British Cardiovascular Society survey of the provision and structure of cardiology multidisciplinary meetings in England

Multidisciplinary meetings (MDMs) are central to clinical decision-making in many areas of cardiology. This study assessed current provision and structure of cardiology MDMs in England in comparison with national guidelines. British Cardiovascular Society (BCS) members were surveyed regarding frequency, core attendees, and organisational aspects of cardiology MDMs for myocardial revascularisation, endocarditis, heart failure, aortic valve, mitral and tricuspid valve MDMs, whether local, regional or outside of the region. Access to electrophysiology (EP), inherited cardiac conditions, and adult congenital heart disease (ACHD) MDMs was also assessed. Survey responses from 64 hospitals across England, of which 40 (62%) were secondary care centres and 24 (38%) were tertiary care centres. All units had access to revascularisation MDMs, although 6% of them (all in secondary care centres) lacked any surgical representation. Heart failure MDMs were available in 94% of centres, but 7% reported no attendance by a cardiologist with specialist interest in heart failure, and 23% reported no attendance by a device specialist. 61% of centres had access to dedicated endocarditis MDMs, however, 11% were not attended by a microbiologist or infectious disease physician, and 22% were not attended by a surgeon. Aortic valve MDMs were available in 69% of centres while mitral and tricuspid valve MDMs were available in 56% of centres. One quarter of centres reported no access to EP, and one third of centres reported no access to ICC or ACHD MDMs. Substantial improvements in provision and structure of cardiology MDMs in England are needed in order to meet national guidance.

Comparing physiological impacts of positive pressure ventilation versus self-breathing via a versatile cardiopulmonary model incorporating a novel alveoli opening mechanism

Mathematical models can be used to generate high-fidelity simulations of the cardiopulmonary system. Such models, when applied to real patients, can provide valuable insights into underlying physiological processes that are hard for clinicians to observe directly. In this work, we propose a novel modelling strategy capable of generating scenario-specific cardiopulmonary simulations to replicate the vital physiological signals clinicians use to determine the state of a patient. This model is composed of a tree-like pulmonary system that features a novel, non-linear alveoli opening strategy, based on the dynamics of balloon inflation, that interacts with the cardiovascular system via the thorax. A baseline simulation of the model is performed to measure the response of the system during spontaneous breathing which is subsequently compared to the same system under mechanical ventilation. To test the new lung opening mechanics and systematic recruitment of alveolar units, a positive end-expiratory pressure (PEEP) test is performed and its results are then compared to simulations of a deep spontaneous breath. The system displays a marked decrease in tidal volume as PEEP increases, replicating a sigmoidal curve relationship between volume and pressure. At high PEEP, cardiovascular function is shown to be visibly impaired, in contrast to the deep breath test where normal function is maintained.

A Molecular Engineering Approach to Achieve Wavelength-Selective Photorelease Using a Dynamic Photocage

We introduce a molecular engineering strategy for wavelength-selective photorelease of alcohols and carboxylic acids, employing a dynamic photocage featuring an (E)-3-(6-acetyl-2-hydroxynaphthalen-1-yl)acrylate moiety. Initially activated by visible light (λ ≥ 410 nm), it releases alcohol, generating a second photocage. Subsequent exposure to shorter wavelengths (λ ≤ 365 nm) selectively releases carboxylic acid, albeit at a reduced rate.

Two-Photon-Responsive "TICT + AIE" Active Naphthyridine-BF2 Photoremovable Protecting Group: Application for Specific Staining and Killing of Cancer Cells

