T-wave alternans poorly prognostic in primary prophylactic ICD patients: a prospective EU-CERT-ICD study

Background

New methods to identify patients who truly benefit from primary prophylactic implantable cardioverter defibrillation (ICD) are urgently needed. T-wave alternans (TWA) represents a beat-to-beat fluctuation in the morphology of the ST-segment and T-wave. It has been shown to associate with arrhythmogenesis of heart and sudden cardiac death [1]. We hypothised that TWA might associate with benefit from ICD implantation in primary prevention.

Methods

In EU-CERT-ICD study, we prospectively enrolled 2327 primary prophylactic ICD candidates from 15 European countries. A 24-hours Holter-monitoring was taken from all recruited patients at enrolment. TWA was assessed from Holter-monitoring using MMA method with Getemed Cardioday software. To assess the benefit from ICD treatment, we used outcomes all-cause mortality, appropriate shock and survival benefit. We conducted Cox regression model, competing risk regression model and propensity score adjusted Cox regression model. TWA was assessed both as contiguous variable and with cut-off points <47 μV and <60 μV.

Results

Final cohort included 1,734 valid T-wave alternans samples, 1,211 patients with ICD and 523 control patients with conservative treatment, with mean follow-up time 2.3 years. TWA <60 μV predicted lower all-cause mortality in ICD patients in univariate cox regression model (HR 1.484, 95% CI 1.024–2.151, p=0.0374). In multivariate models, TWA did not predict death or appropriate shocks in ICD patients. In addition, TWA did not predict death in control patients. In propensity score adjusted Cox regression model, TWA did not predict ICD benefit.

Conclusion

T-wave alternans is poorly prognostic in primary prophylactic ICD patients. Altough it may predict life-threatening arrhythmias and sudden cardiac death in several patient populations, it cannot be used in assessing benefit from implantable cardioverter defibrillator in primary prevention among patients with ejection fraction ≤35%.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Community's 7th Framework Program FP7/2007-2013

Smoking cessation by combined medication and counselling: a feasibility study in lung cancer patients

Purpose

Smoking cessation in patients with diagnosed lung cancer has positive effects on cancer therapy and overall prognosis. Despite this, knowledge on smoking cessation in lung cancer patients is sparse.

Methods

This is an observational single centre, 12-week, prospective, single-arm trial at a tertiary lung cancer centre. Responsive patients were enrolled following confirmed lung cancer diagnosis. Smoking cessation intervention included counselling as well as pharmacotherapy. The primary endpoint was the point prevalence abstinence rate at week 12 based on biochemical verification. Secondary endpoints were the abstinence rate at week 26, quality of life and side effects.

Results

80 patients were enrolled. Mean age was 62.6 ± 7.9 years. Most patients (63%) were treated with chemotherapy or radiochemotherapy. 39 patients used nicotine replacement therapy, 35 varenicline whereas six patients did not use pharmacotherapy. During the study period 13 patients died. Data were available in 72 patients after 12 weeks and 57 patients at week 24. Point prevalence abstinence rates were 37.5% (95% CI 26.4–49.7%) at week 12 and 32.8% (95% CI 21.8–45.4%) at week 26, respectively. Quality of life and side effects were not significantly affected by pharmacotherapy.

Conclusion

In conclusion, our results suggest that smoking cessation is feasible in patients with newly diagnosed lung cancer. The observed abstinence rate is comparable to other patient cohorts. Furthermore, pharmacotherapy in addition to cancer therapy was safe and did not show novel side effects in these seriously ill patients. Thus, smoking cessation should be an integral part of lung cancer treatment.

Trial registration The study was conducted in accordance with good clinical practice standards (GCP) and approved by the local ethics committee (16/3/14), the European PAS registry (EUPAS8748) and the German BfArM (NIS-Studien-Nr. 5508). All patients provided written informed consent before study enrollment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02048-1.

Q waves are the strongest electrocardiographic variable associated with primary prophylactic implantable cardioverter-defibrillator benefit: a prospective multicentre study

AIM

The association of standard 12-lead electrocardiogram (ECG) markers with benefits of the primary prophylactic implantable cardioverter-defibrillator (ICD) has not been determined in the contemporary era. We analysed traditional and novel ECG variables in a large prospective, controlled primary prophylactic ICD population to assess the predictive value of ECG in terms of ICD benefit.

METHODS AND RESULTS

Electrocardiograms from 1477 ICD patients and 700 control patients (EU-CERT-ICD; non-randomized, controlled, prospective multicentre study; ClinicalTrials.gov Identifier: NCT02064192), who met ICD implantation criteria but did not receive the device, were analysed. The primary outcome was all-cause mortality. In ICD patients, the co-primary outcome of first appropriate shock was used. Mean follow-up time was 2.4 ± 1.1 years to death and 2.3 ± 1.2 years to the first appropriate shock. Pathological Q waves were associated with decreased mortality in ICD patients [hazard ratio (HR) 0.54, 95% confidence interval (CI) 0.35-0.84; P < 0.01] and patients with pathological Q waves had significantly more benefit from ICD (HR 0.44, 95% CI 0.21-0.93; P = 0.03). QTc interval increase taken as a continuous variable was associated with both mortality and appropriate shock incidence, but commonly used cut-off values, were not statistically significantly associated with either of the outcomes.

