Quantifying long-term improvements in exercise capacity after cardiac transplantation

Introduction

Cardiac transplantation (CT) is known to improve exercise capacity in patients with advanced heart failure (HF). However, it is unclear whether continued improvements occur after the initial post-operative recovery and whether baseline demographic and disease-related factors influence this improvement.

Purpose

We aimed to quantify the degree of improvement in exercise capacity over time in CT recipients and establish whether baseline characteristics influenced this improvement.

Methods

Retrospective review of the medical records of patients who underwent CT at a single centre was performed. Cardiopulmonary exercise (CPEX) testing is routinely offered pre-CT and at 3, 6, 9, 12, 24, 36 and 48 months post-CT, unless there are contraindications. Baseline demographic and clinical characteristics pre-CT were also collected.

Results

A total of 199 patients underwent CT, of which 138 (69%) were male. The mean age was 44 (SD 14.0) years and mean pre-CT body mass index (BMI) was 25.3 (SD 4.2). In 125 (63%) patients, the underlying aetiology of HF was dilated cardiomyopathy (DCM). 32 (16%) patients had a durable left ventricular assist device (LVAD) as a bridge to CT.

Pre-transplant CPEX was undertaken in 131 (66%) patients, with a mean peak VO2 of 15.5 (SD 6.2) ml/kg/min. Peak VO2 was higher in males (16.6; SD 6.7 vs 13.1; SD 4.0, p=0.002) and those under 50 years old (16.8; 7.2 vs 13.8; 3.9, p=0.005) but was not affected by the underlying aetiology (DCM vs others: 16.3, 6.6 vs 14.1, 5.1, p=0.051), the presence of an LVAD (17.3, 5.0 vs 15.1, 6.3, p=0.119) or pre-transplant obesity (14.5, 3.2 vs 15.7, 6.5, p=0.437).

Peak VO2 increased within the first year post-CT (Figure 1 and 2). Ongoing improvements were also observed beyond the 1-year time-point, although only the 3-year vs 1-year comparison remained significantly when corrected for multiple comparisons. When analysed with mixed models, time post-CT was a significant predictor of peak VO2 (p=0.001). Additionally, there was a significant interaction between peak VO2 over time with gender (p=0.038), but not with age under 50 years (p=0.244), underlying aetiology being DCM (p=0.05), a previous LVAD (p=0.664) and pre-transplant obesity (p=0.301). Post-hoc analysis showed that males had a greater mean improvement than females in peak VO2 at 1-year compared to pre-CT (7.7, SD 5.5 vs 4.8, SD 4.0 ml/kg/min).

Conclusions

These results demonstrate that exercise capacity improves up to and beyond the first year post-CT. The degree of improvement may be greater in males, although it is not influenced by age, BMI, underlying disease aetiology or the presence of an LVAD pre-CT.

Funding Acknowledgement

Type of funding sources: None.

Standardising clinical outcomes measures for adult clinical trials in Fabry disease: A global Delphi consensus

BACKGROUND

Recent years have witnessed a considerable increase in clinical trials of new investigational agents for Fabry disease (FD). Several trials investigating different agents are currently in progress; however, lack of standardisation results in challenges to interpretation and comparison. To facilitate the standardisation of investigational programs, we have developed a common framework for future clinical trials in FD.

METHODS AND FINDINGS

A broad consensus regarding clinical outcomes and ways to measure them was obtained via the Delphi methodology. 35 FD clinical experts from 4 continents, representing 3389 FD patients, participated in 3 rounds of Delphi procedure. The aim was to reach a consensus regarding clinical trial design, best treatment comparator, clinical outcomes, measurement of those clinical outcomes and inclusion and exclusion criteria. Consensus results of this initiative included: the selection of the adaptative clinical trial as the ideal study design and agalsidase beta as ideal comparator treatment due to its longstanding use in FD. Renal and cardiac outcomes, such as glomerular filtration rate, proteinuria and left ventricular mass index, were prioritised, whereas neurological outcomes including cerebrovascular and white matter lesions were dismissed as a primary or secondary outcome measure. Besides, there was a consensus regarding the importance of patient-related outcomes such as general quality of life, pain, and gastrointestinal symptoms. Also, unity about lysoGb3 and Gb3 tissue deposits as useful surrogate markers of the disease was obtained. The group recognised that cardiac T1 mapping still has potential but requires further development before its widespread introduction in clinical trials. Finally, patients with end-stage renal disease or renal transplant should be excluded unless a particular group for them is created inside the clinical trial.

CONCLUSION

This consensus will help to shape the future of clinical trials in FD. We note that the FDA has, coincidentally, recently published draft guidelines on clinical trials in FD and welcome this contribution.

Investigation of Cardiovascular Health and Risk Factors Among the Diverse and Contemporary Population in London (the TOGETHER Study): Protocol for Linking Longitudinal Medical Records

Background

Global trends in cardiovascular disease (CVD) exhibit considerable interregional and interethnic differences, which in turn affect long-term CVD risk across diverse populations. An in-depth understanding of the interplay between ethnicity, socioeconomic status, and CVD risk factors and mortality in a contemporaneous population is crucial to informing health policy and resource allocation aimed at mitigating long-term CVD risk. Generating bespoke large-scale and reliable data with sufficient numbers of events is expensive and time-consuming but can be circumvented through utilization and linkage of data routinely collected in electronic health records (EHR).

Objective

We aimed to characterize the burden of CVD risk factors across different ethnicities, age groups, and socioeconomic groups, and study CVD incidence and mortality by EHR linkage in London.

Methods

The proposed study will initially be a cross-sectional observational study unfolding into prospective CVD ascertainment through longitudinal follow-up involving linked data. The government-funded National Health System (NHS) Health Check program provides an opportunity for the systematic collation of CVD risk factors on a large scale. NHS Health Check data on approximately 200,000 individuals will be extracted from consenting general practices across London that use the Egton Medical Information Systems (EMIS) EHR software. Data will be analyzed using appropriate statistical techniques to (1) determine the cross-sectional burden of CVD risk factors and their prospective association with CVD outcomes, (2) validate existing prediction tools in diverse populations, and (3) develop bespoke risk prediction tools across diverse ethnic groups.

Results

Enrollment began in January 2019 and is ongoing with initial results to be published mid-2021.

