risk of deep SWI as the SVG.

Pragmatic randomized controlled trials: strengthening the concept through a robust international collaborative network: PRIME-9-Pragmatic Research and Innovation through Multinational Experimentation

In an era focused on value-based healthcare, the quality of healthcare and resource allocation should be underpinned by empirical evidence. Pragmatic clinical trials (pRCTs) are essential in this endeavor, providing randomized controlled trial (RCT) insights that encapsulate real-world effects of interventions. The rising popularity of pRCTs can be attributed to their ability to mirror real-world practices, accommodate larger sample sizes, and provide cost advantages over traditional RCTs. By harmonizing efficacy with effectiveness, pRCTs assist decision-makers in prioritizing interventions that have a substantial public health impact and align with the tenets of value-based health care. An international network for pRCT provides several advantages, including larger and diverse patient populations, access to a broader range of healthcare settings, sharing knowledge and expertise, and overcoming ethical and regulatory barriers. The hypothesis and study design of pRCT answers the decision-maker's questions. pRCT compares clinically relevant alternative interventions, recruits participants from diverse practice settings, and collects data on various health outcomes. They are scarce because the medical products industry typically does not fund pRCT. Prioritizing these studies by expanding the infrastructure to conduct clinical research within the healthcare delivery system and increasing public and private funding for these studies will be necessary to facilitate pRCTs. These changes require more clinical and health policy decision-makers in clinical research priority setting, infrastructure development, and funding. This paper presents a comprehensive overview of pRCTs, emphasizing their importance in evidence-based medicine and the advantages of an international collaborative network for their execution. It details the development of PRIME-9, an international initiative across nine countries to advance pRCTs, and explores various statistical approaches for these trials. The paper underscores the need to overcome current challenges, such as funding limitations and infrastructural constraints, to leverage the full potential of pRCTs in optimizing healthcare quality and resource utilization.

Barriers and facilitators for surgical site infection surveillance for adult cardiac surgery in a high-income setting: an in-depth exploration

BACKGROUND

Surgical site infection (SSI) surveillance aims to facilitate a reduction in SSIs through identifying infection rates, benchmarking, triggering clinical review and instituting infection control measures. Participation in surveillance is, however, variable suggesting opportunities to improve wider adoption.

AIM

To gain an in-depth understanding of the barriers and facilitators for SSI surveillance in a high-income European setting.

METHODS

Key informant interviews with 16 surveillance staff, infection prevention staff, nurses and surgeons from nine cardiac hospitals in England. Data were analysed thematically.

FINDINGS

SSI surveillance was reported to be resource intensive. Barriers to surveillance included challenges associated with data collection: data being located in numerous places, multiple SSI data reporting schemes, difficulty in finding denominator data, lack of interface between computerized systems, 'labour intensive' or 'antiquated' methods to collect data (e.g., using postal systems for patient questionnaires). Additional reported concerns included: relevance of definitions, perceived variability in data reporting, lack of surgeon engagement, unsupportive managers, low priority of SSIs among staff, and a 'blame culture' around high SSI rates. Facilitators were increased resources, better use of digital technologies (e.g., remote digital wound monitoring), integrating surveillance within routine clinical work, having champions, mandating surveillance, ensuring a closer relationship between surveillance and improved patient outcomes, increasing the focus on post-discharge surveillance, and integration with primary care data.

CONCLUSION

Using novel interviews with 'front-line' staff, identified opportunities for improving participation in SSI surveillance. Translating these findings into action will increase surveillance activity and bring patient safety benefits to a larger pool of surgical patients.

Comparison of Four Software Packages for Automated Contouring

PURPOSE/OBJECTIVE(S)

We are an academic radiation oncology center and treat 1500-2000 patients annually. The majority of target volume definition and organ at risk (OAR) contouring is performed by radiation oncologists (RO) and is estimated to require 10-15 hours per week for each RO. Artificial intelligence (AI) solutions for contouring are a possible method of reducing the time required. Several packages are commercially available. The purpose of this exercise was to evaluate 4 packages to identify one which would meet our department's need. The primary objective was to calculate the potential time savings associated with each of the 4 packages. The second objective was to perform a qualitative evaluation and comparison.

MATERIALS/METHODS

Approval from the hospital's Research Ethics Committee was obtained. CT Simulation datasets for 15 patients were anonymized for use as test cases for AI contouring. This included 5 datasets from each of 3 sites - head and neck (H+N), breast/thorax, and prostate/pelvis. 4 potential vendors provided access to their product for automated contouring of OARs +/- target volumes of each of the 15 datasets. Analysis was as follows: 1. One RO used a stopwatch to assess the time taken for them to contour each of the OARs +/- targets on each dataset 2. The AI contours from each of the vendors for each of the datasets was reviewed. 3. The time taken to correct each auto-contoured organ to make it clinically useful was timed. These were summed to give a time for each vendor for each dataset. 4. The time saving was calculated by subtracting the result of step (3) from step (1) 5. For the purpose of qualitative assessment, 2 ROs reviewed each dataset and assigned an objective score of 1-5 to each auto-contoured organ (e.g., 5 = no, or almost no, edits required; clinically useful as is) 6. The scores for each organ in each of the 15 datasets were averaged to give a mean value for the software package.

RESULTS

Baseline contouring time was 32.8 minutes for H+N, 23.0 minutes for breast/thorax, and 64.8 minutes for prostate/pelvis. One package was removed from consideration after assessment of H+N only as it was deemed to be of insufficient standard to be of clinical use. The average time saving for each of the remaining 3 software packages ranged were 15.7, 17.9, and 12.8 minutes for H+N, 3.1, 13.1, and 11.0 minutes for breast/thorax, and 32.6, 35.2, and 36.2 minutes for prostate/pelvis. Percentage time savings ranged from 39-55% for H+N, 13-57% for breast/thorax, and 50-56% for prostate/pelvis. The overall qualitative assessments on a 5-point scale were 3.5, 4.0, and 3.6.

CONCLUSION

The AI contouring solutions were associated with meaningful savings in the time taken to contour. The introduction of one of these products into clinical practice within our department will permit ROs to focus more of their time on other clinical activities.

CT in the detection of latent tuberculosis: a systematic review

AIM

To evaluate the use of computed tomography (CT) and low-dose CT in the detection of latent tuberculosis (TB).

MATERIALS AND METHODS

A systematic search of literature in adherence with the PRISMA guidelines was carried out. Quality assessment of the included studies was conducted.

