Early Initiation of Sacubitril/Valsartan in Patients With Acute Heart Failure and Renal Dysfunction: An Analysis of the TRANSITION Study

BACKGROUND

Treatment of patients with heart failure with reduced ejection fraction (HFrEF) and renal dysfunction (RD) is challenging owing to the risk of further deterioration in renal function, especially after acute decompensated HF (ADHF).

METHODS AND RESULTS

We assessed the effect of RD (estimated glomerular filtration rate of ≥30 to <60 mL/min/1.73 m2) on initiation, up-titration, and tolerability of sacubitril/valsartan in hemodynamically stabilized patients with HFrEF admitted for ADHF (RD, n = 476; non-RD, n = 483). At week 10, the target dose of sacubitril/valsartan (97/103 mg twice daily) was achieved by 42% patients in RD subgroup vs 54% in non-RD patients (P < .001). Sacubitril/valsartan was associated with greater estimated glomerular filtration rate improvements in RD subgroup than non-RD (change from baseline least squares mean 4.1 mL/min/1.73 m2, 95% confidence interval 2.2-6.1, P < .001). Cardiac biomarkers improved significantly in both subgroups; however, compared with the RD subgroup, the improvement was greater in those without RD (N-terminal pro-brain natriuretic peptide, -28.6% vs -44.8%, high-sensitivity troponin T -20.3% vs -33.9%) (P < .001). Patients in the RD subgroup compared with those without RD experienced higher rates of hyperkalemia (16.3% vs 6.5%, P < .001), investigator-reported cardiac failure (9.7% vs 5.6%, P = .029), and renal impairment (6.4% vs 2.1%, P = .002).

CONCLUSIONS

Most patients with HFrEF and concomitant RD hospitalized for ADHF tolerated early initiation of sacubitril/valsartan and showed significant improvements in estimated glomerular filtration rate and cardiac biomarkers.

CLINICAL TRIAL REGISTRATION

NCT02661217.

Cardiomyopathy associated with right ventricular apical pacing – systematic review and meta-analysis

Aims

Bradyarrhythmias are potentially life threatening medical conditions. The most widespread type of treatment of slow rhythms is artificial ventricular pacing. From the inception of the idea of artificial pacing, ventricular lead was located in the apex of the right ventricle. Right ventricular pacing (RVP) was thought to have deteriorating effect on left ventricular systolic function. The aim of this study was to systematically assess results of randomized controlled trials of the right ventricular pacing on left ventricular ejection fraction (LVEF).

Methods

We systematically searched the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE databases for studies evaluating the influence of the RVP on the LVEF. Pooled mean difference (MD) with a 95% confidence interval (CI) was estimated using a random effect model.

Results

15 randomized controlled trials (RCTs) comprising 951 patients were included. The mean follow-up in the included studies ranged between 6 to 24 months. In our meta-analysis, RV pacing was associated with statistically significant (MD 2.91; 95% confidence interval (CI): 1.07–4.75) left ventricular systolic function impairment measured by LVEF.

Conclusion

Our meta-analysis confirms, that the right ventricular pacing is associated with progressive deterioration of the left ventricular systolic function.

Funding Acknowledgement

Type of funding sources: None.

Clinical implications and risk factors for QRS width progression in heart failure patients

Background

QRS complex prolongation is an established prognostic marker in patients with heart failure, (HF) and identifies patients for whom standard treatment includes cardiac resynchronization therapy (CRT). In contrast, the role of QRS width progression over time on clinical status and whether it can be predicted has been incompletely explored.

Purpose

To provide pilot data that could help to identify features associated with QRS progression and deteriorating clinical status.

Methods

The present retrospective analysis relates to 100 consecutive attendees to our HF clinic between April and August 2021. Each patient with a least one past visit including an ECG was included and a maximum of 4 past visits were assessed per patient.

Results

In total 240 datasets were generated from at least two consecutive visits and included clinical status, electrocardiographic (ECG), laboratory and echocardiographic data. Mean age and left ventricular ejection fraction were 58±13 years and 36±10%. The mean time between visits was 227 days. Datasets were stratified into tertiles based on change in QRS duration (mm/month). These were labelled as “QRS width regression” (&gt;−0.34 ms/month), “QRS stability” (−0.33 to 0.49 ms/month and “QRS width progression” (&gt;0.50 ms/month).

The incidence of the combined endpoint of worsening symptomatic HF (deterioration in NYHA class by at least one grade) and HF hospitalisation was significantly higher in the QRS progression group compared with the stable group (Log Rank test: progression v stability p=0.013). In addition, patients with QRS progression had a higher baseline plasma NT-pro-BNP levels (p=0.008) and higher baseline heart rate (p=0.007). To explore whether patients at higher risk of QRS progression could be identified at baseline, we built a prediction model based upon baseline NTproBNP levels and baseline heart rate. We determined that an NT-pro-BNP &gt;837 pg/ml and a heart rate &gt;83/bpm were reliable thresholds for greater risk of QRS progression (Figure 1A & B). Both of these variables were independent of guideline-directed medical HF therapy (including beta-antagonist use and dose). An interaction analysis revealed that combining these two risk factors was associated with a 14-fold increased risk of QRS progression compared with neither or either alone, suggesting synergism between these variables (HR: 14.2 [95% 6.9–53.6]; p&lt;0.0001, p for interaction=0.016).

Conclusion

In the current pilot study, we demonstrate that QRS progression is associated with future risk of clinical deterioration of HF. In addition, we show that higher baseline NTproBNP plasma levels combined with higher baseline heart rate indicate a group at markedly increased risk of progression of QRS width, independently of HF therapy. These parameters might therefore identify people potentially benefitting from intensified follow up, optimisation of GDMT and could also help coordinate the application of a more personalised approach to device therapy

Funding Acknowledgement

Type of funding sources: None.

Left ventricular dysfunction, heart failure, and mortality risk factors in de novo pacemaker recipients and those requiring pacemaker generator replacement

Background

Pacing the right ventricle (RV) can lead to adverse remodelling of the left ventricle (LV), LV dysfunction, increased risk of heart failure hospitalisation (HFH) and mortality. Despite RV pacing avoidance programming becoming commonplace, pacemaker patients remain at risk of pacing-induced cardiomyopathy. New pacing strategies and cardiac resynchronisation therapy are available therapeutic options, but it is unclear which patients should be targeted, and when.

Purpose

This study examined the effects of RV pacing on LV function, the risk of heart failure requiring hospitalisation and all-cause mortality in patients during the first 12 months of pacemaker therapy, compared to those at pacemaker generator replacement (PGR).