Conclusions

There is an urgent need for more real-life population health studies based on analyses of routine health data available in EHRs. Findings from our study will help quantify, on a large scale, the contemporaneous burden of CVD risk factors by geography and ethnicity in a large multiethnic urban population. Such detailed understanding (especially interethnic and sociodemographic variations) of the burden of CVD risk and its determinants, including heredity, environment, diet, lifestyle, and socioeconomic factors, in a large population sample, will enable the development of tailored and dynamic (continuously learning from new data) risk prediction tools for diverse ethnic groups, and thereby enable the personalized provision of prevention strategies and care. We anticipate that this systematic approach of linking routinely collected data from EHRs to study CVD can be conducted in other settings as EHRs are being implemented worldwide.

International Registered Report Identifier (IRRID)

PRR1-10.2196/17548

Cardiovascular Remodeling Experienced by Real-World, Unsupervised, Young Novice Marathon Runners

Aims

Marathon running is a popular ambition in modern societies inclusive of non-athletes. Previous studies have highlighted concerning transient myocardial dysfunction and biomarker release immediately after the race. Whether this method of increasing physical activity is beneficial or harmful remains a matter of debate. We examine in detail the real-world cardiovascular remodeling response following competition in a first marathon.

Methods

Sixty-eight novice marathon runners (36 men and 32 women) aged 30 ± 3 years were investigated 6 months before and 2 weeks after the 2016 London Marathon race in a prospective observational study. Evaluation included electrocardiography, cardiopulmonary exercise testing, echocardiography, and cardiovascular magnetic resonance imaging.

Results

After 17 weeks unsupervised marathon training, runners revealed a symmetrical, eccentric remodeling response with 3-5% increases in left and right ventricular cavity sizes, respectively. Blood pressure (BP) fell by 4/2 mmHg (P < 0.01) with reduction in arterial stiffness, despite only 11% demonstrating a clinically meaningful improvement in peak oxygen consumption with an overall non-significant 0.4 ml/min/kg increase in peak oxygen consumption (P = 0.14).

Conclusion

In the absence of supervised training, exercise-induced cardiovascular remodeling in real-world novice marathon runners is more modest than previously described and occurs even without improvement in cardiorespiratory fitness. The responses are similar in men and women, who experience a beneficial BP reduction and no evidence of myocardial fibrosis or persistent edema, when achieving average finishing times.

The yield of postmortem genetic testing in sudden death cases with structural findings at autopsy

Sudden cardiac death (SCD) is often associated with structural abnormalities of the heart during autopsy. This study sought to compare the diagnostic yield of postmortem genetic testing in (1) cases with structural findings of uncertain significance at autopsy to (2) cases with autopsy findings diagnostic of cardiomyopathy. We evaluated 57 SCD cases with structural findings at cardiac autopsy. Next-generation sequencing using a panel of 77 primary electrical disorder and cardiomyopathy genes was performed. Pathogenic and likely pathogenic variants were classified using American College of Medical Genetics (ACMG) consensus guidelines. In 29 cases (51%) autopsy findings of uncertain significance were identified whereas in 28 cases (49%) a diagnosis of cardiomyopathy was established. We identified a pathogenic or likely pathogenic variant in 10 cases (18%); in 1 (3%) case with non-specific autopsy findings compared with 9 (32%) cases with autopsy findings diagnostic of cardiomyopathy (p = 0.0054). The yield of genetic testing in SCD cases with autopsy findings consistent with cardiomyopathy is comparable with the yield in cardiomyopathy patients that are alive. Genetic testing in cases with findings of uncertain significance offers lower clinical utility than in cardiomyopathy, with lower yields than detected previously. This highlights the need for stringent evaluation of variant pathogenicity.

Farmers’ health and wellbeing in the context of changing farming practice: a qualitative study

Background

Farming continues to change globally, with steady industrialization, globalization and climate change and disproportionately high reports of stress and suicide. Little research has been done to understand how changes to farming impact mental health. We aimed to understand how Canadian farmers understand their stressors and experience their health.

Methods

We recruited 16 small-medium scale, diversified farmers through farm organizations in Grey-Bruce counties in Canada. We interviewed them about their perception of changes in farming, associated stressors, mental health and well-being, and community supports. Using a constructivist paradigm, we coded each interview, discussed results, and formulated emergent themes using thematic analysis.

Results

Farmers’ relationship to change was complex with both benefits and challenges of changing farm practices, technology and weather for health - a “double-edged sword”. Farmers described the resilience associated with farming which connects them to the land “essentially being at one with place.” Farmers’ work required them to be active, an asset for keeping them healthy, but also a challenge if mobility became restricted. Farmers’ noted overwhelming stress but stated “...the last thing most farmers want to do is admit that they are stressed or have a mental health issue.” Yet “...if you don’t have strong mental health then you can’t really be resilient and cope with the stresses of climate change and all the things that will happen on a farm.” They voiced a perceived lack of support from governments - dealing with bureaucracy, community - experience of isolation or stigma, and health services - an over-stretched, often distant system.

Conclusions

Farmers’ understandings from Canada will be compared to literature from Europe to demonstrate relevance inform public health programs promoting mental health in rural communities, advocacy for government supports to diversified farmers and evaluation of intervention programs.

Key messages

Farmers experience change as a double edged sword with benefits and challenges for health and mental health. Public health needs to intervene to meet farmers where they are and to advocate with farmers for further support.

The Diagnostic Yield of Brugada Syndrome After Sudden Death With Normal Autopsy

BACKGROUND

Familial evaluation after a sudden death with negative autopsy (sudden arrhythmic death syndrome; SADS) may identify relatives at risk of fatal arrhythmias.

OBJECTIVES

This study aimed to assess the impact of systematic ajmaline provocation testing using high right precordial leads (RPLs) on the diagnostic yield of Brugada syndrome (BrS) in a large cohort of SADS families.

METHODS

Three hundred three SADS families (911 relatives) underwent evaluation with resting electrocardiogram using conventional and high RPLs, echocardiography, exercise, and 24-h electrocardiogram monitor. An ajmaline test with conventional and high RPLs was undertaken in 670 (74%) relatives without a familial diagnosis after initial evaluation. Further investigations were guided by clinical suspicion.

RESULTS

An inherited cardiac disease was diagnosed in 128 (42%) families and 201 (22%) relatives. BrS was the most prevalent diagnosis (n = 85, 28% of families; n = 140, 15% of relatives). Ajmaline testing was required to unmask the BrS in 97% of diagnosed individuals. The use of high RPLs showed a 16% incremental diagnostic yield of ajmaline testing by diagnosing BrS in an additional 49 families. There were no differences of the characteristics between individuals and families with a diagnostic pattern in the conventional and the high RPLs. On follow-up, a spontaneous type 1 Brugada pattern and/or clinically significant arrhythmic events developed in 17% (n = 25) of the concealed BrS cohort.