RESULTS

The search strategy identified a total of 4,621 studies. Sixteen studies were considered eligible and included in the review. There was high heterogeneity among all studies. CT was identified as much more sensitive for the detection of latent TB in all studies despite chest radiography often being recommended in guidelines to assess patients for latent TB. Low-dose CT showed promising results in four of the studies; however, these results were limited due to small sample sizes.

CONCLUSION

CT is much superior to chest radiography consistently identifying additional cases of latent TB. There are limited high-quality publications available using low-dose CT but findings thus far suggest low-dose CT could be used as an alternative to standard-dose CT for the detection of latent TB. It is recommended that a randomised controlled trial investigating low-dose CT should be carried out.

The association between iron deficiency and outcomes: a secondary analysis of the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial

In the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial, the use of intravenous iron did not reduce the need for blood transfusion or reduce patient complications or length of hospital stay. As part of the trial protocol, serum was collected at randomisation and on the day of surgery. These samples were analysed in a central laboratory for markers of iron deficiency. We performed a secondary analysis to explore the potential interactions between pre-operative markers of iron deficiency and intervention status on the trial outcome measures. Absolute iron deficiency was defined as ferritin <30 μg.l^-1 ; functional iron deficiency as ferritin 30-100 μg.l^-1 or transferrin saturation < 20%; and the remainder as non-iron deficient. Interactions were estimated using generalised linear models that included different subgroup indicators of baseline iron status. Co-primary endpoints were blood transfusion or death and number of blood transfusions, from randomisation to 30 days postoperatively. Secondary endpoints included peri-operative change in haemoglobin, postoperative complications and length of hospital stay. Most patients had iron deficiency (369/452 [82%]) at randomisation; one-third had absolute iron deficiency (144/452 [32%]) and half had functional iron deficiency (225/452 [50%]). The change in pre-operative haemoglobin with intravenous iron compared with placebo was greatest in patients with absolute iron deficiency, mean difference 8.9 g.l^-1 , 95%CI 5.3-12.5; moderate in functional iron deficiency, mean difference 2.8 g.l^-1 , 95%CI -0.1 to 5.7; and with little change seen in those patients who were non-iron deficient. Subgroup analyses did not suggest that intravenous iron compared with placebo reduced the likelihood of death or blood transfusion at 30 days differentially across subgroups according to baseline ferritin (p = 0.33 for interaction), transferrin saturation (p = 0.13) or in combination (p = 0.45), or for the number of blood transfusions (p = 0.06, 0.29, and 0.39, respectively). There was no beneficial effect of the use of intravenous iron compared with placebo, regardless of the metrics to diagnose iron deficiency, on postoperative complications or length of hospital stay.

Acute arterial haemodynamics activation of endothelial to mesenchymal transition in long saphenous veins. Impact on vein graft disease

Introduction

The long saphenous vein (LSV) is frequently used in cardiac surgery; however, its use is complicated by late stenosis or occlusion due to the development of intimal hyperplasia (IH). TGF-β has been implicated in the process of IH however the impact of acute haemodynamic changes on the activation of TGF-β endothelial-to mesenchymal transition (EndMT) has not been assessed and it's the focus of this study.

Purpose

To assess the role of acute haemodynamics changes in veins implanted into arterial circulation on EndMT.

Methods

Surplus LSV were exposed to acute arterial haemodynamics using a perfusion bioreactor. Changes in EndMT markers at the RNA and protein level evaluated by quantitative real time PCR, RNAScope and immunofluorescence.

Results

The acute exposure of veins to arterial haemodynamics ex-vivo induced significant increase in inflammatory marker IL-8 expression and transcription factor TWIST1 in LSV (both p≤0.01, Figure 1A) endothelium. Furthermore, immunostaining demonstrated the activation of pSMAD (p≤0.01, Figure 1B) acutely in endothelium after 45 minutes of exposure to arterial haemodynamics. This was followed by significant increase of SMC related markers (Vimentin and α-SMA; Figure 1C, both p≤0.001) and the suppression of endothelial cell related marker CD31 after 4 hours of LSV exposure to acute arterial haemodynamics. RNAScope and IHC results showed localisation of TWIST1 RNA and protein in CD31+ (p≤0.001) and VECAD+ (p≤0.001) cells respectively following exposure to acute arterial haemodynamics (Figure 1D). Furthermore, TGF-β pathway phosphorylation array identified the activation of Smad1 (p≤0.05) but not TAK1 in LSV endothelial cells indicating that acute arterial haemodynamics activates the TGF-β–SMAD pathway specifically (Figure 1E).

Conclusion

The exposure of LSV to acute arterial haemodynamics is associated with the activation of TGF-β–SMAD pathway leading to EndMT changes in the endothelium of vein grafts ex-vivo. This contributes to our understanding of the changes that occur in veins after implantation into arterial circulation and that the acute changes in the endothelium and suggests that strategies to modulate TGF-β–SMAD can be utilised to modulate IH in vein grafts.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Van Geest Foundation Heart and Cardiovascular Diseases Research Fund

Drug-eluting balloons and drug-eluting stents in the treatment of small vessel coronary artery disease: a systematic review and metanalysis of long-term clinical and angiographic outcomes

Introduction

Coronary artery disease is a leading cause of mortality and morbidity worldwide. For those undergoing PCI, there are 20–30% with disease of the small coronary arteries on presentation [1]. Small coronary artery disease asserts a significant risk factor for adverse events. It is often diffuse and multi-vessel on presentation and confers higher rates of major adverse cardiac events, (MACE) and target lesion failure after intervention [2,3]. Best practice guidelines on the management of SvCAD interventions remain limited.

Drug-eluting balloons are a novel therapy, which has shown promise in treating in-stent restenosis (ISR), however their use in small coronary arteries when compared to drug-eluting stents remains unclear.

Purpose

This systematic review and meta-analysis compare long-term outcomes (&gt;1 year), of drug-eluting balloons (DEB), vs. drug-eluting stents (DES), in the treatment of small coronary artery disease (&lt;3mm).

Methods

A systematic review was completed within PRISMA guidelines. The primary outcome was non-inferiority of DEB Vs. DES in major adverse cardiac events (MACE). Secondary outcomes include all-cause mortality, MI, vessel thrombosis, major bleeding and target vessel revascularization at one, two and three years follow-up. Two independent reviewers extracted data. All outcomes used the Mantel-Haenszel and Random effect model. Odds ratios (OR), were presented with a 95% confidence interval (CI).

Result

Of 4661 articles, four RCTs were included (1414 patients). DEB demonstrated reduced rates of non-fatal MI at one year, OR 0.44 (95% CI 0.2, 0.94) and Basket-2 small reported a significant reduction in two-year bleeding rates OR 0.3 (95% CI 0.1, 0.91). DEBs were non-inferior to DES for all other outcomes.

