Morning pulmonary artery pressure measurements by CardioMEMS are most stable and recommended for pressure trends monitoring.

AIMS: The CardioMEMS HF system is used to measure pulmonary artery (PA) pressures of patients with heart failure (HF). The goal of this study was to determine the impact of time in the daily PA pressure measurements, considering variance and influence of circadian rhythms on cardiovascular pathophysiology. METHODS AND RESULTS: The study included 10 patients with HF with reduced ejection fraction (LVEF < 40%; New York Heart Association class III). Individual daily PA pressures were obtained by CardioMEMS sensors, per protocol, measured up to six times throughout the day, for a period of 5 days. Differences between variation of morning versus evening PA pressures were compared with Wilcoxon signed-rank test. Mean PA pressures (mPAP) increased from a morning value of 19.1 ± 2 mm Hg (8 am; mean ± standard error of the mean [SEM]) to 21.3 ± 2 mm Hg late in the evening (11 pm; mean ± SEM). Over the course of 5 days, evening mPAP exhibited a significantly higher median coefficient of variation than morning mPAP (14.9 (interquartile range [IQR] 7.6-21.0) and 7.0 (IQR 5.0-12.8) respectively; p = 0.01). The same daily pattern of pressure variability was observed in diastolic (p = 0.01) and systolic (p = 0.04) pressures, with diastolic pressures being more variable than systolic at all time points. CONCLUSIONS: Morning PA pressure measurements yield more stable values for observing PA trends. Patients should thus be advised to consistently perform their daily PA pressure measurements early in the morning. This will improve reliability and interpretation of the CardioMEMS management, indicating true alterations in the patient's health status, rather than time-of-day-dependent variations.

Listing criteria for heart transplantation in the Netherlands.

The updated listing criteria for heart transplantation are presented on behalf of the three heart transplant centres in the Netherlands. Given the shortage of donor hearts, selection of those patients who may expect to have the greatest benefit from a scarce societal resource in terms of life expectancy and quality of life is inevitable. The indication for heart transplantation includes end-stage heart disease not remediable by more conservative measures, accompanied by severe physical limitation while on optimal medical therapy, including ICD/CRT­D. Assessment of this condition requires cardiopulmonary stress testing, prognostic stratification and invasive haemodynamic measurements. Timely referral to a tertiary centre is essential for an optimal outcome. Chronic mechanical circulatory support is being used more and more as an alternative to heart transplantation and to bridge the progressively longer waiting time for heart transplantation and, thus, has become an important treatment option for patients with advanced heart failure.

Twelve years of circulatory extracorporeal life support at the University Medical Centre Utrecht.

INTRODUCTION: Circulatory extracorporeal life support (ECLS) has been performed at the University Medical Centre Utrecht for 12 years. During this time, case mix, indications, ECLS set-ups and outcomes seem to have substantially changed. We set out to describe these characteristics and their evolution over time. METHODS: All patients receiving circulatory ECLS between 2007 and 2018 were retrospectively identified and divided into six groups according to a 2-year period of time corresponding to the date of ECLS initiation. General characteristics plus data pertaining to comorbidities, indications and technical details of ECLS commencement as well as in-hospital, 30-day, 1­year and overall mortality were collected. Temporal trends in these characteristics were examined. RESULTS: A total of 347 circulatory ECLS runs were performed in 289 patients. The number of patients and ECLS runs increased from 8 till a maximum of 40 runs a year. The distribution of circulatory ECLS indications shifted from predominantly postcardiotomy to a wider set of indications. The proportion of peripheral insertions with or without application of left ventricular unloading techniques substantially increased, while in-hospital, 30-day, 1­year and overall mortality decreased over time. CONCLUSION: Circulatory ECLS was increasingly applied at the University Medical Centre Utrecht. Over time, indications as well as treatment goals broadened, and cannulation techniques shifted from central to mainly peripheral approaches. Meanwhile, weaning success increased and mortality rates diminished.

The role of long-term mechanical circulatory support in patients with advanced heart failure.