CONCLUSION

Pathological Q waves were a strong ECG predictor of ICD benefit in primary prophylactic ICD patients. Excess mortality among Q wave patients seems to be due to arrhythmic death which can be prevented by ICD.

Development and external validation of prediction models to predict implantable cardioverter-defibrillator efficacy in primary prevention of sudden cardiac death

Aims

This study was performed to develop and externally validate prediction models for appropriate implantable cardioverter-defibrillator (ICD) shock and mortality to identify subgroups with insufficient benefit from ICD implantation.

Methods and results

We recruited patients scheduled for primary prevention ICD implantation and reduced left ventricular function. Bootstrapping-based Cox proportional hazards and Fine and Gray competing risk models with likely candidate predictors were developed for all-cause mortality and appropriate ICD shock, respectively. Between 2014 and 2018, we included 1441 consecutive patients in the development and 1450 patients in the validation cohort. During a median follow-up of 2.4 (IQR 2.1–2.8) years, 109 (7.6%) patients received appropriate ICD shock and 193 (13.4%) died in the development cohort. During a median follow-up of 2.7 (IQR 2.0–3.4) years, 105 (7.2%) received appropriate ICD shock and 223 (15.4%) died in the validation cohort. Selected predictors of appropriate ICD shock were gender, NSVT, ACE/ARB use, atrial fibrillation history, Aldosterone-antagonist use, Digoxin use, eGFR, (N)OAC use, and peripheral vascular disease. Selected predictors of all-cause mortality were age, diuretic use, sodium, NT-pro-BNP, and ACE/ARB use. C-statistic was 0.61 and 0.60 at respectively internal and external validation for appropriate ICD shock and 0.74 at both internal and external validation for mortality.

Conclusion

Although this cohort study was specifically designed to develop prediction models, risk stratification still remains challenging and no large group with insufficient benefit of ICD implantation was found. However, the prediction models have some clinical utility as we present several scenarios where ICD implantation might be postponed.

Exploring what is important to patients with regards to quality of life after experiencing a lower limb reconstructive procedure: a qualitative evidence synthesis

BACKGROUND

Patient reported outcome measures (PROMs) are used to understand the impact of lower limb reconstruction surgery on patients' quality of life (QOL). Existing measures have not been developed to specifically capture patient experiences amongst adults with lower limb conditions that require reconstruction surgery. This review aimed to synthesise qualitative evidence to identify what is important to patients requiring, undergoing, or following reconstructive surgery for lower limb conditions.

METHODS

MEDLINE, Embase, PsychINFO and Cinahl were searched from inception until November 2020. Studies were included if they employed qualitative research methods, involved patients requiring, undergoing or following lower limb reconstruction and explored patients' experiences of care, treatment, recovery and QOL. Mixed methods studies that did not separately report qualitative findings, mixed population studies that were not separately reported and studies in languages other than English were excluded. Included studies were analysed using thematic synthesis. The Critical Appraisal Skills Programme qualitative studies checklist was used to undertake quality assessment.

RESULTS

Nine studies met the inclusion criteria. The thematic synthesis identified two overarching themes: (1) areas of living key to QOL for lower limb reconstruction patients and (2) moving towards a new normal. The way in which lower limb reconstruction affects an individual's QOL and their recovery is complex and is influenced by a range of inter-related factors, which will affect patients to varying degrees depending on their individual circumstances. We identified these factors as: pain, daily functioning and lifestyle, identity, income, emotional wellbeing, support, the ability to adapt and adjust and the ability to move forwards.

CONCLUSIONS

The way patients' QOL is affected after a lower limb reconstruction is complex, may change over time and is strongly linked to their recovery. These findings will aid us in developing a conceptual framework which identifies the outcomes important to patients and those that should be included in a PROM. Further research is then required to establish whether the range of factors we identified are captured by existing PROMs. Depending on the outcome of this work, a new PROM for patients following lower limb reconstruction may be required.

Clinical effectiveness of primary prevention implantable cardioverter-defibrillators: results of the EU-CERT-ICD controlled multicentre cohort study

Aims

The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter-Defibrillators (EU-CERT-ICD), a prospective investigator-initiated, controlled cohort study, was conducted in 44 centres and 15 European countries. It aimed to assess current clinical effectiveness of primary prevention ICD therapy.

