Synthesis and preclinical evaluation of BOLD-100 radiolabeled with ruthenium-97 and ruthenium-103

BOLD-100 (formerly IT-139, KP1339), a well-established chemotherapeutic agent, is currently being investigated in clinical trials for the treatment of gastric, pancreatic, colorectal, and bile duct cancer. Despite numerous studies, the exact mode of action is still the subject of discussions. Radiolabeled BOLD-100 could be a powerful tool to clarify pharmacokinetic pathways of the compound and to predict therapy responses in patients using nuclear molecular imaging prior to the therapy. In this study, the radiosyntheses of carrier-added (c.a.) [97/103Ru]BOLD-100 were performed with the two ruthenium isotopes ruthenium-103 (103Ru; β-, γ) and ruthenium-97 (97Ru; EC, γ), of which in particular the latter isotope is suitable for imaging by single-photon emission computed tomography (SPECT). To identify the best tumor-to-background ratio for diagnostic imaging, biodistribution studies were performed with two different injected doses of c.a. [103Ru]BOLD-100 (3 and 30 mg kg-1) in Balb/c mice bearing CT26 allografts over a time period of 72 h. Additionally, ex vivo autoradiography of the tumors (24 h p.i.) was conducted. Our results indicate that the higher injected dose (30 mg kg-1) leads to more unspecific accumulation of the compound in non-targeted tissue, which is likely due to an overload of the albumin transport system. It was also shown that lower amounts of injected c.a. [103Ru]BOLD-100 resulted in a relatively higher tumor uptake and, therefore, a better tumor-to-background ratio, which are encouraging results for future imaging studies using c.a. [97Ru]BOLD-100.

Social representations of intellectual disability; a comparison between cultures

OBJECTIVES

People with Intellectual disability consistently appear to be one of the most looked-down upon and repressed subgroups of society in many cultures. The main aim of this study was to compare social representations of intellectual disability in its various aspects between different cultures.

MATERIALS AND METHODS

The study was conducted in four different sites: Beirut-Lebanon, Algiers-Algeria, Tours-France and Namur-Belgium. Participants were asked to complete a questionnaire evaluating social representations of intellectual disability.

RESULTS

A total of 755 participants consented to take part in the study. Gender only affected social representations in the Lebanese population. Overall, Algerians appeared to have the least positive social representations and Lebanon to have more positive attitudes, while France and Belgium tended to have the most favourable representations.

DISCUSSION AND CONCLUSIONS

Findings highlight the imbalance between a European and a non-European country showing the importance of developing tailored interventions to improve general attitudes towards intellectual disability.

Echocardiographic diversity associated with exercise capacity in heart failure precursor stage B: the Project Baseline Health Study

Background

The current paradigm to stage heart failure (HF) defines precursor stage B (or “pre-HF”) as having any subclinical change in cardiac structure or function. Yet, HF risk factors and type of cardiac abnormality may induce clinically relevant heterogeneity in HF stage B. Therefore, we assessed clinical and echocardiographic heterogeneity within stage B HF and its association with exercise capacity in a large community-based sample.

Methods

2071 participants to the Baseline Health Study (50.4±17.0 years, 56.2% women, 37.8% hypertensive) underwent echocardiography and physical performance testing including 6-minute walk (6MWT) and treadmill exercise test. We defined echocardiographic profiles of left and right heart remodeling and dysfunction using sex-specific internal reference values. We assessed HF stages (0-A-B-C-D) following HF societies recommendations. stage B participants were stratified according to presence/absence of HF risk factors and to the most severe echocardiographic abnormality present (reduced ejection fraction (EF), left ventricular (LV) hypertrophy/diastolic dysfunction or other abnormalities). We reported associations between physical performance metrics and HF (sub)stages.

Results

Stage B HF was present in 516 participants (24.9%). Within stage B HF, we observed a large diversity in echocardiographic profiles. Yet, stage B participants without HF risk factors (n=96, 18.6% of stage B) predominantly presented echo abnormalities other than LV diastolic dysfunction, hypertrophy and reduced EF, while their physical performance profile resembled that of people with normal echocardiography without HF risk factors. In contrast, stage B participants with HF risk factors (n=420) were characterized by LV diastolic dysfunction, hypertrophy or reduced EF, three phenotypes associated with lower 6MWT distance and lower exercise capacity. Concomitant presence of HF risk factors and LV dysfunction/hypertrophy was associated with worst physical performance.

Conclusions

We observed a wide clinical and echocardiographic diversity affecting physical performance in HF precursor stage B when defined by the current staging paradigm. Concomitant presence of HF risk factors and LV dysfunction/hypertrophy may mark individuals at highest risk for progression towards overt HF.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This research was made supported by an institutional research grant from Verily Inc. (CA, USA) and by the Research Foundation Flanders (Belgium).

