Machine learning and artificial intelligence in cardiac transplantation: A systematic review

Background

This review aims to systematically evaluate the currently available evidence investigating the use of artificial intelligence (AI) and machine learning (ML) in the field of cardiac transplantation. Furthermore, based on the challenges identified we aim to provide a series of recommendations and a knowledge base for future research in the field of ML and heart transplantation.

Methods

A systematic database search was conducted of original articles that explored the use of ML and/or AI in heart transplantation in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to November 2021.

Results

Our search yielded 237 articles, of which 13 studies were included in this review, featuring 463 850 patients. Three main areas of application were identified: (1) ML for predictive modeling of heart transplantation mortality outcomes; (2) ML in graft failure outcomes; (3) ML to aid imaging in heart transplantation. The results of the included studies suggest that AI and ML are more accurate in predicting graft failure and mortality than traditional scoring systems and conventional regression analysis. Major predictors of graft failure and mortality identified in ML models were: length of hospital stay, immunosuppressive regimen, recipient's age, congenital heart disease, and organ ischemia time. Other potential benefits include analyzing initial lab investigations and imaging, assisting a patient with medication adherence, and creating positive behavioral changes to minimize further cardiovascular risk.

Conclusion

ML demonstrated promising applications for improving heart transplantation outcomes and patient‐centered care, nevertheless, there remain important limitations relating to implementing AI into everyday surgical practices.

Microbiological quality of street-vended foods sold in Thulamela Municipality of South Africa

The objective of the study was to examine the microbial quality of street-vended foods in Sibasa and Thohoyandou markets of Thulamela Municipality, South Africa. Gravy, salad, beef and chicken stews were randomly sampled from seven markets. Microbiological international standard methods were used for the Total plate counts, coliform bacteria, Salmonella spp., Escherichia coli, Staphylococcus aureus, Bacillus cereus, yeast and mould counts. The microbial counts (log10 CFU/g) of foods sold at Thohoyandou ranged from 2.0±2.08 to too numerous to count for Total plate count, 2.0±1.00 to 6.6±7.57 for Salmonella spp., 2.0±2.64 to 3.9±6.03 for S. aureus, 2.3±1.73 to too numerous to count for yeast. At Sibasa, microbial counts (log10 CFU/g) ranged from 2.1±6.24 to 6.9±5.30 for total plate count, 2.0±0.00 to 3.8±10.00 for coliform bacteria, 2.0±2.64 to 4.7±8.33 for Salmonella spp., 2.0±6.03 to 3.9±9.30, for S. aureus, 2.1±1.00 to 3.7±39.58 for yeast and 2.0±1.15 to 4.9±21.66 for B. cereus. Mould was not detected in all the foods sold at both locations. The total plate count was significantly different (P<0.05) between salads and chicken stews. For Salmonella spp., significant differences (P<0.05) were observed between salads and beef stews. For S. aureus, a significant difference was found in salads (P<0.05). For yeast, significant differences (P<0.05) were observed between salads and beef stews. The fact that most street-vended foods were contaminated with a range of microorganisms is a matter of public concern. Department of Health, South Africa should initiate a food safety program for the vendors to be trained in hygienic preparation of foods and good sanitation practices to better safeguard the health and wellness of consumers. There is also a need for Environmental Health Practitioners to mount a better monitoring system that would contain selling street-vended food that is unfit for human consumption.

Management of temporary epicardial pacing wires in the cardiac surgical patient

Temporary epicardial pacing wires are used after cardiothoracic surgery to maintain a stable cardiac rhythm. They must be distinguished from the more commonly encountered transvenous temporary pacing wires, which are often used in coronary care units for the same purpose. Patients with temporary epicardial pacing wires may be transferred to hospital wards where these wires are not usually encountered, such as COVID wards, the general intensive care unit, the coronary care unit or general surgical wards if a laparotomy was required in the early period following cardiac surgery. Serious complications may arise in managing patients with temporary epicardial pacing wires, which are well known in the cardiothoracic unit but not so well known elsewhere in the hospital. This article discusses the dangers associated with the management of temporary epicardial pacing wires in adult patients, some of which are common to temporary transvenous pacing wires and others are unique to temporary epicardial pacing wires.

102 Peer Teaching in Hip Fracture: Responding to the Medical Needs of Surgical Patients and Educational Needs of Junior Doctors

Introduction

Fractured Neck of Femur (FNOF) patients are complex. A mortality project identified topics for a peer-led teaching programme.