CONCLUSIONS

Systematic use of ajmaline testing with high RPLs increases substantially the yield of BrS in SADS families. Assessment should be performed in expert centers where patients are counseled appropriately for the potential implications of provocation testing.

Total, methyl and inorganic mercury concentrations in blood and environmental exposure sources in newcomer women in Toronto, Canada

Measurements of total blood Hg (tHg), often used as a proxy for methyl Hg (MeHg) concentrations, are most commonly the focus of population-based studies. Data on Hg species in biomarkers can allow for a more nuanced characterization of environmental exposure sources and risk but their availability is limited, especially for newcomer populations. The purpose of the Metals in Newcomer Women (MNW) study was to address existing data gaps on metal concentrations and exposure sources in newcomer women (19-45 years) and to examine tHg, MeHg and inorganic Hg (iHg) in the blood of East and South Asian women recently arrived to Toronto. Study participants were recruited in 2015 (n = 211). Total Hg concentrations were determined using both ICP-Q-MS and isotope dilution (ID)-SPME-GC-ICP-MS. A sample subset (n = 76) was chosen for the analysis of blood MeHg and iHg concentrations (also using ID-SPME-GC-ICP-MS). Hierarchical regression models were used to assess associations between blood tHg concentrations and environmental exposure factors for MNW participants. For the sample subset, a log-linear model was used to examine associations between blood iHg and MeHg concentrations and fish consumption patterns. The geometric mean (GM) blood tHg concentration was 1.05 µg/L (95% CI: 0.88-1.25), which was elevated compared to Canadian-born women (GM: 0.57 µg/L; 95% CI: 0.49-0.66), in a specialized data analysis of the Canadian Health Measures Survey (CHMS). GM concentrations for iHg and MeHg were 0.21 µg/L (95% CI: 0.16-0.28) and 2.66 µg/L (95% CI: 2.00-3.55), respectively. Significant distal determinants associated with blood tHg concentrations were: level of educational attainment, having lived in a coastal/fishing community prior to arrival, and global region of origin. Use of iron supplements and consumption of higher mercury fish species were also associated with tHg concentrations in the fully adjusted model. The study results demonstrate that blood Hg concentrations in newcomer women are slightly elevated, with some individuals in exceedance of recommended concentrations for women of reproductive age. The consumption of fish species low in Hg is recommended for newcomer women, especially those who consume fish frequently.

Extended International Normalized Ratio testing intervals for warfarin-treated patients

Essentials Warfarin typically requires International Normalized Ratio (INR) testing at least every 4 weeks. We implemented extended INR testing for stable warfarin patients in six anticoagulation clinics. Use of extended INR testing increased from 41.8% to 69.3% over the 3 year study. Use of extended INR testing appeared safe and effective.

SUMMARY

Background A previous single-center randomized trial suggested that patients with stable International Normalized Ratio (INR) values could safely receive INR testing as infrequently as every 12 weeks. Objective To test the success of implementation of an extended INR testing interval for stable warfarin patients in a practice-based, multicenter collaborative of anticoagulation clinics. Methods At six anticoagulation clinics, patients were identified as being eligible for extended INR testing on the basis of prior INR value stability and minimal warfarin dose changes between 2014 and 2016. We assessed the frequency with which anticoagulation clinic providers recommended an extended INR testing interval (> 5 weeks) to eligible patients. We also explored safety outcomes for eligible patients, including next INR values, bleeding events, and emergency department visits. Results At least one eligible period for extended INR testing was identified in 890 of 3362 (26.5%) warfarin-treated patients. Overall, the use of extended INR testing in eligible patients increased from 41.8% in the first quarter of 2014 to 69.3% in the fourth quarter of 2016. The number of subsequent out-of-range next INR values were similar between eligible patients who did and did not have an extended INR testing interval (27.3% versus 28.4%, respectively). The numbers of major bleeding events were not different between the two groups, but rates of clinically relevant non-major bleeding (0.02 per 100 patient-years versus 0.09 per 100 patient-years) and emergency department visits (0.07 per 100 patient-years versus 0.19 per 100 patient-years) were lower for eligible patients with extended INR testing intervals than for those with non-extended INR testing intervals. Conclusions Extended INR testing for stable warfarin patients can be successfully and safely implemented in diverse, practice-based anticoagulation clinic settings.

Obesity and sudden cardiac death in the young: Clinical and pathological insights from a large national registry

Aims Obesity is an increasing public health problem and a risk factor for cardiovascular diseases. The aim of the study was to determine the main features and aetiologies in a large cohort of sudden cardiac deaths that occurred in obese subjects. Methods Between 1994 and 2014, 3684 consecutive cases of unexpected sudden cardiac death were referred to our cardiac pathology centre. This study was confined to young individuals (age ≤ 35 years) for whom information about body mass index was available and consisted of 1033 cases. Results Two-hundred and twelve individuals (20%) were obese. In obese sudden cardiac death victims the main post-mortem findings were: normal heart (sudden arrhythmic death syndrome) ( n = 108; 50%), unexplained left ventricular hypertrophy ( n = 25; 12%) and critical coronary artery disease ( n = 25; 12%). Less common were hypertrophic cardiomyopathy ( n = 4; 2%) and arrhythmogenic right ventricular cardiomyopathy ( n = 4;2%). When compared with non-obese sudden cardiac death victims, sudden arrhythmic death syndrome was less common (50% vs. 60%, P < 0.01), whereas left ventricular hypertrophy and critical coronary artery disease were more frequent (12% vs. 2%, P < 0.001 and 12% vs. 3%, P < 0.001, respectively). The prevalence of critical and non-critical coronary artery disease was significantly higher in obese individuals (23% vs. 10% in non-obese individuals, P < 0.001). Conclusions Various conditions underlie sudden cardiac death in obesity, with a prevalence of sudden arrhythmic death syndrome, left ventricular hypertrophy and coronary artery disease. The degree of left ventricular hypertrophy measured by heart weight is excessive even after correction for body size. Almost one in four young obese sudden death patients show some degree of coronary artery disease, underscoring the need for primary prevention in this particular subgroup.

Utility of Post-Mortem Genetic Testing in Cases of Sudden Arrhythmic Death Syndrome

BACKGROUND

Sudden arrhythmic death syndrome (SADS) describes a sudden death with negative autopsy and toxicological analysis. Cardiac genetic disease is a likely etiology.

OBJECTIVES

This study investigated the clinical utility and combined yield of post-mortem genetic testing (molecular autopsy) in cases of SADS and comprehensive clinical evaluation of surviving relatives.

