Pulse oximetry as a screening test for congenital heart defects in newborn infants: a test accuracy study with evaluation of acceptability and cost-effectiveness

Background: Screening for congenital heart defects (CHDs) relies on antenatal ultrasound and postnatal clinical examination; however, life-threatening defects often go undetected. Objective: To determine the accuracy, acceptability and cost-effectiveness of pulse oximetry as a screening test for CHDs in newborn infants. Design: A test accuracy study determined the accuracy of pulse oximetry. Acceptability of testing to parents was evaluated through a questionnaire, and to staff through focus groups. A decision-analytic model was constructed to assess cost-effectiveness. Setting: Six UK maternity units. Participants: These were 20,055 asymptomatic newborns at = 35 weeks’ gestation, their mothers and health-care staff. Interventions: Pulse oximetry was performed prior to discharge from hospital and the results of this index test were compared with a composite reference standard (echocardiography, clinical follow-up and follow-up through interrogation of clinical databases). Main outcome measures: Detection of major CHDs – defined as causing death or requiring invasive intervention up to 12 months of age (subdivided into critical CHDs causing death or intervention before 28 days, and serious CHDs causing death or intervention between 1 and 12 months of age); acceptability of testing to parents and staff; and the cost-effectiveness in terms of cost per timely diagnosis. Results: Fifty-three of the 20,055 babies screened had a major CHD (24 critical and 29 serious), a prevalence of 2.6 per 1000 live births. Pulse oximetry had a sensitivity of 75.0% [95% confidence interval (CI) 53.3% to 90.2%] for critical cases and 49.1% (95% CI 35.1% to 63.2%) for all major CHDs. When 23 cases were excluded, in which a CHD was already suspected following antenatal ultrasound, pulse oximetry had a sensitivity of 58.3% (95% CI 27.7% to 84.8%) for critical cases (12 babies) and 28.6% (95% CI 14.6% to 46.3%) for all major CHDs (35 babies). False-positive (FP) results occurred in 1 in 119 babies (0.84%) without major CHDs (specificity 99.2%, 95% CI 99.0% to 99.3%). However, of the 169 FPs, there were six cases of significant but not major CHDs and 40 cases of respiratory or infective illness requiring medical intervention. The prevalence of major CHDs in babies with normal pulse oximetry was 1.4 (95% CI 0.9 to 2.0) per 1000 live births, as 27 babies with major CHDs (6 critical and 21 serious) were missed. Parent and staff participants were predominantly satisfied with screening, perceiving it as an important test to detect ill babies. There was no evidence that mothers given FP results were more anxious after participating than those given true-negative results, although they were less satisfied with the test. White British/Irish mothers were more likely to participate in the study, and were less anxious and more satisfied than those of other ethnicities. The incremental cost-effectiveness ratio of pulse oximetry plus clinical examination compared with examination alone is approximately £24,900 per timely diagnosis in a population in which antenatal screening for CHDs already exists. Conclusions: Pulse oximetry is a simple, safe, feasible test that is acceptable to parents and staff and adds value to existing screening. It is likely to identify cases of critical CHDs that would otherwise go undetected. It is also likely to be cost-effective given current acceptable thresholds. The detection of other pathologies, such as significant CHDs and respiratory and infective illnesses, is an additional advantage. Other pulse oximetry techniques, such as perfusion index, may enhance detection of aortic obstructive lesions.