Nickel Increases Chromosomal Abnormalities by Interfering With the Initiation of DNA Repair Pathways

Background: Nickel is a carcinogenic, heavy metal released through industrial activities and via natural resources. It is able to cause DNA damages by reducing the efficiency of DNA repair mechanisms. However, the exact time point at which it is able to interfere with these mechanisms is not yet clearly understood. Methods: To find the most nickel-vulnerable time of repair mechanisms, human dermal fibroblasts (HDF) were treated with three doses of nickel before and after X-irradiation. The induced frequency of chromosomal abnormality was studied using micronucleus assay in binucleated cells. The cytotoxicity of different treatments was established using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The results revealed that nickel treatment had a synergistic effect on inducing Micronucleus frequency only when cells were treated 2 hours before X-irradiation. The X-ray treatment of the cells with 5 and 10 mM nickel had a cytotoxic effect mainly when given 6 hours after the irradiation. Conclusion: The results suggest that nickel can interfere with human DNA repair mechanisms only at the start of the process, while having no significant effect on the human DNA repair mechanisms when activated.

Sclerostin and bone turnover markers response to cycling and running at the same moderate-to-vigorous exercise intensity in healthy men

BACKGROUND

Recreational cycling is a popular activity which stimulates and improves cardiovascular fitness. The corresponding benefits for bone are unclear.

PURPOSE

This study examined the effect of running (high-impact) vs. cycling (low-impact), at the same moderate-to-vigorous exercise intensity, on markers of bone formation (N-terminal propeptide of type I collagen, PINP) and bone resorption (C-telopeptide of type I collagen, CTX-1), a non-collagenous bone remodeling marker (osteocalcin), as well as bone-modulating factors, including parathyroid hormone (PTH), irisin (myokine) and sclerostin (osteokine).

METHODS

Thirteen healthy men (23.7 ± 1.0 y) performed two progressive exercise tests to exhaustion (peak VO₂) on a cycle ergometer (CE) and on a treadmill (TM). On subsequent separate days, in randomized order, participants performed 30-min continuous running or cycling at 70% heart rate reserve (HRR). Blood was drawn before, immediately post- and 1 h into recovery.

RESULTS

PTH transiently increased (CE, 51.7%; TM, 50.6%) immediately after exercise in both exercise modes. Sclerostin levels increased following running only (27.7%). Irisin increased following both running and cycling. In both exercise modes, CTX-1 decreased immediately after exercise, with no significant change in PINP and osteocalcin.

CONCLUSION

At the same moderate-to-vigorous exercise intensity, running appears to result in a greater transient sclerostin response compared with cycling, while the responses of bone markers, PTH and irisin are similar. The longer-term implications of this differential bone response need to be further examined.

Proteomic profiling for detection of early-stage heart failure in the community

Background and purpose

Biomarkers may provide insight into the molecular mechanisms underlying cardiac remodelling and dysfunction. Using a targeted proteomic approach, we aimed to identify circulating biomarkers associated with early-stage heart failure and extract a proteome-based risk classifier for this condition.

Methods

575 community-based participants (mean age, 57 years; 51.7% women) underwent echocardiography and proteomic profiling (CVD II panel, Olink Proteomics). We applied partial least squares-discriminant analysis (PLS-DA) and a machine learning algorithm (extreme gradient boosting, XGBoost) to identify key proteins associated with echocardiographic abnormalities. We used Gaussian Mixture modelling for unbiased clustering to construct phenogroups based on influential proteins in PLS-DA and XGBoost.

Results

Of 87 proteins, 13 were important in PLS-DA and XGBoost modelling for detection of left ventricular (LV) remodelling, LV diastolic dysfunction and/or left atrial reservoir dysfunction: placenta growth factor, kidney injury molecule-1, prostasin, angiotensin-converting enzyme-2, galectin-9, cathepsin L1, matrix metalloproteinase-7, TNFR superfamily members 10A, 10B and 11A, interleukins-6 and 16 and alpha-1-microglobulin/bikunin precursor. Based on these proteins, the clustering algorithm divided the cohort into two distinct phenogroups, with each cluster grouping individuals with a similar protein profile. Participants belonging to the second cluster (n=118) were characterized by an unfavourable cardiovascular risk profile and adverse cardiac structure and function. The adjusted risk of presenting cardiac maladaptation was higher in this phenogroup than in the other cluster (P<0.0001).

Conclusion

We identified proteins reflecting renal function, extracellular matrix remodelling, angiogenesis and inflammation to be associated with echocardiographic signs of early-stage heart failure. Focused proteomic phenomapping discriminated individuals at high risk for cardiac maladaptation in the community.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders

Temporal shift and accuracy of machine learning in heart transplant outcomes

Background

Accurate prediction of outcomes following a heart transplant is critical to explaining risks and benefits to patients and decision-making when considering potential organ offers. Given the large number of potential variables to be considered, this task may be most efficiently performed using machine learning (ML).

Purpose

We trained and tested different ML algorithms to accurately predict outcomes following a cardiac transplant using the United Network of Organ Sharing (UNOS) database.