Methods and results

We recruited 2327 patients with ischaemic cardiomyopathy (ICM) or dilated cardiomyopathy (DCM) and guideline indications for prophylactic ICD implantation. Primary endpoint was all-cause mortality. Clinical characteristics, medications, resting, and 12-lead Holter electrocardiograms (ECGs) were documented at enrolment baseline. Baseline and follow-up (FU) data from 2247 patients were analysable, 1516 patients before first ICD implantation (ICD group) and 731 patients without ICD serving as controls. Multivariable models and propensity scoring for adjustment were used to compare the two groups for mortality. During mean FU of 2.4 ± 1.1 years, 342 deaths occurred (6.3%/years annualized mortality, 5.6%/years in the ICD group vs. 9.2%/years in controls), favouring ICD treatment [unadjusted hazard ratio (HR) 0.682, 95% confidence interval (CI) 0.537–0.865, P = 0.0016]. Multivariable mortality predictors included age, left ventricular ejection fraction (LVEF), New York Heart Association class <III, and chronic obstructive pulmonary disease. Adjusted mortality associated with ICD vs. control was 27% lower (HR 0.731, 95% CI 0.569–0.938, P = 0.0140). Subgroup analyses indicated no ICD benefit in diabetics (adjusted HR = 0.945, P = 0.7797, P for interaction = 0.0887) or those aged ≥75 years (adjusted HR 1.063, P = 0.8206, P for interaction = 0.0902).

Conclusion

In contemporary ICM/DCM patients (LVEF ≤35%, narrow QRS), primary prophylactic ICD treatment was associated with a 27% lower mortality after adjustment. There appear to be patients with less survival advantage, such as older patients or diabetics.

Nocturnal respiratory rate predicts ICD benefit: A prospective, controlled, multicentre cohort study

BACKGROUND

Implantable cardioverter defibrillators (ICDs) prevent sudden cardiac death. ICD implantation decisions are currently based on reduced left ventricular ejection fraction (LVEF≤35%). However, in some patients, the non-arrhythmic death risk predominates thus diminishing ICD-therapy benefits. Based on previous observations, we tested the hypothesis that compared to the others, patients with nocturnal respiratory rate (NRR) ≥18 breaths per minute (brpm) benefit less from prophylactic ICD implantations.

METHODS

This prospective cohort study was a pre-defined sub-study of EU-CERT-ICD trial conducted at 44 centers in 15 EU countries between May 12, 2014, and September 6, 2018. Patients with ischaemic or non-ischaemic cardiomyopathy were included if meeting primary prophylactic ICD implantation criteria. The primary endpoint was all-cause mortality. NRR was assessed blindly from pre-implantation 24-hour Holters. Multivariable models and propensity stratification evaluated the interaction between NRR and the ICD mortality effect. This study is registered with ClinicalTrials.gov (NCT0206419).

FINDINGS

Of the 2,247 EU-CERT-ICD patients, this sub-study included 1,971 with complete records. In 1,363 patients (61.7 (12) years; 244 women) an ICD was implanted; 608 patients (63.2 (12) years; 108 women) were treated conservatively. During a median 2.5-year follow-up, 202 (14.8%) and 95 (15.6%) patients died in the ICD and control groups, respectively. NRR statistically significantly interacted with the ICD mortality effect (p = 0.0070). While the 1,316 patients with NRR<18 brpm showed a marked ICD benefit on mortality (adjusted HR 0.529 (95% CI 0.376-0.746); p = 0.0003), no treatment effect was demonstrated in 655 patients with NRR≥18 brpm (adjusted HR 0.981 (95% CI 0.669-1.438); p = 0.9202).

INTERPRETATION

In the EU-CERT-ICD trial, patients with NRR≥18 brpm showed limited benefit from primary prophylactic ICD implantation. Those with NRR<18 brpm benefitted substantially.

FUNDING

European Community's 7th Framework Programme FP7/2007-2013 (602299).

Electrocardiogram as a predictor of survival without appropriate shocks in primary prophylactic ICD patients: A retrospective multi-center study

BACKGROUND

Abnormal 12-lead electrocardiogram (ECG) can predict cardiovascular events, including sudden cardiac death. We tested the hypothesis that ECG provides useful information on guiding implantable cardioverter defibrillator (ICD) therapy into individuals with impaired left ventricular ejection fraction (LVEF).

METHODS

Retrospective data of primary prevention ICD implantations from 14 European centers were gathered. The registry included 5111 subjects of whom 1687 patients had an interpretable pre-implantation ECG available (80.0% male, 63.3 ± 11.4 years). Primary outcome was survival without appropriate ICD shocks or heart transplantation. A low-risk ECG was defined as a combination of ECG variables that were associated with the primary outcome.

RESULTS

A total of 1224 (72.6%) patients survived the follow-up (2.9 ± 1.7 years) without an ICD shock, 224 (13.3%) received an appropriate shock and 260 (15.4%) died. Low-risk ECG defined as QRS duration <120 ms, QTc interval <450 ms for men and <470 ms for women, and sinus rhythm, were met by 515 patients (30.5%). Multivariable Cox regression showed that the hazard (HR) for death, heart transplantation or appropriate shock were reduced by 42.5% in the low-risk group (HR 0.575; 95% CI 0.45-0.74; p < 0.001), compared to the high-risk group. The HR for the first appropriate shock was 42.1% lower (HR 0.58; 95% CI 0.41-0.82; p = 0.002) and the HR for death was 48.0% lower (HR 0.52; 95% CI 0.386-0.72; p < 0.001) in the low-risk group.

CONCLUSION

Sinus rhythm, QRS <120 ms and normal QTc in standard 12-lead ECG provides information about survival without appropriate ICD shocks and might improve patient selection for primary prevention ICD therapy.