The development and investigation of a novel pulsatile heart assist device

Cardiovascular diseases (CVD) contributed to almost 30% of worldwide mortality; with heart failure being one class of CVD. One popular and widely available treatment for heart failure is the intra-aortic balloon pump (IABP). This heart assist device is used in counterpulsation to improve myocardial function by increasing coronary perfusion, and decreasing aortic end-diastolic pressure (i.e. the resistance to blood ejection from the heart). However, this device can only be used acutely, and patients are bedridden. The subject of this research is a novel heart assist treatment called the Chronic Intermittent Mechanical Support (CIMS) which was conceived to offer advantages of the IABP device chronically, whilst overcoming its disadvantages. The CIMS device comprises an implantable balloon pump, a percutaneous drive line, and a wearable driver console. The research here aims to determine the haemodynamic effect of balloon pump activation under in vitro conditions. A human mock circulatory loop (MCL) with systemic and coronary perfusion was constructed, capable of simulating various degrees of heart failure. Two prototypes of the CIMS balloon pump were made with varying stiffness. Several experimental factors (balloon inflation/deflation timing, Helium gas volume, arterial compliance, balloon pump stiffness and heart valve type) form the factorial design experiments. A simple modification to the MCL allowed flow visualisation experiments using video recording. Suitable statistical tests were used to analyse the data obtained from all experiments. Balloon inflation and deflation in the ascending aorta of the MCL yielded favourable results. The sudden balloon deflation caused the heart valve to open earlier, thus causing longer valve opening duration in a cardiac cycle. It was also found that pressure augmentation in diastole was significantly correlated with increased cardiac output and coronary flowrate. With an optimum combination (low arterial compliance and low balloon pump stiffness), systemic and coronary perfusions were increased by 18% and 21% respectively, while the aortic end-diastolic pressure (forward flow resistance) decreased by 17%. Consequently, the ratio of oxygen supply and demand to myocardium (endocardial viability ratio, EVR) increased between 33% and 75%. The increase was mostly attributed to diastolic augmentation rather than systolic unloading.

Effectiveness and uptake of screening programmes for coronary heart disease and diabetes:a realist review of design components used in interventions

Objective - To evaluate behavioural components and strategies associated with increased uptake and effectiveness of screening for coronary heart disease and diabetes with an implementation science focus. Design - Realist review. Data sources - PubMed, Web of Knowledge, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register and reference chaining. Searches limited to English language studies published since 1990. Eligibility criteria - Eligible studies evaluated interventions designed to increase the uptake of cardiovascular disease (CVD) and diabetes screening and examined behavioural and/or strategic designs. Studies were excluded if they evaluated changes in risk factors or cost-effectiveness only. Results - In 12 eligible studies, several different intervention designs and evidence-based strategies were evaluated. Salient themes were effects of feedback on behaviour change or benefits of health dialogues over simple feedback. Studies provide mixed evidence about the benefits of these intervention constituents, which are suggested to be situation and design specific, broadly supporting their use, but highlighting concerns about the fidelity of intervention delivery, raising implementation science issues. Three studies examined the effects of informed choice or loss versus gain frame invitations, finding no effect on screening uptake but highlighting opportunistic screening as being more successful for recruiting higher CVD and diabetes risk patients than an invitation letter, with no differences in outcomes once recruited. Two studies examined differences between attenders and non-attenders, finding higher risk factors among non-attenders and higher diagnosed CVD and diabetes among those who later dropped out of longitudinal studies. Conclusions - If the risk and prevalence of these diseases are to be reduced, interventions must take into account what we know about effective health behaviour change mechanisms, monitor delivery by trained professionals and examine the possibility of tailoring programmes according to contexts such as risk level to reach those most in need. Further research is needed to determine the best strategies for lifelong approaches to screening.

Blastocyst environment and its influence on offspring cardiovascular health:the heart of the matter

The development of adult-onset diseases such as type II diabetes, obesity and cardiovascular disease is traditionally attributed to adult lifestyle characteristics such as a lack of physical exercise, poor diet and smoking. However, evidence from both human and animal model studies has demonstrated that environmental factors such as an imbalance or reduction in maternal nutrition during gestation can have adverse effects on offspring metabolism and cardiovascular health. The severity and nature of the phenotypic changes induced in offspring is influenced by the period of gestation manipulated. In particular, the mammalian preimplantation embryo in different animal models displays particular sensitivity to environmental factors, either in vivo (maternal diet) or in vitro (embryo culture) that is associated with the onset of cardiovascular dysfunction in adult life. The detailed mechanisms by which environmental conditions can alter postnatal cardiovascular physiology are poorly understood. However, various factors including endothelial function, vascular responsiveness, the renin-angiotensin system, kidney structure and early postnatal growth dynamics have all been recognize as potential contributors. Here, we review the relationship between preimplantation embryo environment and postnatal cardiovascular disease risk, and consider biochemical, molecular, genetic and physiological pathways implicated in this association. © 2009 The Authors Journal compilation © 2009 Anatomical Society of Great Britain and Ireland.