Conclusion

Long duration follow-up of DEB and DES use in small coronary arteries demonstrates DEB to be non-inferior to DES in all outcomes across all years of follow-up. There was a significant reduction in rates of non-fatal MI at one year in the DEB arm and a reduction in major bleeding episodes at two years in the Basket Small 2 trial. These data highlight the potential utility and long-term safety of novel DEBs in small coronary artery disease revascularization.

Funding Acknowledgement

Type of funding sources: None.

Reporting conflicts of interest in randomised trials of patient blood management interventions in patients requiring major surgery: a systematic review and meta-analysis

OBJECTIVE

This study aimed to systematically review the effects of declared and undeclared conflicts of interest on randomised controlled trials (RCTs) of patient blood management (PBM) interventions.

DESIGN

We performed a secondary analysis of a recently published meta-analysis of RCTs evaluating five common PBM interventions in patients undergoing major surgery.

DATA SOURCES

The databases searched by the original systematic reviews were searched using subject headings and Medical Subject Headings terms according to search strategies from the final search time-points until 1 June 2019.

ELIGIBILITY CRITERIA

RCTs on PBM irrespective of blinding, language, date of publication and sample size were included. Abstracts and unpublished trials were excluded. Conflicts of interest were defined as sponsorship, funding or authorship by industry, professional PBM advocacy groups or blood services.

DATA EXTRACTION AND SYNTHESIS

Three independent reviewers extracted the data and assessed the risk of bias. Pooled treatment effect estimates were reported as risk ratios (RRs) or standardised mean difference with 95% CIs. Heterogeneity was quantified using the I² statistic.

RESULTS

Three hundred and eighty-nine RCTs totalling 53 635 participants were included. Thirty-two trials (8%) were considered free from important sources of bias. There was reporting bias favouring PBM interventions on transfusion across all analyses. In trials with no declared author conflicts of interest, the treatment effect on mortality was RR 1.12 (0.86 to 1.45). In trials where author conflicts of interest were declared, the treatment effect on mortality was RR 0.84 (0.69 to 1.03), with significant reporting bias favouring PBM interventions. Trials with declared conflicts linked to professional PBM advocacy groups (five studies, n=977 patients) reported statistically significant reductions in mortality RR 0.40 (0.17 to 0.92), unlike other groups.

CONCLUSIONS

Low certainty of the evidence that guides PBM implementation is confounded by evidence of reporting bias, and the effects of declared and undeclared conflicts of interest, favouring PBM on important trial outcomes.

A systematic review of micro-RNAs in aortic stenosis and cardiac fibrosis

Aortic stenosis (AS) is the commonest valve lesion requiring surgery in the Western world. The presence of myocardial fibrosis is associated with mortality even after valve replacement. MicroRNAs could serve as biomarkers of fibrosis and risk stratify patients for earlier intervention. This study aimed to systematically review reports of micro-RNA (miR) associated with fibrosis in AS and identify potential biomarkers. We searched EMBASE, Medline, and Web of Science up to May 2020. Studies that reported on the role of miRs in AS and cardiac fibrosis were included. Study quality was assessed using the Newcastle-Ottawa scale. Of 4230 reports screened, 25 were included. All studies were of low to moderate quality. MiRs were analyzed in myocardial tissue (n = 10), aortic valve tissue (n = 5), plasma (n = 5), and serum (n = 5). A total of 365 miRs were reported, of which only a few were reported in more than one paper (3 in the myocardium, 5 in the aortic valve, and 1 in plasma). miR-21 was upregulated in plasma and myocardial tissue. MiR-19b was downregulated in the myocardium. Papers reporting myocardial miR-1 contradicted each other, and miR-133a was associated with increased left ventricular mass regression post-surgery. In the aortic valve, miRs-665, 602 and 939 were downregulated, and miRs-193b and 214 were upregulated. The data on miR in fibrosis in AS is scarce and of low to moderate quality. Further studies are needed to identify novel miRs as biomarkers, especially at an earlier asymptomatic phase of the disease.

P-432 Biologic use during conception and pregnancy and its impact on fetal and maternal outcomes: systematic review and meta-analysis

Study question

To determine pregnancy outcomes in women with chronic inflammatory disease exposed to biologics during conception and pregnancy.

Summary answer

Meta-analysis of 11172 pregnancies exposed to biologic medications show no evidence of harm for the fetus or the mother.

What is known already

Chronic inflammatory diseases (CIDs) are a group of autoimmune diseases which affect between 5-7% of the population and include rheumatoid arthritis (RA), psoriatic arthritis and inflammatory bowel disease (IBD). Many CIDs have a female preponderance and are often associated with activity during reproductive years. Biologic medications, specifically the TNF-α inhibitors, have become increasingly prevalent in the treatment of chronic inflammatory disease (CID) in women of childbearing age.

Study design, size, duration

PubMed and EMBASE databases January 1998-July 2021.Peer reviewed, English language cohort, case-control, cross-sectional studies, and case series which contained original data. P- diagnosis of CID pregnancy. I- Biologic medication. C- diagnosis of CID without treatment with biologics and a CID free population. O- fetal:congenital malformations, preterm delivery (&lt;37 weeks), severe neonatal infection requiring hospitalisation, low birth weight (&lt;2.5Kg) and small for gestational age (&lt;10th Centile). Maternal: severe maternal infection requiring hospitalisation, miscarriage and pre-eclampsia.

Participants/materials, setting, methods

Two authors independently conducted data extraction. A meta-analysis of proportions using a random-effects model was used to pool outcomes. Linear regression analysis was used to compare the mean of proportions of outcomes across exposure groups using the ‘treated’ group as the reference category. All studies were evaluated using an appropriate quality assessment tool described by McDonald et al. The GRADE approach was used to assess the overall certainty of evidence.

Main results and the role of chance

35 studies, 11172 pregnancies, were eligible for inclusion. Analysis showed pooled proportions for congenital malformations: treated 0.04(95% CI 0.03-0.04; I2 77) vs disease matched 0.04(0.03-0.05. I2 86) p = 0.238. Preterm delivery treated 0.04(0.10-0.14. I2 88) vs disease matched 0.10(0.09-0.12. I2 87) p = 0.250. Severe neonatal infection: treated 0.05(0.03-0.07. I2 88) vs disease matched 0.05(0.02-0.07. I2 94) p = 0.970. Low birth weight: treated 0.10(0.07-0.12. I2 93) vs disease matched 0.08(0.07-0.09. I2 0) p = 0.241. The pooled Miscarriage: treated 0.13(0.10-0.15. I2 77) vs disease matched 0.08(0.04-0.11. I2 5) p = 0.078. Pre-eclampsia; treated 0.01(0.01-0.02. I2 0) vs disease matched 0.01(0.00-0.01. I2 0). p = 0.193. No statistical differences in proportions were observed.