Sample size recalculation in multicenter randomized controlled clinical trials based on noncomparative data

Many late-phase clinical trials recruit subjects at multiple study sites. This introduces a hierarchical structure into the data that can result in a power-loss compared to a more homogeneous single-center trial. Building on a recently proposed approach to sample size determination, we suggest a sample size recalculation procedure for multicenter trials with continuous endpoints. The procedure estimates nuisance parameters at interim from noncomparative data and recalculates the sample size required based on these estimates. In contrast to other sample size calculation methods for multicenter trials, our approach assumes a mixed effects model and does not rely on balanced data within centers. It is therefore advantageous, especially for sample size recalculation at interim. We illustrate the proposed methodology by a study evaluating a diabetes management system. Monte Carlo simulations are carried out to evaluate operation characteristics of the sample size recalculation procedure using comparative as well as noncomparative data, assessing their dependence on parameters such as between-center heterogeneity, residual variance of observations, treatment effect size and number of centers. We compare two different estimators for between-center heterogeneity, an unadjusted and a bias-adjusted estimator, both based on quadratic forms. The type 1 error probability as well as statistical power are close to their nominal levels for all parameter combinations considered in our simulation study for the proposed unadjusted estimator, whereas the adjusted estimator exhibits some type 1 error rate inflation. Overall, the sample size recalculation procedure can be recommended to mitigate risks arising from misspecified nuisance parameters at the planning stage.

Appropriate Shocks and Mortality in Patients With Versus Without Diabetes With Prophylactic Implantable Cardioverter Defibrillators

OBJECTIVE

Diabetes increases the risk of all-cause mortality and sudden cardiac death (SCD). The exact mechanisms leading to sudden death in diabetes are not well known. We compared the incidence of appropriate shocks and mortality in patients with versus without diabetes with a prophylactic implantable cardioverter defibrillator (ICD) included in the retrospective EU-CERT-ICD registry.

RESEARCH DESIGN AND METHODS AND RESULTS

A total of 3,535 patients from 12 European EU-CERT-ICD centers with a mean age of 63.7 ± 11.2 years (82% males) at the time of ICD implantation were included in the analysis. A total of 995 patients (28%) had a history of diabetes. All patients had an ICD implanted for primary SCD prevention. End points were appropriate shock and all-cause mortality. Mean follow-up time was 3.2 ± 2.3 years. Diabetes was associated with a lower risk of appropriate shocks (adjusted hazard ratio [HR] 0.77 [95% CI 0.62-0.96], P = 0.02). However, patients with diabetes had significantly higher mortality (adjusted HR 1.30 [95% CI 1.11-1.53], P = 0.001).

CONCLUSIONS

All-cause mortality is higher in patients with diabetes than in patients without diabetes with primary prophylactic ICDs. Subsequently, patients with diabetes have a lower incidence of appropriate ICD shocks, indicating that the excess mortality might not be caused primarily by ventricular tachyarrhythmias. These findings suggest a limitation of the potential of prophylactic ICD therapy to improve survival in patients with diabetes with impaired left ventricular function.

Prediction of mortality benefit based on periodic repolarisation dynamics in patients undergoing prophylactic implantation of a defibrillator: a prospective, controlled, multicentre cohort study

BACKGROUND

A small proportion of patients undergoing primary prophylactic implantation of implantable cardioverter defibrillators (ICDs) experiences malignant arrhythmias. We postulated that periodic repolarisation dynamics, a novel marker of sympathetic-activity-associated repolarisation instability, could be used to identify electrically vulnerable patients who would benefit from prophylactic implantation of ICDs by way of a reduction in mortality.

METHODS

We did a prespecified substudy of EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators (EU-CERT-ICD), a prospective, investigator-initiated, non-randomised, controlled cohort study done at 44 centres in 15 EU countries. Patients aged 18 years or older with ischaemic or non-ischaemic cardiomyopathy and reduced left ventricular ejection fraction (≤35%) were eligible for inclusion if they met guideline-based criteria for primary prophylactic implantation of ICDs. Periodic repolarisation dynamics from 24-h Holter recordings were assessed blindly in patients the day before ICD implantation or on the day of study enrolment in patients who were conservatively managed. The primary endpoint was all-cause mortality. Propensity scoring and multivariable models were used to assess the interaction between periodic repolarisation dynamics and the treatment effect of ICDs on mortality.

FINDINGS

Between May 12, 2014, and Sept 7, 2018, 1371 patients were enrolled in our study. 968 of these patients underwent ICD implantation, and 403 were treated conservatively. During follow-up (median 2·7 years [IQR 2·0-3·3] in the ICD group and 1·2 years [0·8-2·7] in the control group), 138 (14%) patients died in the ICD group and 64 (16%) patients died in the control group. We noted a 43% reduction in mortality in the ICD group compared with the control group (adjusted hazard ratio [HR] 0·57 [95% CI 0·41-0·79]; p=0·0008). Periodic repolarisation dynamics significantly predicted the treatment effect of ICDs on mortality (adjusted p=0·0307). The mortality benefits associated with ICD implantation were greater in patients with periodic repolarisation dynamics of 7·5 deg or higher (n=199; adjusted HR 0·25 [95% CI 0·13-0·47] for the ICD group vs the control group; p<0·0001) than in those with periodic repolarisation dynamics less than 7·5 deg (n=1166; adjusted HR 0·69 [95% CI 0·47-1·00]; p=0·0492; p_interaction=0·0056). The number needed to treat was 18·3 (95% CI 10·6-4895·3) in patients with periodic repolarisation dynamics less than 7·5 deg and 3·1 (2·6-4·8) in those with periodic repolarisation dynamics of 7·5 deg or higher.