Use of Google as a tool to aid diagnosis by optometry students

Background: Previous work has shown that medical problems can be diagnosed by practitioners using Google. The aim of this study was to determine whether optometry students would benefit from using Google when diagnosing eye diseases. Methods: Participants were given symptoms and signs and instructed to list three key words and use them to search Aston University e-Library and Google UK. Results: Aston University e-Library only search resulted in correct diagnosis in 16 of 60 simulated cases. Aston e-Library plus Google search resulted in correct diagnosis in 31 of 60 simulated cases. Conclusion: Google is a useful aid to help optometry students improve their success rate when diagnosing eye conditions.

HIV, cardiovascular diseases, and chronic arsenic exposure co-exist in a positive synergy

Recent epidemiological evidences indicate that arsenic exposure increases risk of atherosclerosis, cardio vascular diseases (CVD) such as hypertension, atherosclerosis, coronary artery disease (CAD) and microangiopathies in addition to the serious global health concern related to its carcinogenic effects. In experiments on animals, acute and chronic exposure to arsenic directly correlates with cardiac tachyarrhythmia, and atherogenesis in a concentration and duration dependent manner. Moreover, the other effects of long-term arsenic exposure include induction of non-insulin dependent diabetes by mechanisms yet to be understood. On the other hand, there are controversial issues, gaps in knowledge, and future research priorities in accelerated incidences of CVD and mortalities in patients with HIV who are under long-termanti-retroviral therapy (ART). Although, both HIV infection itself and various components of ART initiate significant pathological alterations in the myocardium and the vasculature, simultaneous environmental exposure to arsenic which is more convincingly being recognized as a facilitator of HIV viral cycling in the infected immune cells, may contribute an additional layer of adversity in these patients. A high degree of suspicion and early screening may allow appropriate interventional guidelines to improve the quality of lives of those affected. In this mini-review which have been fortified with our own preliminary data, we will discuss some of the key current understating of chronic arsenic exposure, and its possible impact on the accelerated HIV/ART induced CVD. The review will conclude with notes on recent developments in mathematical modeling in this field that probabilistically forecast incidence prevalence as functions of aging and life style parameters, most of which vary with time themselves; this interdisciplinary approach provides a complementary kernel to conventional biology.

Preimplantation genetic diagnosis: Analysis of gene expression, nuclear DNA and cytoplasmic DNA

Preimplantation genetic diagnosis (PGD) following in vitro fertilization (IVF) offers couples at risk for transmitting genetic disorders the opportunity to identify affected embryos prior to replacement. In particular, embryo gender determination permits screening for X-linked diseases of unknown etiology. Analysis of embryos can be performed by polymerase chain reaction (PCR) amplification of material obtained by micromanipulation. This approach provides an alternative to the termination of an established pregnancy following chorionic villi sampling or amniocentesis. ^ Lately, the focus of preimplantation diagnosis and intervention has been shifting toward an attempt to correct cytoplasmic deficiencies. Accordingly, it is the aim of this investigation to develop methods to permit the examination of single cells or components thereof for clinical evaluation. In an attempt to lay the groundwork for precise therapeutic intervention for age related aneuploidy, transcripts encoding proteins believed to be involved in the proper segregation of chromosomes during human oocyte maturation were examined and quantified. Following fluorescent rapid cycle RT-PCR analysis it was determined that the concentration of cell cycle checkpoint gene transcripts decreases significantly as maternal age increases. Given the well established link between increasing maternal age and the incidence of aneuploidy, these results suggest that the degradation of these messages in aging oocytes may be involved with inappropriate chromosome separation during meiosis. ^ In order to investigate the cause of embryonic rescue observed following clinical cytoplasmic transfer procedures and with the objective of developing a diagnostic tool, mtDNA concentrations in polar bodies and subcellular components were evaluated. First, the typical concentration of mtDNA in human and mouse oocytes was determined by fluorescent rapid cycle PCR. Some disparity was noted between the copy numbers of individual cytoplasmic samples which may limit the use of the current methodology for the clinical assessment of the corresponding oocyte. ^

