Gated myocardial perfusion single photon emission computed tomography in the clinical outcomes utilizing revascularization and aggressive drug evaluation (COURAGE) trial, Veterans Administration Cooperative study no. 424

Background  Stress gated myocardial perfusion single photon emission computed tomography (gSPECT) is increasingly used before and after intercurrent therapeutic intervention and is the basis for ongoing evaluation in the Department of Veterans Affairs clinical outcomes utilizing revascularization and aggressive drug evaluation (COURAGE) trial. Methods and Results  The COURAGE trial is a North American multicenter randomized clinical trial that enrolled 2287 patients to aggressive medical therapy vs percutaneous coronary intervention plus aggressive medical therapy. Three COURAGE nuclear substudies have been designed. The goals of substudy 0 are to examine the diagnostic accuracy of the extent and severity of inducible ischemia at baseline in COURAGE patients compared with patient symptoms and quantitative coronary angiography and to explore the relationship between inducible ischemia and the benefit from revascularization when added to medical therapy. Substudy 1 will correlate the extent and severity of provocative ischemia with the frequency, quality, and instability of recurrent symptoms in postcatheterization patients. Substudy 2 (n _ 300) will examine the usefulness of sequential gSPECT monitoring 6 to 18 months after therapeutic intervention. Together, these nuclear substudies will evaluate the role of gSPECT to determine the effectiveness of aggressive risk-factor modifications, lifestyle interventions, and anti-ischemic medical therapies with or without revascularization in reducing patients’ ischemic burdens. Conclusions  The unfolding of evidence on the application of gSPECT in trials such as COURAGE defines a new era for nuclear cardiology. We hope the evidence that emerges from the COURAGE trial will further establish the role of nuclear imaging in the evidence-based management of patients with stable coronary disease. The COURAGE trial was supported by the Cooperative Studies Program of the Department of Veterans Affairs Office of Research and Development in collaboration with the Canadian Institutes of Health Research. Unrestricted research grants were obtained from Merck & Co; Pfizer Pharmaceuticals; Bristol-Myers Squibb Medical Imaging; Astellas Pharma; Kos Pharmaceuticals; Data Scope; Astra Zeneca Pharmaceuticals; Astra-Zeneca-Canada; Schering-Plough Coorporation, Ltd; Sanofi-Aventis, Inc; First Horizon; and GE Healthcare. All industrial funding for this trial was directed through the Department of Veterans Affairs. Additional funding for this substudy was provided by grants to the Department of Veterans Affairs and Canadian Institutes of Health Research from Astellas Pharma and Bristol-Myers-Squibb Medical Imaging.     

A randomized,double‐blind,placebo controlled,multi‐center study of intravenous iron sucrose and placebo in the treatment of restless legs syndrome

Iron deficiency may exacerbate symptoms in the Restless Legs Syndrome (RLS). We investigated the effect of intravenous iron sucrose or placebo on symptoms in patients with RLS and mild to moderate iron deficit. Sixty patients with primary RLS (seven males, age 46 (9) years, S‐ferritin ≤45 μg/L) recruited from a cohort of 231 patients were randomly assigned in a 12‐months double‐blind, multi‐centre study of iron sucrose 1000 mg (n = 29) or saline (n = 31). The primary efficacy variable was the RLS severity scale (IRLS) score at week 11. Median IRLS score decreased from 24 to 7 (week 11) after iron sucrose and from 26 to 17 after placebo (P = 0.123, N.S. for between treatment comparison). The corresponding scores at week 7 were 12 and 20 in the two groups (P = 0.017). Drop out rate because of lack of efficacy at 12 months was 19/31 after placebo and 5/29 patients after iron sucrose (Kaplan–Meier estimate, log rank test P = 0.0006) suggesting an iron induced superior long term RLS symptom control. Iron sucrose was well tolerated. This study showed a lack of superiority of iron sucrose at 11 weeks but found evidence that iron sucrose reduced RLS symptoms both in the acute phase (7 weeks) and during long‐term follow up in patients with variable degree of iron deficiency. Further studies on target patient groups, dosing and dosing intervals are warranted before iron sucrose could be considered for treatment of iron deficient patients with RLS. © 2009 Movement Disorder Society     