METHODS

We evaluated 302 expertly validated SADS cases with suitable DNA (median age: 24 years; 65% males) who underwent next-generation sequencing using an extended panel of 77 primary electrical disorder and cardiomyopathy genes. Pathogenic and likely pathogenic variants were classified using American College of Medical Genetics (ACMG) consensus guidelines. The yield of combined molecular autopsy and clinical evaluation in 82 surviving families was evaluated. A gene-level rare variant association analysis was conducted in SADS cases versus controls.

RESULTS

A clinically actionable pathogenic or likely pathogenic variant was identified in 40 of 302 cases (13%). The main etiologies established were catecholaminergic polymorphic ventricular tachycardia and long QT syndrome (17 [6%] and 11 [4%], respectively). Gene-based rare variants association analysis showed enrichment of rare predicted deleterious variants in RYR2 (p = 5 × 10^-5). Combining molecular autopsy with clinical evaluation in surviving families increased diagnostic yield from 26% to 39%.

CONCLUSIONS

Molecular autopsy for electrical disorder and cardiomyopathy genes, using ACMG guidelines for variant classification, identified a modest but realistic yield in SADS. Our data highlighted the predominant role of catecholaminergic polymorphic ventricular tachycardia and long QT syndrome, especially the RYR2 gene, as well as the minimal yield from other genes. Furthermore, we showed the enhanced utility of combined clinical and genetic evaluation.

Pooling and expanding registries of familial hypercholesterolaemia to assess gaps in care and improve disease management and outcomes: Rationale and design of the global EAS Familial Hypercholesterolaemia Studies Collaboration

BACKGROUND

The potential for global collaborations to better inform public health policy regarding major non-communicable diseases has been successfully demonstrated by several large-scale international consortia. However, the true public health impact of familial hypercholesterolaemia (FH), a common genetic disorder associated with premature cardiovascular disease, is yet to be reliably ascertained using similar approaches. The European Atherosclerosis Society FH Studies Collaboration (EAS FHSC) is a new initiative of international stakeholders which will help establish a global FH registry to generate large-scale, robust data on the burden of FH worldwide.

METHODS

The EAS FHSC will maximise the potential exploitation of currently available and future FH data (retrospective and prospective) by bringing together regional/national/international data sources with access to individuals with a clinical and/or genetic diagnosis of heterozygous or homozygous FH. A novel bespoke electronic platform and FH Data Warehouse will be developed to allow secure data sharing, validation, cleaning, pooling, harmonisation and analysis irrespective of the source or format. Standard statistical procedures will allow us to investigate cross-sectional associations, patterns of real-world practice, trends over time, and analyse risk and outcomes (e.g. cardiovascular outcomes, all-cause death), accounting for potential confounders and subgroup effects.

CONCLUSIONS

The EAS FHSC represents an excellent opportunity to integrate individual efforts across the world to tackle the global burden of FH. The information garnered from the registry will help reduce gaps in knowledge, inform best practices, assist in clinical trials design, support clinical guidelines and policies development, and ultimately improve the care of FH patients.

Space-charge compensation measurements in electron cyclotron resonance ion source low energy beam transport lines with a retarding field analyzer

In this paper we describe the first systematic measurement of beam neutralization (space charge compensation) in the ECR low energy transport line with a retarding field analyzer, which can be used to measure the potential of the beam. Expected trends for the space charge compensation levels such as increase with residual gas pressure, beam current, and beam density could be observed. However, the overall levels of neutralization are consistently low (<60%). The results and the processes involved for neutralizing ion beams are discussed for conditions typical for ECR injector beam lines. The results are compared to a simple theoretical beam plasma model as well as simulations.

Biomarkers of diabetes risk in the National Diet and Nutrition Survey rolling programme (2008-2011)

This study describes the distribution of glycosylated haemoglobin (Hb_A1c) and glucose concentrations in the combined year 1 (2008–2009), year 2 (2009–2010) and year 3 (2010–2011) of the National Diet and Nutrition Survey (NDNS) rolling programme. The NDNS rolling programme is a nationally representative survey of food consumption, nutrient intakes and nutritional status of people aged 1.5 years and over living in England, Wales, Scotland and Northern Ireland. The study population comprised survey members who completed three or four days of dietary recording and who provided a blood sample. After excluding survey members with self-reported diabetes (n=25), there were 1016 results for Hb_A1c and 942 for glucose (not the same individuals in each case). Around 5.4% of men and 1.7% of women aged 19–64 years, and 5.1% of men and 5.9% of women aged ≥65 years had impaired fasting glucose (glucose concentrations 6.1–6.9 mmol/L). Over 20% of men aged ≥65 years had fasting glucose concentrations above the clinical cut-off for diabetes (≥7 mmol/L) compared to 2.1% of women of similar age (p=0.007). Similarly, 16.4% of men had Hb_A1c concentrations ≥6.5%, compared to 1.5% of women (p=0.003). Children and teenagers had fasting glucose and Hb_A1c values largely within the normal range. To conclude, this is the first study to provide data on the distribution of Hb_A1c and glucose concentrations in a nationally representative sample of the British population. The high prevalence of men aged ≥65 years with Hb_A1c and glucose concentrations above the clinical cut-off of diabetes warrants further attention.

Detection of Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio cholerae with respect to seasonal fluctuations in temperature and plankton abundance

Over a 1-year period, bi-monthly estuarine surface water and plankton samples (63-200 and > 200 μm fractions) were assayed by polymerase chain reaction for the prevalence of total Vibrio parahaemolyticus, V. vulnificus and V. cholerae and select genes associated with clinical strains found in each species. Neither temperature nor plankton abundance was a significant correlate of total V. parahaemolyticus; however, the prevalence of genes commonly associated with clinical strains (trh, tdh, ORF8) increased with temperature and copepod abundance (P < 0.05). The prevalence of total V. vulnificus and the siderophore-related viuB gene also increased with temperature and copepod and decapod abundance (P < 0.001). Temperature and copepod abundance also covaried with the prevalence of V. cholerae (P < 0.05), but there was no significant relationship with ctxA or other genes commonly found in clinical strains. Results show that genes commonly associated with clinical Vibrio strains were more frequently detected in association with chitinous plankton. We conclude that V. parahaemolyticus, V. vulnificus, V. cholerae and subpopulations that harbour genes common to clinical strains respond distinctly to seasonal changes in temperature as well as shifts in the taxonomic composition of discrete plankton fractions.

Left ventricular hypertrophy and endothelial dysfunction in chronic kidney disease

Aim Mortality, predominantly due to cardiovascular events, is high in patients with chronic kidney disease (CKD) and left ventricular hypertrophy (LVH) is a strong risk factor. Vascular endothelial dysfunction (ED) is common in CKD, but its potential contribution to LVH in non-dialysis CKD is unknown. This study investigated the association of ED with LVH in non-dialysis CKD patients.