Explaining the increase in coronary heart disease mortality in Syria between 1996 and 2006

Background Despite advances made in treating coronary heart disease (CHD), mortality due to CHD in Syria has been increasing for the past two decades. This study aims to assess CHD mortality trends in Syria between 1996 and 2006 and to investigate the main factors associated with them. Methods The IMPACT model was used to analyze CHD mortality trends in Syria based on numbers of CHD patients, utilization of specific treatments, trends in major cardiovascular risk factors in apparently healthy persons and CHD patients. Data sources for the IMPACT model included official statistics, published and unpublished surveys, data from neighboring countries, expert opinions, and randomized trials and meta-analyses. Results Between 1996 and 2006, CHD mortality rate in Syria increased by 64%, which translates into 6370 excess CHD deaths in 2006 as compared to the number expected had the 1996 baseline rate held constant. Using the IMPACT model, it was estimated that increases in cardiovascular risk factors could explain approximately 5140 (81%) of the CHD deaths, while some 2145 deaths were prevented or postponed by medical and surgical treatments for CHD. Conclusion Most of the recent increase in CHD mortality in Syria is attributable to increases in major cardiovascular risk factors. Treatments for CHD were able to prevent about a quarter of excess CHD deaths, despite suboptimal implementation. These findings stress the importance of population-based primary prevention strategies targeting major risk factors for CHD, as well as policies aimed at improving access and adherence to modern treatments of CHD.

Validity of the portable piko-6 spirometer used for screening obstructive airway diseases in community pharmacy practice

Background: Obstructive airway diseases (OADs) are among the leading causes of morbidity and mortality worldwide. Shortness of breath (SOB) is the main symptom associated with OADs. International guidelines from the Global Initiative for Chronic Lung Disease (GOLD) and the Global Initiative for Asthma (GINA) have recommended spirometry as an indispensable tool for the diagnosis of asthma and chronic obstructive pulmonary diseases (COPD), but spirometry is rarely used in family practice. Simple and reliable diagnostic tools are necessary for screening community patients with onset of OADs for timely management. Purpose: This thesis examined screening utility of the PiKo-6 forced expiratory volume in one second (pFEV₁) , in six second (pFEV₆), and the pRatio ( pFEV₁/pFEV₆) in SOB patients for OADs in community pharmacy settings. FEV₆ has recently been suggested an excellent surrogate for Forced Vital Capacity (FVC), which requires maximum exhalation of the lungs. Methods: Patients with SOB symptoms who were prescribed pulmonary inhalers, by their family physicians, were recruited via community pharmacies. Trained pharmacists collected two PiKo-6 tests to assess the repeatability of the PiKo-6 device. All patients performed laboratory spirometry ( FEV₁, FVC and FEV₁/FVC) to obtain physician diagnosis of their OADs. The results of the PiKo-6 spirometer and laboratory spirometer were compared. In addition, the PiKo-6 pRatio and laboratory FEV₁/FVC were assessed against physician diagnosed COPD. Results: Sixty three patients volunteered to perform the PiKo-6 spirometry. Of these, 52.4 % were men (age 53.9 ± 15.3 years; BMI 31.9 ± 7.40 kg/m2). Repeated testing with pFEV₁, pFEV6 and pRatio correlated significantly (within correlation, r = 0.835, p-Value≤ 0.05 ; 0.872, p- Value≤ 0.05; and 0.664, p-Value≤ 0.05). In addition, pFEV₁, pFEV6 and pRatio correlated significantly with FEV₁, FVC and FEV₁/FVC, respectively (between correlation = 0.630, p- Value≤ 0.05 ; 0.660, p-Value≤ 0.05 and 0.580, p-Value≤ 0.05). The cut-off value corresponding to the greatest sum of sensitivity and specificity of pRatio for physician-diagnosed COPD was <0.80, the sensitivity and specificity were 84 % and 50%, respectively. Conclusions The portable PiKo-6 correlates moderately well with the standard spirometry, when delivered by community pharmacists to patients with OADs. The PiKo-6 spirometer may play a role in screening patients suspected of having an OAD in community pharmacies that may benefit from early physician diagnosis and appropriate management.