Method

Eight bite-sized case-based sessions were devised, to provide a framework to approach the following topics: Anaemia, delirium/dementia, ECG abnormalities, metastatic cancer, osteoporosis, renal disease, respiratory disease, and vascular complications. Attendees were asked to complete pre- and post- teaching programme questionnaires using a Likert Scale to indicate agreement with statements relating to the topic areas chosen (1=strongly disagree and 5=strongly agree).

Result

Pre-programme questionnaire: respondents were neutral (average 3.04) when asked whether topic areas were currently “well managed”. Attendees lacked confidence, indicating preparedness as neutral (average 3.35). Trainees agreed that they would benefit from teaching (average 4.56).

Post-programme questionnaire: increased confidence was reported when considering preparedness (average 4.3). Attendees felt the teaching programme was “accessible” and the “topics well-chosen”. 100% of attendees regarded the teaching as ‘excellent’ or ‘very-good’.

Conclusions

Matching patient needs to an educational programme is important.

The “bite-sized” nature of the programme paired with case-based learning increased confidence. A peer-led teaching programme is a positive response to themes emerging from morbidity and mortality reviews.

Right ventricular morphology and function analysis in moderately preterm-born young adults

Background

Previous studies have shown that prematurity leads to altered right ventricular (RV) geometry and performance with persistent impairments in RV systolic function in young adulthood. It is unknown to what extent pulmonary physiology impacts these findings.

Purpose

To better quantify known alterations in RV morphology and function in preterm-born young adults and to determine to what extent these changes are influenced by the pulmonary circulation.

Methods

A total of 101 normotensive preterm-born (n=47, mean gestational age 32.8±3.2 weeks) and term-born (n=54) young adults were recruited. Echocardiography and cardiovascular magnetic resonance (CMR) imaging were performed to characterise RV morphology, RV function, pulmonary hemodynamics and RV-pulmonary arterial vascular (PA) coupling. CMR cine images were used to create a 3D computational atlas of the RV geometry and principal component analysis was undertaken to identify the key modes of shape variation. Spirometry was performed to assess lung function.

Results

RV CMR revealed a higher absolute and indexed RV mass (P&lt;0.05) and lower ejection fraction (54.90±5.17 versus 57.48±4.39%, P=0.008) in young adults born preterm. RV end-diastolic areas and volumes for CMR and echocardiography were lower in preterm-born compared to term-born young adults (P≤0.001). Principal component analysis of the computational atlas defined the anatomical modes of the RV geometry, with mode 1 accounting for 25.3% of the population variance. Preterm and term cohorts showed significant differences (P&lt;0.001) in mode 1, which represented a smaller and shorter RV cavity in the preterm group (Figure 1). Measurements of RV function by echocardiography, including RV fractional area of change (FAC) and tricuspid annular plane systolic excursion (TAPSE), were lower in preterm-born compared to term-born adults (P&lt;0.05). Despite lower pulmonary artery acceleration times (PAAT) in those born preterm (141.1±15.1 versus 159.2±21.6msec, P&lt;0.001), indicating increased pulmonary vascular resistance, the RV remained coupled to its pulmonary circulation (TAPSE/PAAT: 0.13±0.02 versus 0.14±0.03m/sec, P=0.153). Reduced RV performance in preterm-born individuals remained significant when adjusting for pulmonary function parameters (P&lt;0.05).

Conclusions

Multimodality cardiac imaging demonstrated that moderately preterm-born young adults exhibit structural and functional RV alterations, independent of lung physiology. Their RV remains hemodynamically coupled to its pulmonary circulation despite higher RV afterload, lower RV function and altered morphology.

Figure 1. Statistical shape model of the RV

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation

P3133Single parasternal long axis echocardiography by briefly trained health workers using handheld devices for detection of rheumatic heart disease: a prospective study of diagnostic accuracy

Introduction

Echocardiographic screening can detect rheumatic heart disease (RHD) in high-risk populations,but is limited by reliance on highly-trained experts and equipment. We sought to determine the diagnostic utility of an ultra-abbreviated single parasternal-long-axis-sweep of the heart (SPLASH) echocardiography protocol to detect RHD, performed by briefly-trained health workers.

Methods

In Timor-Leste and Northern Australia, individuals aged 5–20y were offered school-based echocardiographic screening. Health workers completed online modules followed by one-week of practical training, logging 50 echocardiograms prior to study. The index test was SPLASH, performed and reported by health workers using handheld GE V-scan devices. The index test was abnormal if any mitral or aortic regurgitation was detected. The reference test was a comprehensive echocardiogram, performed by an echocardiographers or cardiologist on a GE Vivid-Q, reported according to World Heart Federation criteria. The diagnostic accuracy of the index test was determined.