METHODS AND RESULTS

We studied 30 CKD patients (17 pre-dialysis and 13 renal transplant recipients) and 29 age-gender-matched controls. In both groups, high-sensitivity C-reactive protein (hsCRP) levels, systemic ED (brachial artery flow-mediated dilatation, FMD), and LVH using two-dimensional echocardiography were measured. LV mass index (LVMI) was calculated using Penn formula and indexed by height. CKD patients had higher CRP levels (3.9 ± 2.8 vs. 1.0 ± 0.7 mg/L; P < 0.001), reduced FMD (3.2 ± 2.1 vs. 6.1 ± 1.9%; P < 0.001), and increased LVMI (146.1 ± 40.2 vs. 105.3 ± 26.2 g/m; P < 0.001), compared with controls. In CKD patients, LVMI increased with decreasing FMD (r = -0.371; P = 0.043) and FMD decreased with increasing CRP (r = -0.741; P < 0.001). Patients with low FMD <2.3% had higher CRP and LVMI (161.9 ± 48.9 vs. 130.4 ± 20.7 g/m; P = 0.033), compared with CKD patients with FMD ≥2.3%. There was no significant difference in age, blood pressure, cholesterol, FMD, and LVMI between pre-dialysis and post-renal transplant CKD patients. In multivariate regression, the relationship between LVMI and FMD remained significant after adjusting for age, diabetes, and smoking (adjacent beta = -0.396; P = 0.004).

CONCLUSION

This pilot study demonstrates for the first time a relationship of ED with LVH in non-dialysis CKD patients; suggesting but not proving a cause-effect relationship.

Blood glucose testing and primary prevention of Type 2 diabetes-evaluation of the effect of evidence-based patient information: a randomized controlled trial

AIMS

To compare the effect of our newly developed online evidence-based patient information vs. standard patient information about sub-threshold elevated blood glucose levels and primary prevention of diabetes on informed patient decision making.

METHODS

We invited visitors to the cooperating health insurance company, Techniker Krankenkasse, and the German Diabetes Center websites to take part in a web-based randomized controlled trial. The population after randomization comprised 1120 individuals aged between 40 and 70 years without known diabetes, of whom 558 individuals were randomly assigned to the intervention group receiving evidence-based patient information, and 562 individuals were randomly assigned to the control group receiving standard information from the Internet. The primary endpoint was acquired knowledge of elevated blood glucose level issues and the secondary outcomes were attitude to metabolic testing, intention to undergo metabolic testing, decisional conflict and satisfaction with the information.

RESULTS

Overall, knowledge of elevated glucose level issues and the intention to undergo metabolic testing were high in both groups. Participants who had received evidence-based patient information, however, had significantly higher knowledge scores. The secondary outcomes in the evidence-based patient information subgroup that completed the 2-week follow-up period yielded significantly lower intention to undergo metabolic testing, significantly more critical attitude towards metabolic testing and significantly higher decisional conflict than the control subgroup (n=466). Satisfaction with the information was not significantly different between both groups.

CONCLUSIONS

Evidence-based patient information significantly increased knowledge about elevated glucose levels, but also increased decisional conflict and critical attitude to screening and treatment options. The intention to undergo metabolic screening decreased. Future studies are warranted to assess uptake of metabolic testing and satisfaction with this decision in a broader population of patients with unknown diabetes.

Diabetes due to exocrine pancreatic disease--a review of patients attending a hospital-based diabetes clinic

BACKGROUND

Diabetes secondary to underlying exocrine pancreatic disease is a specific, but heterogeneous, type of diabetes mellitus. Studies such as UKPDS and DCTT excluded patients with pancreatic diabetes, so there is a paucity of evidence regarding best clinical practice in this group.

AIM

To characterize the clinical features of patients with diabetes secondary to underlying pancreatic disease attending general diabetes clinics in a single hospital.

DESIGN AND METHODS

A cross-sectional observational cohort study, identifying patients with pancreatic diabetes from clinic letters and medical notes at the University Hospital of Wales, Cardiff, UK.

RESULTS

The notes of 38 patients with pancreatic diabetes were reviewed. Of these, six had pancreatic malignancy and the remainder had a range of benign disorders. The majority (29/38) had diabetes diagnosed at or shortly after the pancreatic diagnosis was made. There was a lack of consistency regarding initial hypoglycaemic therapy, with metformin alone being the most common initial therapy, but with 30/38 taking insulin within 12 months of diagnosis. Similarly, a broad range of insulin regimens were employed with twice daily pre-mixed insulin being most prevalent. Sixty-three percent of patients were prescribed lipid lowering therapy and 42% were taking anti-hypertensives. Glycaemic control, as estimated by the latest HbA1C, was no different in patients with pancreatic diabetes compared to the general clinic population and there were no reports of severe hypoglycaemia.

CONCLUSION

There is great variability in how patients with pancreatic diabetes are currently managed. Future clinical trials should specifically address this group.

Fate and transport of zoonotic, bacterial, viral, and parasitic pathogens during swine manure treatment, storage, and land application

Members of the public are always somewhat aware of foodborne and other zoonotic pathogens; however, recent illnesses traced to produce and the emergence of pandemic H1N1 influenza virus have increased the scrutiny on all areas of food production. The Council for Agricultural Science and Technology has recently published a comprehensive review of the fate and transport of zoonotic pathogens that can be associated with swine manure. The majority of microbes in swine manure are not zoonotic, but several bacterial, viral, and parasitic pathogens have been detected. Awareness of the potential zoonotic pathogens in swine manure and how treatment, storage, and handling affect their survival and their potential to persist in the environment is critical to ensure that producers and consumers are not at risk. This review discusses the primary zoonotic pathogens associated with swine manure, including bacteria, viruses, and parasites, as well as their fate and transport. Because the ecology of microbes in swine waste is still poorly described, several recommendations for future research are made to better understand and reduce human health risks. These recommendations include examination of environmental and ecological conditions that contribute to off-farm transport and development of quantitative risk assessments.

Recommended evaluation of adrenal incidentalomas is costly, has high false-positive rates and confers a risk of fatal cancer that is similar to the risk of the adrenal lesion becoming malignant; time for a rethink?

OBJECTIVE

To assess the performance of current clinical recommendations for the evaluation of an adrenal incidentaloma. DESIGN AND METHODS LITERATURE REVIEW: Electronic databases (Pubmed, Ovid and citation searches from key articles) from 1980 to 2008 were searched. Eligible studies were those deemed most applicable to the clinical scenario of a patient referred to an endocrinologist for assessment of an incidentally detected adrenal mass. Surgical series, histopathological series and oncological series were reviewed and most were excluded.