Methods

We included 67 939 adult and pediatric patients enrolled in the UNOS database between January 1994 and December 2016 who underwent cardiac transplantation (median age 53 [IQR 38 – 60], 72.7% males). In our models, as an input, we included 114 features that have been collected from recipients and donors prior to transplant. The primary outcome was all-cause mortality at one-year post-transplant. We evaluated three different ML methods: XGBoost, Random Forest (RF) and L2 regularized logistic regression. Algorithms were trained and tested using shuffled 10-fold cross-validation (CV) as well as rolling CV. In the rolling CV, to mimic prospective procedure, ML models were trained by incrementally adding patients according to transplant year and testing models on the data in the following year. The hyperparameters, controlling the learning process, were tuned using Bayesian optimization. Prognostic accuracy for one-year all-cause mortality was characterized using the area under the receiver-operating characteristic curve (AUC).

Results

In total, 8,394 patients died within 1 year of transplant. We observed a substantial difference in prognostic accuracy between the shuffled 10-fold CV and the rolling CV. In the 10-fold CV, XGBoost and RF achieved high predictive performance with AUC of 0.848 (95% CI: 0.842–0.854) and 0.891 (95% CI: 0.886–0.896), respectively. In the rolling CV, which is a more realistic setting, AUC dropped to 0.673 (95% CI: 0.661–0.684) for XGBoost and 0.670 (0.657–0.683) for RF. Predictive performance of L2 regularized logistic regression remained stable across the two CV procedures, achieving AUC 0.669 (95% CI: 0.662–0.676) in the 10-fold shuffled CV and 0.665 (95% CI: 0.649–0.680) in the rolling CV procedure (Figure).

Conclusions

Our study suggests that ML models could be used to predict mortality in the first year post-transplant. We also show that the choice of CV procedure is crucial for evaluating ML models, particularly in data collected over a long period of time. The difference between the shuffled and rolling CV in the predictive performance of the tree-based ML models might indicate temporal dataset shift. In the rolling CV, all three methods achieved similar predictive performance.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders (FWO)

The association of soluble ACE2 change with metabolic health, body composition and proteome dynamics during a weight loss diet intervention: implications for the COVID-19 pandemic

Background

Angiotensin-converting enzyme 2 (ACE2) serves protective functions in metabolic, cardiovascular, renal and pulmonary diseases and is linked to COVID-19 pathology. We explored the association between soluble AC2 (sACE2) and metabolic health and proteome dynamics during a weight loss diet intervention.

Methods

We analyzed 457 healthy individuals (mean age 39.8±6.6) with BMI 28–40 kg/m2 who participated in the Diet Intervention Examining the Factors Interacting with Treatment Success (DIETFITS). Biochemical markers of metabolic health and 236 proteins measured by Olink CVD II, CVD III and Inflammation arrays were available at baseline and 6 months following dietary intervention. We determined clinical and routine biochemical correlates of the diet-induced change in sACE2 (ΔsACE2) using stepwise linear regression. We then combined feature selection models and multivariable-adjusted linear regression to identify protein dynamics associated with ΔsACE2.

Results

sACE2 decreased significantly on average at 6-months in the diet intervention. A stronger decline in sACE2 during the diet intervention was independently associated with female sex, lower HOMA-IR and LDL cholesterol at baseline, and a stronger decline in HOMA-IR, triglycerides, HDL-cholesterol and fat mass. In line, participants with decreasing HOMA-IR and triglycerides had significantly higher odds for a decrease in sACE2 during the diet intervention than those who did not (P≤0.0073 for both). Feature selection models linked ΔsACE2 to changes in AMBP, E-selectin, HAOX1, KIM-1, MERTK, PGF, thrombomodulin and TRAIL-R2. ΔsACE2 remained independently associated with these protein changes in multivariable-adjusted linear regression.

Conclusion

Decrease in sACE2 during a weight loss diet intervention was associated with improvements in metabolic health, fat mass and markers of angiotensin peptide metabolism, vascular injury, renal function, chronic inflammation and oxidative stress. Our findings may improve the risk stratification, prevention, and management of cardiometabolic and COVID-19-related complications.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHResearch Foundation Flanders

Production of scandium radionuclides for theranostic applications: towards standardization of quality requirements

In the frame of "precision medicine", the scandium radionuclides have recently received considerable interest, providing personalised adjustment of radiation characteristics to optimize the efficiency of medical care or therapeutic benefit for particular groups of patients. Radionuclides of scandium, namely scandium-43 and scandium-44 (43/44Sc) as positron emitters and scandium-47 (47Sc), beta-radiation emitter, seem to fit ideally into the concept of theranostic pair. This paper aims to review the work on scandium isotopes production, coordination chemistry, radiolabeling, preclinical studies and the very first clinical studies. Finally, standardized procedures for scandium-based radiopharmaceuticals have been proposed as a basis to pave the way for elaboration of the Ph.Eur. monographs for perspective scandium radionuclides.