The combined effects of twisted intramolecular charge transfer (TICT) and aggregation-induced emission (AIE) phenomena have demonstrated a significant influence on excited-state chemistry. These combined TICT and AIE features have been extensively utilized to enhance photodynamic and photothermal therapy. Herein, we demonstrated the synergistic capabilities of TICT and AIE phenomena in the design of the photoremovable protecting group (PRPG), namely, NMe2-Napy-BF2. This innovative PRPG incorporates TICT and AIE characteristics, resulting in four remarkable properties: (i) red-shifted absorption wavelength, (ii) strong near-infrared (NIR) emission, (iii) viscosity-sensitive emission property, and (iv) accelerated photorelease rate. Inspired by these intriguing attributes, we developed a nanodrug delivery system (nano-DDS) using our PRPG for cancer treatment. In vitro studies showed that our nano-DDS manifested effective cellular internalization, specific staining of cancer cells, high-resolution confocal imaging of cancerous cells in the NIR region, and controlled release of the anticancer drug chlorambucil upon exposure to light, leading to cancer cell eradication. Most notably, our nano-DDS exhibited a substantially increased two-photon (TP) absorption cross section (435 GM), exhibiting its potential for in vivo applications. This development holds promise for significant advancements in cancer treatment strategies.

Complete agenesis of dorsal pancreas: A rare cause of insulin-dependent diabetes mellitus

ABSTRACT

We report a 16-year-old boy who presented with abdominal pain and severe hyperglycemia. His random blood glucose on admission was above 300 mg/dL, without ketosis. Urine examination revealed mild ketonuria. Renal function tests were normal. Antibodies to glutamate acid decarboxylase (anti-GAD) and islet tyrosine phosphatase 2 (anti-IA2) were negative. Findings on enhanced abdominal computed tomography scan were compatible with complete dorsal pancreatic agenesis. The body and tail of the pancreas were not visualized. Additionally, ectopic and malrotated left kidney was detected. Magnetic resonance cholangiopancreatography confirmed the absence of the dorsal pancreatic duct. The patient was treated with multiple subcutaneous insulin injections and attained good glycemic control. He is currently doing well on follow-up. The present case is a rare combination of complete agenesis of the dorsal pancreas with an ectopic, malrotated kidney. Clinical awareness of this rare association will help improve patient management.

Rapid expansion of Neisseria gonorrhoeae ST7827 clone in Australia, with variable ceftriaxone phenotype unexplained by genotype

BACKGROUND

Neisseria gonorrhoeae is identified as a priority pathogen due to its capacity to rapidly develop antimicrobial resistance (AMR). Following the easing of SARS-CoV-2 pandemic travel restrictions across international borders in the state of New South Wales (NSW), Australia, a surge of gonococcal isolates with raised ceftriaxone MIC values were detected.

METHODS

All N. gonorrhoeae isolates (n = 150) with increased ceftriaxone MIC values in NSW between 1 January 2021 and July 2022 from males and females from all sites were sequenced.

RESULTS

A new emergence and rapid expansion of an N. gonorrhoeae ST7827 clone was documented within NSW, Australia and provides further evidence of the ability of N. gonorrhoeae to undergo sufficient genomic changes and re-emerge as a geographically restricted subclone. Mapping AMR determinants to MIC results did not reveal any genomic pattern that correlated with MIC values.

CONCLUSIONS

The rapid dissemination and establishment of this clone at the population level is a new and concerning demonstration of the agility of this pathogen, and underscores concerns about similar incursions and establishment of MDR clones. Moreover, it is notable that in this context the AMR genotype-phenotype correlates remain unclear, which requires further investigation to enable better understanding of genomic aspects of AMR in N. gonorrhoeae.

ESIPT-, AIE-, and AIE + ESIPT-Based Light-Activated Drug Delivery Systems and Bioactive Donors for Targeted Disease Treatment

Targeted release of bioactive molecules for therapeutic purposes is a key area in the biomedical field that is growing quickly, where bioactive molecules are released passively or actively from drug delivery systems (DDSs) or bioactive donors. In the past decade, researchers have identified light as one of the prime stimuli that can implement the efficient spatiotemporally targeted delivery of drugs or gaseous molecules with minimal cytotoxicity and a real-time monitoring ability. This perspective emphasizes recent advances in the photophysical properties of ESIPT- (excited-state intramolecular proton transfer), AIE- (aggregation-induced emission), and AIE + ESIPT-attributed light-activated delivery systems or donors. The three major sections of this perspective describe the distinctive features of DDSs and donors concerning their design, synthesis, photophysical and photochemical properties, and in vitro and in vivo studies demonstrating their relevance as carrier molecules for releasing cancer drugs and gaseous molecules in the biological system.