The Effect of Selective Heart Rate Slowing in Heart Failure with Preserved Ejection Fraction

Acknowledgments Dr Ashrafian acknowledges support from the BHF Center of Research Excellence, Oxford, UK. The research was also supported by the National Institute for Health Research Oxford Biomedical Research Center Program and by the National Institute for Health Research Rare Diseases Translational Research Collaboration (NIHR RD-TRC)

The Effect of Selective Heart Rate Slowing in Heart Failure with Preserved Ejection Fraction

Acknowledgments Dr Ashrafian acknowledges support from the BHF Center of Research Excellence, Oxford, UK. The research was also supported by the National Institute for Health Research Oxford Biomedical Research Center Program and by the National Institute for Health Research Rare Diseases Translational Research Collaboration (NIHR RD-TRC)

Habitual chocolate consumption and the risk of incident heart failure among healthy men and women

Acknowledgments The authors would like to thank the participants of the EPIC-Norfolk cohort. We thank the nutritionist team and data management team of the EPIC-Norfolk cohort. The EPIC-Norfolk study was supported by grants from the Medical Research Council and Cancer Research UK. Funders had no role in study design or interpretation of the findings.

Habitual chocolate consumption and the risk of incident heart failure among healthy men and women

Acknowledgments The authors would like to thank the participants of the EPIC-Norfolk cohort. We thank the nutritionist team and data management team of the EPIC-Norfolk cohort. The EPIC-Norfolk study was supported by grants from the Medical Research Council and Cancer Research UK. Funders had no role in study design or interpretation of the findings.

Les mécanismes sous-jacents aux effets pathologiques cardiaques de l’angiotensine II dans le remodelage électrique et contractile entre les sexes