INTERPRETATION

Periodic repolarisation dynamics predict mortality reductions associated with prophylactic implantation of ICDs in contemporarily treated patients with ischaemic or non-ischaemic cardiomyopathy. Periodic repolarisation dynamics could help to guide treatment decisions about prophylactic ICD implantation.

FUNDING

The European Community's 7th Framework Programme.

Present criteria for prophylactic ICD implantation: Insights from the EU-CERT-ICD (Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators in EUrope) project

BACKGROUND

The clinical effectiveness of primary prevention implantable cardioverter defibrillator (ICD) therapy is under debate. It is urgently needed to better identify patients who benefit from prophylactic ICD therapy. The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators (EU-CERT-ICD) completed in 2019 will assess this issue.

SUMMARY

The EU-CERT-ICD is a prospective investigator-initiated non-randomized, controlled, multicenter observational cohort study done in 44 centers across 15 European countries. A total of 2327 patients with heart failure due to ischemic heart disease or dilated cardiomyopathy indicated for primary prophylactic ICD implantation were recruited between 2014 and 2018 (>1500 patients at first ICD implantation, >750 patients non-randomized non-ICD control group). The primary endpoint was all-cause mortality, and first appropriate shock was co-primary endpoint. At baseline, all patients underwent 12‑lead ECG and Holter-ECG analysis using multiple advanced methods for risk stratification as well as documentation of clinical characteristics and laboratory values. The EU-CERT-ICD data will provide much needed information on the survival benefit of preventive ICD therapy and expand on previous prospective risk stratification studies which showed very good applicability of clinical parameters and advanced risk stratifiers in order to define patient subgroups with above or below average ICD benefit.

CONCLUSION

The EU-CERT-ICD study will provide new and current data about effectiveness of primary prophylactic ICD implantation. The study also aims for improved risk stratification and patient selection using clinical risk markers in general, and advanced ECG risk markers in particular.

Laquinimod, a prototypic quinoline-3-carboxamide and aryl hydrocarbon receptor agonist, utilizes a CD155-mediated natural killer/dendritic cell interaction to suppress CNS autoimmunity

Background

Quinoline-3-carboxamides, such as laquinimod, ameliorate CNS autoimmunity in patients and reduce tumor cell metastasis experimentally. Previous studies have focused on the immunomodulatory effect of laquinimod on myeloid cells. The data contained herein suggest that quinoline-3-carboxamides improve the immunomodulatory and anti-tumor effects of NK cells by upregulating the adhesion molecule DNAX accessory molecule-1 (DNAM-1).

Methods

We explored how NK cell activation by laquinimod inhibits CNS autoimmunity in experimental autoimmune encephalomyelitis (EAE), the most utilized model of MS, and improves immunosurveillance of experimental lung melanoma metastasis. Functional manipulations included in vivo NK and DC depletion experiments and in vitro assays of NK cell function. Clinical, histological, and flow cytometric read-outs were assessed.

Results

We demonstrate that laquinimod activates natural killer (NK) cells via the aryl hydrocarbon receptor and increases their DNAM-1 cell surface expression. This activation improves the cytotoxicity of NK cells against B16F10 melanoma cells and augments their immunoregulatory functions in EAE by interacting with CD155⁺ dendritic cells (DC). Noteworthy, the immunosuppressive effect of laquinimod-activated NK cells was due to decreasing MHC class II antigen presentation by DC and not by increasing DC killing.

Conclusions

This study clarifies how DNAM-1 modifies the bidirectional crosstalk of NK cells with CD155⁺ DC, which can be exploited to suppress CNS autoimmunity and strengthen tumor surveillance.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1437-0) contains supplementary material, which is available to authorized users.

Sample size calculation in multi-centre clinical trials

Background

Multi-centre randomized controlled clinical trials play an important role in modern evidence-based medicine. Advantages of collecting data from more than one site are numerous, including accelerated recruitment and increased generalisability of results. Mixed models can be applied to account for potential clustering in the data, in particular when many small centres contribute patients to the study. Previously proposed methods on sample size calculation for mixed models only considered balanced treatment allocations which is an unlikely outcome in practice if block randomisation with reasonable choices of block length is used.

Methods

We propose a sample size determination procedure for multi-centre trials comparing two treatment groups for a continuous outcome, modelling centre differences using random effects and allowing for arbitrary sample sizes. It is assumed that block randomisation with fixed block length is used at each study site for subject allocation. Simulations are used to assess operation characteristics such as power of the sample size approach. The proposed method is illustrated by an example in disease management systems.