Limitations, reasons for caution

GRADE certainty of findings were low to very low.

Wider implications of the findings

We demonstrated comparable pregnancy outcomes in pregnancies exposed to biologics, disease matched controls and CID free pregnancies using the GRADE approach.

Trial registration number

NA

A Systematic Review of Autistic People and the Criminal Justice System: An Update of King and Murphy (2014)

The purpose of this paper was to determine whether recommendations made by King & Murphy (Journal of Autism and Developmental Disorders 44:2717-2733, 2014) in their review of the evidence on autistic people in contact with the criminal justice system (CJS) have been addressed. Research published since 2013 was systematically examined and synthesised. The quality of 47 papers was assessed using the Mixed Methods Appraisal Tool. Findings suggest a limited amount of good quality research has been conducted that has focused on improving our understanding of autistic people in contact with the CJS since 2013. Methodological limitations make direct comparisons between autistic and non-autistic offenders difficult. Autistic people commit a range of crimes and appear to have unique characteristics that warrant further exploration (i.e., vulnerabilities, motivations for offending).

Evaluating the Feasibility of Screening Relatives of Patients Affected by Nonsyndromic Thoracic Aortic Diseases: The REST Study

Background

Diseases of the thoracic aorta are characterized by a familial etiology in up to 30% of the cases. Nonsyndromic thoracic aorta diseases (NS‐TADs) lack overt clinical signs and systemic features, which hinder early detection and prompt surgical intervention. We hypothesize that tailored genetic testing and imaging of first‐degree and second‐degree relatives of patients affected by NS‐TADs may enable early diagnosis and allow appropriate surveillance or intervention.

Methods and Results

We conducted a feasibility study involving probands affected by familial or sporadic NS‐TADs who had undergone surgery, which also offered screening to their relatives. Each participant underwent a combined imaging (echocardiogram and magnetic resonance imaging) and genetic (whole exome sequencing) evaluation, together with physical examination and psychological assessment. The study population included 16 probands (8 sporadic, 8 familial) and 54 relatives (41 first‐degree and 13 second‐degree relatives) with median age 48 years (range: 18–85 years). No syndromic physical features were observed. Imaging revealed mild‐to‐moderate aortic dilation in 24% of relatives. A genetic variant of uncertain significance was identified in 3 families. Imaging, further phenotyping, or a form of secondary prevention was indicated in 68% of the relatives in the familial group and 54% in the sporadic group. No participants fulfilled criteria for aortic surgery. No differences between baseline and 3‐month follow‐up scores for depression, anxiety, and self‐reported quality of life were observed.

Conclusions

In NS‐TADs, imaging tests, genetic counseling, and family screening yielded positive results in up to 1 out of 4 screened relatives, including those in the sporadic NS‐TAD group.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03861741.

Effect of high-flow nasal therapy on patient-centred outcomes in patients at high risk of postoperative pulmonary complications after cardiac surgery: a study protocol for a multicentre adaptive randomised controlled trial

BACKGROUND

High-flow nasal therapy is a non-invasive form of respiratory support that delivers low-level, flow dependent positive airway pressure. The device can be better tolerated by patients than alternatives such as continuous positive airway pressure. The primary objective is to determine if prophylactic high-flow nasal therapy after tracheal extubation can result in an increase in the number of days alive and at home within the first 90 days after surgery, when compared with standard oxygen therapy. The co-primary objective is to estimate the incremental cost-effectiveness and cost-utility of high-flow nasal therapy vs standard oxygen therapy at 90 days, from the view-point of the public sector, the health service and patients.

METHODS

This is an adaptive, multicentre, international parallel-group, randomised controlled trial with embedded cost-effectiveness analysis comparing the use of high-flow nasal therapy with control in patients at high risk of respiratory complications following cardiac surgery. Participants will be randomised before tracheal extubation and allocated either high-flow nasal therapy or standard oxygen therapy for a minimum of 16 h immediately post extubation. Participants will be followed up until 90 days after surgery. The total sample size needed to detect a 2-day increase in DAH90 with 90% power with an intention to treat analysis is 850 patients. The adaptive design includes an interim sample size re-estimation which will provide protection against deviations from the original sample size assumptions made from the single-centre pilot study and will allow for a maximum sample size increase to 1152 patients.

DISCUSSION

Evidence to support routine use of high-flow nasal therapy will inform the development of effective enhanced recovery care bundles. Reducing complications should reduce length of stay and re-admission to hospital and provide an important focus for cost reduction. However; high-quality studies evaluating the clinical and cost effectiveness of high-flow nasal therapy after cardiothoracic surgery are lacking.

TRIAL REGISTRATION

The study has been registered with ISRCTN ( ISRCTN14092678 , 13/05/2020) Clinicaltrials.gov Registration Pending.

POS1465-HPR THE RELATIONSHIP BETWEEN SEDENTARY BEHAVIOR AND SLEEP IN RHEUMATOID ARTHRITIS: A CROSS-SECTIONAL STUDY

Background:

Rheumatoid arthritis (RA) is a chronic, autoimmune inflammatory condition that affects 0.5% of the adult population worldwide (1). Sedentary behavior (SB) is any waking behavior characterized by an energy expenditure of ≤1.5 METs (metabolic equivalent) and a sitting or reclining posture, e.g. computer use (2) and has a negative impact on health in the RA population (3). Sleep is an important health behavior, but sleep quality is an issue for people living with RA (4, 5). Poor sleep quality is associated with low levels of physical activity in RA (4) however the association between SB and sleep in people who have RA has not been examined previously.

Objectives:

The aim of this study was to investigate the relationship between SB and sleep in people who have RA.

Methods:

A cross-sectional study was conducted. Patients were recruited from rheumatology clinics in a large acute public hospital serving a mix of urban and rural populations. Inclusion criteria were diagnosis of RA by a rheumatologist according to the American College of Rheumatology criteria age ≥ 18 and ≤ 80 years; ability to mobilize independently or aided by a stick; and to understand written and spoken English. Demographic data on age, gender, disease duration and medication were recorded. Pain and fatigue were measured by the Visual Analogue Scale (VAS), anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS), and sleep quality was assessed using the Pittsburgh Sleep Quality Index. SB was measured using the ActivPAL4™ activity monitor, over a 7-day wear period. Descriptive statistics were calculated to describe participant characteristics. Relationships between clinical characteristics and SB were examined using Pearson’s correlation coefficients and regression analyses.