Assessing post-exercise respiratory gas kinetics in clinical sample - a pilot study

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiopulmonary exercise testing (CPX) is established in the evaluation of patients with cardiac and pulmonary diseases, and its clinical utility seems to be expanding.  Currently the most important diagnostic and prognostic ventilatory metrics of CPX rely on the exercise phase. Nevertheless, a consistent body of evidence suggests that important information can be derived from the recovery phase, especially in the first few minutes after exercise. In this context, patients with heart failure (HF) demonstrate a slower recovery of the oxygen consumption (VO2) compared with healthy individuals. Purpose: To comprehensively investigate the behavior of respiratory gases during recovery from CPX in a diverse cohort of HF patients. Methods: All individuals who performed CPX at the department of cardiology of Stanford University Hospital were eligible for the study. Patients were included in the experimental group if they (i) were recorded for five minutes after the exercise phase of CPX and (ii) had documented heart failure. They were excluded if they had other clinical diagnoses which may be responsible for exercise intolerance or symptoms or were unable to give informed consent. Healthy controls were recruited from the local community and were included if they did not have documented or suspected disease. Respiratory gases were collected on a breath-by-breath basis and analysed after applying a 30 second rolling average filter. Metrics were analyzed as absolute values, percentage change from peak and the half-time of recovery (T ½; i.e. the duration until a metric had returned to ½ of its value at peak). Data was analyzed over time within patients and averages between groups using parametric statistical methods. In accordance with previous studies, the amount of change in a metric after exercise is presented as the "magnitude" of overshoot. Results: 32 patients with HF (11 Female, 47 ± 13 yrs) and 30 healthy subjects (14 Female, 43 ± 12 yrs) were included. A comparison of ventilatory metrics during recovery between HF and controls is depicted in Figure 1. Peak VO2 was 1135 ± 419 mL/min (13.5 ± 3.8 mL/Kg/min) vs 2408 ± 787 mL/min (32.5 ± 9.0 mL/Kg/min); P <0.01. A significant difference between patients with HF and healthy subjects was found in T ½ of VO2 (111.3 ± 51.0s vs 58.0 ± 13.2s, p < 0.01) and VCO2 (132.0 ± 38.8s vs 74.3 ± 21.1s, p < 0.01). The magnitude of the overshoot was also found to be significantly reduced in patients with HF for VE/VO2 (41.9 ± 29.1% vs 62.1 ± 17.7%, P < 0.01), RQ (25.0 ± 13.6% vs 38.7 ± 15.1%, p < 0.01) and PETO2 (7.2 ± 3.3% vs 10.1 ± 4.6%, p < 0.01). Finally, the magnitude of the RQ overshoot showed a moderate correlation with peak VO2 (ϱ=0.58, p < 0.01). Conclusions: We observed that ventilatory kinetics measured in early recovery after CPX differ significantly between healthy subjects and patients with HF. The assessment of post exercise respiratory gases in a clinical setting may add to the prognostic and diagnostic value of CPX in heart failure.

Abstract Figure.

Left atrial reservoir strain in relation to metabolic and inflammatory biomarkers: a community-based study

Background

The pathophysiological mechanisms that underlie progressive left atrium (LA) remodelling and dysfunction are only partially understood. Metabolic disturbances and chronic inflammation might mediate LA dysfunction. To date, population data investigating the contribution of these processes to LA reservoir dysfunction remain scarce.

Purpose

In a large population sample, we investigated the association between LA reservoir function and a panel of 38 metabolic and inflammatory biomarkers.

Methods

In 1236 community-dwelling individuals (mean age, 51.0 years; 51.5% women), we echocardiographically assessed LA reservoir strain (LARS) using 2D speckle-tracking analysis. LA reservoir dysfunction was defined as having LARS <23%. We applied partial least squares-discriminant analysis (PLS-DA) to identify biomarkers associated with LA dysfunction. We further explored the associations between LARS and selected biomarkers that were the most influential in PLS-DA, while adjusting for important clinical correlates such as age, sex, body mass index (BMI), heart rate, systolic blood pressure (BP) and antihypertensive treatment. We applied stepwise regression to identify the clinical features and circulating biomarkers most valuable for prediction of abnormal LARS.

Results

The three latent factors constructed from the panel of 38 biomarkers during PLS-DA explained 16.9% of the variation between the normal and the impaired LA function group. The PLS-DA model discriminated between normal and abnormal LA reservoir strain with 79% accuracy (P<0.0001). In PLS-DA, serum uric acid, serum insulin, γ-glutamyl transferase, interleukin-6, D-dimer and triglycerides were the top biomarkers responsible for class discrimination. On average, these top biomarkers were higher in the LA dysfunction group as compared to their normal counterparts (P<0.0001 for all). In multivariable-adjusted continuous analyses, LARS decreased significantly with the level of serum insulin, serum uric acid and γ-glutamyl transferase (P≤0.0035 for all). Of the clinical correlates and the top biomarkers selected in PLS-DA, stepwise regression models highlighted age, BMI, systolic BP, serum insulin, serum uric acid and interleukin-6 as the main predictors of an impaired LA reservoir function (see figure). Conjointly, these clinical and biochemical features identified LA reservoir dysfunction with an overall accuracy of 85%.

Conclusions

Circulating markers of insulin resistance, hyperuricemia and chronic inflammation were independently associated with impaired LA reservoir function. These markers may help to further unravel the pathophysiological processes behind LA maladaptation and improve the management of early LA dysfunction in the community.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders

Subclinical left atrial dysfunction profiles for prediction of cardiac outcome in the general population

Background

Echocardiographic screening for subclinical left atrial (LA) dysfunction might enhance the prediction of cardiac diseases such as atrial fibrillation (AFib) in the community. To date, however, outcome-driven definitions of early-stage LA dysfunction remain scarce.

