Simultaneous influence of sex and age on blood pressure difference between supine and sitting body positions

OBJECTIVES

Doctors' offices and outpatient departments typically measure blood pressure (BP) with the patient in a sitting position, whereas inpatient departments also use the supine position. As sex and age influence the autonomic function associated with BP regulation our study compared BP measurements in supine and sitting positions for men and women of different ages.

METHODS

We included 91 men and 118 women (≥18 years) without severe diseases. Hypertension was not an exclusion criterion because it is common in older persons. Mean left brachial BP and heart rate were determined by a digital sphygmomanometer in supine position as well as in sitting position before and after hand force measurement.

RESULTS

In a supine position women had slightly lower diastolic BP values than men. After sitting up, the diastolic BP increased in nearly all subjects. This increase was greater in women older than 50 years than for aged-matched men. In contrast to diastolic BP the systolic BP increased after sitting up in only two thirds of the subjects. Especially in women younger than 50 years the systolic BP often did not increase but decreased in response to postural change. The pulse pressure was mostly reduced after sitting up. This reduction was more pronounced in women than men independent of age and physical effort (i.e. hand force measurement). The sitting position also caused an increased heart rate, which was independent of sex and age.

CONCLUSION

Postural changes in the systolic and diastolic BP simultaneously depend on sex and age that needs to be considered for BP measurements in supine and sitting body positions.

It's all in our skin-Skin autofluorescence-A promising outcome predictor in cardiac surgery: A single centre cohort study

BACKGROUND

The optimum risk score determining perioperative mortality and morbidity in cardiac surgery remains debated. Advanced glycation end products (AGEs) derived from glycaemic and oxidative stress accumulate to a comparable amount in skin and the cardiovascular system leading to a decline in organ function. We aimed to study the association between AGE accumulation measured as skin autofluorescence (sAF) and the outcome of cardiac surgery patients.

METHODS

Between April 2008 and November 2016, data from 758 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement or a combined procedure were analyzed. Skin autofluorescence was measured using an autofluorescence reader. Beside mortality, for the combined categorical morbidity outcome of each patient failure of the cardiac-, pulmonary-, renal- and cerebral system, as well as reoperation and wound healing disorders were counted. Patients without or with only one of the outcomes were assigned zero points whereas more than one outcome failure resulted in one point. Odds ratios (ORs) were estimated in multivariable logistic regression analysis with other preoperative parameters and the established cardiac surgery risk score systems EuroSCORE II and STS score.

RESULTS

Skin autofluorescence as non-invasive marker of tissue glycation provided the best prognostic value in identifying patients with major morbidity risks after cardiac surgery (OR = 3.13; 95%CI 2.16-4.54). With respect to mortality prediction the STS score (OR = 1.24; 95%CI 1.03-1.5) was superior compared to the EuroSCORE II (OR = 1.17: 95%CI 0.96-1.43), but not superior when compared to sAF (OR = 6.04; 95%CI 2.44-14.95).

CONCLUSION

This finding suggests that skin autofluorescence is a good biomarker candidate to assess the perioperative risk of patients in cardiac surgery. Since the EuroSCORE does not contain a morbidity component, in our view further sAF measurement is an option.

Characterization of Biostable Atomic Layer Deposited (ALD) Multilayer Passivation Coatings for Active Implants

The next generation of flexible, electrically active implants, such as brain implants or retina chips require a flexible, biostable as well as biocompatible passivation, ensuring a degradation-free usage for long time periods on the order of several years. Until today, these passivations are prepared mostly by polyimides or parylene, both of which are water vapor permeable to a certain degree. To remedy this deficiency, Atomic Layer Deposited (ALD) thin films are characterized regarding their electrical passivating features under conditions of accelerated aging, such as elevated temperatures in a liquid environment. The initial electrical passivation by various ALD deposited multilayers, combining alternating thin Al₂O₃ and TiO₂ layers is the goal of this research as well as the stability of these layers under induced degradation. Such layers, in combination with a parylene passivation, would ensure a water vapor impermeable and biocompatible coating.

Evidence for Arrhythmogenic Effects of A2A-Adenosine Receptors

Adenosine can be released from the heart and may stimulate four different cardiac adenosine receptors. A receptor subtype that couples to the generation of cyclic adenosine monophosphate (cAMP) is the A_2A-adenosine receptor (A_2A-AR). To better understand its role in cardiac function, we studied mechanical and electrophysiological effects in transgenic mice that overexpress the human A_2A-AR in cardiomyocytes (A_2A-TG). We used isolated preparations from the left atrium, the right atrium, isolated perfused hearts with surface electrocardiogram (ECG) recording, and surface body ECG recordings of living mice. The hypothesized arrhythmogenic effects of transgenicity per se and A_2A-AR stimulation were studied. We noted an increase in the incidence of supraventricular and ventricular arrhythmias under these conditions in A_2A-TG. Moreover, we noted that the A_2A-AR agonist CGS 21680 exerted positive inotropic effect in isolated human electrically driven (1 Hz) right atrial trabeculae carneae. We conclude that A_2A-ARs are functional not only in A_2A-TG but also in isolated human atrial preparations. A_2A-ARs in A_2A-TG per se and their stimulation can lead to cardiac arrhythmias not only in isolated cardiac preparations from A_2A-TG but also in living A_2A-TG.