Methods

Data were obtained from a cohort of patients who underwent de novo pacemaker implantation between 2014 and 2017, and patients requiring PGR between 2008 and 2011 at a single tertiary UK hospital, with follow-up from 12 months. Clinical, echocardiographic, and pacemaker variables, medication, and past medical history data were collected. Predictors of a combined endpoint of all-cause mortality or HFH were assessed using cox-regression analysis, with predictors of impaired LV function analysed using multivariable regression analysis.

Results

514 newly implanted (NI) patients (mean age, 75 years; 66% male) were recruited, and 491 patients (mean age, 76 years; 56% male) requiring PGR. After a mean follow up of 887 days, 79 NI patients (16%) were deceased (n=27) or had been hospitalised for HF (n=52), whereas after a mean follow up of 668 days, 56 patients after PGR (12%) were deceased (n=34) or had been hospitalised (n=22) for HF. After 12 months of pacemaker therapy, 182 (35%) NI patients had a LV ejection fraction (LVEF) &lt;50%, which had a higher incidence at PGR of 197 (40%). Age was the only significant predictor of mortality or HFH for both NI and PGR (hazard ratio (HR), 1.068; 95% confidence interval (CI), 1.039 to 1.098; p&lt;0.001 vs 1.035; 95% CI, 1.007 to 1.064; p=0.014), respectively). Univariate analysis revealed baseline LVEF (2.439; 95 percent CI, 1.279 to 4.659; p=0.007), RV pacing burden, medication and blood chemistry were significant predictors of the combined outcome at PGR but not at NI (Table 2). Multivariable analysis of predictors of LV impairment (&lt;50% LVEF) showed history of MI (odds ratio (OR), 0.47; 95% CI, 0.29 to 0.78; p=0.003), RV pacing burden (1.01; 95% CI, 1.01 to 1.02; p&lt;0.001) and creatinine (1.06; 95% CI, 1.02 to 1.10; p=0.004) were independently associated in both cohorts.

Conclusions

Our data suggest that there remains a similar subgroup of people from initial implantation to PGR at risk of LV impairment that might benefit from medication optimisation or novel pacing strategies. Further research is required to better identifying these people to direct more complex therapies to those with the most to gain.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The research is supported by a National Institute for Health Research (NIHR) clinician scientist fellowship (NIHRCS-2012-032). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. This research was supported by the NIHR Leeds Clinical Research Facility.

Effects of heart failure and diabetes on invasive biomarkers of skeletal muscle wasting

Funding Acknowledgements

Type of funding sources: None.

Background

Muscle wasting is common in patients with diabetes mellitus (DM) and chronic heart failure (HF), which exacerbates cachexia and poor quality of life. However, a gap in clinical translation remains as the mechanisms underlying muscle wasting in DM and HF remain poorly validated, with most evidence assumed from experimental small-animal models.

Purpose

Validate if markers of muscle wasting (e.g., autophagy, proteolysis, myogenesis) were correlated to muscle phenotype and clinical indices in humans with DM and HF.

Method

Male patients with DM (n=4), HF (n=4; NYHA=2), DMHF (n=7; NYHA=2) were included. DM was classified as a HbA1c level ≥48mmol/mol and HF classified as a left ventricular ejection fraction (LVEF) ≤40%, with patients on optimised medication. Muscle biopsies of pectoralis major were excised during routine pacemaker surgery and frozen at -80°C for both histological and gene expression analysis. Muscle samples were sectioned, stained, and imaged for fibre cross-sectional area and fibre type. RT-PCR gene expression was conducted for markers of muscle regeneration (myod, myogenin), protein degradation (myostatin and autophagy-related LC3B, ATG7, CTSL), and anabolic signalling (IGF-1). Statistical analysis included ANOVAs and correlation analysis to identify relationships between variables. Values of p&lt;0.05 were accepted as significant.

Results

Groups (DM, HF, DMHF) were not different (P&gt;0.05) in relation to age (79±9, 72±8, 72±10 years) or BMI (24.5±3.6, 28.5±4.2, 29.5±6.0) respectively. Fibre size or fibre type were not different (P&gt;0.05) between groups. In line with this, gene expression for markers of myogenesis and anabolism as well as myostatin were not different (P&gt;0.05) between groups, but a trend in downregulation of the proteolytic autophagy-related genes (LC3B, ATG7, CTSL) in DMHF vs DM or HF was found on average by 21, 36, and 30% respectively. Autophagy-related genes LC3B, ATG7, CTSL were positively correlated (P&lt;0.05) to type IIa fibre numerical density (R=0.82, 0.86, 0.89) and LVEF (R=0.85, 0.92, 0.83), respectively.

Conclusion

Our findings indicate that gene expression of autophagy could represent a robust marker of muscle wasting and cardiac dysfunction in humans with DM and HF. Muscle biopsies from patients with DM and HF identified the proteolytic system of autophagy, important for cellular homeostasis, may be inhibited and this was correlated to fibre phenotype and LVEF. However, the process of muscle wasting in DM and HF within the clinical setting may not necessarily reflect those reported in animal models given various other markers were not changed.

Differences in Hip Muscle Strength and Static Balance in Patients with Transfemoral Amputations Classified at Different K-Levels: A Preliminary Cross-Sectional Study

BACKGROUND

Following amputation, patients with lower limb amputations (LLA) are classified into different functional mobility levels (K-levels) ranging from K0 (lowest) to K4 (highest). However, K-level classification is often based on subjective criteria. Objective measures that are able to differentiate between K-levels can help to enhance the objectivity of K-level classification.

OBJECTIVES

The goal of this preliminary cross-sectional study was to investigate whether differences in hip muscle strength and balance parameters exist among patients with transfemoral amputations (TFA) assigned to different K-levels.

METHODOLOGY

Twenty-two participants with unilateral TFA were recruited for this study, with four participants assigned to K1 or K2, six assigned to K3 and twelve assigned to K4. Maximum isometric hip strength of the residual limb was assessed in hip flexion, abduction, extension, and adduction using a custom-made diagnostic device. Static balance was investigated in the bipedal stance on a force plate in eyes open (EO) and eyes closed (EC) conditions. Kruskal-Wallis tests were used to evaluate differences between K-level groups.

FINDINGS

Statistical analyses revealed no significant differences in the parameters between the three K-level groups (p>0.05). Descriptive analysis showed that all hip strength parameters differed among K-level groups showing an increase in maximum hip torque from K1/2-classified participants to those classified as K4. Group differences were also present in all balance parameters. Increased sway was observed in the K1/2 group compared to the K4 group, especially for the EC condition.

CONCLUSION

Although not statistically significant, the magnitude of the differences indicates a distinction between K-level groups. These results suggest that residual limb strength and balance parameters may have the potential to be used as objective measures to assist K-level assignment for patients with TFA. This potential needs to be confirmed in future studies with a larger number of participants.