Beta-blockers and mechanical dyssynchrony in heart failure assessed by radionuclide ventriculography

BACKGROUND

Radionuclide ventriculography (RNVG) can be used to quantify mechanical dyssynchrony and may be a valuable adjunct in the assessment of heart failure with reduced ejection fraction (HFrEF). The study aims to investigate the effect of beta-blockers on mechanical dyssynchrony using novel RNVG phase parameters.

METHODS

A retrospective study was carried out in a group of 98 patients with HFrEF. LVEF and dyssynchrony were assessed pre and post beta-blockade. Dyssynchrony was assessed using synchrony, entropy, phase standard deviation, approximate entropy, and sample entropy from planar RNVG phase images. Subgroups split by ischemic etiology were also investigated.

RESULTS

An improvement in dyssynchrony and LVEF was measured six months post beta-blockade for both ischemic and non-ischemic groups.

CONCLUSIONS

A significant improvement in dyssynchrony and LVEF was measured post beta-blockade using novel measures of dyssynchrony.

Periplasmic stress contributes to a tradeoff between protein secretion and cell growth in E. Coli Nissile

Maximizing protein secretion is an important target in the design of engineered living systems. In this paper, we characterize a tradeoff between cell growth and per cell protein secretion in the curli biofilm secretion system of E Coli Nissile 1917. Initial characterization using 24-hour continuous growth and protein production monitoring confirms decreased growth rates at high induction leading to a local maximum in total protein production at intermediate induction. Propidium iodide staining at the endpoint indicates that cellular death is a dominant cause of growth reduction. Assaying variants with combinatorial constructs of inner and outer membrane secretion tags, we find that diminished growth at high production is specific to secretory variants associated with accumulation of protein containing the outer membrane transport tag in the periplasmic space. RNA sequencing experiments indicate upregulation of known periplasmic stress response genes in the highly secreting variant, further implicating periplasmic stress in the growth-secretion tradeoff. Overall, these results motivate additional strategies for optimizing total protein production and longevity of secretory engineered living systems.

Radionuclide ventriculography phase analysis for risk stratification of patients undergoing cardiotoxic cancer therapy

BACKGROUND

Accurate diagnostic tools to identify patients at risk of cancer therapy-related cardiac dysfunction (CTRCD) are critical. For patients undergoing cardiotoxic cancer therapy, ejection fraction assessment using radionuclide ventriculography (RNVG) is commonly used for serial assessment of left ventricular (LV) function.

METHODS

In this retrospective study, approximate entropy (ApEn), synchrony, entropy, and standard deviation from the phase histogram (phase SD) were investigated as potential early markers of LV dysfunction to predict CTRCD. These phase parameters were calculated from the baseline RNVG phase image for 177 breast cancer patients before commencing cardiotoxic therapy.

RESULTS

Of the 177 patients, 11 had a decline in left ventricular ejection fraction (LVEF) of over 10% to an LVEF below 50% after treatment had commenced. This patient group had a significantly higher ApEn at baseline to those who maintained a normal LVEF throughout treatment. Of the parameters investigated, ApEn was superior for predicting the risk of CTRCD. Combining ApEn with the baseline LVEF further improved the discrimination between the groups.

CONCLUSIONS

The results suggest that RNVG phase analysis using approximate entropy may aid in the detection of sub-clinical LV contraction abnormalities, not detectable by baseline LVEF measurement, predicting a subsequent decline in LVEF.