RESULTS

The prevalence of functional and malignant lesions presenting as adrenal incidentaloma was similar to that quoted in most reviews, other than a lower incidence of adrenal carcinoma (1.9 vs 4.7%) and metastases (0.7 vs 2.3%). The development of functionality or malignancy during follow-up was rare (<1% becoming functional and 0.2% becoming malignant). During follow-up, false-positive rates of the recommended investigations are typically 50 times greater than true positive rates. The average recommended computed tomography (CT) scan follow-up exposes each patient to 23 mSv of ionising radiation, equating to a 1 in 430 to 2170 chance of causing fatal cancer. This is similar to the chance of developing adrenal malignancy during 3-year follow-up of adrenal incidentaloma.

CONCLUSION

Current recommendations for evaluation of adrenal incidentaloma are likely to result in significant costs, both financial and emotional, due to high false-positive rates. The dose of radiation involved in currently recommended CT scan follow-up confers a risk of fatal cancer that is similar to the risk of the adrenal becoming malignant. This argues for a review of current guidelines.

The effects of sorafenib and sunitinib on bone turnover markers in patients with bone metastases from renal cell carcinoma

e16145

Background: Bone metastases (BM) from renal cell carcinoma (RCC) are common and associated with poor outcomes. While the multi-tyrosine kinase inhibitors (TKI's) sunitinib and sorafenib have advanced the treatment of metastatic RCC, their efficacy on BM is unknown. Urinary N-telopeptide (uNTX) is a marker of bone turnover measured in nmol/mmol creatinine. Elevated uNTX levels correlate with an increased risk of skeletal related events and mortality in patients receiving bisphosphonates for BM from a range of primaries. In this pilot biomarker study we sought to prospectively evaluate the effects on BM of these multi-TKI's in RCC patients. Methods: Eligible patients had advanced RCC, at least one BM evident on imaging and no bisphosphonate exposure within 4 weeks. UNTX levels (OsteoMark) were measured at; baseline and weeks-1, 4, 8 and 12 after commencing either sunitinib or sorafenib. The primary endpoint was the percentage change (Ch) in uNTX levels from baseline. Serum samples were also collected for KIT and VEGFR-2 (Quantikine). Patients also completed pain (including bone pain) and quality of life questionnaires. Results: The uNTX results on the first 9 patients are presented in the table below (7 received sunitinib and 2 sorafenib). In this group, sVEGFR-2 and sKIT levels fell by week-1 and 4 respectively and at week-12 the mean % changes (95% CI) were -34% (-0.53,-0.14) and -38% (-0.58,-0.18). Conclusions: In patients with BM from RCC and at least moderately elevated uNTX levels at baseline, these multi-TKI's show a significant trend to decrease uNTX levels, but perhaps not as effectively as bone-specific therapies (e.g. bisphosphonates) do in other malignancies. SVEGFR-2 and sKIT levels also fell across the patient group over the same period. This pilot data raises questions about the activity of the multi-TKI's in BM from RCC and further research is needed. [Table: see text]

[Table: see text]

Differential pathways govern CD4+ CD28- T cell proinflammatory and effector responses in patients with coronary artery disease

Patients with acute coronary syndromes experience circulatory and intraplaque expansion of an aggressive and unusual CD4(+) lymphocyte subpopulation lacking the CD28 receptor. These CD4(+)CD28(-) cells produce IFN-gamma and perforin, and are thought to play an important role in coronary atheromatous plaque destabilization. Aberrant expression of killer Ig-like receptors (KIRs) in CD4(+)CD28(-) cells is broadly thought to be responsible for their cytotoxicity, but the mechanisms involved remain poorly defined. We therefore sought to investigate the mechanism and regulation of CD4(+)CD28(-) cell functionality using T cell clones (n = 536) established from patients with coronary artery disease (n = 12) and healthy volunteers (n = 3). Our functional studies demonstrated that KIR2DS2 specifically interacted with MHC class I-presenting human heat shock protein 60 (hHSP60) inducing cytotoxicity. Further investigations revealed the novel finding that hHSP60 stimulation of TCR alone could not induce a cytotoxic response, and that this response was specific and KIR dependent. Analysis of CD4(+)CD28(-)2DS2(+) clones (n = 162) showed that not all were hHSP60 cytotoxic; albeit, their prevalence correlated with coronary disease status (p = 0.017). A higher proportion of clones responded to hHSP60 by IFN-gamma compared with perforin (p = 0.008). In this study, for the first time, we define the differential regulatory pathways involved in CD4(+)CD28(-) cell proinflammatory and effector responses. We describe in this study that, contrary to previous reports, CD4(+)CD28(-) cell recognition and killing can be specific and discriminate. These results, in addition to contributing to the understanding of CD4(+)CD28(-) cell functionality, may have implications for the monitoring and management of coronary artery disease progression.

Design, construction, and first commissioning results of superconducting source for ions at NSCL/MSU

A new electron cyclotron resonance ion source (ECRIS) was constructed at the NSCL/MSU to replace the existing SC-ECRIS. This ECRIS operates at 18+14.5 GHz microwave frequencies with a planned upgrade to 24-28 GHz in the second phase of commissioning. A superconducting hexapole coil system produce the radial magnetic field; the axial trapping is produced with six superconducting solenoid coils enclosed in an iron yoke to allow the optimization of the distance between the plasma electrode and the resonant zone in the plasma. We report the details of the design, construction, and initial commissioning results of this new ECRIS.

Effects of Varying Lactation Length on Milk Production Capacity of Cows in Pasture-Based Dairying Systems

The aim of this experiment was to quantify the milk production capacity of cows undergoing extended lactations while fed a pasture-based diet typical of those used in the seasonal-calving dairying systems of Victoria, Australia. One hundred twenty-five Holstein cows were randomly assigned to 1 of 5 groups. Breeding was progressively delayed after calving to enable management of the groups for lactation lengths of 10, 13, 16, 19, and 22 mo (equivalent to calving intervals of 12 to 24 mo). Cows were provided with a daily energy intake of at least 180 MJ of metabolizable energy/cow. This was supplied primarily by grazed pasture with supplementary cereal grain, pasture silage, and hay. Cows were dried off when milk volume fell below 30 kg/wk or when they reached 56 d before their expected calving date. Most cows (>96%) could lactate above this threshold for 16 mo, >80% for 19 mo, and >40% for 22 mo. There were negative relationships between lactation length and annual production of milk and milk solids (milk fat + protein), but losses were small until 16 mo. Annualized yields of milk solids were 497, 498, 495, 474, and 463 kg/cow for the 10, 13, 16, 19, and 22 mo groups, respectively. This reduction in annual production of milk solids with increasing lactation length was relatively less than for milk volume because during extended lactation, cows produced milk with higher concentrations of protein. Cows undergoing extended lactations also finished their lactations having gained more body weight and body condition than cows lactating for only 10 mo. The data showed that many cows on pasture-based diets were capable of lactating longer than the 10 mo that is standard for Victorian herds with seasonally concentrated calving patterns. Further, such extended lactations could be achieved with little penalty in terms of annual milk solids production.