Influence of a multidimensional music-based exercise program on selected cognitive and motor skills in dementia patients—a pilot study

One of the most common causes of needing care in old age is dementia. In order to enjoy a pleasant retirement for people with dementia, it is essential for them to maintain their independence. Studies have shown that a combination of physical activity and music has positive effects on dementia patients. Therefore, this study aimed to investigate the feasibility of implementing a multidimensional music-based exercise program for dementia patients and the effects on an intervention group (IG) compared to a control group (CG, usual care). The study design was based on a 12-week intervention with two (IG/CG) by two (pretest/posttest) parallel groups and block randomization with unequal group sizes. Participants had to be able to move independently or with a walker and not have severe cardiovascular disease or cardiac arrhythmias. Fifty-three blinded dementia patients (age: 83.63 ± 6.03 years) from inpatient facilities participated in the study and were assigned from the exercise instructors to IG (n = 34) and CG (n = 19). The primary outcomes were feasibility (Observation sheet), modified Chair Rising test, Timed Up and Go test, hand dynamometer test, FICSIT‑4 (Frailty and Injuries: Cooperative Studies of Intervention Techniques), and drop bar test. Secondary endpoints included: verbal fluency (“animals”), the Mini-Mental State Examination, memory, Trail Making Test A, and Qualidem. Forty-nine subjects were analyzed (IG = 32; CG = 17). There were significant differences between the groups in the modified Chair Rising test (p = 0.033), FICSIT‑4 (p = 0.035), and Timed Up and Go test (p = 0.005) at posttest, which showed improved performance of the IG compared to the CG. The IG additionally showed improvements in the modified Chair Rising test (p = 0.000), drop bar test (p = 0.033), hand dynamometer test (p = 0.001), Timed Up and Go test (p = 0.000), verbal fluency (p = 0.002) and Trail Making Test A (p = 0.04) after 12 weeks. There were no adverse events or side effects. The multidimensional music-based exercise program could be performed by the dementia patients and was well received. The improved functional mobility could contribute to a lower risk of falls and thus maintain independence. For the follow-up study, the number of subjects, randomization, and parameters should be considered.

Mechanistic insights from a multiparametric magnetic resonance imaging study regarding the role of sodium glucose co-transporter 2 inhibitors

Background

Type 2 diabetes (T2D) is associated with an increased risk of heart failure (HF) and cardiovascular (CV) mortality. Sodium–glucose-co transporter-2 (SGLT2) inhibitors reduce the risk of major adverse CV events and hospitalisation for HF in T2D patients with high cardiovascular risk, despite only a modest improvement in glycemic control. Restoring cellular energy homeostasis and reversing adverse cardiac remodelling in diabetes have been speculated as a potential metabolic modulatory effect of SGLT2 inhibitors leading to their beneficial CV outcomes. Myocardial energy deficient states can be detected non-invasively by 31-phosphorus magnetic resonance spectroscopy (31P-MRS).

Objectives

Utilising cardiovascular magnetic resonance imaging (CMR) and 31P-MRS in a single centre longitudinal cohort study, we aimed to investigate the effects of the selective SGLT2 inhibitor empagliflozin on myocardial energetics, function, perfusion, and myocardial cellular volume in patients with T2D.

Methods

Eighteen consecutive T2D patients who were commenced on empagliflozin in cardiometabolic optimisation clinics underwent CMR and 31P-MRS scans before and after twelve-week empagliflozin treatment, and plasma N-terminal pro hormone B-type natriuretic peptide (NT-proBNP) levels were measured. Ten controls with no diabetes underwent an identical 31P-MRS and CMR protocol on a single visit.

Results

When compared to controls, patients with T2D showed: lower myocardial energetics (1.52±0.40 vs 2.20±0.5, p=0.0005), lower stress myocardial blood flow (1.60±0.50 vs 2.10±0.50, p=0.02) and lower left ventricular ejection fraction (52±13% vs 63±4%, p=0.01). Treatment with empagliflozin led to significant improvements in myocardial energetics (PCr/ATP: 1.52 to 1.76, p=0.009). This was accompanied by a relative 13% improvement in left ventricular ejection fraction (p=0.001), 3% improvement in global longitudinal strain (p=0.01), 61% reduction in NTproBNP (p=0.05), and 9% reduction in myocardial cell volume (p=0.04). No significant change in myocardial blood flow or diastolic strain was detected.

Conclusions

For the first time, we demonstrate that empagliflizon improves myocardial energetics and function, reduces myocardial cellular volume, and reduces NT-proBNP levels in patients with T2D.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation PCr/ATPLVEF

Divergent transcriptomic profiles in skeletal muscle of diabetics with and without heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with type 2 diabetes mellitus (DM) that have coexistent heart failure (HF) have exacerbated symptoms and prognosis, however beside cardiac dysfunction the mechanisms governing these features are incompletely understood. Evidence indicates abnormalities in the periphery could contribute to this worse clinical phenotype, including a role for skeletal muscle whereby disturbances in the transcriptome could disrupt muscle homeostasis/repair to offer a novel therapeutic approach.

Purpose

Is the skeletal muscle transcriptome distinguishable between DM patients with and without HF?

Methods

DM patients without (n = 11) or with HF with reduced left ventricular ejection fraction (LVEF) (n = 16) were included. Muscle biopsies were collected from the pectoralis major during pacemaker implantation. Following RNA extraction and cDNA synthesis, non-bias RNA sequencing (RNAseq) was performed (Cambridge Genomic Services, UK) followed by targeted RT-PCR gene expression of relevant targets. DESeq2 identified differentially expressed genes (DEGs) with a false discovery rate (p &lt; 0.05). Gene enrichment analysis was performed with clusterProfiler v3.16.0 to interrogate the gene ontology database, while pathway analysis was conducted using ReactomePA v1.32.0 to interrogate the Reactome database, using an adjusted p value. Values of p &lt; 0.05 were accepted as significant.

Results

Groups were not different (p &gt; 0.05) for age (74 ± 11 vs. 66 ± 10 years), BMI (31 ± 7 vs 29 ± 6), sex (n = 2 females per group), or HbA1c (56 ± 10 vs. 57 ± 8 mmol/mol), although LVEF was lower in the group with HF (27 ± 8 vs. 54 ± 2%; p &lt; 0.05).  Of the 19,544 genes analysed, RNAseq identified 53 DEGs between DM patients with and without HF, with several relevant targets related to myofiber homeostasis such as autophagy (RUBCN), protein synthesis (DGKζ), and inflammation/apoptosis (TLE1). Follow-up RT-PCR analysis confirmed a trend towards upregulation of the autophagy-related machinery p62 (p = 0.043) and BNIP3 (p = 0.085) in the HF group, but not ubiquitin-proteasome (MuRF1, MAFbx; p &gt; 0.05). Gene-enrichment analysis of DEGs identified 7 overrepresented terms (P &lt; 0.05), including lipid metabolism/signalling alongside epigenetic modifications related to histone deacetylases (HDAC6/10). Furthermore, pathway analysis identified 4 terms (p &lt; 0.05) related to NOTCH signalling and phosphatidyl inositol-bisphosphate (PIP2) hydrolysis thus indicating alterations to muscle repair and lipid signalling respectively.

