1411The effect of eplerenone on fibrosis in hypertrophic cardiomyopathy. A randomised controlled trial assessed using cardiopulmonary exercise testing and cardiovascular magnetic resonance

Background

Recent studies have implicated aldosterone, a hormone of the renin-angiotensin-aldosterone system to cardiac hypertrophy, and cardiac and vascular fibrosis in cardiomyopathy. High levels of circulating aldosterone have been shown to cause myocardial and aortic fibrosis in animal models. In humans, high aldosterone concentrations have been associated with endothelial dysfunction, myocardial infarction, left ventricular hypertrophy and death. Aldosterone antagonism with spironolactone or eplerenone reverses the process of fibrosis in animal models.

Purpose

Left ventricular dysfunction due to hypertrophic cardiomyopathy (HCM) is a disorder associated with an increased risk of morbidity and premature mortality. An important pathological feature seen in cardiomyopathy is the development of fibrosis and its association with functional impairment and arrhythmia, including predisposition to sudden cardiac death. This trial observes the effect of eplerenone on myocardial fibrosis and exercise tolerance in patients with HCM.

Methods

42 patients were recruited into a double-blinded, placebo-controlled randomised study. Each patient had an established diagnosis of HCM without exclusion criteria (figure 1). 2 patients withdrew before enrolment. Enrolled patients were established on maximally tolerated doses of standard drugs used in the treatment of HCM and the doses of these drugs remained unchanged in the 2 months preceding enrolment to the trial. Patients were randomised to receive a maximal dose of 50mg eplerenone (n=21) or placebo (n=19). The patients underwent cardiopulmonary exercise testing and cardiovascular magnetic resonance (CMR) scan at baseline and 52 week follow up.

Results

At 52 weeks follow up there was no difference between placebo and treatment groups in peak oxygen consumption (−1.05 vs 0.63, p=0.32), anaerobic threshold (0.4 vs 1.45, p=0.31) or ventilatory efficiency slope (−0.77 vs 1.76, p=0.065). In addition, there was no significant difference observed in LV mass or fibrosis as assessed by CMR.

Inclusion and Exclusion Criteria

Conclusion

In the first randomised controlled trial using eplerenone in humans with HCM, we report no effect of treatment after 52 weeks on exercise capacity compared with placebo. In addition, we report no effect of treatment on the presence of fibrosis detected by CMR. Interpretation of these results are limited by small sample size and further studies will require a multi-centre recruitment process. The data presented here support the feasibility of eplerenone treatment in patients with HCM and provide statistical power calculation for future trials.

Work-related asthma from cleaning agents versus other agents

Background

Cleaning agents have been commonly implicated as causative or triggering factors in work-related asthma (WRA), mainly from epidemiologic studies. Relatively few clinical series have been reported.

Aims

We aimed to compare socio-demographic and clinical features among tertiary clinic patients with WRA exposed to cleaning and non-cleaning products.

Methods

Analyses were conducted on a patient database containing 208 patients with probable WRA referred to the asthma and airway centre at a tertiary centre hospital in Canada from 2000 to 2014. Chi-squared and independent samples t-tests were used to analyse categorical and continuous data, respectively.

Results

Twenty-two (11%) WRA cases were attributed to a variety of cleaning product exposures, 12 were diagnosed as occupational asthma (OA) and 10 as work-exacerbated asthma (WEA) (10% of all OA and 11% of all WEA). There were multiple exposures and the responsible agent(s) could seldom be clearly identified. Most frequent categories of exposure were surfactants, alcohols, disinfectants and acids. Compared to WRA with other exposures, those with cleaning agent exposures had a significantly larger proportion of females (82 versus 35%, P < 0.001), included a higher percentage of workers in healthcare (41 versus 4%, P < 0.001), and submitted more workers' compensation claims (86 versus 64%, P = 0.05). Other characteristics were comparable.

Conclusions

In a tertiary referral clinic, patients with WRA from cleaning agent exposure had clinical characteristics that were similar to those with WRA from other causes. Most frequent exposures were surfactants, alcohols, disinfectants and acids.

Roy Glauber (1925–2018)

Father of quantum optics

Food and Nutrition Policy

An article by Mogens Jul in volume 1, number 3, of the Food and Nutrition Bulletin (1979) indicated benefits for the poor from the Amul Dairy Development Scheme in Gujarat State, India; and an update by the same author was published in volume 7, number 2. However, there have continued to be doubts. This article has been accepted because it provides direct data to confirm the suggestions of the earlier articles. It leaves no doubt that well-designed and implemented dairy operations of this type can benefit medium-size as we/l as large farms, and also improve the income and diet of landless labourers.

Quantum Limited Superresolution of an Incoherent Source Pair in Three Dimensions

The error in estimating the separation of a pair of incoherent sources from radiation emitted by them and subsequently captured by an imager is fundamentally bounded below by the inverse of the corresponding quantum Fisher information (QFI) matrix. We calculate the QFI for estimating the full three-dimensional pair separation vector, extending previous work on pair separation in one and two dimensions. We also show that the pair-separation QFI is, in fact, identical to source localization QFI, which underscores the fundamental importance of photon-state localization in determining the ultimate estimation-theoretic bound for both problems. We also propose general coherent-projection bases that can attain the QFI in two special cases. We present simulations of an approximate experimental realization of such quantum limited pair superresolution using the Zernike basis, confirming the achievability of the QFI bounds.

Build better bones with exercise (B3E pilot trial): results of a feasibility study of a multicenter randomized controlled trial of 12 months of home exercise in older women with vertebral fracture

We pilot-tested a trial of home exercise on individuals with osteoporosis and spine fracture. Our target enrollment was met, though it took longer than expected. Participants stayed in the study and completed the exercise program with no safety concerns. Future trials should expand the inclusion criteria and consider other changes.

PURPOSE

Osteoporotic fragility fractures create a substantial human and economic burden. There have been calls for a large randomized controlled trial examining the effect of exercise on fracture incidence. The B3E pilot trial was designed to evaluate the feasibility of a large trial examining the effects of home exercise on individuals at high risk of fracture.

METHODS

Community-dwelling women ≥ 65 years with radiographically confirmed vertebral compression fractures were recruited at seven sites in Canada and Australia. We randomized participants in a 1:1 ratio to a 12-month home exercise program or equal attention control group, both delivered by a physiotherapist (PT). Participants received six PT home visits in addition to monthly phone calls from the PT and a blinded research assistant. The primary feasibility outcomes of the study were recruitment rate (20 per site in 1 year), retention rate (75% completion), and intervention adherence rate (60% of weeks meeting exercise goals). Secondary outcomes included falls, fractures and adverse events.

RESULTS

One hundred forty-one participants were recruited; an average of 20 per site, though most sites took longer than anticipated. Retention and adherence met the criteria for success: 92% of participants completed the study; average adherence was 66%. The intervention group did not differ significantly in the number of falls (IRR 0.97, 95% CI 0.58 to 1.63) or fragility fractures (OR 1.11, 95% CI 0.60 to 2.05) compared to the control group. There were 18 serious adverse events in the intervention group and 12 in the control group.

CONCLUSION

An RCT of home exercise in women with vertebral fractures is feasible but recruitment was a challenge. Suggestions are made for the conduct of future trials.