Results

A sample size formula as well as a lower and upper boundary for the required overall sample size are given. We demonstrate the superiority of the new sample size formula over the conventional approach of ignoring the multi-centre structure and show the influence of parameters such as block length or centre heterogeneity. The application of the procedure on the example data shows that large blocks require larger sample sizes, if centre heterogeneity is present.

Conclusion

Unbalanced treatment allocation can result in substantial power loss when centre heterogeneity is present but not considered at the planning stage. When only few patients by centre will be recruited, one has to weigh the risk of imbalance between treatment groups due to large blocks and the risk of unblinding due to small blocks. The proposed approach should be considered when planning multi-centre trials.

Electronic supplementary material

The online version of this article (10.1186/s12874-018-0602-y) contains supplementary material, which is available to authorized users.

The influence of hospitalisation on the initiation, continuation and discontinuation of benzodiazepines and Z-drugs - an observational study

BACKGROUND AND OBJECTIVES

Hospitalisation influences drug therapy in ambulatory care and this influence is generally negatively perceived. The few studies that have explored changes in benzodiazepine or sleep medication use as a function of hospitalisation failed to precisely determine the hospital's role in initiating, continuing and discontinuing these drugs on a valid basis. The aim of the study was to ascertain the overall influence of hospitalisation on the prescription of benzodiazepines and Z-drugs in outpatient care with a special focus on the role of different hospital departments and drug classes.

METHODS

In a secondary data analysis, we used prescription data for 181 037 patients who visited 127 hospitals and compared the numbers of patients with prescriptions of benzodiazepines and Z-drugs 50 days before and 50 or 100 days after hospitalisation.

RESULTS

The proportion of patients who received benzodiazepines or Z-drugs increased from 3.1% before admission to 3.6% at 50 days after discharge and fell to the former level after an additional 50 days. A multivariable logistic regression showed that gender and department had an additional impact on these results. Of those patients without a prescription for a benzodiazepine or Z-drug before admission, 0.6% received a prescription in both time-windows after discharge. Of those patients who were prescribed a benzodiazepine, 38.0% received short-acting substances and 40.3% received long-acting substances before hospitalisation. After hospitalisation, these rates changed to favour short-acting substances (44.4% and 34.4%, respectively).

CONCLUSIONS

The hospital effect on initiating and increasing hypnotic or sedative drug use seems to be only moderate and temporary. A change in favour of short-acting substances is even welcome. In less than 1% of patients, the hospital initiated the continuous use of benzodiazepines and Z-drugs, which may put pressure on primary care physicians. However, the widespread use of these drugs in hospitals does not seem to be continued on a large scale in primary care.

Results of medial patellofemoral ligament reconstruction compared with trochleoplasty plus individual extensor apparatus balancing in patellar instability caused by severe trochlear dysplasia: a systematic review and meta-analysis

PURPOSE

Many studies have reported satisfactory clinical outcomes and low redislocation rates after reconstruction of the medial patellofemoral ligament (MPFL) for the treatment of lateral patellar instability. Despite uncorrected severe trochlear dysplasia (Dejour type B to D) being acknowledged as a major reason for less favourable clinical outcomes and a higher incidence of patellar redislocations after an isolated MPFL reconstruction, the evidence for a deepening trochleoplasty procedure remains scarce in the current literature. The hypothesis of this systematic review and meta-analysis was that a deepening trochleoplasty in combination with an a la carte extensor apparatus balancing procedure provides lower redislocation rates and superior clinical outcomes than isolated MPFL reconstruction in patients with lateral patellar instability caused by severe trochlear dysplasia.

METHODS

A systematic review of the literature was conducted using specific inclusion and exclusion criteria for clinical studies reporting index operations (trochleoplasty and MPFL reconstruction) for the treatment of patellar instability caused by severe trochlear dysplasia. The Kujala score was analysed as the primary clinical outcome parameter in a random effects meta-analysis.

RESULTS

Ten uncontrolled studies with a total of 407 knees (374 patients) were included in this analysis. The MPFL group comprised 4 studies with a total of 221 knees (210 patients), and the trochleoplasty group comprised 6 studies with a total of 186 knees (164 patients). The mean preoperative Kujala score ranged between 50.4 and 70.5 in the MPFL group and between 44.8 and 75.1 in the trochleoplasty group. The pooled Kujala score increased significantly by 26.4 (95% CI 21.4, 31.3; P < 0.00001) points in the MPFL group and by 26.2 (95% CI 19.8, 32.7; P < 0.00001) points in the trochleoplasty group. The post-operative patellar redislocation/subluxation rate was 7% in the MPFL group and 2.1% in the trochleoplasty group.

CONCLUSION

This analysis found significant post-operative improvements in patient-reported outcomes for patients undergoing both an MPFL reconstruction and in those undergoing a trochleoplasty plus an individual extensor apparatus balancing procedure when assessed using the Kujala score. The likelihood of preventing the patella from subsequent post-operative redislocation/subluxation was, however, greater in patients who underwent trochleoplasty plus extensor balancing.