L’insuffisance cardiaque (IC) est associée à un taux de mortalité et d’hospitalisations élevé causant un fardeau économique important. Les deux causes majeures de décès de l’IC sont les arythmies ventriculaires létales et les sidérations myocardiques. Il est maintenant reconnu que l’angiotensine II (ANGII) est l'un des principaux médiateurs de l’IC. Ses effets délétères découlent de l’activation du récepteur de type 1 de l’ANGII (AT1) et entraînent le développement d’hypertrophie. Toutefois, son rôle dans la genèse d’arythmies demeure incompris. De ce fait, l'étude des mécanismes électriques et contractiles sous-jacents aux effets pathologiques de l’ANGII s’avère essentielle afin de mieux comprendre et soigner cette pathologie. Il est souvent perçu que les femmes sont protégées envers les maladies cardiovasculaires. Cependant, le nombre total de femmes décédant d’IC est plus grand que le nombre d’hommes. Également, l’impact des facteurs de risque diffère entre chaque sexe. Ces différences existent, mais les mécanismes sous-jacents sont encore peu connus. De plus, les femmes reçoivent fréquemment un diagnostic ou un traitement inapproprié en raison d’un manque d’information sur les différences entre les sexes dans la manifestation d’une pathologie. Ce manque de données peut découler du fait que les sujets de sexe féminin sont souvent sous-représentés dans les essais cliniques ou la recherche fondamentale ce qui a grandement limité l’avancement de nos connaissances sur ~50 % de la population. Ainsi, il semble plus que nécessaire d’approfondir notre compréhension des différences entre les sexes, notamment dans la progression de l’IC. L’utilisation d’un modèle de souris transgénique surexprimant le récepteur AT1 (souris AT1R) a permis d’étudier les changements électriques, structurels et contractiles avant et après le développement d’hypertrophie. Premièrement, chez les souris AT1R mâles, un ralentissement de la conduction ventriculaire a été observé indépendamment de l’hypertrophie. Ce résultat était expliqué par une réduction de la densité du courant Na+, mais pas de l’expression du canal. Ensuite, le rôle des protéines kinases C (PKC) dans la régulation du canal Na+ par l’ANGII a été exploré. Les évidences ont suggéré que la PKCα était responsable de la modulation de la diminution du courant Na+ chez les souris AT1R mâles et dans les cardiomyocytes humains dérivés de cellules souches induites pluripotentes (hiPSC-CM) en réponse à un traitement chronique à l’ANGII. Ensuite, les différences entre les sexes ont été comparées chez la souris AT1R. Une plus grande mortalité a été constatée chez les femelles AT1R suggérant qu’elles sont plus sensibles à la surexpression de AT1R. Le remodelage électrique ventriculaire a donc été comparé entre les souris AT1R des deux sexes. Les courants ioniques étaient altérés de façon similaire entre les sexes excluant ainsi leur implication dans la mortalité plus élevée chez les femelles. Ensuite, l’homéostasie calcique et la fonction cardiaque ont été étudiées. Il a été démontré que les femelles développaient une hypertrophie et une dilatation ventriculaire plus sévère que les mâles. De plus, les femelles AT1R avaient de petits transitoires calciques, une extrusion du Ca2+ plus lente ainsi qu’une augmentation de la fréquence des étincelles Ca2+ pouvant participer à des troubles contractiles et à la venue de post-dépolarisations précoces. En conclusion, l’ANGII est impliquée dans le remodelage électrique, structurel et calcique associé à l'émergence de l’IC. De surcroît, ces altérations affectent plus sévèrement les femelles soulignant la présence de différences entre les sexes dans le développement de l’IC.

Patient perspectives of a diagnosis of myeloproliferative neoplasm in a case control study

Background: Myeloproliferative neoplasms (MPNs) including the classic entities; polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis are rare diseases with unknown aetiology. The MOSAICC study, is an exploratory case–control study in which information was collected through telephone questionnaires and medical records. Methods: As part of the study, 106 patients with MPN were asked about their perceived diagnosis and replies correlated with their haematologist’s diagnosis. For the first time, a patient perspective on their MPN diagnosis and classification was obtained. Logistic regression analyses were utilised to evaluate the role of variables in whether or not a patient reported their diagnosis during interview with co-adjustment for these variables. Chi square tests were used to investigate the association between MPN subtype and patient reported categorisation of MPN. Results: Overall, 77.4 % of patients reported a diagnosis of MPN. Of those, 39.6 % recognised MPN as a ‘blood condition’,23.6 % recognised MPN as a ‘cancer’ and 13.2 % acknowledged MPN as an ‘other medical condition’. There was minimal overlap between the categories. Patients with PV were more likely than those with ET to report their disease as a ‘blood condition’. ET patients were significantly more likely than PV patients not to report their condition at all.Patients from a single centre were more likely to report their diagnosis as MPN while age, educational status, and WHO re-classification had no effect. Conclusions: The discrepancy between concepts of MPN in patients could result from differing patient interest in their condition, varying information conveyed by treating hematologists, concealment due to denial or financial concerns. Explanations for the differences in patient perception of the nature of their disease, requires further, larger scale investigation.