Results:

N=76 participants enrolled in the study with valid data provided by N=72 participants. Mean age of participants was 61.5years (SD10.6) and the majority 63% (n = 47) were female. Participant mean disease duration was 17.8years (SD10.9). Mean SB time was 533.7 (SD100.1) minutes (8.9 hours per day/59.9% of waking hours). Mean sleep quality score was 7.2 (SD5.0) (Table 1). Correlation analysis and regression analysis found no significant correlation between sleep quality and SB variables. Regression analysis demonstrated positive statistical associations for SB time and body mass index (p-value=0.03846, R2 = 0.05143), SB time and pain VAS (p-value=0.009261, R2 = 0.07987), SB time and HADS (p-value = 0.009721, R2 = 0.08097) and SB time and HADSD (p-value = 0.01932, R2 = 0.0643).

Conclusion:

We found high levels of sedentary behavior and poor sleep quality in people who have RA, however no statistically significant relationship was found in this study. Future research should further explore the complex associations between sedentary behavior and sleep quality in people who have RA.

References:

[1]Carmona L, et al. Rheumatoid arthritis. Best Pract Res Clin Rheumatol 2010;24:733–745.

[2]Anon. Letter to the editor: standardized use of the terms “sedentary” and “sedentary behaviours”. Appl Physiol Nutr Metab = Physiol Appl Nutr Metab 2012;37:540–542.

[3]Fenton, S.A.M. et al. Sedentary behaviour is associated with increased long-term cardiovascular risk in patients with rheumatoid arthritis independently of moderate-to-vigorous physical activity. BMC Musculoskelet Disord 18, 131 (2017).

[4]McKenna S, et al. Sleep and physical activity: a cross-sectional objective profile of people with rheumatoid arthritis. Rheumatol Int. 2018 May;38(5):845-853.

[5]Grabovac, I., et al. 2018. Sleep quality in patients with rheumatoid arthritis and associations with pain, disability, disease duration, and activity. Journal of clinical medicine, 7(10)336.

Table 1.

Sleep quality in people who have RA

Sleep variableBed Time N(%) before 10pm13(18%) 10pm-12pm43 (60%) after 12pm16 (22%)Hours Sleep mean(SD)6.56 (1.54)Fall Asleep minutes mean(SD)33.3(27.7)Night Waking N(%)45(63%)Self-Rate Sleep mean(SD)2.74 (0.90)Hours Sleep mean(SD)6.56 (1.54)

Disclosure of Interests:

None declared

Dyslipidaemia management in the cardiac rehabilitation clinic of a tertiary referral centre; analysis of the impact of new ESC guidance on LDL-C target achievement

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac rehabilitation (CR) programs provide an opportunity to measure low density lipoprotein cholesterol (LDL-C) levels and optimise lipid lowering therapy (LLT) accordingly. New ESC guidelines released in August 2019 recommend lower absolute LDL-C target levels and an &gt;50% reduction from baseline in those at the highest risk.

Purpose

This study investigated the proportion of those patients who finished CR in 2019 that reached both their absolute and relative reduction in LDL-C levels, before and after the introduction of these new guidelines. We also analysed the choice and appropriateness of LLT. 

Methods

A retrospective chart review of 163 patients who completed CR in 2019. A database was created containing baseline patient characteristics and LDL-C levels both prior and post CR; as well as the patient’s contemporary LLT. Those patients who did not have a previous diagnosis of atherosclerotic cardiovascular disease (ASCVD) were risk stratified as per ESC guidance. 

Baseline LDL-C levels were recorded, where possible, and otherwise calculated using pre-CR LDL profile with an adjustment made based on the projected effects of their LLT.

Results

Mean (SD) patient age was 62 (10) years, 123/163 (75%) were male and 142 (87%) patients had established ASCVD. 90/142 (63%) of very high-risk patients were treated with a high intensity LLT and 5/163 overall (3%) were prescribed ezetimibe.

Overall, 96/163 (59%) patients in 2019 met their absolute LDL-C targets; 62% of applicable patients achieved an &gt;50% reduction in LDL-C levels. 104 (64%) of patients were treated in compliance with their contemporary guidelines.

Both pre (n = 112) and post (n = 51) September 2019 cohorts were well matched. Fewer patients who were treated under the August 2019 guidelines reached their absolute LDL-C (51% v 63%, p &lt; 0.005) targets; achieved a &gt;50% reduction in LDL-C from baseline (48% vs 61%, p &lt; 0.005), or were compliant with the guidelines for their risk category (43% vs 73%, p &lt; 0.005).

Conclusions

Both high intensity statin therapy and ezetimibe are under-prescribed. Fewer patients are meeting the lower absolute LDL-C targets set out in the 2019 ESC guidelines. For those at high risk, determining the reduction in LDL-C from baseline reveals that even those meeting their absolute LDL-C targets may still be undertreated.

LDL-C Target Achievement N Mean LDL Pre-CR (95% CI) Mean LDL-C Post CR (95% CI) Absolute LDL-C Target Met (%) Mean % LDL-C Reduction from Baseline (95% CI) &gt; 50% Reduction (% of applicable patients) Guidelines Achieved Pre-Sept"20 112 2.7 (2.46-2.93) 1.64 (1.49- 1.79) 70 (63) 61 (56-66) 50 (65) 82 (73) Post Sept 20 51 2.83 (2.41-3.25) 1.83 (1.41-2.25) 26 (51) 48 (37-59) 11 (34) 22 (43) Total 163 2.72 (2.52- 2.91) 1.69 (1.57-1.82) 96 (59) 57 (52- 62) 61 (52) 104 (64 LDL-C targets met, stratified by contemporary guidelines followed.

Abstract Figure. Choice of lipid lowering therapy in 2019

Comparison of alternate preparative techniques on wall thickness in coronary artery bypass grafts: The HArVeST randomized controlled trial

BACKGROUND

The success of coronary artery bypass grafting surgery (CABG) is dependent on long-term graft patency, which is negatively related to early wall thickening. Avoiding high-pressure distension testing for leaks and preserving the surrounding pedicle of fat and adventitia during vein harvesting may reduce wall thickening.

METHODS

A single-centre, factorial randomized controlled trial was carried out to compare the impact of testing for leaks under high versus low pressure and harvesting the vein with versus without the pedicle in patients undergoing CABG. The primary outcomes were graft wall thickness, as indicator of medial-intimal hyperplasia, and lumen diameter assessed using intravascular ultrasound after 12 months.