LEVEL OF EVIDENCE

IV.

Graft-derived cell-free DNA, a noninvasive early rejection and graft damage marker in liver transplantation: A prospective, observational, multicenter cohort study

BACKGROUND

Graft-derived cell-free DNA (GcfDNA), which is released into the blood stream by necrotic and apoptotic cells, is a promising noninvasive organ integrity biomarker. In liver transplantation (LTx), neither conventional liver function tests (LTFs) nor immunosuppressive drug monitoring are very effective for rejection monitoring. We therefore hypothesized that the quantitative measurement of donor-derived cell-free DNA (cfDNA) would have independent value for the assessment of graft integrity, including damage from acute rejection.

METHODS AND FINDINGS

Traditional LFTs were performed and plasma GcfDNA was monitored in 115 adults post-LTx at three German transplant centers as part of a prospective, observational, multicenter cohort trial. GcfDNA percentage (graft cfDNA/total cfDNA) was measured using droplet digital PCR (ddPCR), based on a limited number of predefined single nucleotide polymorphisms, enabling same-day turn-around. The same method was used to quantify blood microchimerism. GcfDNA was increased >50% on day 1 post-LTx, presumably from ischemia/reperfusion damage, but rapidly declined in patients without graft injury within 7 to 10 d to a median <10%, where it remained for the 1-y observation period. Of 115 patients, 107 provided samples that met preestablished criteria. In 31 samples taken from 17 patients during biopsy-proven acute rejection episodes, the percentage of GcfDNA was elevated substantially (median 29.6%, 95% CI 23.6%-41.0%) compared with that in 282 samples from 88 patients during stable periods (median 3.3%, 95% CI 2.9%-3.7%; p < 0.001). Only slightly higher values (median 5.9%, 95% CI 4.4%-10.3%) were found in 68 samples from 17 hepatitis C virus (HCV)-positive, rejection-free patients. LFTs had low overall correlations (r = 0.28-0.62) with GcfDNA and showed greater overlap between patient subgroups, especially between acute rejection and HCV+ patients. Multivariable logistic regression modeling demonstrated that GcfDNA provided additional LFT-independent information on graft integrity. Diagnostic sensitivity and specificity were 90.3% (95% CI 74.2%-98.0%) and 92.9% (95% CI 89.3%-95.6%), respectively, for GcfDNA at a threshold value of 10%. The area under the receiver operator characteristic curve was higher for GcfDNA (97.1%, 95% CI 93.4%-100%) than for same-day conventional LFTs (AST: 95.7%; ALT: 95.2%; γ-GT: 94.5%; bilirubin: 82.6%). An evaluation of microchimerism revealed that the maximum donor DNA in circulating white blood cells was only 0.068%. GcfDNA percentage can be influenced by major changes in host cfDNA (e.g., due to leukopenia or leukocytosis). One limitation of our study is that exact time-matched GcfDNA and LFT samples were not available for all patient visits.

CONCLUSIONS

In this study, determination of GcfDNA in plasma by ddPCR allowed for earlier and more sensitive discrimination of acute rejection in LTx patients as compared with conventional LFTs. Potential blood microchimerism was quantitatively low and had no significant influence on GcfDNA value. Further research, which should ideally include protocol biopsies, will be needed to establish the practical value of GcfDNA measurements in the management of LTx patients.

Psychiatric symptoms in patients with sporadic Creutzfeldt-Jakob disease in Germany

BACKGROUND

Psychiatric symptoms in sporadic Creutzfeldt-Jakob disease (sCJD) are still not sufficiently evaluated.

AIM

To describe psychiatric symptoms in sCJD with respect to molecular subtype.

METHOD

Patients in this retrospective study were classified according to established diagnostic criteria. 248 sCJD patients with known molecular subtype were recruited from January 1993 to December 2004 and investigated. Psychiatric symptoms were defined according to Möller and colleagues and the AMDP system (Study Group for Methods and Documentation in Psychiatry) and were collected by direct examination by study physicians or extracted from medical documentation. Our data were compared with published data on variant CJD (vCJD).

RESULTS

Psychiatric symptoms were common in sCJD patients (90%) and mostly found already at the disease onset (agitation in 64% of the patients, hallucinations in 45%, anxiety in 50%, depression in 37%). All psychiatric symptoms but illusions were found early in the disease course. Psychiatric symptoms in sCJD were less frequent than in vCJD.

CONCLUSIONS

We provide the first detailed analysis of psychiatric symptoms in a large group of patients with sCJD with respect to differences concerning frequency and time point of occurrence of psychiatric symptoms between molecular subtypes. These data suggest that psychiatric symptoms occurring early in the disease course are common not only in vCJD but also in other CJD types.

Systematic review of the limited evidence base for treatments of Eustachian tube dysfunction: a health technology assessment

BACKGROUND

The Health Technology Assessment programme commissioned a wide-ranging review of treatments for adult Eustachian tube dysfunction. Treatments range from advice and observation and pharmacological treatments to surgical options.

OBJECTIVE

(i) To assess the evidence for interventions for adults with a clinical diagnosis of Eustachian tube dysfunction and (ii) to identify priorities for future research.