Urinary n-telopeptide (NTX) predicts palliative pain response in metastatic breast cancer patients receiving second-line zoledronic acid

679

Background: A substantial number of breast cancer patients will have bony progression or develop skeletal related events (SRE) despite treatment with a bisphosphonate (BP) such as clodronate or pamidronate. What could be of use to the practicing oncologist is a marker for predicting which patients will derive palliative benefit with the second-line use of a more potent BP such as zoledronic acid. In this study, we assessed the clinical utility of using early changes in urinary NTX as a predictor of palliative response to second-line zoledronic acid. Methods: 30 patients with either a documented SRE or bony progression while on either clodronate or pamidronate were switched to infusions of zoledronic acid (4 mg) every 4 weeks for 12 weeks. Urinary NTX and worst pain score using the Brief Pain Inventory were evaluated weekly for the first 4 weeks & again at week 8. No change in systemic anti-cancer treatment was allowed in the month before or after commencing study treatment. A palliative response was defined as a reduction of at least two units in the worst pain score. Logistic regression analysis was used to determine if a decrease in urinary NTX at week 1 relative to baseline was a significant predictor of palliative response to zoledronic acid when measured at week 8. Results: At week 1, 23 of 30 (76.7%) had a drop in their urinary NTX excretion relative to baseline. At week 8, these 23 patients experienced a 2.4 unit decline in their worst pain score, compared to only a 0.28 unit reduction in the 7 patients whose week 1 urinary NTX increased relative to baseline (P=0.11). A week 1 drop in urinary NTX was identified as an important predictor for palliative response to zoledronic acid when measured at week 8 (OR=9.4; 95%CI: 2.28 to 79.8, P=0.014). Conclusions: Our findings imply that a decline in urinary NTX at week 1 is a useful marker for identifying which patients will derive palliative benefits from second-line zoledronic acid. Additional data on a larger sample of patients is needed to validate the clinical utility of using early changes in urinary NTX as a rapid predictor of patient benefit.

[Table: see text]

The Ets transcription factor Esx regulates expression of metastasis-associated genes in non-small cell lung cancer (NSCLC)

17077

Background: The overall 5-yr survival for the treatment of lung cancer patients is less than 20% due to the inability to control metastatic disease. Methods: To identify genes that promote the development of metastases in NSCLC and other solid tumors, we first performed three separate microarray analyses using Affymetrix U133A chips whereby expression values of a pool of normal lymph nodes was compared to: lung cancer cell lines (n = 4), and metastatic lymph nodes from breast (n = 3) and pancreatic (n = 3) cancer patients. Separate lists of the 35 most highly overexpressed genes for each cancer type were compiled. Results: We observed that each list contained EpCAM, XAG, CK19, and CK8 (p = 1.1E-18). To search for genes that might regulate expression of these four genes, we queried the CGAP NCI60 gene expression database with the 87 genes contained on the three lists and constructed a connectivity map such that the presence of a gene on the map required: 1) high correlation (p < 8.0E-6) with at least two other genes, and 2), direct or indirect contact to EpCAM or XAG. The map contained two gene clusters (XAG cluster = 6 genes; EpCAM/CK19/CK8 cluster = 7 genes) that were connected to, and potentially regulated by, the Ets transcriptional factor Esx. Genes from both clusters, as well as Esx, were highly overexpressed in metastatic mediastianal lymph nodes obtained from NSCLC patients. To investigate whether Esx might regulate expression of one or more genes in the two clusters, we transfected an NSCLC cell line derived from lymph node metastases with siRNA to Esx and observed: 1) a reduction in expression of EpCAM (4-fold), XAG (7-fold), and the orphan nuclear receptor ESRRα (1,000-fold), and 2), an inhibition of cell growth. Conclusions: Based on our ability to simultaneously inhibit cell growth and expression of multiple metastasis-associated genes with a single siRNA, we conclude that Esx is a major regulator of lymph node metastasis.

No significant financial relationships to disclose.

Engineering and functional evaluation of a single-chain antibody against HIV-1 external glycoprotein gp120

The HIV-1 envelope glycoprotein surface subunit gp120 is an attractive target for molecular intervention. This is because anti-HIV-1 gp120 neutralizing antibodies display the potential ability to inhibit HIV-1 infection. The present investigation describes the construction of a genetically engineered single chain antibody (scFv102) against HIV-1 gp120, its expression and functional evaluation. The parental hybridoma cell line (102) produces an immunoglobulin directed against the conserved CD4-binding region of gp120. cDNAs encoding the variable regions of the heavy (V(H)) and light (V(L)) chains were prepared by reverse transcription PCR and linked together with an oligonucleotide encoding a linker peptide (Gly(4)Ser)(3) to produce a single chain antibody gene. The resulting DNA construct was cloned into a prokaryotic expression vector (pET28) and recombinant scFv102 was expressed in Eserichia coli as an insoluble protein. The denatured scFv102 was refolded and purified by immobilized metal ion affinity chromatography. Purified scFv102 had the same specificity as the intact IgG in immuno-blotting assays and immuno-fluorescence (IF) detection, but ELISA analyses demonstrated the affinity of scFv102 to be 5-fold lower than that of the parental monoclonal antibody. In neutralization assays, scFv102 at concentrations lower than 40 microg/ml exhibited efficient interference with viral replication and inhibition of viral infection (90%) across a range of primary isolates of subtype B HIV-1. These results suggest that the constructed anti-HIV-1 gp120 scFv102 has good biological activity and can potentially be used for in vitro diagnostic and in vivo therapeutic applications.

Relationship among pregnancy associated plasma protein-A levels, clinical characteristics, and coronary artery disease extent in patients with chronic stable angina pectoris

AIMS

To assess, in chronic stable angina (CSA) patients, the relationship among clinical characteristics and cardiovascular risk factors, extent of coronary artery disease (CAD), and pregnancy-associated plasma protein-A (PAPP-A) levels.