Impact of plasma glucose and duration of type 2 diabetes mellitus on SYNTAX Score II in patients suffering from non ST-elevation myocardial infarction

Aim    The objective was to assess the correlation of fasting plasma glucose (FPG), HbA1c, and the duration of type 2 diabetes mellitus (T2DM) with SYNTAX score (SS) II in patients with non-ST elevation myocardial infarction (NSTEMI).Material and methods    FPG and HbA1C were measured in 398 patients presenting with NSTEMI at admission. SS II was calculated using an online calculator. Patients were stratified according to SS II (≤21.5, 21.5-30.6, and ≥30.6), defined as SS II low, mid, and high, respectively.Results    37.7 % of subjects were diabetic. Correlations of FPG (R=0.402, R2=0.162, p<0.001) and HbA1c (R=0.359, R2=0.129, p<0.001) with SS II were weak in the overall population. Duration of T2DM showed very strong correlation with SS II (R=0.827, R2=0.347). For the prediction of high SS II in the study population, FPG≥98.5 mg / dl demonstrated a sensitivity of 58 % and a specificity of 60 %, and HbA1c ≥6.05 demonstrated a sensitivity of 63 % and a specificity of 69 %. Duration of T2DM (adjusted odds ratio (OR): 1.182; 95 % confidence interval (CI): 1.185-2.773) and FPG (OR: 0.987; 95 % CI: 0.976-0.9959) were significantly associated with high SS II after controlling for other risk factors. Duration of T2DM (Beta=0.439) contributed strongly to variance of SS II, whereas HbA1c (Beta=0.063) contributed weakly.Conclusion    Duration of T2DM is a very important risk factor for severity of coronary artery disease.

Relative contribution of different members of OsDREB gene family to osmotic stress tolerance in indica and japonica ecotypes of rice

Drought/osmotic stress is the single largest production constraint in rain-fed rice cultivation. Different members of the DREB gene family are known to contribute to osmotic stress tolerance. In this study, an attempt was made to understand their relative contribution towards osmotic stress tolerance in indica and japonica ecotypes of rice. Two genotypes (one tolerant and one susceptible) from each ecotype were grown hydroponically, and 21-day-old seedlings were subjected to polyethylene glycol-induced osmotic stress (15% PEG-6000, equivalent to -3.0 bars osmotic potential). The tolerant genotypes CR143 and Moroberekan were found to have superior root traits (total root length, surface area and volume), better plant water status and increased total dry biomass as compared to their susceptible counterparts after 10 days of osmotic stress. Different members of the DREB gene family were differentially induced in response to osmotic shock (1 h after stress) and osmotic stress (24 h after stress), which also differed between the two rice ecotypes. From the gene expression profiles of 10 DREB genes (both DREB1 and DREB2 families), in indica two DREB genes, DREB1B and DREB1G, were significantly correlated with stress tolerance indices, whereas in japonica significant correlations with five DREB genes (DREB1A, DREB1B, DREB1D, DREB1E and DREB2B) were observed. We found that only one member, i.e. DREB1B, showed a significant correlation with drought tolerance indices in both indica and japonica ecotypes. This study provides an overview of the relative contribution of different members of the DREB gene family and their association with drought/osmotic stress tolerance in rice.

Switching photorelease to singlet oxygen generation by oxygen functionalization of phenothiazine photocages

A phenothiazine-based photoremovable protecting group (PRPG) for single and dual release of carboxylic acids was developed. The change in the oxidation state of the sulfur atom of the phenothiazine PRPG resulted in singlet oxygen generation, rather than photorelease. The difference in the photochemistry between oxygen-free and oxygen-functionalized phenothiazine was investigated and supported by DFT calculations.

Green Light-Activated Single-Component Organic Fluorescence-Based Nano-Drug Delivery System for Dual Uncaging of Anticancer Drugs

Developing green or red light-activated drug delivery systems (DDSs) for cancer treatment is highly desirable. Herein, we have reported a green light-responsive single component-based organic fluorescence nano-DDS by simply anchoring 2-hydroxy-6-naphthacyl (phototrigger) on both sides of the 1,5-diaminonaphthalene (DAN) chromophore. This green light (λ ≥ 500 nm)-activated DDS released two equivalents of the anticancer drug (valproic acid) in a spatio-temporally controlled manner. Our photoresponsive DDS [DAN-bis(HO-Naph-VPA)] exhibited interesting properties such as excited-state intramolecular proton transfer (ESIPT) accompanied with aggregation-induced emission (AIE) phenomena. AIE initiated the photorelease, and ESIPT enhanced the rate of the photorelease. Further, in vitro studies revealed that our green light-activated nano-DDS exhibited good cytocompatibility, excellent cellular internalization, and effective cancer cell killing ability.