Results

2590 subjects underwent index and reference tests. Prevalence of definite RHD was 3.2% (83/2590). Sensitivity and specificity of index test were 0.75 (95% CI 0.64–0.83) and 0.77 (95% CI 0.75–0.78) respectively for detection of any definite RHD, and 0.91 (95% CI 0.74–0.98) and 0.76 (95% CI 0.74–0.78) respectively for detection of moderate or severe RHD.

Conclusion

Health workers using SPLASH detected the vast majority of moderate and severe RHD cases, but lacked sensitivity for detection of mild RHD. Further analysis is underway to evaluate the learning curve and other performance indicators of health workers performing and interpreting echocardiograms. This will allow refinement of SPLASH protocol and augmentation of health worker training to increase detection rates and accuracy for future population screening initiatives.

Acknowledgement/Funding

Heart Foundation Australia Vanguard Grant, Menzies HOT-NORTH pilot project grant, Snow Foundation, Rotary, Bawinanga Aboriginal Corporation, Mala'la

Systemic therapy for recurrent epithelial ovarian cancer: a clinical practice guideline

Objective

The purpose of this guideline is to recommend systemic therapy options for women with recurrent epithelial ovarian cancer, including fallopian tube and primary peritoneal cancers.

Methods

This document updates the recommendations published in the 2011 Optimal Chemotherapy for Recurrent Ovarian Cancer guideline from Cancer Care Ontario. Draft recommendations were formulated based on evidence obtained through a systematic review of phase ii and iii randomized controlled trials (rcts). The draft recommendations underwent internal review by clinical and methodology experts, and external review by clinical practitioners through a survey assessing the clinical relevance and overall quality of the guideline. Feedback from the internal and external reviews was integrated into the clinical practice guideline.

Results

The primary literature search yielded thirty-six primary research papers representing thirty rcts that met the eligibility criteria. The guideline provides recommendations for patients with serous tumour histologies and with recurrent, platinum-resistant, and platinum-sensitive ovarian cancer.

Conclusions

The body of evidence from trials that included olaparib and bevacizumab consistently shows a benefit in progression-free survival (pfs) without a corresponding benefit in overall survival (os). The Working Group for this guideline designated pfs, which is associated with symptom control, as a critical outcome. A finding of net benefit can therefore be concluded based on significant differences in pfs. However, that benefit is not without identified harms. Given the identified harms, patient involvement in the decision-making process must take into consideration the side effect profiles of olaparib and bevacizumab within the context of improved pfs but minimal change in os.

Reactivity to unpredictable threat as a treatment target for fear-based anxiety disorders

BACKGROUND

Heightened reactivity to unpredictable threat (U-threat) is a core individual difference factor underlying fear-based psychopathology. Little is known, however, about whether reactivity to U-threat is a stable marker of fear-based psychopathology or if it is malleable to treatment. The aim of the current study was to address this question by examining differences in reactivity to U-threat within patients before and after 12-weeks of selective serotonin reuptake inhibitors (SSRIs) or cognitive-behavioral therapy (CBT).

METHODS

Participants included patients with principal fear (n = 22) and distress/misery disorders (n = 29), and a group of healthy controls (n = 21) assessed 12-weeks apart. A well-validated threat-of-shock task was used to probe reactivity to predictable (P-) and U-threat and startle eyeblink magnitude was recorded as an index of defensive responding.

RESULTS

Across both assessments, individuals with fear-based disorders displayed greater startle magnitude to U-threat relative to healthy controls and distress/misery patients (who did not differ). From pre- to post-treatment, startle magnitude during U-threat decreased only within the fear patients who received CBT. Moreover, within fear patients, the magnitude of decline in startle to U-threat correlated with the magnitude of decline in fear symptoms. For the healthy controls, startle to U-threat across the two time points was highly reliable and stable.

CONCLUSIONS

Together, these results indicate that startle to U-threat characterizes fear disorder patients and is malleable to treatment with CBT but not SSRIs within fear patients. Startle to U-threat may therefore reflect an objective, psychophysiological indicator of fear disorder status and CBT treatment response.