In patients with end-stage heart failure, advanced therapies such as heart transplantation and long-term mechanical circulatory support (MCS) with a left ventricular assist device (LVAD) have to be considered. LVADs can be implanted as a bridge to transplantation or as an alternative to heart transplantation: destination therapy. In the Netherlands, long-term LVAD therapy is gaining importance as a result of increased prevalence of heart failure together with a low number of heart transplantations due to shortage of donor hearts. As a result, the difference between bridge to transplantation and destination therapy is becoming more artificial since, at present, most patients initially implanted as bridge to transplantation end up receiving extended LVAD therapy. Following LVAD implantation, survival after 1, 2 and 3 years is 83%, 76% and 70%, respectively. Quality of life improves substantially despite important adverse events such as device-related infection, stroke, major bleeding and right heart failure. Early referral of potential candidates for long-term MCS is of utmost importance and positively influences outcome. In this review, an overview of the indications, contraindications, patient selection, clinical outcome and optimal time of referral for long-term MCS is given.

Outcome of mechanical circulatory support at the University Medical Centre Utrecht.

BACKGROUND: The prevalence of heart failure (HF) is increasing substantially and, despite improvements in medical therapy, HF still carries a poor prognosis. Mechanical circulatory support (MCS) by a continuous-flow left ventricular assist device (cf-LVAD) improves survival and quality of life in selected patients. This holds especially for the short-term outcome, but experience regarding long-term outcome is growing as the waiting time for heart transplantation is increasing due to the shortage of donor hearts. Here we present our results from the University Medical Centre Utrecht. METHODS: Data of all patients with a cf-LVAD implant between March 2006 and January 2018 were collected. The primary outcome was survival. Secondary outcomes included adverse events defined according to the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) definitions, described per patient year. RESULTS: A total of 268 patients (69% male, mean age 50 ± 13 years) received a cf-LVAD. After a median follow-up of 542 (interquartile range 205-1044) days, heart transplantation had been performed in 82 (31%) patients, the cf-LVAD had been explanted in 8 (3%) and 71 (26%) had died. Survival at 1, 3 and 5 years was 83%, 72% and 57%, respectively, with heart transplantation, cf-LVAD explantation or death as the end-point. Death was most often caused by neurological complications (31%) or infection (20%). Major bleeding occurred 0.51 times and stroke 0.15 times per patient year. CONCLUSION: Not only short-term results but also 5­year survival after cf-LVAD support demonstrate that MCS is a promising therapy as an extended bridge to heart transplantation. However, the incidence of several major complications still has to be addressed.

Oil droplet formation on pellicle covered tooth surfaces studied with environmental scanning electron microscopy.

Lipophilic components are known to modulate the process of bioadhesion on the tooth surface. However, the presence of lipid droplets at the acquired pellicle under oral conditions has not been demonstrated, yet. The purpose of the present study was to establish a method for direct visualisation of lipids on the surface of hydrated, pellicle covered tooth samples by environmental scanning electron microscopy (ESEM), and to use this technique for studying the effects of rinsing with edible oils on the acquired pellicle under in vivo conditions. In situ pellicle formation was performed by 3 min exposure of enamel and dentin specimens in the oral cavity of volunteers. Subsequently, the volunteers rinsed in vivo with safflower oil or linseed oil for 30 s, and the specimens were further carried intraorally for periods from 0 min up to several hours. After intraoral exposure the specimens were treated by osmium tetroxide vapour, and were subsequently analysed by ESEM. This technique was capable to directly visualise the presence of lipid droplets at the pellicle's surface under hydrated conditions. ESEM analyses revealed that surface bound nano- and micro-sized lipid droplets were present at the acquired pellicle's surface even several hours after rinsing with edible oils indicating that these droplets had tightly adhered to the pellicle surface. Pellicle modification by edible oil rinsing as demonstrated in the present study might have the potential to be beneficial as an adjunct in dental prophylaxis.

Cardiac amyloidosis: the need for early diagnosis.