Efficacy and safety of bisoprolol compared to other selective beta-1 blockers in the treatment of hypertension: a systematic review and meta-analysis of randomized parallel clinical trials

Background

Bisoprolol, a highly cardioselective beta-1 blocker (s-BB) has theoretical advantage over other cardio selective betablockers by way of better potency and tolerability in treating hypertension (HT). Individual published trials comparing s-BB are typically small. Meta-analysis of such trials clarifies the issue and position of bisoprolol in HT therapy.

Purpose

This meta-analysis compares bisoprolol with other s-BBs (Atenolol, Betaxolol, Esmolol, Acebutolol, Metoprolol, Nebivolol) for their efficacy and safety in patients with HT.

Methods

Literature databases PubMed, Embase, Cochrane Library, Clinicaltrials.gov, Surveillance, Epidemiology and End Results Program and 12 PV databases were searched systematically to identify randomized, parallel clinical trials published from inception to October 2019. Studies which compared bisoprolol with other s-BBs in HT patients were evaluated in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Random effects meta-analyses were conducted to assess mean difference (MD) and 95% confidence interval (95% CI) for blood pressure (BP), heart rate (HR) and lipid profile.

Results

13 studies compared bisoprolol with other s-BBs (metoprolol, atenolol) were included in this meta-analysis. Bisoprolol reported significant reduction in aortic systolic BP [MD: −8.00; 95% CI: −11.57, −4.43; P<0.01] and diastolic BP [MD: −2.90; 95% CI: −4.98, −0.82; P<0.01] during 8 weeks (w) treatment compared to other s-BBs. Bisoprolol treatment for 12w showed significant change in ambulatory heart rate (AHR) [MD: −5.22; 95% CI: −8.37, −2.07; P<0.01], daytime AHR [MD: −5.75; 95% CI: −9.16, 2.34; P<0.01] and nighttime AHR [MD: −3.22; 95% CI: −6.18, −0.26; P=0.03] in comparison to other s-BBs. Significant increase in low frequency HR variability [MD: 100.79; 95% CI: 16.66, 184.91; P=0.02] was reported with bisoprolol treated for 8w compared to other s-BBs. Baroreflex sensitivity significantly favored bisoprolol treated for 8w [MD: 1.01; 95% CI: 0.03, 1.98; P=0.04] in comparison to other s-BBs. HDL-C significantly increased with bisoprolol treated for 52w [MD: 6.80; 95% CI: 3.01, 10.60; P<0.01], 104w [MD: 12.00; 95% CI: 5.04, 18.96; P<0.01] and 156w [MD: 8.00; 95% CI: 0.58, 15.42; P=0.03]. There were no significant changes in total cholesterol [MD: −3.06; P=0.38], LDL-C [MD: −3.60; P=0.18] and triglyceride [MD: −21.00; P=0.26] on treatment with bisoprolol. Serious adverse events did not differ significantly on treatment with bisoprolol compared to other s-BBs.

Conclusion

The results of this meta-analysis reveal that bisoprolol showed a significant reduction of BP, HR, baroreflex sensitivity and improved HDL cholesterol levels compared to other s-BBs. Our results highlight the heterogeneity amongst the s-BBs and highlights the benefit of choosing bisoprolol in comparison to other s-BB in the management of HT.

Funding Acknowledgement

Type of funding sources: None.

Effectiveness of bisoprolol versus selective beta-1 blockers in the management of hypertension: a systematic review and meta-analysis of randomized cross-over trials

Background

Cross-over trials carry a higher weightage in choosing a therapeutic agent in clinical practice. A meta-analysis of cross-over trials involving the use of bisoprolol in hypertension (HT) would bring about clarity in positioning this drug.