Conclusion(s): This study confirms that DM patients with and without HF demonstrate distinct skeletal muscle transcriptome profiles. Key differences related to skeletal muscle myogenesis, autophagy, epigenetic regulation, and lipid signalling were identified that could form part of important therapeutic targets. Whether these underlying muscle transcriptome differences contribute to poorer clinical outcomes in DM patients with HF remains to be determined.

Detrimental immediate and long-term clinical effects of right ventricular pacing in patients with myocardial fibrosis

Funding Acknowledgements

Type of funding sources: None.

Background

Long-term right ventricular (RV) pacing leads to heart failure or a decline in left ventricular (LV) function in up to a fifth of patients.

Objectives

We aimed to establish whether patients with focal fibrosis detected on late gadolinium enhancement cardiovascular magnetic resonance (CMR) have deterioration in LV function after RV pacing.

Methods

We recruited 110 patients (84 in final analysis) into two observational CMR studies. Patients (n = 34) with a dual chamber device and preserved atrioventricular (AV) conduction underwent CMR in two asynchronous pacing modes (AOO & DOO) to compare intrinsic conduction with RV pacing. Patients (n = 50) with high-grade AV block underwent CMR before and 6 months after pacemaker implantation to investigate the long-term effects of RV pacing.

Results: The three key findings were

1) Initiation of RV pacing in patients with fibrosis, compared to those without, was associated with greater immediate changes in both LV end-systolic volume index (LVESVi) (5.3 ± 3.5 vs 2.1 ± 2.4 mL/m2; p &lt; 0.01) and LV ejection fraction (LVEF) (-5.7 ± 3.4% vs -3.2 ± 2.6%; p = 0.02); 2) Long-term RV pacing in patients with fibrosis, compared to those without, was associated with greater changes in LVESVi (8.0 ± 10.4 vs -0.6 ± 7.3 mL/m2; p = 0.008) and LVEF (-12.3 ± 7.9 vs -6.7 ± 6.2%; p = 0.012); 3) Patients with fibrosis did not experience an improvement in quality of life, biomarkers or functional class after pacemaker implantation.

Conclusions

Fibrosis detected on CMR is associated with immediate and long-term deterioration in LV function following RV pacing and could be used to identify those at risk of heart failure prior to pacemaker implantation.

Characteristics before and after pacing Study 1 No fibrosis (n = 16) Fibrosis (n = 18) AOO DOO p-value AOO DOO p-value LVEDVi - mL/m&sup2; 66 ± 13 66 ± 12 0.67 78 ± 14 79 ± 13 0.34 LVESVi - mL/m&sup2; 30 ± 10 32 ± 9 0.003 38 ± 11 43 ± 12 &lt;0.001 LVEF - % 56 ± 6 53 ± 5 &lt;0.001 52 ± 8 47 ± 9 &lt;0.001 Mechanical Dyssynchrony index - ms 61 ± 17 71 ± 25 0.07 81 ± 18 89 ± 21 0.04 Study 2 No fibrosis (n = 19) Fibrosis (n = 31) Pre-PPM Post-PPM p-value Pre-PPM Post-PPM p-value LVEDVi -mL/m&sup2; 88 ± 21 73 ± 14 &lt;0.001 90 ± 18 83 ± 21 0.007 LVESVi -mL/m&sup2; 35 ± 9 34 ± 9 0.71 41 ± 14 49 ± 21 0.001 LVEF - % 60 ± 5 54 ± 7 &lt;0.001 56 ± 8 43 ± 12 &lt;0.001 Mechanical Dyssynchrony index - ms 70 ± 29 81 ± 22 0.15 84 ± 30 98 ± 31 0.03 Abstract Figure. Mechanism for heart failure after pacing

Spatial orientation in virtual environment compared to real-world

Virtual reality (VR) is popular across many disciplines and has been increasingly used in sports as a training tool lately. However, it is not clear whether the spatial orientation of humans works equally within VR and in the real-world. In this paper, two studies are presented, in which natural body movements were allowed and demanded. Firstly, a series of verbal and walking distance estimation tests were conducted in both the virtual and the real environment. The non-parametric Friedman test with pairwise comparisons showed no significant differences neither in verbal nor in walking distance estimations between the conditions (all p > 0.05). However, shorter distances (0.9-1.5 m) were estimated more precisely than larger distances (2.6-2.8 m) in both environments. Secondly, a self-developed route recall test to examine the spatial orientation was performed in the virtual and the real environment. The participants visually perceived the predefined route and were instructed to follow these routes with their eyes blindfolded and afterward to return to their starting position. Between the ending and the starting position, no difference between the two environments was observed (p > 0.05). Based on these two studies, the performance of the human spatial orientation preliminarily verified the same in a virtual and real environment.

The role of cardiopulmonary exercise testing and echocardiography prior to elective endovascular aneurysm repair

INTRODUCTION

Cardiopulmonary exercise testing (CPET) and transthoracic echocardiography (TTE) are common preparative investigations prior to elective endovascular aneurysm repair (EVAR). Whether these investigations can predict survival following EVAR and contribute to shared decision making is unknown.

METHODS

Patients who underwent EVAR at a tertiary centre between June 2007 and December 2014 were identified from the National Vascular Registry. Variables obtained from preoperative investigations were assessed for their association with survival at three years. Regression analysis was used to determine variables that independently predicted survival at three years.

RESULTS

A total of 199 patients underwent EVAR during the study period. Of these, 120 had preoperative CPET and 123 had TTE. Lower forced expiratory ventilation (FEV₁), ratio of FEV₁ to forced vital capacity, work at peak oxygen consumption and higher ventilatory equivalent for carbon dioxide were associated with increased mortality. Variables obtained from TTE were not associated with survival at three years although there was a low incidence of left ventricular systolic dysfunction and significant valvular disease in this cohort.

CONCLUSIONS

CPET might be a useful adjunct to assist in shared decision making in patients undergoing elective EVAR and may influence anaesthetic technique. TTE does not appear to be able to discriminate between high and low risk individuals. However, a low rate of significant ventricular dysfunction and valvular disease in patients undergoing elective EVAR may account for these findings.