Amyloidosis is a collection of systemic diseases characterised by misfolding of previously soluble precursor proteins that become infiltrative depositions, thereby disrupting normal organ structure and function. In the heart, accumulating amyloid fibrils lead to progressive ventricular wall thickening and stiffness, resulting in diastolic dysfunction gradually progressing to a restrictive cardiomyopathy. The main types of cardiac amyloidosis are amyloid light chain (AL) amyloidosis caused by an underlying plasma cell dyscrasia, amyloid transthyretin (TTR) amyloidosis of wild-type (normal) TTR at older age (ATTRwt) and hereditary or mutant amyloid TTR (ATTRm) in which a genetic mutation leads to an unstable TTR protein. Overall survival is poor once heart failure develops, underlining the need for early referral and diagnosis. Treatment for AL amyloidosis has improved markedly over the last decades, and TTR amyloidosis gene silencers and orally available transthyretin stabilisers are ready to enter the clinical arena after recent positive outcome trials. Novel therapies aiming at fibril degradation with monoclonal antibodies are under investigation. In this review, we focus on 'red flag' signs and symptoms, diagnosis and management of cardiac amyloidosis which differs considerably from the general management of heart failure. Only by increasing awareness, prognosis for patients with this devastating disease can be improved.

UNRAVEL: big data analytics research data platform to improve care of patients with cardiomyopathies using routine electronic health records and standardised biobanking.

INTRODUCTION: Despite major advances in our understanding of genetic cardiomyopathies, they remain the leading cause of premature sudden cardiac death and end-stage heart failure in persons under the age of 60 years. Integrated research databases based on a large number of patients may provide a scaffold for future research. Using routine electronic health records and standardised biobanking, big data analysis on a larger number of patients and investigations are possible. In this article, we describe the UNRAVEL research data platform embedded in routine practice to facilitate research in genetic cardiomyopathies. DESIGN: Eligible participants with proven or suspected cardiac disease and their relatives are asked for permission to use their data and to draw blood for biobanking. Routinely collected clinical data are included in a research database by weekly extraction. A text-mining tool has been developed to enrich UNRAVEL with unstructured data in clinical notes. PRELIMINARY RESULTS: Thus far, 828 individuals with a median age of 57 years have been included, 58% of whom are male. All data are captured in a temporal sequence amounting to a total of 18,565 electrocardiograms, 3619 echocardiograms, data from over 20,000 radiological examinations and 650,000 individual laboratory measurements. CONCLUSION: Integration of routine electronic health care in a research data platform allows efficient data collection, including all investigations in chronological sequence. Trials embedded in the electronic health record are now possible, providing cost-effective ways to answer clinical questions. We explicitly welcome national and international collaboration and have provided our protocols and other materials on www.unravelrdp.nl .

Membrane protein stoichiometry studied in intact mammalian cells using liquid-phase electron microscopy.

Receptor membrane proteins in the plasma membranes of cells respond to extracellular chemical signals by conformational changes, spatial redistribution, and (re-)assembly into protein complexes, for example, into homodimers (pairs of the same protein type). The functional state of the proteins can be determined from information about how subunits are assembled into protein complexes. Stoichiometric information about the protein complex subunits, however, is generally not obtained from intact cells but from pooled material extracted from many cells, resulting in a lack of fundamental knowledge about the functioning of membrane proteins. First, functional states may dramatically differ from cell to cell on account of cell heterogeneity. Second, extracting the membrane proteins from the plasma membrane may lead to many artefacts. Liquid-phase scanning transmission electron microscopy (STEM), in short liquid STEM, is a new technique capable of determining the locations of individual membrane proteins within the intact plasma membranes of cells in liquid. Many tens of whole cells can readily be imaged. It is possible to analyse the stoichiometry of membrane proteins in single cells while accounting for heterogenic cell populations. Liquid STEM was used to image epidermal growth factor receptors in whole COS7 cells. A study of the dimerisation of the HER2 protein in breast cancer cells revealed the presence of rare cancer cells in which HER2 was in a different functional state than in the bulk cells. Stoichiometric information about receptors is essential not only for basic science but also for biomedical application because they present many important pharmaceutical targets.