Purpose

The present study aimed to clarify the underlying benefits of bisoprolol in the reduction of blood pressure (BP) in HT patients when compared to selective beta-1 blockers (s-BBs - Atenolol, Betaxolol hydrochloride, Esmolol, Acebutolol hydrochloride, Metoprolol succinate, Nebivolol) by performing a meta-analysis of “cross-over” trials published in literature.

Methods

Systematic search was undertaken in PubMed, Embase, Cochrane Library, Clinicaltrials.gov registry, Surveillance, Epidemiology and End Results Program and 12 pharmacovigilance databases. Randomized, cross-over studies published up to October 2019 which compared bisoprolol with other s-BBs in HT patients were evaluated in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A meta-analysis was performed using random effects model in terms of mean difference (MD) and 95% confidence intervals (95% CI) for BP, heart rate (HR) and lipid profile.

Results

Nine randomized cross-over studies which compared bisoprolol with other s-BBs (atenolol and nebivolol) were included in this meta-analysis. Bisoprolol reported significant reduction of sitting BP [MD: −3.35, 95% CI: −6.75, 0.05; P=0.05] and reduction of diastolic BP [MD: −2.00; 95% CI: −8.04, 4.04; P=0.52, non-significant] among patients with HT when compared to other s-BBs. Heart rate (HR) decreased significantly among HT patients in bisoprolol group treated for 2 w [MD: −6.00; 95% CI: −11.30, −0.70; P=0.03] when compared to those treated with other s-BBs. Analysis of lipid profile showed non-significant reduction of serum cholesterol [MD: −7.74; 95% CI: −17.18, 1.70; P=0.11] and triglyceride [MD: −26.57; 95% CI: −64.34, 11.20; P=0.17] levels in the bisoprolol group compared to other s-BBs. Bisoprolol treatment for 8 w resulted in a slight but statistically significant change in potassium levels [MD: −0.10; 95% CI: −0.16, −0.04; P<0.01] among HT patients.

Conclusion

The results of this meta-analysis reported significant efficacy of bisoprolol on BP and HR in comparison to other s-BBs in a meta-analysis of cross-over trials. Our findings show that use of bisoprolol as a therapeutic option is efficacious and safe compared to other s-BBs in this patient population.

Funding Acknowledgement

Type of funding sources: None.

Effects of Vector Maturation Time on the Dynamics of Cassava Mosaic Disease

Many plant diseases are caused by plant viruses that are often transmitted to plants by vectors. For instance, the cassava mosaic disease, which is spread by whiteflies, has a significant negative effect on plant growth and development. Since only mature whiteflies can contribute to the spread of the cassava mosaic virus, and the maturation time is non-negligible compared to whitefly lifetime, it is important to consider the effects this maturation time can have on the dynamics. In this paper, we propose a mathematical model for dynamics of cassava mosaic disease that includes immature and mature vectors and explicitly includes a time delay representing vector maturation time. A special feature of our plant epidemic model is that vector recruitment is negatively related to the delayed ratio between vector density and plant density. We identify conditions of biological feasibility and stability of different steady states in terms of system parameters and the time delay. Numerical stability analyses and simulations are performed to explore the role of various parameters, and to illustrate the behaviour of the model in different dynamical regimes. We show that the maturation delay may stabilise epidemiological dynamics that would otherwise be cyclic.

The role of infrared dermal thermometry in the management of neuropathic diabetic foot ulcers

AIM

This prospective observational study evaluated the role of infrared (IR) dermal thermometry in the management of diabetic foot ulcers.

METHODS

Thirty participants with unilateral neuropathic diabetic foot ulcers of University of Texas grade 1 or 2 (stage A) were followed up monthly for 1 year. At each visit, skin temperatures were measured with an IR dermal thermometer at corresponding sites on both feet, using the contralateral feet without ulcers as controls.