Purpose

In a large population sample, we sought to extract outcome-driven thresholds for echocardiographic indexes of LA function to define subclinical left atrial (LA) dysfunction and assess the prognostic value of these echocardiographic criteria for prediction of cardiac events.

Methods

In 1306 community-dwelling individuals (mean age, 50.7 years; 51.6% women), we assessed LA function and left ventricular (LV) global longitudinal strain (LS) by echocardiography. Using receiver-operating curve threshold analysis, we derived outcome-driven cut-offs for LA emptying fraction (LAEF) and LA reservoir strain (LARS) that best balanced the cardiac event prediction (i.e. cut-offs yielding the highest Youden index (=sensitivity+specificity-1)). Next, we constructed LA dysfunction profiles and integrative LA/LV strain profiles based on the extracted cut-offs for LAEF and LARS and a validated definition of impaired LV global LS. We assessed the prognostic performance of these profiles in predicting the incidence of cardiac events and AFib (mean follow-up, 8.5 years).

Results

During follow-up, 93 participants experienced a cardiac event (8.3 events/1000 person-years) and 27 developed AFib (2.3 events/1000 person-years). LAEF<55% and LARS<23% yielded the highest Youden indexes and thus provided the most balanced prediction of incident AFib. When applying these cut-offs, abnormal LAEF and LARS were respectively present in 27.0% and 18.1% of the cohort. Abnormal LARS was independently associated with higher risk for cardiac events (hazard ratio (HR) versus normal LA phenotype: 2.11, P=0.0021). Both abnormal LAEF (HR: 2.57) and abnormal LARS (HR: 3.28) predicted incident AFib (P≤0.029). As compared to subjects free from any LA dysfunction, those with both LAEF<55% and LARS<23% had a significantly higher risk to develop cardiac events (HR: 2.10; P=0.014) and AFib (HR: 6.45; P=0.0036). Of the integrative LA/LV strain profiles, the concomitant presence of an impaired LARS and LV global LS independently elevated the risk for cardiac events (HR: 2.81; P=0.0012) and AFib (HR: 4.36, P=0.0071) as compared to normal counterparts. Both the degree of LA dysfunction and the integrative LA/LV strain profiles improved the prognostic accuracy beyond clinical risk models and risk scores.

Conclusions

We validated population-based and outcome-driven definitions of subclinical LA dysfunction predicting cardiac events independent of conventional risk factors. Echocardiographic screening for subclinical LA and LV systolic dysfunction might enhance the prediction of cardiac diseases such as AFib in the community, empowering clinicians to timely intervene with the disease development.

Prediction of cardiac events

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders, Internal Funds KU Leuven

P2488The 2013 ACC/AHA pooled cohort equations and insulin resistance status for detection of early-stage heart failure in the community

Objectives

Detection of heart failure (HF) in its subclinical phase would allow timely initiation of preventive measures that counter its pathophysiology. Here, we assessed the usefulness of traditional cardiovascular (CV) risk assessment and insulin resistance status to detect early-stage HF.

Methods

In 984 participants (mean age, 57.0 years, 52.3% women), we derived echocardiographic indexes of left ventricular (LV) structure and function and calculated the 10-year risk for a first atherosclerotic CV disease (ASCVD) using the 2013 ACC/AHA risk score. We assessed the discriminatory value of this risk score to detect LV maladaptation and the improvements in reclassification by insulin resistance status (HOMA-IR).

Results

The probability for LV maladaptation rose progressively with the 10-year ASCVD risk increasing. Participants at high 10-year ASCVD risk (>7.5%) had indeed significantly higher odds for LV concentric remodeling (odds ratio, 4.84), LV hypertrophy (OR, 5.93), abnormal LV longitudinal strain (OR, 2.04) and LV diastolic dysfunction (OR, 25.3) as compared to those at low ASCVD risk (<2.5%; P≤0.0003). Adding markers of insulin resistance to the ACC/AHA risk score moderately improved the integrated discrimination and net reclassification of all LV maladaptive phenotypes (P≤0.022) except LV diastolic dysfunction (P≥0.059). LV remodeling and abnormal LS was particularly more likely in insulin-resistant participants with a 10-year ASCVD risk between 5% and 15% than in their insulin-sensitive counterparts.

Prediction of early-stage HF profiles 2013 ACC/AHA risk score Addition of insulin resistance status to the 2013 ACC/AHA risk score AUC (95% CI) Integrated Discrimination Improvement Net Reclassification Improvement Absolute IDI (%) P value NRI (95% CI) P value LV concentric remodeling 0.70 (0.66 to 0.74) 0.0083 (11.3%) 0.022 0.23 (0.067 to 0.39) 0.0058 LV hypertrophy 0.70 (0.66 to 0.74) 0.017 (20.7%) 0.0033 0.27 (0.11 to 0.43) 0.0011 Abnormal LV LS 0.56 (0.53 to 0.62) 0.022 (202.0%) <0.0001 0.33 (0.18 to 0.49) <0.0001 LV diastolic dysfunction 0.82 (0.78 to 0.86) 0.0007 (0.45%) 0.84 0.093 (−0.11 to 0.30) 0.38 ≥2 LV abnormalities 0.76 (0.72 to 0.80) 0.0087 (7.3%) 0.071 0.22 (0.042 to 0.40) 0.016 The integrated discrimination improvement (IDI) and net reclassification improvement (NRI) reflect the improvements in classification by adding insulin resistance (by HOMA-IR) to the 2013 ACC/AHA risk score. HOMA-IR, Homeostatic Model for Assessment of Insulin Resistance; LS, longitudinal strain; LV, left ventricular.