不同剂量和疗程伐昔洛韦治疗带状疱疹的多中心随机双盲对照研究

目的：比较不同剂量和疗程伐昔洛韦治疗带状疱疹的疗效和安全性。方法：选择带状疱疹患者为研究对象，采用多中心、随机、双盲、对照的临床试验。试验组患者采用伐昔洛韦1000mg每日3次口服，共服7d；对照组患者采用伐昔洛韦300mg每日2次口服，共服10d。用药后第3、6和10天观察疗效和不良反应。结果：共入组128例，全分析集（FAS）分析128例，符合方案集（PPS）分析118例。治疗后第3、6和10天，试验组和对照组患者的症状、体征积分下降值及有效率比较差异无统计学意义（P〉0．05）；疼痛视觉模拟评分法（visnal analogue scale，VAS）值比较，两组间差异无统计学意义（P〉0．05），但入组时疼痛VAS值≥8的患者，FAS集分析显示，在治疗后第6、10天VAS值下降两组均存在统计学差异（P〈0．05）；PPS集分析显示治疗后第10天VAS值下降，两组间存在统计学差异俨〈0．05）。试验组和对照组不良反应发生率分别为17．18％和12．50％．主要为嗜睡和恶心。结论：增加伐昔洛韦用量治疗带状疱疹安全、有效，与较低剂量伐昔洛韦组相比，对疼痛程度较严重的患者能更显著地减轻疼痛。     

Open, Double-Blind and Long-Term Study of Vigabatrin in Chronic Epilepsy

We performed an open, double-blind, and long-term study of vigabatrin (gamma-vinyl-GABA, GVG) in patients with treatment-resistant epilepsy who were receiving only one or at most two standard antiepileptic drugs (AEDs). The novel design included a parallel, double-blind, placebo-controlled phase that minimized the number of patients receiving placebo and allowed determination of the optimum dose of GVG for each patient before initiation of the double-blind phase. The study was divided into four phases. The first phase was a 6-week period of baseline observation. In the second phase, GVG was added openly to previous AEDs for 8 weeks. During the first 2 weeks of this phase, the dose of GVG was increased weekly and then, in the absence of adverse effects, was held constant for the next 6 weeks. At the end of this open phase, seizure frequency during the 6 weeks of constant treatment was compared with the baseline seizure frequency for each patient. Patients who experienced reduction greater than 50% in the frequency of any seizure type during the open phase were defined as responders. These responders were then entered into the third and double-blind phase, in which they were randomly allocated wither to continue active GVG treatment or placebo for 8 weeks. Thirty-three patients entered the study; 31 of 33 patients completed the initial open phase. Twenty patients achieved a reduction greater than or equal to 50% in the frequency of one or more seizure types and were eligible for the double-blind phase; 10 were randomized to continue GVG and 10 were randomized to placebo.(ABSTRACT TRUNCATED AT 250 WORDS)     

Design of clinical trials for chronic diseases: implications for periodontal disease

In order to make effective use of the statistical theory of design of clinical trials for chronic diseases such as periodontal disease, certain issues must be considered. Any clinical trial requires that the disease definition be well-specified; that patient eligibility be explicit; that the observation times be explicit; that the duration and endpoint of therapy be specified; that the duration of subsequent followup observation be specified; and that the unit of observation (e.g., tooth, set of teeth, patient) be defined. In a chronic disease, the potential biases that can readily be introduced by self-selection of patients who enter the trial and/or who return for subsequent observation become more important, because subjects are required to remain on treatment and/or observation for prolonged periods. Further, the cyclical nature of some chronic diseases may require special attention to baseline definitions of active disease and disease outcome. These issues are illustrated with examples from clinical trials of hypertension, breast cancer screening, and Polycythemia Vera. Implications for periodontal disease are discussed.     