Extracorporeal life support in cardiogenic shock: indications and management in current practice.

Veno-arterial extracorporeal life support (VA-ECLS) provides circulatory and respiratory stabilisation in patients with severe refractory cardiogenic shock. Although randomised controlled trials are lacking, the use of VA-ECLS is increasing and observational studies repeatedly have shown treatment benefits in well-selected patients. Current clinical challenges in VA-ECLS relate to optimal management of the individual patient on extracorporeal support given its inherent complexity. In this review article we will discuss indications, daily clinical management and complications of VA-ECLS in cardiogenic shock refractory to conventional treatment strategies.

Donor-Specific Antibodies Are Produced Locally in Ectopic Lymphoid Structures in Cardiac Allografts.

Cardiac allograft vasculopathy (CAV) is a transplant pathology, limiting graft survival after heart transplantation. CAV arteries are surrounded by ectopic lymphoid structures (ELS) containing B cells and plasma cells. The aim of this study was to characterize the antigenic targets of antibodies produced in ELS. Coronary arteries and surrounding epicardial tissue from 56 transplant recipients were collected during autopsy. Immunofluorescence was used to identify antibody-producing plasma cells. Immunoglobulin levels in tissue lysates were measured by enzyme-linked immunosorbent assay and analyzed for donor-specific HLA antibodies by Luminex assay. Cytokine and receptor expression levels were quantified using quantitative polymerase chain reaction. Plasma cells in ELS were polyclonal and produced IgG and/or IgM antibodies. In epicardial tissue, IgG (p < 0.05) and IgM levels were higher in transplant patients with larger ELS than smaller ELS. In 4 of 21 (19%) patients with ELS, donor-specific HLA type II antibodies were detected locally. Cytokine and receptor expression (CXCR3, interferon γ and TGF-ß) was higher in large ELS in the epicardial tissue than in other vessel wall layers, suggesting active recruitment and proliferation of T and B lymphocytes. ELS exhibited active plasma cells producing locally manufactured antibodies that, in some cases, were directed against the donor HLA, potentially mediating rejection with major consequences for the graft.

Thirty years of heart transplantation at the University Medical Centre Utrecht.

PURPOSE: To analyse patient demographics, indications, survival and donor characteristics for heart transplantation (HTx) during the past 30 years at the University Medical Centre Utrecht (UMCU). METHODS: Data have been prospectively collected for all patients who underwent HTx at the UMCU from 1985 until 2015. Patients who were included underwent orthotopic HTx at an age >14 years. RESULTS: In total, 489 hearts have been transplanted since 1985; 120 patients (25%) had left ventricular assist device (LVAD) implantation prior to HTx. A shift from ischaemic heart disease to dilated cardiomyopathy has been seen as the leading indication for HTx since the year 2000. Median age at HTx was 49 years (range 16-68). Median waiting time and donor age have also increased from 40 to 513 days and from 27 to 44 years respectively (range 11-65). Donor cause of death is now primarily stroke, in contrast to head and brain injury in earlier years. Estimated median survival is 15.4 years (95% confidence interval 14.2-16.6) There is better survival throughout these years. CONCLUSION: Over the past 30 years, patient and donor demographics and underlying diseases have shifted substantially. Furthermore, the increase in waiting time due to lack of available donor hearts has led to a rise in the use of LVADs as bridge to transplant. Importantly, an improvement in survival rates is found over time which could be explained by better immunosuppressive therapy and improvements in follow-up care.

Left ventricular assist devices: a kidney's perspective.