Risk enhancers of LV maladaptation

Conclusions

The 2013 ACC/AHA risk score adequately captured the risk for echocardiographic phenotypes of early-stage HF. As risk enhancer, insulin resistance might improve risk stratification of subclinical HF in subjects at intermediate risk.

Acknowledgement/Funding

The European Union, European Research Council and the Flanders Scientific Research Fund supported this study.

P4419The association between ECG voltage and left-ventricular mass, sex, body size and the distance between the heart and chest wall in college athletes

Background

The ECG is widely used in pre-participation evaluation (PPE) of athletes (ATH). While it is assumed that greater than normal QRS voltages reflect physiologically increased left ventricular mass (LVM), this has not been adequately demonstrated in ATH.

Purpose

To examine the relation between QRS voltage on surface ECG and LVM and explore if the distance from the chest wall to mid-LV (CWLVdis) affects QRS voltage in ATH.

Methods

We examined digitized ECG data and echocardiograms in college ATH, obtained as part of routine PPE in years 2010–16. ECG parameters included R and S-wave voltage components of the Sokolow-Lyon (S-L) and Cornell criteria for LV hypertrophy (i.e. SV1 + RV5-V6 and RaVL + SV3, respectively). Transthoracic 2D echocardiography was used to determine LVM (area-length method) and the CWLVdis (detailed in Fig1A). S-L positive (SV1 + RV5-V6 >35 mV or RaVL >11 mV) ATH were compared to S-L negative by t-test, and univariate correlation and multivariable regression analysis was used to explore independent effects of body characteristics, sex, LVM and CWLVdis on QRS voltage.

Results

Included were 227 ATH (age 18.6±0.7 yr; 85% male; 60%/33% Caucasian/Afro-american). Of these, 66% played American football, 18% volleyball and 16% basketball.

Overall, mean LVM was 174±37 g (range 96–284 g), and BSA-indexed LVM was 78±12 g/m2 (range 49–108 g/m2). Mean CWLVdis was 8.5±1.1 cm (range 5.6–11.3 cm) and was greater in males (p<0.001, Fig1B).

Forty-six ATH (24%, all male) were S-L positive and no ATH were positive according to Cornell criteria. S-L positive ATH had lower BMI (25.3±3.5 vs 26.9±4.9, p=0.012), greater absolute LVM (189.1±31.3 vs. 170.1±37.4 g, p=0.002) and greater BSA-indexed LVM (85.3±10.3 vs. 76.6±11.7 g/m2, p<0.001) than S-L negative ATH. The CWLVdis was similar between S-L positive and negative ATH (8.4±1.2 vs. 8.6±1.1, respectively, p=0.213).

CWLVdis was more strongly correlated to body mass (r=0.73, p<0.001, Fig. 1C) than to height (r=0.34, p<0.001). LVM correlated weakly to ECG voltage as combined in the S-L or Cornell criteria (Fig. 1C). CWLVdis was weakly correlated with R in aVL, V5 and V6 (r=0.21, 0.16 and 0.16, all p<0.02).

In multivariate analysis, male sex (β=0.31), LVM (β=0.45) and body mass index (β=-0.37) were independently associated with the S-L summed voltage (R2 0.26, p<0.001). For Cornell summed voltage, only sex was an independent predictor (β=0.48, R2 0.22, p<001).

Figure 1

Conclusion

The R and S wave ECG amplitudes used in the two most common ECG criteria for LV hypertrophy were weakly related in the highest to lowest order to sex, LVM, body size and the distance from the LV to the chest wall in our college ATH.

P3819Machine learning for predicting early left ventricular abnormalities in the general population

Background

Current heart failure guidelines emphasize the importance of timely detection of subclinical left ventricular (LV) remodelling and dysfunction for more precise risk stratification of asymptomatic subjects. Both LV diastolic dysfunction (LVDD) and LV hypertrophy (LVH) as assessed by echocardiography are known independent prognostic markers of future cardiovascular events in the community. However, selective screening strategies of individuals at risk who would benefit most from in-depth cardiac phenotyping are lacking.

Purpose

We assess the utility of several Machine Learning (ML) classifiers built on clinical and biochemical features for detecting subclinical LV abnormalities.

Methods

We included 1407 participants (mean age, 51 years, 51% women) randomly recruited from the general population. We used echocardiographic parameters reflecting LV diastolic function and structure to define LV abnormalities (LVDD, n=239; LVH, n=135). After that four supervised ML algorithms (Random Forest (RF), Gradient Boosting (GD), Stochastic Gradient Descent (SGD) and Support Vector Machines (SV)) were built based on routine clinical, hemodynamic and laboratory data (features; n=61) to categorize LVDD and LVH (two prediction tasks). We applied a 10-fold stratified cross-validation set-up.