P2506Prognostic importance of ventilatory efficiency in healthy subjects

Background

Low cardiorespiratory fitness, defined by reduced maximal oxygen consumption (VO2), is a predictor of mortality in patients without chronic disease. However, the relation between ventilatory efficiency (as measured by the slope of the relation between ventilation (VE) and carbon dioxide production (VCO2)) and all-cause mortality is unknown.

Purpose

To assess the relation between variables derived from cardiopulmonary exercise testing and long-term survival in normal subjects

Method

We recruited 145 healthy subjects, with no history of chronic disease (57% male, mean age 63±12) from primary care at random. All participants underwent cardiopulmonary exercise testing at baseline. Participants were followed for 15.5±3.5 years. The primary end-point was all-cause mortality. Cox-proportional hazard models were used to assess the relationship between measures of exercise performance and outcome. Hazard ratios (HR) are reported with 95% confidence intervals (CI).

Results

During follow up, 34 participants (23.4%) died. On univariable analysis, VE/VCO2 slope, peak VO2, respiratory exchange ratio at peak exercise, peak heart rate and 6-minute walk test distance were significant predictors of all-cause mortality (table 1). However, only VE/VCO2 slope (HR per unit increase: 1.13, 95% CI: 1.00–1.28, P=0.043) and peak heart rate (HR per 10 unit increase: 0.73, 95% CI: 0.57–0.93, P=0.010) were independent predictors of all-cause mortality on multivariable analysis.

Table 1. Cox regression analysis (univariable and multivariable) for cardiopulmonary exercise testing measures and all-cause mortality HR Presentation Univariable analysis Multivariable analysis HR 95% CI p value HR 95% CI p value Peak VO2 (ml/kg/min) Per unit increase 0.90 0.86–0.95 &lt;0.001 0.94 0.86–1.03 0.214 VE/VCO2 slope Per unit increase 1.08 1.01–1.17 0.049 1.13 1.00–1.28 0.043 Exercise RER Per 0.1 unit increase 0.46 0.31–0.67 &lt;0.001 0.72 0.45–1.17 0.185 Peak heart rate (bpm) Per 10 unit increase 0.73 0.65–0.81 &lt;0.001 0.73 0.57–0.93 0.010 6MWT (metre) Per 25 unit increase 0.92 0.86–0.98 0.009 1.02 0.86–1.17 0.789 Peak systolic BP (mmHg) Per 10 unit increase 1.13 0.98–1.31 0.101 – – – Multivariable analysis is adjusted for age, body mass index, sex, smoking, resting systolic blood pressure and forced vital capacity. Abbreviations: 6MWT, 6-minute walk test; CI, confidence interval; HR, hazard ratio; RER, respiratory exchange ratio.

Conclusions

Raised VE/VCO2 slope is an independent predictor of all-cause mortality in healthy patients with no history of chronic disease.

P773Initiation of sacubitril/valsartan and optimisation of evidence-based heart failure therapies after hospitalisation for acute decompensated heart failure: An analysis of the TRANSITION study

Background

Optimisation of chronic heart failure (HF) therapy remains the key strategy to improve outcomes after hospitalisation for acute decompensated HF (ADHF) with reduced ejection fraction (HFrEF). Initiation and uptitration of disease-modifying therapies is challenging in this vulnerable patient population. We aimed to describe the patterns of treatment optimisation including sacubitril/valsartan (S/V) in the TRANSITION study.

Methods

TRANSITION (NCT02661217) was a randomised, open-label study comparing S/V initiation pre- vs. post-discharge (1–14 days) in patients admitted for ADHF after haemodynamic stabilisation. The primary endpoint was the proportion of patients achieving 97/103 mg S/V twice daily (bid) at 10 weeks post-randomisation. Up-titration of S/V was as per label. Information on dose of S/V and on the use of concomitant HF medication was collected at each study visit up to week 26.

Results

A total of 493 patients received at least one dose of S/V in the pre-discharge arm and 489 patients in the post-discharge arm. One month after randomisation, 45% of patients in the pre-d/c arm vs. 44% in the post-discharge arm used 24/26 mg bid starting dose and 42% vs. 40% were on 49/51 mg S/V bid, respectively. At week 10, 47% of patients had achieved the target dose in the pre-discharge arm vs. 51% in the post-discharge arm. At the end of the follow-up at 26 weeks, the proportion of patients on S/V target dose further increased to 53% in the pre-discharge and 61% in the post-discharge arm (Figure 1). At week 10, the mean dose of S/V was 132 mg in the pre-discharge arm and 136 mg in the post-discharge arm, and at week 26, it was 140 mg and 147 mg, respectively.

Before hospital admission, 52% and 54% of the patients received a beta-blocker (BB) in the pre-discharge and post-discharge group, respectively, and 42% in both arms received a mineralcorticoid receptor antagonist (MRA). At time of discharge, 68% and 71%% of the patients received a BB and 68% and 65% an MRA, in the pre-discharge and post-discharge groups, respectively. These proportions remained stable to week 10 and week 26.

Uptitration of sacubitril/valsartan

Conclusions

In the vulnerable post-ADHF population, initiation of S/V and up-titration to target dose was feasible within 10 weeks in half of the patients alongside with a 20% increase in the use of other disease-modifying medications that remained stable through the end of the 6-month follow-up.

Acknowledgement/Funding

The TRANSITION study was funded by Novartis

P1236Revealing cardiac mechanics with CMR whilst CRT is active: the first step

Introduction

Cardiac resynchronisation therapy (CRT) is a routine treatment for heart failure with reduced ejection fraction and conduction delay to improve symptoms and prognosis. Technological advancements both in cardiac magnetic resonance (CMR) and devices (MRI-conditional modes) now enable investigation of the haemodynamic response to CRT over a range of heart rates.

Methods

Patients with a CRT-D device were enrolled from heart failure clinics at a single tertiary centre. A complete device system assessment and baseline device check was conducted to ensure MRI compatibility and suitability. Left ventricular (LV) volumes and systolic blood pressure were measured at baseline and heart rates of 75, 90, 100, 115, 125, and 140 bpm (randomised order) with CRT active and intrinsic conduction (AOO). MRI conditional mode parameters were replicated through standard parameter modification to ensure biventricular pacing during CRT active scans. All scans were conducted using a 3.0 T Siemens Prisma MRI scanner with analysis on commercially available software. Contractility was derived from the systolic blood pressure and left ventricular end systolic volume. A post scan device and lead assessment was conducted to assess for scanning safety.

Results

Scanning was conducted in 22 patients (safety cohort). Post scan battery voltage reduced by 2.9±1.0%. Mean change in atrial, right ventricular and left ventricular lead impedance was 0.5±0.06%, 3.0±0.04% and −1.7±0.05% respectively. Mean change in atrial, right ventricular and left ventricular pacing threshold was 0.0±0.3%, 8.3±0.3% and 5.6±0.3%. No patient experienced symptoms related to scanning or device failure.