RESULTS

Ninety-six eligible participants were recruited. With conventional harvest, low-pressure testing tended to yield a thinner vessel wall compared with high-pressure (mean difference [MD; low minus high] -0.059 mm, 95% confidence interval (CI) -0.12, +0.0039, p = .066). With high pressure testing, veins harvested with the pedicle fat tended to have a thinner vessel wall than those harvested conventionally (MD [pedicle minus conventional] -0.057 mm, 95% CI: -0.12, +0.0037, p = .066, test for interaction p = .07). Lumen diameter was similar across groups (harvest comparison p = .81; pressure comparison p = .24). Low-pressure testing was associated with fewer hospital admissions in the 12 months following surgery (p = .0008). Harvesting the vein with the pedicle fat was associated with more complications during the index admission (p = .0041).

CONCLUSIONS

Conventional saphenous vein graft preparation with low-pressure distension and harvesting the vein with a surrounding pedicle yielded similar graft wall thickness after 12 months, but low pressure was associated with fewer adverse events.

Preoperative intravenous iron for anaemia in elective major open abdominal surgery: the PREVENTT RCT

BACKGROUND

Anaemia affects 30-50% of patients before they undergo major surgery. Preoperative anaemia is associated with increased need for blood transfusion, postoperative complications and worse patient outcomes after surgery. International guidelines support the use of intravenous iron to correct anaemia in patients before surgery. However, the use of preoperative intravenous iron for patient benefit has not been assessed in the setting of a formal clinical trial.

OBJECTIVES

To assess if intravenous iron given to patients with anaemia before major abdominal surgery is beneficial by reducing transfusion rates, postoperative complications, hospital stay and re-admission to hospital, and improving quality of life outcomes.

DESIGN

A multicentre, double-blinded, randomised, controlled, Phase III clinical trial, with 1 : 1 randomisation comparing placebo (normal saline) with intravenous iron (intravenous ferric carboxymaltose 1000 mg). Randomisation and treatment allocation were by a secure web-based service.

SETTING

The study was conducted across 46 hospitals in England, Scotland and Wales between September 2013 and September 2018.

PARTICIPANTS

Patients aged > 18 years, undergoing elective major open abdominal surgery, with anaemia [Hb level of > 90 g/l and < 120 g/l (female patients) and < 130 g/l (male patients)] who could undergo randomisation and treatment 10-42 days before their operation.

INTERVENTION

Double-blinded study comparing placebo of normal saline with 1000 mg of ferric carboxymaltose administered 10-42 days prior to surgery.

MAIN OUTCOME MEASURES

Co-primary end points were risk of blood transfusion or death at 30 days postoperatively, and rate of blood transfusions at 30 days post operation.

RESULTS

A total of 487 patients were randomised (243 given placebo and 244 given intravenous iron), of whom 474 completed the trial and provided data for the analysis of the co-primary end points. The use of intravenous iron increased preoperative Hb levels (mean difference 4.7 g/l, 95% confidence interval 2.7 to 6.8 g/l; p < 0.0001), but had no effect compared with placebo on risk of blood transfusion or death (risk ratio 1.03, 95% confidence interval 0.78 to 1.37; p = 0.84; absolute risk difference +0.8%, 95% confidence interval -7.3% to 9.0%), or rates of blood transfusion (rate ratio 0.98, 95% confidence interval 0.68 to 1.43; p = 0.93; absolute rate difference 0.00, 95% confidence interval -0.14 to 0.15). There was no difference in postoperative complications or hospital stay. The intravenous iron group had higher Hb levels at the 8-week follow-up (difference in mean 10.7 g/l, 95% confidence interval 7.8 to 13.7 g/l; p < 0.0001). There were a total of 71 re-admissions to hospital for postoperative complications in the placebo group, compared with 38 re-admissions in the intravenous iron group (rate ratio 0.54, 95% confidence interval 0.34 to 0.85; p = 0.009). There were no differences between the groups in terms of mortality (two per group at 30 days post operation) or in any of the prespecified safety end points or serious adverse events.

CONCLUSIONS

In patients with anaemia prior to elective major abdominal surgery, there was no benefit from giving intravenous iron before the operation.

FUTURE WORK

The impact of iron repletion on recovery from postoperative anaemia, and the association with reduced re-admission to hospital for complications, should be investigated.

LIMITATIONS

In the preoperative intravenous iron to treat anaemia in major surgery (PREVENTT) trial, all patients included had anaemia and only 20% had their anaemia corrected before surgery. The definition and causality of iron deficiency in this setting is not clear.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN67322816 and ClinicalTrials.gov NCT01692418.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25 No. 11. See the NIHR Journals Library website for further project information.

Mini-sternotomy versus conventional sternotomy for aortic valve replacement: a randomised controlled trial

OBJECTIVE

To compare clinical and health economic outcomes after manubrium-limited mini-sternotomy (intervention) and conventional median sternotomy (usual care).

DESIGN

A single-blind, randomised controlled trial.

SETTING

Single centre UK National Health Service tertiary hospital.

PARTICIPANTS

Adult patients undergoing aortic valve replacement (AVR) surgery.

INTERVENTIONS

Intervention was manubrium-limited mini-sternotomy performed using a 5-7 cm midline incision. Usual care was median sternotomy performed using a midline incision from the sternal notch to the xiphisternum.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the proportion of patients who received a red cell transfusion postoperatively and within 7 days of index surgery. Secondary outcomes included proportion of patients receiving a non-red cell blood component transfusion and number of units transfused within 7 days and during index hospital stay, quality of life and cost-effectiveness analyses.

RESULTS

270 patients were randomised, received surgery and contributed to the intention to treat analysis. No difference between mini and conventional sternotomy in red-cell transfusion within 7 days was found; 23/135 patients in each arm received a transfusion, OR 1.0 (95% CI 0.5 to 2.0) and risk difference 0.0 (95% CI -0.1 to 0.1). Mini-sternotomy reduced chest drain losses (mean 181.6 mL (SD 138.7) vs conventional, mean 306·9 mL (SD 348.6)); this did not reduce red-cell transfusions. Mean valve size and postoperative valve function were comparable between mini-sternotomy and conventional groups; 23 mm vs 24 mm and 6/134 moderate or severe aortic regurgitation vs 3/130, respectively. Mini-sternotomy resulted in longer bypass (82.7 min (SD 23.5) vs 59.6 min (SD 15.1)) and cross-clamp times (64.1 min (SD 17.1) vs 46·3 min (SD 10.7)). Conventional sternotomy was more cost-effective with only a 5.8% probability of mini-sternotomy being cost-effective at a willingness to pay of £20 000/QALY (Quality Adjusted Life Years).