METHODS AND RESULTS

We studied 643 CSA patients (63+/-10 years, 482 men) undergoing diagnostic coronary angiography; 97 with angiographically normal coronary arteries or <50% stenosis, 127 with single vessel disease (VD), and 419 with multi-VD. Patients' age, gender, cardiovascular risk factors, body mass index, history of previous myocardial infarction, angina class, left ventricular ejection fraction (LVEF), and treatment were assessed at study entry. PAPP-A levels (mIU/L) were higher in men than in women (6.2+/-2.4 vs. 5.2+/-1.8; P<0.001) and in hypertensive vs. normotensive patients (6.4+/-2.8 vs. 5.8+/-2.1; P=0.01). PAPP-A correlated directly with age (r=0.19, P<0.001) and inversely with LVEF (r=-0.11, P=0.01). Patients with multivessel disease (VD) had higher PAPP-A levels (6.45+/-2.58) than those with single-VD (5.49+/-1.54, P<0.001) or normal coronaries (4.62+/-1.17, P<0.001). Male gender, age, history of a previous MI, hypercholesterolaemia, and PAPP-A levels were independent predictors for the presence of CAD.

CONCLUSION

In CSA patients PAPP-A levels correlate with age, male gender, hypertension, and CAD extent. In the present study, PAPP-A was an independent predictor for the presence and extent of CAD.

A protective contribution of the Q allele of the R353Q polymorphism of the Factor VII gene in individuals with chronic stable angina?

BACKGROUND

Factor VII polymorphisms have been suggested in some studies to show an association with some aspects of coronary disease, and there is a known association between FVII levels and polymorphic variants in the gene. The aim of the study was to assess whether Factor VII polymorphism R353Q is associated with the extent of coronary artery disease in patients with chronic stable angina.

METHODS AND RESULTS

There is evidence that Factor VII polymorphisms are markers of susceptibility to coronary artery disease (CAD), but two studies have suggested that there is no association between the degree of vessel disease and these polymorphisms. One of these studies did not exclude patients with unstable angina or MI. We therefore set up a prospective cohort study to determine Factor VIIa, VIIc and VIIAg levels, genotype for R353Q, lipid status, smoking history and the degree of vessel disease, in patients attending the hospital for routine day case angiography over a 20 month period. From 519 cases, 400 had no previous MI or revascularisation, including 153 with zero vessel disease, and were successfully genotyped: 9 (2%) QQ, 78 (20%) RQ and 313 (78%) RR. Compared with RR subjects, heterozygotes were 2.7 years older (95% CI: 0.3, 5.0; p=0.027), but were not significantly different regarding gender, cholesterol, extent of vessel disease or smoking history. If those with vessel disease were considered, then the heterozygotes were 3.5 years older than the RR homozygotes (95% CI: 0.6-6.4, p=0.016). There was a significant association between all measures of Factor VII and the R353Q polymorphism, with the Q allele associating with lower levels. There was no significant association between the degree of vessel disease and genotype.

CONCLUSIONS

The degree of vessel disease as seen at day case angiography is independent of polymorphism status, but there appears nonetheless to be a moderate protective effect of the Q allele against stable angina, in that angiographic investigation occurs a few years later for RQ heterozygotes than RR homozygotes. The effect may be mediated by reduced levels of Factor VII.

Prospective audit of conversion from regular to lispro insulin during routine clinical care

BACKGROUND

Randomized controlled trials show that lispro insulin has the potential to improve glycaemic control. Observational, practice-based studies provide information that is complementary to that obtained from randomized controlled trials and results of both types of studies are of relevance when advising patients of likely outcomes during routine clinical care.

AIMS

This prospective audit aimed to determine whether conversion from regular (short-acting, soluble) preprandial insulin to lispro during routine clinical care improved glycated haemoglobin.

METHODS

Eligible patients were those using regular insulin before main meals and a basal neutral protamine Hagedorn (NPH) insulin. Study group patients were those who chose to convert to lispro insulin. Patients who elected not to change their regimen were used as a comparison group. Follow up was for a minimum of 1 year.

RESULTS

Glycated haemoglobin (HbA(1c)) and body mass index showed no change in either the study or comparison groups. Post-hoc analysis revealed that the patients most likely to improve their HbA(1c) on lispro were those with a higher baseline HbA(1c). Patients using lispro reported a decreased frequency of hypoglycaemia and improved convenience of use.

CONCLUSIONS

Administration of lispro insulin was perceived by patients as convenient to use and was also associated with less hypoglycaemia when compared with the use of regular insulin. There was, however, no improvement in HbA(1c). This finding may be informative when advising patients during routine clinical care of the likely metabolic outcome of changing their insulin regimen.

Pregnancy-Associated Plasma Protein A and Its Endogenous Inhibitor, the Proform of Eosinophil Major Basic Protein (proMBP), Are Related to Complex Stenosis Morphology in Patients With Stable Angina Pectoris

Background— The metalloproteinase pregnancy-associated plasma protein-A (PAPP-A) has been implicated in coronary plaque disruption. Its endogenous inhibitor, the proform of eosinophil major basic protein (proMBP), may also play a role in this process. Atheromatous plaque disruption often presents as complex angiographic lesions. We sought to assess whether PAPP-A, proMBP, and PAPP-A/ProMBP ratio are markers of angiographic plaque complexity in patients with chronic stable angina.

Methods and Results— We studied 396 stable angina patients (age 63±10 years, 230 men) of whom 289 had angiographically documented coronary artery disease (≥75% stenosis). All coronary stenoses ≥30% diameter reduction (n =531 in 322 patients) were assessed and classified as complex (n =228) or smooth (n =303) by previously validated criteria. PAPP-A, proMBP, and C-reactive protein (hs-CRP) serum levels were measured by ELISA. Patients with complex coronary stenoses had a significantly ( P <0.001) higher PAPP-A/proMBP ratio (3.1±1.2 versus 2.7±0.8×10 −3 ) and PAPP-A levels (5.9±1.6 versus 5.1±1.4 mIU/L) than those without. On univariate analysis, male gender ( P <0.001), age ( P <0.001), previous history of myocardial infarction ( P =0.013), reduced ejection fraction ( P <0.001), severe coronary artery disease ( P <0.001), aspirin treatment ( P <0.001), PAPP-A levels ( P <0.001), and PAPP-A/proMBP ratio ( P <0.001) were correlated with the number of complex stenoses. Multiple regression analysis showed that male gender, age, severe coronary artery disease, and PAPP-A/proMBP ratio were independent predictors of the number of angiographically complex stenoses.

Conclusions— In patients with stable angina, PAPP-A and PAPP-A/proMBP ratio are associated with angiographic plaque complexity.