Perinatal lead (Pb) exposure results in sex and tissue-dependent adult DNA methylation alterations in murine IAP transposons

Epidemiological and animal data suggest that adult chronic disease is influenced by early-life exposure-induced changes to the epigenome. Previously, we observed that perinatal lead (Pb) exposure results in persistent murine metabolic- and activity-related effects. Using phylogenetic and DNA methylation analysis, we have also identified novel intracisternal A particle (IAP) retrotransposons exhibiting regions of variable methylation as candidate loci for environmental effects on the epigenome. Here, we now evaluate brain and kidney DNA methylation profiles of four representative IAPs in adult mice exposed to human physiologically relevant levels of Pb two weeks prior to mating through lactation. When IAPs across the genome were evaluated globally, average (sd) methylation levels were 92.84% (3.74) differing by tissue (P < 0.001), but not sex or dose. By contrast, the four individual IAPs displayed tissue-specific Pb and sex effects. Medium Pb-exposed mice had 3.86% less brain methylation at IAP 110 (P < 0.01), while high Pb-exposed mice had 2.83% less brain methylation at IAP 236 (P = 0.01) and 1.77% less at IAP 506 (P = 0.05). Individual IAP DNA methylation differed by sex for IAP 110 in the brain and kidney, IAP 236 in the kidney, and IAP 1259 in the kidney. Using Tomtom, we identified three binding motifs that matched to each of our novel IAPs impacted by Pb, one of which (HMGA2) has been linked to metabolic-related conditions in both mice and humans. Thus, these recently identified IAPs display tissue-specific environmental lability as well as sex-specific differences supporting an epigenetic link between early exposure to Pb and later-in-life health outcomes. Environ. Mol. Mutagen. 58:540-550, 2017. © 2017 Wiley Periodicals, Inc.

Core requirements for successful data linkage: an example of a triangulation method

OBJECTIVES

The aim was to explore the views of professional stakeholders and healthcare professionals (HCPs) on the linkage of UK National Health Service (NHS) data for paediatric pharmacovigilance purposes and to make recommendations for such a system.

METHODS

A mixed methods approach including a literature review, interviews, focus groups and a three-round Delphi survey with HCPs in Scotland was followed by a triangulation process using a systematic protocol. The survey was structured using the Theoretical Domains Framework of behaviour change. Items retained after applying the matrix-based triangulation process were thematically coded. Ethical approval was granted by the North of Scotland Research Ethics Service.

RESULTS

Results from 18 papers, 23 interviewees, 23 participants of focus groups and 61 completed questionnaires in the Delphi survey contributed to the triangulation process. A total of 25 key findings from all four studies were identified during triangulation. There was good convergence; 21 key findings were agreed and remained to inform recommendations. The items were coded as practical/technical (eg, decision about the unique patient identifier to use), mandatory (eg, governed by statute), essential (consistently mentioned in all studies and therefore needed to ensure professional support) or preferable.

CONCLUSIONS

The development of a paediatric linked database has support from professional stakeholders and HCPs in Scotland. The triangulation identified three sets of core requirements for a new system of data linkage. An additional fourth set of 'preferable' requirements might increase engagement of HCPs and their support for the new system.

Behavioural recovery after treatment for varicose veins

BACKGROUND

The aim of this study was to assess behavioural recovery from the patient's perspective as a prespecified secondary outcome in a multicentre parallel-group randomized clinical trial comparing ultrasound-guided foam sclerotherapy (UGFS), endovenous laser ablation (EVLA) and surgery for the treatment of primary varicose veins.

METHODS

Participants were recruited from 11 UK sites as part of the CLASS trial, a randomized trial of UGFS, EVLA or surgery for varicose veins. Patients were followed up 6 weeks after treatment and asked to complete the Behavioural Recovery After treatment for Varicose Veins (BRAVVO) questionnaire. This is a 15-item instrument that covers eight activity behaviours (tasks or actions an individual is capable of doing in an idealized situation) and seven participation behaviours (what the individual does in an everyday, real-world situation) that were identified to be important from the patient's perspective.

RESULTS

A total of 798 participants were recruited. Both UGFS and EVLA resulted in a significantly quicker recovery compared with surgery for 13 of the 15 behaviours assessed. UGFS was superior to EVLA in terms of return to full-time work (hazard ratio 1·43, 95 per cent c.i. 1·11 to 1·85), looking after children (1·45, 1·04 to 2·02) and walks of short (1·48, 1·19 to 1·84) and longer (1·32, 1·05 to 1·66) duration.

CONCLUSION

Both UGFS and EVLA resulted in more rapid recovery than surgery, and UGFS was superior to EVLA for one-quarter of the behaviours assessed. The BRAVVO questionnaire has the potential to provide important meaningful information to patients about their early recovery and what they may expect to be able to achieve after treatment.