The left ventricular assist device (LVAD) has become an established treatment option for patients with refractory heart failure. Many of these patients experience chronic kidney disease (CKD) due to chronic cardiorenal syndrome type II, which is often alleviated quickly following LVAD implantation. Nevertheless, reversibility of CKD remains difficult to predict. Interestingly, initial recovery of GFR appears to be transient, being followed by gradual but significant late decline. Nevertheless, GFR often remains elevated compared to preimplant status. Larger GFR increases are followed by a proportionally larger late decline. Several explanations for this gradual decline in renal function after LVAD therapy have been proposed, yet a definitive answer remains elusive. Mortality predictors of LVAD implantation are the occurrence of either postimplantation acute kidney injury (AKI) or preimplant CKD. However, patient outcomes continue to improve as LVAD therapy becomes more widespread, and adverse events including AKI appear to decline. In light of a growing destination therapy population, it is important to understand the cumulative effects of long-term LVAD support on kidney function. Additional research and passage of time are required to further unravel the intricate relationships between the LVAD and the kidney.

Plasma levels of alpha-1-antichymotrypsin are elevated in patients with chronic heart failure, but are of limited prognostic value.

BACKGROUND: There is increasing interest in utilising novel markers of cardiovascular disease risk in patients with chronic heart failure (HF). Recently, it was shown that alpha-1-antichymotrypsin (ACT), an acute-phase protein and major inhibitor of cathpesin G, plays a role in the pathophysiology of HF and may serve as a marker for myocardial distress. OBJECTIVE: To assess whether ACT is independently associated with long-term mortality in chronic HF patients. METHODS: ACT plasma levels were categorised into quartiles. Survival times were analysed using Kaplan-Meier curves and Cox proportional hazards regression, without and with correction for clinically relevant risk factors, including sex, age, duration of HF, kidney function (MDRD), ischaemic HF aetiology and NT-proBNP. RESULTS: Twenty healthy individuals and 224 patients (mean age 71 years, 72 % male, median HF duration 1.6 years) with chronic HF were included. In total, 159 (71 %) patients died. The median survival time was 5.3 (95 % CI 4.5-6.1) years. ACT was significantly elevated in patients (median 433 µg/ml, IQR 279-680) in comparison with controls (median 214 µg/ml, IQR 166-271; p < 0.001). Cox regression analysis demonstrated that ACT was not independently related to long-term mortality in chronic HF patients (crude HR = 1.03, 95 % CI 0.75-1.41, p = 0.871; adjusted HR = 1.12, 95 % CI 0.78-1.60, p = 0.552), which was confirmed by Kaplan-Meier curves. CONCLUSION: ACT levels are elevated in chronic HF patients, but no independent association with long-term mortality can be established.

Integrated biological system for remediation and valorization of tannery wastewater: Focus on microbial communities responsible for methanogenesis and sulfidogenesis.

Microbial communities in hybrid linear flow channel reactors and anaerobic sequencing batch reactors operated in series for remediation and beneficiation of tannery wastewater were assessed. Despite concurrent sulfidogenesis, more intensive pre-treatment in hybrid linear flow channel reactors reduced methanogenic inhibition usually associated with anaerobic digestion of tannery effluent and promoted efficiency (max 321 mLCH4/gCODconsumed, 59% biogas CH4). Nitrification and biological sulfate reduction were key metabolic pathways involved in overall and sulfate reducing bacterial community selection, respectively, during pre-treatment. Taxonomic selection could be explained by the proteinaceous and saline character of tannery effluent, with dominant genera being protein and/or amino acid degrading, halotolerant and/or ammonia tolerant. Complete oxidizers dominated the sulfidogenic populations during pre-treatment, while aceticlastic genera dominated the methanogenic populations during anaerobic digestion. With more intensive pre-treatment, the system shows promise for remediation and recovery of biogas and sulfur from tannery wastewater in support of a bio-circular economy.

Beta-blocker therapy in unstable severe heart failure, evidence or experience?

Currently, no evidence exists on the effects of beta-receptor blocker (BRB) treatment in patients with unstable severe heart failure. When confronted with this specific patient category, clinical experience in our centre has consistently guided us to lower the dose or stop BRB therapy. To share this experience, we present three clinical case scenarios and discuss background literature motivating our approach in these patients.

Electron microscopy of whole cells in liquid with nanometer resolution.