On inotropic effects of UTP in the human heart

Uridine 5'-triphosphate (UTP) exerts a positive inotropic effect (PIE) in isolated electrically driven isolated right atrial trabeculae carneae from patients undergoing heart surgery. This review discusses some aspects of the current knowledge on the putative receptor(s) involved and the potential biochemical transduction steps leading to the PIE.

Regularized differential evolution for a blind phase retrieval problem in ultrashort laser pulse characterization

Obtaining the temporal shape of an ultrashort laser pulse using the method of dispersion scan entails solving a nonlinear inverse problem, a challenging prospect on its own, yet still aggravated when the pulse shape being measured is temporally varying from pulse to pulse. For this purpose, we use a Differential Evolution (DE) algorithm enhanced by three different regularization methods. The DE algorithm in its standard form is insufficient for reconstructing the pulse in the case of unstable pulse trains. By modifying it to retrieve two independent functions and with the help of regularization, we were able to show that it is possible to simultaneously infer the average length and the coherence length of the pulses. The latter is the shortest pulse the laser source can produce. We also discuss the three different approaches for regularization used in this paper, and from the numerical results we present, we can conclude that a spline-based regularization method is far superior compared to the two other methods under investigation.

Positive impact of retrograde autologous priming in adult patients undergoing cardiac surgery: a randomized clinical trial

BACKGROUND

Adult cardiac surgery with extracorporeal circulation is known to be associated with increased risk of blood transfusion leading to adverse outcomes. Procedures like retrograde autologous priming (RAP) may reduce these negative side effects. This randomized prospective study was initiated to assess whether RAP using specifically designed RAP bag (Terumo) has immediate effects on patient outcome.

METHODS

One hundred eighteen adults undergoing elective CABG or elective aortic valve replacement were randomly assigned by a computer program into two groups: the RAP group (n = 54) in which the retrograde autologous priming was applied and the non-RAP (n = 64) group in which the same setting was used without the possibility to save priming volume. Patient demographics, preoperative characteristics and postoperative outcomes were analyzed for both groups.

RESULTS

The primary endpoint defined as rate of intraoperative blood transfusion was significantly reduced in the RAP-group (p = 0.04). The absolute risk reduction for RAP managed patients was 13.5 percent points. There were no significant differences in operation time and blood loss. No deaths and no myocardial infarctions were observed. The number of patients needed to treat to prevent at least one red blood cell transfusion was around 8 (NNT = 7.42).

CONCLUSIONS

Retrograde autologous priming is a safe and less invasive procedure which achieves clear benefits for adult cardiac surgery patients. In the light of increasing red blood cell transfusion risks and costs and the wish of patients to avoid a transfusion implementation of retrograde autologous priming is an interesting option.

TRIAL REGISTRATION

German Clinical Trials Register ID: DRKS00013512 , registered 04 December 2017.

Mechanism underlying the contractile activity of UTP in the mammalian heart

We previously reported that uridine 5'-triphosphate (UTP), a pyrimidine nucleoside triphosphate produced a concentration- and time-dependent increase in the contraction force in isolated right atrial preparations from patients undergoing cardiac bypass surgery due to angina pectoris. The stimulation of the force of contraction was sustained rather than transient. In the present study, we tried to elucidate the underlying receptor and signal transduction for this effect of UTP. Therefore, we measured the effect of UTP on force of contraction, phosphorylation of p38 and ERK1/2, in human atrial preparations, atrial preparations from genetically modified mice, cardiomyocytes from adult mice and cardiomyocytes from neonatal rats. UTP exerted a positive inotropic effect in isolated electrically driven left atrial preparations from wild-type (WT) mice and P2Y₂-, P2Y₄- and P2Y₆-receptor knockout mice. Therefore, we concluded that these P2Y receptors did not mediate the inotropic effects of UTP in atrial preparations from mice. However, UTP (like ATP) increased the phosphorylation states of p38 and ERK1/2 in neonatal rat cardiomyocytes, adult mouse cardiomyocytes and human atrial tissue in vitro. U0126, a MEK 1/2- signal cascade inhibitor, attenuated this phosphorylation and the positive inotropic effects of UTP in murine and human atrial preparations. We suggest that presently unknown receptors mediate the positive inotropic effect of UTP in murine and human atria. We hypothesize that UTP stimulates inotropy via p38 or ERK1/2 phosphorylation. We speculate that UTP may be a valuable target in the development of new drugs aimed at treating human systolic heart failure.