RESULTS

Average temperature and ulcer temperature in affected feet were significantly higher than in unaffected feet, with a mean difference of 1.2 °C [95% confidence interval (CI) 0.7 to 1.7] and 3.1 °C (95% CI 2.3 to 3.9), respectively. Although the gradient between average temperature of affected foot and that of unaffected foot normalized (mean difference 0.2 °C, 95% CI -0.2 to 0.7) at healing, the temperature gradient between the ulcer and a corresponding site on the unaffected foot decreased but did not normalize (mean difference 2.1 °C, 95% CI 1.2 to 3.1) even at healing, as documented by skin closure, and persisted for up to 1 month after skin closure. A gradient of ≥1 °C between average temperature of affected foot and that of unaffected foot at initial presentation or at any time during ulcer healing was found to predict impaired healing and should alert clinicians to ulcers requiring more attention. An incremental trend in temperature gradient (median difference 2.2 °C; range 0.1-6.3 °C) at a site on the foot was predictive of a recurrent ulcer involving the same site.

CONCLUSIONS

IR dermal thermometry may have a role in predicting diabetic foot ulcer healing, in determining the completeness of healing and in guiding the duration of offloading. Serial monitoring of the temperature gradient may predict the development of recurrent diabetic foot ulcers.

Global sensitivity analysis of randomized trials with nonmonotone missing binary outcomes: Application to studies of substance use disorders

In this paper, we present a method for conducting global sensitivity analysis of randomized trials in which binary outcomes are scheduled to be collected on participants at prespecified points in time after randomization and these outcomes may be missing in a nonmonotone fashion. We introduce a class of missing data assumptions, indexed by sensitivity parameters, which are anchored around the missing not at random assumption introduced by Robins (Statistics in Medicine, 1997). For each assumption in the class, we establish that the joint distribution of the outcomes is identifiable from the distribution of the observed data. Our estimation procedure uses the plug-in principle, where the distribution of the observed data is estimated using random forests. We establish n asymptotic properties for our estimation procedure. We illustrate our methodology in the context of a randomized trial designed to evaluate a new approach to reducing substance use, assessed by testing urine samples twice weekly, among patients entering outpatient addiction treatment. We evaluate the finite sample properties of our method in a realistic simulation study. Our methods have been implemented in an R package entitled slabm.

Discrepancies between the decisions of an endocarditis team and the modified Duke's Criteria for the diagnosis of infective endocarditis

Background/Introduction

The 2015 ESC endocarditis guidelines recommend that a multi-disciplinary endocarditis team should be involved in caring for patients with endocarditis. This approach recognises the heterogeneity of infective endocarditis, and the difficulty in distinguishing endocarditis from other infective and non-infective diseases.

Purpose

This study looks at suspected cases of infective endocarditis discussed at the endocarditis MDT, discrepancies between MDT outcome and the modified Duke's criteria in diagnosing endocarditis, and number of referrals to MDT over time.

Methods

Patients were identified by review of MDT outcome forms. Demographic data, predisposing conditions, imaging findings, microbiology results and final diagnosis were identified by reviewing MDT forms and electronic charts.

Results

234 patients were identified from MDT outcome forms. 118 (50.4%) patients were over 65, 165 (70.5%) were male, and 65 (27.8%) had previous valve surgery. Crosstabulation of MDT decision against outcome by modified Duke's criteria are seen in Table 1. The endocarditis team identified 7 patients with definite or possible endocarditis who were excluded by applying the modified Duke's criteria. 1 of these patients required aortic valve replacement. 2 patients with disseminated Staphylococcal infections without endocarditis were classed as definite endocarditis by the modified Duke's criteria. Referral data and outcomes are included in Figure 1.

Conclusions

The endocarditis team can be used to improve the sensitivity and specificity of the modified Duke's criteria. As the endocarditis team became established the volume of referrals has increased, along with the number of patients who have alternate diagnoses. Practitioners should bear this in mind when establishing endocarditis teams.

Figure 1. Referrals over time by outcome

Funding Acknowledgement

Type of funding source: None