Selective activation of angiotensin AT2 receptors attenuates progression of pulmonary hypertension and inhibits cardiopulmonary fibrosis

BACKGROUND AND PURPOSE

Pulmonary hypertension (PH) is a devastating disease characterized by increased pulmonary arterial pressure, which progressively leads to right-heart failure and death. A dys-regulated renin angiotensin system (RAS) has been implicated in the development and progression of PH. However, the role of the angiotensin AT2 receptor in PH has not been fully elucidated. We have taken advantage of a recently identified non-peptide AT2 receptor agonist, Compound 21 (C21), to investigate its effects on the well-established monocrotaline (MCT) rat model of PH.

EXPERIMENTAL APPROACH

A single s.c. injection of MCT (50 mg·kg(-1) ) was used to induce PH in 8-week-old male Sprague Dawley rats. After 2 weeks of MCT administration, a subset of animals began receiving either 0.03 mg·kg(-1) C21, 3 mg·kg(-1) PD-123319 or 0.5 mg·kg(-1) A779 for an additional 2 weeks, after which right ventricular haemodynamic parameters were measured and tissues were collected for gene expression and histological analyses.

KEY RESULTS

Initiation of C21 treatment significantly attenuated much of the pathophysiology associated with MCT-induced PH. Most notably, C21 reversed pulmonary fibrosis and prevented right ventricular fibrosis. These beneficial effects were associated with improvement in right heart function, decreased pulmonary vessel wall thickness, reduced pro-inflammatory cytokines and favourable modulation of the lung RAS. Conversely, co-administration of the AT2 receptor antagonist, PD-123319, or the Mas antagonist, A779, abolished the protective actions of C21.

CONCLUSIONS AND IMPLICATIONS

Taken together, our results suggest that the AT2 receptor agonist, C21, may hold promise for patients with PH.

Views of healthcare professionals to linkage of routinely collected healthcare data: a systematic literature review

Objective

To review the literature on the views of healthcare professionals to the linkage of healthcare data and to identify any potential barriers and/or facilitators to participation in a data linkage system.

Methods

Published papers describing the views of healthcare professionals (HCPs) to data sharing and linkage were identified by searches of Medline, EMBASE, SCOPUS, CINAHL, and PsychINFO. The searches were limited to papers published in the English language from 2001 to 2011.

Results

A total of 2917 titles were screened. From these, 18 papers describing the views of HCPs about data linkage or data sharing of routinely collected healthcare data at an individual patient level were included. Views were generally positive, and potential benefits were reported. Facilitators included having trust in the system including data governance, reliability, and feedback. Some negative views, identified as barriers were also expressed including costs, data governance, technical issues, and privacy concerns. Effects on the physician–patient relationship, and workload were also identified as deterrent.

Discussion

From the published literature included in this review, the views of HCPs were in general positive towards data sharing for public health purposes. The identification of barriers to contributing to a data linkage system allows these to be addressed in a planned data linkage project for pharmacovigilance. The main barriers identified were concerns about costs, governance and interference with the prescriber–patient relationship. These would have to be addressed if healthcare professionals are to support a data linkage system to improve patient safety.

Patterns of chemotherapy treatment for women with invasive epithelial ovarian cancer--a population-based study

OBJECTIVE

Ovarian cancer five-year survival is poor at <40%. In the absence of effective screening or new treatments, ensuring all women receive optimal treatment is one avenue to improve survival. There is little population-based information regarding the primary chemotherapy treatment that women with epithelial ovarian cancer receive. This information is essential to identify potential gaps in care.

METHODS

Cancer registries identified all women diagnosed with invasive epithelial ovarian cancer in Australia in 2005 (n=1192). Histopathology, chemotherapy and comorbidity information was abstracted from medical records. Multivariable logistic regression was used to identify factors associated with chemotherapy commencement, regimen, and completion.

RESULTS

Women >70 years (p<0.0001), those with high-grade, stage IA/IB cancers (vs. stages IC-IV, p=0.003) and those with mucinous cancers (p=0.0002) were less likely to start chemotherapy. Most treated women received platinum-based drugs (97%), but only 68% received combination carboplatin-paclitaxel and only half completed six cycles without treatment modification/delay. Approximately 19% received single-agent carboplatin: mostly those aged >70 (p<0.0001) and/or with co-morbidities (p<0.0001). Age was the strongest predictor of completing six cycles of combination therapy.

CONCLUSIONS

For specific patient groups, particularly older women, there is notable variation from standard treatment. Understanding how treatment variations affect survival and determining optimal regimens for these groups are research priorities.