CONCLUSIONS

AVR via mini-sternotomy did not reduce red blood cell transfusion within 7 days following surgery when compared with conventional sternotomy.

TRIAL REGISTRATION NUMBER

ISRCTN29567910; Results.

Preoperative intravenous iron to treat anaemia before major abdominal surgery (PREVENTT): a randomised, double-blind, controlled trial

BACKGROUND

Preoperative anaemia affects a high proportion of patients undergoing major elective surgery and is associated with poor outcomes. We aimed to test the hypothesis that intravenous iron given to anaemic patients before major open elective abdominal surgery would correct anaemia, reduce the need for blood transfusions, and improve patient outcomes.

METHODS

In a double-blind, parallel-group randomised trial, we recruited adult participants identified with anaemia at preoperative hospital visits before elective major open abdominal surgery at 46 UK tertiary care centres. Anaemia was defined as haemoglobin less than 130 g/L for men and 120 g/L for women. We randomly allocated participants (1:1) via a secure web-based service to receive intravenous iron or placebo 10-42 days before surgery. Intravenous iron was administered as a single 1000 mg dose of ferric carboxymaltose in 100 mL normal saline, and placebo was 100 mL normal saline, both given as an infusion over 15 min. Unblinded study personnel prepared and administered the study drug; participants and other clinical and research staff were blinded to treatment allocation. Coprimary endpoints were risk of the composite outcome of blood transfusion or death, and number of blood transfusions from randomisation to 30 days postoperatively. The primary analysis included all randomly assigned patients with data available for the primary endpoints; safety analysis included all randomly assigned patients according to the treatment received. This study is registered, ISRCTN67322816, and is closed to new participants.

FINDINGS

Of 487 participants randomly assigned to placebo (n=243) or intravenous iron (n=244) between Jan 6, 2014, and Sept 28, 2018, complete data for the primary endpoints were available for 474 (97%) individuals. Death or blood transfusion occurred in 67 (28%) of the 237 patients in the placebo group and 69 (29%) of the 237 patients in the intravenous iron group (risk ratio 1·03, 95% CI 0·78-1·37; p=0·84). There were 111 blood transfusions in the placebo group and 105 in the intravenous iron group (rate ratio 0·98, 95% CI 0·68-1·43; p=0·93). There were no significant differences between the two groups for any of the prespecified safety endpoints.

INTERPRETATION

Preoperative intravenous iron was not superior to placebo to reduce need for blood transfusion when administered to patients with anaemia 10-42 days before elective major abdominal surgery.

FUNDING

UK National Institute of Health Research Health Technology Assessment Program.

A plastic surgery service response to COVID-19 in one of the largest teaching hospitals in Europe

COVID-19 is presenting a colossal challenge to frontline NHS staff. This paper highlights how plastic surgery teams can use their diverse skills and resources in times of crisis. Through effective strategy and leadership we present how we are adapting as a department to serve our plastic surgery patients, other hospital teams and the Trust.

IgG4 Related Disease, A Case of Large Vessel Vasculitis

Aim This report describes a case of large vessel vasculitis highlighting diagnostic and therapeutic challenges. It describes the use of the B cell depleting agent Rituximab in this setting. This is the case of a 50 year old lady with bipolar disorder presenting with lower limb pain. Method PET CT and CT angiography were employed in the diagnosis of a large vessel vasculitic process. Serum IgG4 was elevated. Histological sampling was not clinically feasible. A presumptive diagnosis of IgG4 related disease was made. Results The patient responded well to steroids and later rituximab. A prompt taper of steroids was required due to labile mood and Rituximab proved to be effective in this case as a maintenance therapy. Conclusion This case demonstrates that a combination of clinical findings, laboratory results and radiological imaging may be necessary for diagnosis for IgG4 related disease, especially in the absence of a histological diagnosis. Rituximab was used in this case as a maintenance therapy allowing for a relatively rapidly reducing course of steroids.

Hypoglycemia in Diabetics on Dialysis with Poor Glycemic Control: Hemodialysis versus Continuous Ambulatory Peritoneal Dialysis

Eight diabetic men with poor glycemic control, probably worsened by severe congestive heart failure and gastroparesis, were sequentially dialyzed by CAPD and hemodialysis. Mean blood glucose concentration, blood glycosylated hemoglobin, and insulin dose were higher during CAPD than during hemodialysis. Among blood glucose determinations, however, the frequency of hypoglycemia (glucose <3.3 mmol/L) was higher during hemodialysis (13.2 ± 8.9%) than during CAPD (2.8 ± 2.1% p = 0.012), whereas the frequencies of hyperglycemia (glucose >11.1 mmol/L) and euglycemia (glucose between 3.5 and 11.1 mmol/L) did not differ between the two dialysis modalities. Furthermore, hypoglycemia was severe during hemodialysis and was associated with two deaths. There were no deaths linked to abnormalities in blood glucose concentration during CAPD. When hypoglycemia is frequent in diabetics with poor glycemic control, CAPD is preferable to hemodialysis.

Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: case-control study

Chronic fatigue syndrome (CFS) is characterized by fatigue after exertion. A systematic review suggested that transforming growth factor (TGF)-β concentrations are often elevated in cases of CFS when compared to healthy controls. This study attempted to replicate this finding and investigate whether post-exertional symptoms were associated with altered cytokine protein concentrations and their RNA in CFS patients. Twenty-four patients fulfilling Centers for Disease Control criteria for CFS, but with no comorbid psychiatric disorders, were recruited from two CFS clinics in London, UK. Twenty-one healthy, sedentary controls were matched by gender, age and other variables. Circulating proteins and RNA were measured for TGF-β, tumour necrosis factor (TNF), interleukin (IL)-8, IL-6 and IL-1β. We measured six further cytokine protein concentrations (IL-2, IL-4, IL-5, IL-10, IL-12p70, and interferon (IFN)-γ). Measures were taken at rest, and before and after both commuting and aerobic exercise. CFS cases had higher TGF-β protein levels compared to controls at rest (median (quartiles) = 43·9 (19·2, 61·8) versus 18·9 (16·1, 30·0) ng/ml) (P = 0·003), and consistently so over a 9-day period. However, this was a spurious finding due to variation between different assay batches. There were no differences between groups in changes to TGF-β protein concentrations after either commuting or exercise. All other cytokine protein and RNA levels were similar between cases and controls. Post-exertional symptoms and perceived effort were not associated with any increased cytokines. We were unable to replicate previously found elevations in circulating cytokine concentrations, suggesting that elevated circulating cytokines are not important in the pathophysiology of CFS.