Effect of impact exercise on bone mineral density in elderly women with low BMD: a population-based randomized controlled 30-month intervention

Evidence of the effect of exercise on bone loss comes mainly from studies in voluntary postmenopausal women, and no population-based, long-term interventions have been performed. The purpose of this population-based, randomized, controlled trial was to determine the effect of long-term impact exercise on bone mass at various skeletal sites in elderly women with low bone mineral density (BMD) at the radius and hip. Participants ( n =160) were randomly assigned to 30 months either of supervised and home-based impact exercise training or of no intervention. The primary outcome measures were femoral neck, trochanter and total hip BMD, and the secondary outcomes were bone density measures at the radius and calcaneum. Outcomes were assessed at baseline, 12 months and 30 months using blinded operators. The analyses were performed on an intention-to-treat analysis. Mean femoral neck and trochanter BMD decreased in the control group [–1.1%, 95% confidence interval (CI) –0.1% to –2.1% and –1.6%, 95% CI –0.4% to –2.7%], while no change occurred in the exercise group. Mean trochanter BMC decreased more in the control group (–7.7%, 95% CI –9.7% to –5.6% vs. –2.9%, 95% CI –5.3 to –0.9). There were six falls that resulted in fractures in the exercise group and 16 in the control group during the 30-month intervention ( P =0.019). A significant bone loss occurred in both groups at the radius and calcaneum. In multivariate analysis, weight gain was associated with increased BMD and BMC at all femur sites both in the exercise group and in the pooled groups. In conclusion, impact exercise had no effect on BMD, while there was a positive effect on BMC at the trochanter. Exercise may prevent fall-related fractures in elderly women with low bone mass.There was no conflict of interest.     

One‐ and two‐stage design proposals for a phase II trial comparing three active treatments with control using an ordered categorical endpoint

Phase II clinical trials are performed to investigate whether a novel treatment shows sufficient promise of efficacy to justify its evaluation in a subsequent definitive phase III trial, and they are often also used to select the dose to take forward. In this paper we discuss different design proposals for a phase II trial in which three active treatment doses and a placebo control are to be compared in terms of a single‐ordered categorical endpoint. The sample size requirements for one‐stage and two‐stage designs are derived, based on an approach similar to that of Dunnett. Detailed computations are prepared for an illustrative example concerning a study in stroke. Allowance for early stopping for futility is made. Simulations are used to verify that the specified type I error and power requirements are valid, despite certain approximations used in the derivation of sample size. The advantages and disadvantages of the different designs are discussed, and the scope for extending the approach to different forms of endpoint is considered. Copyright © 2008 John Wiley & Sons, Ltd.     

绝经后骨质疏松症中药治疗研究文献的质量评价

目的 了解目前国内中药治疗绝经后骨质疏松症的临床治疗研究的现状。方法 对检索到的50篇有关中药治疗绝经后骨质疏松症的临床研究论文，按照牛津循证医学中心证据水平标准和临床试验的没计原则，从诊断标准、纳入和排除标准、组间基线可比性、随机、对照、双盲、统计学方法、疗效判断、疗程及药物的不良反应、随访等多个方面进行分析评价。结果 50篇相关文献中，按照牛津循证医学中心证据水平标准评价，推荐级别为B级的占44.0％，C级的占56.0％；证据水平为2b级的占40.0％，3b级的占4.0％，4级的占56.0％；随机对照试验文献占44.0％；临床对照试验文献占4.0％；采用随机双盲者占9.1％，随机单盲者占18.2％，说明组间基线可比的占31.8％，有诊断标准的占90.9％，有纳入和排除标准的占86.4％，说明统计方法的占52.4％，有客观疗效评价指标的占90.9％，说明药物不良反应的占9.1％。结论 有关中医药治疗绝经后骨质疏松症的临床研究论文日益增多，但随机对照试验比例偏低，研究设计及论文撰写水平有待进一步提高。