Preliminary data for patients with CRT on and off have been analysed (paired analysis cohort, n=8, 6 men). Mean age was 71.1±8.2, aetiology was primarily ischaemic (62.5%) with the remainder dilated cardiomyopathy. The mean LV ejection fraction at baseline was 29.4±12.9%. Biventricular pacing led to acute improvements in ejection fraction (p=0.005), left ventricular cardiac output (p<0.0001) and contractility (p=0.05) over the entire range of heart rates studied. We also noted an improvement in the force frequency relationship during biventricular pacing with a higher peak contractility (p=0.05), a higher heart rate at which this occurred (HR=130) and a generally up sloping relationship when compared with intrinsic conduction.

Conclusion

We have demonstrated for the first time, the mechanistic improvements in cardiac contractility consequent to CRT using CMR and also that MRI scans of conditional devices can be safe with CRT active.

Acknowledgement/Funding

Dr A Koshy is conducting a PhD supported by grant from Medtronic. Dr Klaus Witte has received honoraria from Medtronic

P1637Rehospitalisations during 26 weeks of follow up from initiation of sacubitril/valsartan after acute decompensated heart failure: An analysis of the TRANSITION study

Background

Patients with acute decompensated heart failure (ADHF) are at high risk of recurrent hospitalisations and death. In-hospital initiation of sacubitril/valsartan (S/V) reduced the risk for HF re-hospitalisation by 44% compared to enalapril in the PIONEER-HF study during the 8-week follow-up period. We aimed to describe the pattern of readmissions and their causes in the TRANSITION study, which randomised participants to pre-discharge or post-discharge initation of S/V.

Methods

TRANSITION (NCT02661217) was a randomised, open-label study comparing S/V initiation pre- vs. post-discharge (1–14 days) in haemodynamically stabilised patients with HF with reduced ejection fraction, admitted for ADHF. The primary endpoint was the proportion of patients achieving 97/103 mg S/V twice daily at 10 weeks post-randomisation. Information on rehospitalisation was collected throughout the study up to 26 weeks.

Results

A total of 493 patients received S/V in the pre-discharge arm and 489 patients in the post-discharge arm. Readmissions due to any cause were reported in 9.7% and 18.1% in the pre-discharge arm vs. 10.6% and 21.3% in the post-discharge arm within 30 days, and 10 weeks respectively. During the 26-weeks follow-up, all-cause readmission was reported in 34.5% of patients in the pre-discharge arm vs. 34.6% in the post-discharge arm. Median time to first rehospitalisation was 67 days in the pre-discharge arm (IQR: 26–110 days) and 50 days (IQR: 23–108 days) in the post-discharge arm. At least one HF hospitalisation was reported in 7.5% of patients in the pre-discharge arm and 7.4% in the post-discharge arm during 10 weeks and in 11.8% and 12.3% of patients, respectively, during 26 weeks of follow-up. Median duration of HF readmission was 7 days (IQR: 4–11 days) in the pre-discharge group and 6.5 days (IQR: 6.5–10 days) in the post-discharge arm. In total 2.6% and 5.5% patients in pre-discharge arm and 3.9% and 7% in the post-discharge arm visited an emergency room during 10 weeks and 26 weeks, respectively.

Conclusions

Initiation of S/V in patients hospitalised for ADHF either before or shortly after discharge, results in comparable rates of all cause and HF rehospitalisations, as well as emergency room visits without hospital admission over the 26 week follow-up period. HF re-hospitalisations rates at 10 weeks in TRANSITION are in line with the 8% in S/V arm reported in PIONEER-HF during the 8-weeks follow-up.

Acknowledgement/Funding

The TRANSITION study was funded by Novartis

Bacteria-laden microgels as autonomous three-dimensional environments for stem cell engineering

A one-step microfluidic system is developed in this study which enables the encapsulation of stem cells and genetically engineered non-pathogenic bacteria into a so-called three-dimensional (3D) pearl lace-like microgel of alginate with high level of monodispersity and cell viability. The alginate-based microgel constitutes living materials that control stem cell differentiation in either an autonomous or heteronomous manner. The bacteria (Lactococcus lactis) encapsulated within the construct surface display adhesion fragments (III7-10 fragment of human fibronectin) for integrin binding while secreting growth factors (recombinant human bone morphogenetic protein-2) to induce osteogenic differentiation of human bone marrow-derived mesenchymal stem cells. We concentrate on interlinked pearl lace microgels that enabled us to prototype a low-cost 3D bioprinting platform with highly tunable properties.

Laboratory Setup for Scanning-Free Grazing Emission X-ray Fluorescence

Grazing incidence and grazing emission X-ray fluorescence spectroscopy (GI/GE-XRF) are techniques that enable nondestructive, quantitative analysis of elemental depth profiles with a resolution in the nanometer regime. A laboratory setup for soft X-ray GEXRF measurements is presented. Reasonable measurement times could be achieved by combining a highly brilliant laser produced plasma (LPP) source with a scanning-free GEXRF setup, providing a large solid angle of detection. The detector, a pnCCD, was operated in a single photon counting mode in order to utilize its energy dispersive properties. GEXRF profiles of the Ni-L_α,β line of a nickel-carbon multilayer sample, which displays a lateral (bi)layer thickness gradient, were recorded at several positions. Simulations of theoretical profiles predicted a prominent intensity minimum at grazing emission angles between 5° and 12°, depending strongly on the bilayer thickness of the sample. This information was used to retrieve the bilayer thickness gradient. The results are in good agreement with values obtained by X-ray reflectometry, conventional X-ray fluorescence and transmission electron microscopy measurements and serve as proof-of-principle for the realized GEXRF setup. The presented work demonstrates the potential of nanometer resolved elemental depth profiling in the soft X-ray range with a laboratory source, opening, for example, the possibility of in-line or even in situ process control in semiconductor industry.

Prospective development and validation of a model to predict heart failure hospitalisation

Objective

Acute heart failure syndrome (AHFS) is a major cause of hospitalisation and imparts a substantial burden on patients and healthcare systems. Tools to define risk of AHFS hospitalisation are lacking.

Methods

A prospective cohort study (n=628) of patients with stable chronic heart failure (CHF) secondary to left ventricular systolic dysfunction was used to derive an AHFS prediction model which was then assessed in a prospectively recruited validation cohort (n=462).