International cancer seminars: a focus on esophageal squamous cell carcinoma

The International Agency for Research on Cancer (IARC) and the US National Cancer Institute (NCI) have initiated a series of cancer-focused seminars [Scelo G, Hofmann JN, Banks RE et al. International cancer seminars: a focus on kidney cancer. Ann Oncol 2016; 27(8): 1382-1385]. In this, the second seminar, IARC and NCI convened a workshop in order to examine the state of the current science on esophageal squamous cell carcinoma etiology, genetics, early detection, treatment, and palliation, was reviewed to identify the most critical open research questions. The results of these discussions were summarized by formulating a series of 'difficult questions', which should inform and prioritize future research efforts.

HIV incidence in the Estonian population in 2013 determined using the HIV-1 limiting antigen avidity assay

OBJECTIVES

Estonia has one the highest number of new HIV diagnoses in the European Union, mainly among injecting drug users and heterosexuals. Little is known of HIV incidence, which is crucial for limiting the epidemic. Using a recent HIV infection testing algorithm (RITA) assay, we aimed to estimate HIV incidence in 2013.

METHODS

All individuals aged ≥18 years newly-diagnosed with HIV in Estonia January- December 2013, except blood donors and those undergoing antenatal screening, were included. Demographic and clinical data were obtained from the Estonian Health Board and the Estonian HIV-positive patient database. Serum samples were tested for recent infection using the LAg-avidity EIA assay. HIV incidence was estimated based on previously published methods.

RESULTS

Of 69,115 tested subjects, 286 (0.41%) were newly-diagnosed with HIV with median age of 33 years (IQR: 28-42) and 65% male. Self-reported routes of HIV transmission were mostly heterosexual contact (n = 157, 53%) and injecting drug use (n = 62, 21%); 64 (22%) were with unknown risk group. Eighty two (36%) were assigned recent, resulting in estimated HIV incidence of 0.06%, corresponding to 642 new infections in 2013 among the non-screened population. Incidence was highest (1.48%) among people who inject drugs.

CONCLUSIONS

These high HIV incidence estimates in Estonia call for urgent action of renewed targeted public health promotion and HIV testing campaigns.

Manubrium-limited ministernotomy versus conventional sternotomy for aortic valve replacement (MAVRIC): study protocol for a randomised controlled trial

Background

Aortic valve replacement is one of the most common cardiac surgical procedures performed worldwide. Conventional aortic valve replacement surgery is performed via a median sternotomy; the sternum is divided completely from the sternal notch to the xiphisternum. Minimally invasive aortic valve replacement, using a new technique called manubrium-limited ministernotomy, divides only the manubrium from the sternal notch to 1 cm below the manubrio-sternal junction.

More than one third of patients undergoing conventional sternotomy develop clinically significant bleeding requiring post-operative red blood cell transfusion. Case series data suggest a potentially clinically significant difference in red blood cell transfusion requirements between the two techniques. Given the implications for National Health Service resources and patient outcomes, a definitive trial is needed.

Methods/design

This is a single-centre, single-blind, randomised controlled trial comparing aortic valve replacement surgery using manubrium-limited ministernotomy (intervention) and conventional median sternotomy (usual care). Two hundred and seventy patients will be randomised in a 1:1 ratio between the intervention and control arms, stratified by baseline logistic EuroSCORE and haemoglobin value. Patients will be followed for 12 weeks from discharge following their index operation. The primary outcome is the proportion of patients who receive a red blood cell transfusion post-operatively within 7 days of surgery. Secondary outcomes include red blood cell and blood product transfusions, blood loss, re-operation rates, sternal wound pain, quality of life, markers of inflammatory response, hospital discharge, health care utilisation, cost and cost effectiveness and adverse events.

Discussion

This is the first trial to examine aortic valve replacement via manubrium-limited ministernotomy versus conventional sternotomy when comparing red blood cell transfusion rates following surgery. Surgical trials present significant challenges; strengths of this trial include a rigorous research design, standardised surgery performed by experienced consultant cardiothoracic surgeons, an agreed anaesthetic regimen, patient blinding and consultant-led patient recruitment. The MAVRIC trial will demonstrate that complex surgical trials can be delivered to exemplary standards and provide the community with the knowledge required to inform future care for patients requiring aortic valve replacement surgery.

Trial registration

International Standard Randomised Controlled Trial Number (ISRCTN) ISRCTN29567910. Registered on 3 February 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1768-4) contains supplementary material, which is available to authorized users.

Informing etiologic research priorities for squamous cell esophageal cancer in Africa: A review of setting-specific exposures to known and putative risk factors

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in most Eastern and Southern African countries, but its etiology has been understudied to date. To inform its research agenda, we undertook a review to identify, of the ESCC risk factors which have been established or strongly suggested worldwide, those with a high prevalence or high exposure levels in any ESCC-affected African setting and the sources thereof. We found that for almost all ESCC risk factors known to date, including tobacco, alcohol, hot beverage consumption, nitrosamines and both inhaled and ingested PAHs, there is evidence of population groups with raised exposures, the sources of which vary greatly between cultures across the ESCC corridor. Research encompassing these risk factors is warranted and is likely to identify primary prevention strategies.

The microphysics of collisionless shock waves

Collisionless shocks, that is shocks mediated by electromagnetic processes, are customary in space physics and in astrophysics. They are to be found in a great variety of objects and environments: magnetospheric and heliospheric shocks, supernova remnants, pulsar winds and their nebulæ, active galactic nuclei, gamma-ray bursts and clusters of galaxies shock waves. Collisionless shock microphysics enters at different stages of shock formation, shock dynamics and particle energization and/or acceleration. It turns out that the shock phenomenon is a multi-scale non-linear problem in time and space. It is complexified by the impact due to high-energy cosmic rays in astrophysical environments. This review adresses the physics of shock formation, shock dynamics and particle acceleration based on a close examination of available multi-wavelength or in situ observations, analytical and numerical developments. A particular emphasis is made on the different instabilities triggered during the shock formation and in association with particle acceleration processes with regards to the properties of the background upstream medium. It appears that among the most important parameters the background magnetic field through the magnetization and its obliquity is the dominant one. The shock velocity that can reach relativistic speeds has also a strong impact over the development of the micro-instabilities and the fate of particle acceleration. Recent developments of laboratory shock experiments has started to bring some new insights in the physics of space plasma and astrophysical shock waves. A special section is dedicated to new laser plasma experiments probing shock physics.