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.