Results

Within the derivation cohort, 44 (7%) patients were hospitalised as a result of AHFS during 1 year of follow-up. Predictors of AHFS hospitalisation included furosemide equivalent dose, the presence of type 2 diabetes mellitus, AHFS hospitalisation within the previous year and pulmonary congestion on chest radiograph, all assessed at baseline. A multivariable model containing these four variables exhibited good calibration (Hosmer–Lemeshow p=0.38) and discrimination (C-statistic 0.77; 95% CI 0.71 to 0.84). Using a 2.5% risk cut-off for predicted AHFS, the model defined 38.5% of patients as low risk, with negative predictive value of 99.1%; this low risk cohort exhibited <1% excess all-cause mortality per annum when compared with contemporaneous actuarial data. Within the validation cohort, an identically applied model derived comparable performance parameters (C-statistic 0.81 (95% CI 0.74 to 0.87), Hosmer–Lemeshow p=0.15, negative predictive value 100%).

Conclusions

A prospectively derived and validated model using simply obtained clinical data can identify patients with CHF at low risk of hospitalisation due to AHFS in the year following assessment. This may guide the design of future strategies allocating resources to the management of CHF.

[Dynamic vision of sportsmen with different requirement profiles for the visual apparatus]

AIM OF STUDY

In particular, in the quick ball and racket games a good dynamic seeing is required . The afferent dynamic seeing occurs via the retiina which mediates the stimuli for efferent dynamic seeing . The aim of this study was to examine the dynamic visual acuity of sportsmen from sports with different demands on their dynamic seeing (DS).

METHODS

19 sports students took part in the study. 10 subjects participated in coached team sports (group I) and 9 remaining performed individual sports (group II). The DS was assessed by means of the Düsseldorfer test for dynamic seeing of Wist which was performed twice on one day.

RESULTS

The DS of the two groups in the first study did not differ (right eye 95.7 ± 10.6 % in group I vs. 94.3 ± 6.9 % in group II and left eye 97.6 ± 4.8 % vs. 95.3 ± 5.6 %; p ≥ 0.05). Also the second study there was no different in DS for the two groups (right eye 98.3 ± 2.6 % vs. 93.8 ± 8.0 % and left eye 99.3 ± 1.2 % vs. 95.6 ± 7.0 %; p ≥ 0.05).

DISCUSSION

Our hypothesis about a different DS in players of ball games compared with non-ball sport players could not be proved. It is to be critically noted that a generalization is not possible due to the small sample numbers. Because DS is a necessary precondition in ball games further studies should be concentrated on its trainability.

Electron bunch length measurements from laser-accelerated electrons using single-shot THz time-domain interferometry

Laser-plasma wakefield-based electron accelerators are expected to deliver ultrashort electron bunches with unprecedented peak currents. However, their actual pulse duration has never been directly measured in a single-shot experiment. We present measurements of the ultrashort duration of such electron bunches by means of THz time-domain interferometry. With data obtained using a 0.5 J, 45 fs, 800 nm laser and a ZnTe-based electro-optical setup, we demonstrate the duration of laser-accelerated, quasimonoenergetic electron bunches [best fit of 32 fs (FWHM) with a 90% upper confidence level of 38 fs] to be shorter than the drive laser pulse, but similar to the plasma period.

The prevalence of a raised aldosterone–renin ratio (ARR) among new referrals to a hypertension clinic

The wider application of the plasma aldosterone to renin activity ratio (ARR) test has led independent groups to report a 10-fold or higher prevalence in the detection and prevalence of primary aldosteronism than previously suggested, although such figures have been contested. We determined the prevalence of a raised ARR in an unselected group of patients who were referred to the hypertension clinic at Aberdeen Royal Infirmary. Over a 4-month period, all newly referred patients had an ARR, urea and electrolytes, and 24-h ambulatory blood pressure monitoring (ABPM) performed in addition to a detailed clinical examination. One hundred and twenty-two patients (mean age 51 +/- 16 years) were examined over the study period; 57 (47%) were receiving no anti-hypertensive medication, 32(26% of total) had a normal 24-h ABPM of which 15 patients were receiving antihypertensive medication ("controlled" hypertensives) and 17(14%) were receiving no anti-hypertensive medication ("white-coat hypertensives). Twenty patients (mean age 58 +/- 11 years) were found to have a raised ARR (> 750), of which 10 patients were receiving beta-blocker therapy as part of their anti-hypertensive regimen. Patients with a raised ARR were more likely (odds ratio 3.6, 95% confidence interval 1.2-13.2, p < 0.05) to be classified as a "non-dipper" compared with those whose blood pressure fell at night. The proportion of newly referred hypertensive patients with a raised ARR is still significant and confirms that of previous studies The ratio appears to be significantly driven by a suppressed renin value and further investigation is required to clarify the status of those patients receiving anti-hypertensive medications, particularly beta-blockers.

Motion pattern analysis of gait in horseback riding by means of Principal Component Analysis

As a consequence of the three interacting systems of horse, saddle, and rider, horseback riding is a very complex movement that is difficult to characterize by a limited number of biomechanical parameters or characteristic curves. Principal Component Analysis (PCA) is a technique for reducing multidimensional datasets to a minimal (i.e., optimally economic) set of dimensions. To apply PCA to horseback riding data, a "pattern vector" composed of the horizontal velocities of a set of body markers was determined. PCA was used to identify the major dynamic constituents of the three natural gaits of the horse: walk, trot, and canter. It was found that the trot is characterized by only one major component accounting for about 90% of the data's variance. Based on a study involving 13 horses with the same rider, additional phase plane analyses of the order parameter dynamics revealed a potential influence of the saddle type on movement coordination for the majority of horses.

[Thoracic actinomycosis: diagnostic pitfalls and therapeutic considerations]

We report two patients admitted to our hospital suspected to suffer from cancer in the lung or mediastinum, respectively. Both patients had a diagnosis of thoracic actinomycosis. A 76 year old man revealed pulmonary and endobronchial actinomycosis associated with broncholithiasis. Diagnosis was achieved by bronchoscopy. Therapy with ampicillin/sulbactam was successful. A 36 year old patient presented with bilateral pleural effusions, extended pericardial, mediastinal and pulmonary actinomycosis with pericarditis constrictiva and superior vena cava syndrome. Diagnosis was finally made by cardiac surgery with therapeutic pericardectomy. Prolonged therapy with ampicillin/sulbactam was administered with satisfactory result. Here we discuss the importance to include actinomycosis in the differential diagnosis of pulmonary affections and mediastinal masses in order to avoid diagnostic errors and to limit invasive procedures to the necessary amount. We illustrate the need of an individualized treatment approach.

Detection of adverse events in a Scottish hospital using a consensus-based methodology

OBJECTIVE

To determine, using a consensus based methodology, the rate and nature of adverse events (AEs) among patients admitted to acute medicine, acute surgery and obstetrics in a large teaching hospital in Scotland.