Results

ML classifiers exhibited a high area under the ROC (AUC) for predicting LVDD with values between 88.5% and 93.1% (Figure, left panel). Age, BMI, different components of blood pressure, antihypertensive treatment, routine biomarkers such as serum electrolytes, creatinine, blood sugar, leptin, uric acid, lipid profile, as well as blood cell counts were the top selected features for predicting LVDD. Prediction AUC of ML algorithms for detection of LVH was somewhat lower than for LVDD and ranged from 72.5% to 78.7% (Figure, right panel). The top selected features for LVH classifier were similar to those of LVDD, but also included social class, serum gamma-glutamyl transferase, fasting insulin, plasma renin activity and cortisol.

ROC curves (sensitivity-1-specificity)

Conclusions

ML algorithms combining routinely measured clinical and laboratory data have shown high accuracy of LVDD and LVH prediction. These ML classifiers might be useful to preselect individuals at risk for further in depth echocardiographic examination, monitoring and implementation of preventive strategies in order to delay transition to disease symptoms.

6075Workload adjusted blood pressure response rather than peak systolic blood pressure is associated with increased all-cause mortality in males; results from 7097 treadmill exercise tests

Background

Systolic blood pressure (SBP) is routinely measured during exercise testing (ET) and is in part determined by cardiac output and peripheral vascular resistance. A frequently used threshold for defining hypertensive response to exercise is ≥210 mmHg but this does not account for the fact that SBP is related to workload, via cardiac output.

Purpose

To examine the prognostic implications of considering external workload (METs) adjusted SBP response to exercise.

Methods

We reviewed all symptom-limited treadmill ET in males between 1987 and 2007 at a single centre (inclusion/exclusion criteria detailed in figure 1A). SBP was measured standing at rest and at peak exercise. Workload adjusted BP response with exercise (SBP/MET slope) was calculated as ΔSBP/ΔMET. METs were calculated from peak speed and grade according to the standard American College of Sports Medicine (ACSM) formula. Age-predicted peak METs was calculated as: 18 - 0.15 × age. Ten-year Cox proportional hazard ratios (HR) with 95% confidence intervals were calculated and adjusted as outlined in figure 1B.

Results

7097 subjects were included, of which 1559 (22%) died within 10 years. Survivors were younger (57.2±10.6 y vs. 64.5±10.3 y, p<0.001) and reached higher % of age-predicted METs (97±33% vs. 82±33%, p<0.001). Survivors had higher peak SBP (181±26 vs. 176±27 mmHg, p<0.001) as well as greater ΔSBP (49±22 vs. 42±22 mmHg, p<0.001), while they had lower SBP/MET slope (7.0±4.4 vs. 8.9±6.5 mmHg/MET, p<0.001). A peak SBP ≥210 mmHg was associated with better survival; 10-yr adjusted HR: 0.76 (0.64–0.88, p<0.001). In contrast, a higher SBP/MET slope was associated with increased mortality (table 1).

Table 1. Ten year adjusted hazard ratios Variable HR (95% CI) P Variable HR (95% CI) P Variable HR (95% CI) P Peak SBP, Q1: 100–159 mmHg REF REF Delta SBP, Q1: 1–29 mmHg REF REF SBP/MET slope, Q1: 0.2–4.2 REF REF Peak SBP, Q2: 160–179 mmHg 0.81 (0.71–0.94) 0.006 Delta SBP, Q2: 30–46 mmHg 0.80 (0.70–0.91) 0.001 SBP/MET slope, Q2: 4.3–6.2 0.95 (0.81–1.12) 0.562 Peak SBP, Q3: 180–199 mmHg 0.68 (0.58–0.78) <0.001 Delta SBP, Q3: 47–61 mmHg 0.76 (0.66–0.88) <0.001 SBP/MET slope, Q3: 6.2–9.1 1.18 (1.01–1.37) 0.032 Peak SBP, Q4: ≥200 mmHg 0.60 (0.51–0.69) <0.001 Delta SBP, Q4: ≥62 mmHg 0.59 (0.50–0.69) <0.001 SBP/MET slope, Q4: ≥9.1 1.40 (1.22– 1.62) <0.001 HR, hazard ratio (adjusted according to figure 1B); SBP, systolic blood pressure; MET, metabolic equivalent of task; Q1–Q4, quartiles (Q1 as reference).

Figure 1

Conclusion

Workload adjusted blood pressure response to exercise in contrast to peak BP response was associated with increased mortality in male patients referred for ET. Of note, reaching a BP of at least 210 mmHg (suggested to define a hypertensive response to exercise) was associated with a 24% reduction in all-cause mortality.