Pharmacological and physiological assessment of serotonin formation and degradation in isolated preparations from mouse and human hearts

Using transgenic (TG) mice that overexpress the human serotonin (5-HT)4a receptor specifically in cardiomyocytes, we wanted to know whether 5-HT can be formed and degraded in the mammalian heart and whether this can likewise lead to inotropic and chronotropic effects in this TG model. We noted that the 5-HT precursor 5-hydroxy-tryptophan (5-HTP) can exert inotropic and chronotropic effects in cardiac preparations from TG mice but not from wild-type (WT) mice; similar results were found in human atrial preparations as well as in intact TG animals using echocardiography. Moreover, by immunohistochemistry we could detect 5-HT metabolizing enzymes and 5-HT transporters in mouse hearts as well as in human atria. Hence, in the presence of an inhibitor of aromatic l-amino acid decarboxylase, the positive inotropic effects of 5-HTP were absent in TG and isolated human atrial preparations, and, moreover, inhibitors of enzymes involved in 5-HT degradation enhanced the efficacy of 5-HT in TG atria. A releaser of neurotransmitters increased inotropy in the isolated TG atrium, and this effect could be blocked by a 5-HT4a receptor antagonist. Fluoxetine, an inhibitor of 5-HT uptake, elevated the potency of 5-HT to increase contractility in the TG atrium. In addition, inhibitors of organic cation and monoamine transporters apparently reduced the positive inotropic potency of 5-HT in the TG atrium. Hence, we tentatively conclude that a local production and degradation of 5-HT in the mammalian heart and more specifically in mammalian myocytes probably occurs. Conceivably, this formation of 5-HT and possibly impaired degradation may be clinically relevant in cases of unexplained tachycardia and other arrhythmias.

NEW & NOTEWORTHY The present work suggests that inotropically active serotonin (5-HT) can be formed in the mouse and human heart and probably by cardiomyocytes themselves. Moreover, active degradation of 5-HT seems to occur in the mammalian heart. These findings may again increase the interest of researchers for cardiac effects of 5-HT.

Cardiac surgery score (CASUS) improves outcome prediction in patients treated with extracorporal life support (ECLS)

INTRODUCTION

The often-unexpected necessity of extracorporeal life support (ECLS) implies that information on patients and end-organ functions at time of implantation is scarce. However, there is a need for early prognostic indicators and a score predicting the outcome. Therefore, we evaluated established laboratory parameters and widely used intensive care scores - cardiac surgery score (CASUS) and sequential organ failure assessment (SOFA) after ECLS implantation.

METHODS

In this retrospective analysis, 90 consecutive adult patients with veno-arterial ECLS were included. Baseline demographic data, laboratory markers, CASUS and SOFA were acquired 12 h after ECLS implantation.

RESULTS

A total of 61 patients (67.8%) could be weaned from ECLS and 48 patients (53.3%) were discharged from hospital. Four patients were switched to a left ventricular assist device. The outcome did not depend on indication for ECLS. Furthermore, multivariable regression analysis identified lactate (OR=1.08; 95%CI: 1.01-1.26; p=0.03) and urine output (OR=0.99; 95%CI: 0.986-0.998; p=0.01) as independent predictors of in-hospital mortality. Evaluating intensive care scores, CASUS (AUROC=0.68; 95%CI: 0.57-0.77; p=0.002) had a higher prognostic relevance in comparison with SOFA (AUROC=0.58; 95%CI: 0.47-0.69; p=0.187).

CONCLUSIONS

Our data indicate that lactate and urine output are early independent predictors for in-hospital mortality of ECLS patients. The CASUS proved to be a satisfactory evaluation tool with good prognostic abilities in these special patients.

Why is it so difficult to integrate ethics in Health Technology Assessment (HTA)? The epistemological viewpoint

Ethics has been identified as a key element in Health Technology Assessment (HTA) since its conception. However, ethical issues are still not frequently addressed explicitly in HTA. Several valuable reasons have been identified. The basis of the article is the claim that ethics is often not part of HTA for "epistemological reasons". Hence, the main aim of the contribution is to explore in more details and emphasize them by using the fact/value dichotomy. Our conclusion is that current HTA configuration is predominantly based on the comparison among objective and empirically testable "facts", whilst ethics is not empirically testable. In this sense, there is a sort of "epistemological gap", which can explain why it is so difficult to integrate ethics in HTA. We suggest that the epistemological differences among the various domains of HTA are addressed more explicitly.