METHODS

Retrospective case-note review of 450 medical, nursing and medication records to identify and classify adverse events. For 354 patients whose length of stay was greater than 24 hours, the overall adverse event rate was 7.9% which ranged from 0% in obstetrics, 7.2% in acute medicine to 13% in acute surgery. Among all AEs, 43% were deemed preventable by a consensus group and 59% of the AEs contributed to a proportion of the patients' hospital stay or led to hospital readmission. Whilst nurse identification of adverse events was highly specific (94%), its sensitivity was poor (43%). Only 10% of the identified AEs were identified by the hospital's voluntary reporting system for adverse events. The estimated additional cost of adverse events in terms of bed days was ł69,189 which if extrapolated Scotland-wide could cost ł297 million per annum.

CONCLUSIONS

This study supports the need to continue the traditional retrospective record review to identify adverse events. The current hospital-based reporting of adverse events does not provide a complete measure of adverse events and needs to be complemented by other measures.

[Bullectomy as emergency intervention in a mechanically ventilated patient with refractory type II respiratory failure due to chronic obstructive lung disease (COPD)]

A 44-year-old female patient presented with an extensive exacerbation of severe chronic obstructive lung disease (COPD) and bullous emphysema. Because of a severe type II respiratory failure, the patient was intubated and mechanically ventilated. Respiratory failure was refractory despite appropriate ventilation regimes and pCO2 values ranged from 110 mm Hg to 180 mm Hg. Chest radiography revealed hyperinflation of two giant bullae with mediastinal shifting to the left lung. We describe a successful rescue bullectomy.

Reliability and performance-dependent variations of muscle function variables during isometric knee extension

Despite the common use of standardised methods analysing neuromuscular function during knee extension, there is a lack of test-retest reliability studies. Furthermore, for most of the investigated variables it is unknown which changes of values indicate an enhancement of performance. The aim of the present study was to investigate performance-dependent variations of muscle functions during isometric contraction of knee extensors and to examine test-retest reliability of their measurement methods. For test-retest reliability sports students completed three test sessions. Highly skilled athletes, sports students and untrained subjects were investigated to determine the performance-dependent variations. The following variables were analysed: maximal voluntary contraction (MVC), voluntary activation (VA), absolute muscle reaction time (AR), muscle endurance (ME), and EMG frequency analysis (MF) of m. vastus lateralis (VL), m. vastus medialis (VM) and m. rectus femoris (RF). RESULTS TEST-RETEST-RELIABILITY: A high reliability between session 1 vs. 2 and session 2 vs. 3 was shown for MVC (ICC=0.92 and .97), VA (0.92/0.95) and ME (0.87/0.95). ICC in AR (0.23) was low between the first and second session and moderate between the second and third session (0.74). MF of VL, VM and RF showed low ICC between sessions. PERFORMANCE DEPENDENT VARIATIONS: Significant differences in nearly all variables (except VA) were found between trained (athletes and sports students) and untrained subjects.

Birth plans and health facility based delivery in rural Uganda

OBJECTIVES

To evaluate whether the completion of birth plans is associated with delivery in a health facility and the perceptual causes of birth plan completion and health facility based delivery were explored according to a well-tested health behaviour theory.

DESIGN

A community survey.

SETTING

Rakai and Luwero districts.

SUBJECTS

A total of 415 (202 in Rakai and 213 in Luwero district) respondents were randomly selected and interviewed using a mixed survey questionnaire composed of open and close-ended questions.

MAIN OUTCOME MEASURES

Health facility based delivery.

RESULTS

The results demonstrate a statistically significant relationship between the completion of birth plans and delivery in a health facility (OR = 1.86, 95% CI =1.1, 3.1). The fear of consequences of delivering at home was found to be an important driving force in promoting the completion of birth plans, thereby indirectly influencing the likelihood of delivery in a health facility.

CONCLUSION

Given the empirical evidence presented here, this study suggests that birth plans are an important tool in improving the rate of health facility based deliveries and thus essential in the fight against maternal mortality in Uganda. It is further recommended that campaigns market the use of birth plans as a way to reduce uncertainty and manage fear and the unknown about pregnancy.

Inverse blood pressure rhythm of transgenic hypertensive TGR(mREN2)27 rats: role of norepinephrine and expression of tyrosine-hydroxylase and reuptake1-transporter

Transgenic hypertensive TGR(mREN2)27 rats (TGR) exhibit an inverse circadian blood pressure profile from the age of 8 to 9 wk. To investigate the role of the sympathetic nervous system in this pathological blood pressure rhythm, we examined postnatal changes in catecholamine concentration, expression of tyrosine-hydroxylase (TH), and norepinephrine (NE) reuptake(1)-transporter (NET) in the heart, adrenal glands, and hypothalamus of non-hypertensive TGR at an age of 4 wk and of hypertensive TGR at an age of 10 wk and compared these to normotensive, age-matched Sprague-Dawley rats. Rats were kept under synchronized light:dark (LD) conditions of 12:12 h. Blood pressure and heart rate were monitored by radiotelemetry, catecholamines by high performance liquid chromatography, expression of TH and NET (mRNA) by RT-PCR, and TH protein by Western blots. In normotensive 4 wk-old Sprague-Dawley rats, cardiac NE concentrations were circadian phase-dependent with lower values at ZT12.5, with no differences observed, in 10-wk-old animals. At both ages however, sympathetic tone was higher during the dark phase, as shown by a higher turnover of NE. This observation confirms earlier data, which indicate that the endogenous amine concentration may not mirror its turnover rate. TGR at either age had lower cardiac NE as well as lower TH expression and did not display a circadian phase-dependency. The increased cardiac NE turnover rate in the dark phase in non-hypertensive TGR was lost in hypertensive rats. Both cardiac NE concentrations and TH expression decreased with age in both strains. In adrenal glands, NE and epinephrine (E) were not circadian phase-dependent in both strains but increased with age. NE concentrations in the hypothalamus were neither circadian phase-dependent nor different in both strains and at both ages. However, sympathetic tone of NE in the hypothalamus, as indicated by the turnover rate, was greater during the dark phase in both strains at an age of 10 wk. Expression of TH and NET were greatly reduced in adrenal glands when compared to Sprague-Dawley rats; whereas, expression of TH in the hypothalamus was significantly increased in hypertensive TGR. These data indicate that the transgene in TGR leads to an increased central stimulation of the sympathetic nervous system and to a consecutive down-regulation in the peripheral organs. It is of interest that rhythmicity in the studied parameters was lost in hypertensive TGR, except in the turnover of NE in the hypothalamus. We concluded that the data on key mechanisms of regulation of the sympathetic system in TGR cannot explain the inverse blood pressure rhythm observed in this transgenic rat strain.