Single gold-tagged epidermal growth factor (EGF) molecules bound to cellular EGF receptors of fixed fibroblast cells were imaged in liquid with a scanning transmission electron microscope (STEM). The cells were placed in buffer solution in a microfluidic device with electron transparent windows inside the vacuum of the electron microscope. A spatial resolution of 4 nm and a pixel dwell time of 20 micros were obtained. The liquid layer was sufficiently thick to contain the cells with a thickness of 7 +/- 1 microm. The experimental findings are consistent with a theoretical calculation. Liquid STEM is a unique approach for imaging single molecules in whole cells with significantly improved resolution and imaging speed over existing methods.

Indwelling time of peripherally inserted central catheters and incidence of bloodstream infections in haematology patients: a cohort study.

BACKGROUND: We aimed to assess whether longer indwelling time of peripherally inserted central catheters (PICC) increases risk of central line associated bloodstream infections (CLABSI) in haematology patients. METHODS: Multicentre retrospective cohort study among haematology patients receiving PICCs between 2013 and 2015. Occurrence of CLABSI based on CDC definitions was assessed. We calculated incidence rates, determined risk factors for CLABSI and used Poisson regression models to assess the risk of developing CLABSI as a function of PICC dwell time. We compared diagnoses and treatment characteristics between 2013-2015 and 2015-2020. RESULTS: 455 PICCs placed in 370 patients were included, comprising 19,063 catheter days. Median indwelling time was 26 days (range 0-385) and CLABSI incidence was 4.0 per 1000 catheter days, with a median time to CLABSI of 33 days (range 18-158). Aplastic anaemia (AA) was associated with an increased risk of CLABSI; patients undergoing autologous stem cell transplantation (SCT) were less likely to develop CLABSI. In the unadjusted analysis, PICCs with an indwelling time of 15-28 days, 29-42 days, 43-56 days and > 56 days each had an increased CLABSI incidence rate ratio of 2.4 (1.2-4.8), 2.2 (0.95-5.0), 3.4 (1.6-7.5) and 1.7 (0.9-3.5), respectively, compared to PICCs in place for < 15 days. However, after adjusting for AA and SCT, there was no significant difference in incidence rates between dwell times (p 0.067). CONCLUSIONS: Our study shows that risk of CLABSI does not appear to increase with longer PICC indwelling time. Routine replacement of PICCs therefore is unlikely to prevent CLABSI in this population.

Transmission electron microscopy with a liquid flow cell.

The imaging of microscopic structures at nanometre-scale spatial resolution in a liquid environment is of interest for a wide range of studies. Recently, a liquid flow transmission electron microscopy (TEM) holder equipped with a microfluidic cell has been developed and shown to exhibit flow of nanoparticles through an electron transparent viewing window. Here we demonstrate the application of the flow cell system for both scanning and conventional transmission electron microscopy imaging of immobilized nanoparticles with a resolution of a few nanometres in liquid water of micrometre thickness. The spatial resolution of conventional TEM bright field imaging is shown to be limited by chromatic aberration due to multiple inelastic scattering in the water, and we demonstrate that the liquid in the cell can be displaced by a gas phase that forms under intense electron irradiation. Our data suggest that under appropriate conditions, TEM imaging with a liquid flow cell is a promising method for understanding the in situ behaviour of nanoscale structures in a prescribed and dynamically changing chemical environment.

Silicon nitride windows for electron microscopy of whole cells.

Silicon microchips with thin, electron transparent silicon nitride windows provide a sample support that accommodates both light-, and electron microscopy of whole eukaryotic cells in vacuum or liquid, with minimum sample preparation steps. The windows are robust enough that cellular samples can be cultured directly onto them, with no addition of a supporting film, and there is no need to embed or section the sample, as is typically required in electron microscopy. By combining two microchips, a microfluidic chamber can be constructed for the imaging of samples in liquid in the electron microscope. We provide microchip design specifications, a fabrication outline, instructions on how to prepare the microchips for biological samples, and examples of images obtained using different light and electron microscopy modalities. The use of these microchips is particularly advantageous for correlative light and electron microscopy.