Acknowledgement/Funding

K Hedman was supported by post-doc. grants from the Fulbright Commission, the Swedish Society of Medicine, County Council of Östergötland, Sweden

Protecting Effect of Vitamin E against Chromosomal Damage Induced by an Extremely Low-frequency Electromagnetic Field in Murine Bone Marrow Erythrocytes

Living organisms including human are exposed to an electromagnetic field from natural and industrial sources. Genotoxic effects of electromagnetic fields have been reported by several studies. Vitamin E is a lipid-soluble antioxidant that plays an important role in maintaining the integrity and function of cell membranes, nervous system, and reproductive system, among others, by functioning as a defence against oxidative damage. In this research, the protective effects of vitamin E against the chromosomal damage induced by extremely low-frequency electromagnetic field (ELEM) on bone marrow erythrocytes of adult male BALB/c mouse have been studied. Adult male BALB/c mice were intraperitoneally injected with vitamin E, with the dose of 200 mg/kg for 8 days and then exposed to ELEM with the intensity of 50Hz for 4 hours for 4 consecutive days. The mice were dissected and micronucleus assay was performed on the polychromatic erythrocytes (PCE) of their bone marrow. Results show that ELEM could increase the chromosomal damage judged by the higher frequency of MN compared to control. Results also revealed that the frequency of micronucleated polychromatic erythrocytes (MNPCE) had substantially decreased (p<0.00 1) in vitamin E- treated mice compared to untreated. Data suggest the protecting effect of vitamin E in bone marrow cells of Balb/C mice against the ELEM.

Investigating the Vinblastine Induced-Chromosomal Abnormality in the Already Gamma Irradiated L929 Cell Line Using Micronucleus Assay in Cytokinesis Blocked Binucleated Cells

Objectives: Vast number of studies show the relationship between aneuploidy and cancer. Ionizing radiation in addition to induce all kinds of damages to the cells and structure of chromosomes, is also able to induce aneuploidy through direct damages to chromosome division apparatus. Also irradiation of the cells induces mutations in several genes which might be involved in cell division fidelity and play a role in reversing the effect of aneugens. Therefore, irradiation of cells and tissues might produce sensitivity to agents with aneugenic capability in irradiated cells. Methods: To investigate the persistent genomic effect of ionizing irradiation on chromosomal instability, L929 cells were gamma irradiated with the dose of 2 Gy. Cells were left to recover from the harmful effect of irradiation. They were treated with low dose of vinblastine (0.5 ng.ml-1) 72h post-gamma irradiation. Finally, the induced chromosomal abnormalities were scored using micronucleus assay in cytokinesis-blocked binucleated cells (MnBi). Results: Irradiation-recovered L929 cells treated with vinblastine showed a statistically higher frequency of MnBi compared to non-irradiated and vinblastine treated cells. Conclusion: The results indicate that gamma irradiation, in addition to direct induction of chromosomal damages, is also able to create persisting genomic sensitivity in the cells to chromosomal instability, which is detectable when exposed to the second stimulus.

Diagnostic workup, etiologies and management of acute right ventricle failure : A state-of-the-art paper

INTRODUCTION

This is a state-of-the-art article of the diagnostic process, etiologies and management of acute right ventricular (RV) failure in critically ill patients. It is based on a large review of previously published articles in the field, as well as the expertise of the authors.

RESULTS

The authors propose the ten key points and directions for future research in the field. RV failure (RVF) is frequent in the ICU, magnified by the frequent need for positive pressure ventilation. While no universal definition of RVF is accepted, we propose that RVF may be defined as a state in which the right ventricle is unable to meet the demands for blood flow without excessive use of the Frank-Starling mechanism (i.e. increase in stroke volume associated with increased preload). Both echocardiography and hemodynamic monitoring play a central role in the evaluation of RVF in the ICU. Management of RVF includes treatment of the causes, respiratory optimization and hemodynamic support. The administration of fluids is potentially deleterious and unlikely to lead to improvement in cardiac output in the majority of cases. Vasopressors are needed in the setting of shock to restore the systemic pressure and avoid RV ischemia; inotropic drug or inodilator therapies may also be needed. In the most severe cases, recent mechanical circulatory support devices are proposed to unload the RV and improve organ perfusion CONCLUSION: RV function evaluation is key in the critically-ill patients for hemodynamic management, as fluid optimization, vasopressor strategy and respiratory support. RV failure may be diagnosed by the association of different devices and parameters, while echocardiography is crucial.

Pilot feasibility study to detect mesenchymal stem cell biomarkers of bronchopulmonary dysplasia in the tracheal aspirate fluid of preterm infants

OBJECTIVE

This study aimed to detect novel mesenchymal stem cell peptides/biomarkers of bronchopulmonary dysplasia (BPD) in the tracheal aspirate fluid (TAF) of preterm infants.

STUDY DESIGN

Participants included infants less than 32 weeks' gestational age or birth weight under 1500 grams who required endotracheal intubation and mechanical ventilation within first 24 hours of life. TAF sample collection was performed at the time of the first clinically indicated routine suctioning. Standardization curves for human levels of osteopontin (Opn), macrophage colony stimulating factor 1 (Csf1), transforming growth factor beta 1 (TGF-β1), and secretory immunoglobulin A (sIgA) were generated for 15 enrolled participants.

RESULTS

We demonstrated that stem cell biomarkers are secreted into the TAF of preterm infants and their concentrations can be easily measured during the first week of life.

CONCLUSIONS

Further studies are warranted to determine a causal relationship between these biomarkers and BPD development and severity.