TYPE OF REVIEW

Systematic review (PROSPERO registration CRD42012003035) adhering to PRISMA guidance.

SEARCH

An extensive search of 15 databases including MEDLINE, EMBASE and CENTRAL (up to October 2012).

EVALUATION METHOD

Controlled and uncontrolled studies of interventions for adult Eustachian tube dysfunction were included. Because of insufficient data, the protocol was amended to also include controlled studies with mixed adult/child populations. Risk of bias was assessed. Narrative synthesis was employed due to high clinical heterogeneity.

RESULTS

Interventions assessed were pharmacological treatments [two randomised controlled trials (RCTs), one controlled non-randomised trial (CCT), 159 patients]; mechanical pressure equalisation devices (one randomised controlled trial, one CCT, 48 patients); and surgery, including laser tuboplasty (seven case series, 192 patients), balloon dilatation (three case series, 103 patients), myringotomy without grommet insertion (two case series, 121 patients), transtubal steroids (one case series, 11 patients) and laser coagulation (one retrospective controlled study, 40 patients). All studies had high risk of bias except two pharmacological trials; one had low risk and one unclear risk. No evidence was found for many treatments. The single low risk of bias RCT (n = 91; 67% adults) showed no effect of nasal steroids and favoured placebo for improved middle ear function (RR 1.20, 95% CI 0.91-1.58) and symptoms (P = 0.07). Other studies showed improvements in middle ear function for mechanical devices, antihistamine/ephedrine and nasal decongestant, but they had significant methodological weaknesses including insufficient length of follow-up. None of the surgical studies were adequately controlled, and many reported high levels of co-intervention. Therefore, observed benefits for tuboplasty and balloon dilatation in symptoms, middle ear function or hearing could not be reliably attributed to the interventions assessed. There was variability in definitions of the condition.

CONCLUSION

Eustachian tube dysfunction is a poorly defined condition. Due to the limited and poor-quality evidence, it is inappropriate to make conclusions on the effectiveness of any intervention; the evidence base is insufficient to guide recommendations for a trial of any particular intervention. Consensus on diagnostic criteria for Eustachian tube dysfunction is required to inform inclusion criteria of future trials.

Acupuncture and other physical treatments for the relief of pain due to osteoarthritis of the knee: network meta-analysis

OBJECTIVE

To compare the effectiveness of acupuncture with other relevant physical treatments for alleviating pain due to knee osteoarthritis.

DESIGN

Systematic review with network meta-analysis, to allow comparison of treatments within a coherent framework. Comprehensive searches were undertaken up to January 2013 to identify randomised controlled trials in patients with osteoarthritis of the knee, which reported pain.

RESULTS

Of 156 eligible studies, 114 trials (covering 22 treatments and 9,709 patients) provided data suitable for analysis. Most trials studied short-term effects and many were classed as being of poor quality with high risk of bias, commonly associated with lack of blinding (which was sometimes impossible to achieve). End of treatment results showed that eight interventions: interferential therapy, acupuncture, TENS, pulsed electrical stimulation, balneotherapy, aerobic exercise, sham acupuncture, and muscle-strengthening exercise produced a statistically significant reduction in pain when compared with standard care. In a sensitivity analysis of satisfactory and good quality studies, most studies were of acupuncture (11 trials) or muscle-strengthening exercise (9 trials); both interventions were statistically significantly better than standard care, with acupuncture being statistically significantly better than muscle-strengthening exercise (standardised mean difference: 0.49, 95% credible interval 0.00-0.98).

CONCLUSIONS

As a summary of the current available research, the network meta-analysis results indicate that acupuncture can be considered as one of the more effective physical treatments for alleviating osteoarthritis knee pain in the short-term. However, much of the evidence in this area of research is of poor quality, meaning there is uncertainty about the efficacy of many physical treatments.

The clinical effectiveness and cost-effectiveness of low-intensity psychological interventions for the secondary prevention of relapse after depression: a systematic review

BACKGROUND

Depression is the most common mental disorder in community settings and a major cause of disability across the world. The objective of treatment is to achieve remission or at least adequate control of depressive symptoms; however, even after successful treatment, the risk of relapse after remission is significant. Although the effectiveness of low-intensity interventions has been extensively evaluated to treat primary symptoms of psychological difficulties, there has been substantially less research examining the use of these interventions as a relapse prevention strategy.

OBJECTIVE

To systematically review the clinical effectiveness and cost-effectiveness of low-intensity psychological or psychosocial interventions to prevent relapse or recurrence in patients with depression. As the broader definition of 'low-intensity' psychological intervention is somewhat contested, the review was conducted in two parts: A, a systematic review of all evaluations of 'low-intensity' interventions that were delivered by para-professionals, peer supporters or psychological well-being practitioners as defined by the Improving Access to Psychological Therapies programme; and B, a scoping review of relevant evaluations of interventions involving qualified mental health professionals (e.g. psychiatrists, clinical psychologists, cognitive behavioural therapists) involving < 6 hours of contact per patient.

DATA SOURCES

Comprehensive literature searches were developed; electronic databases were searched from inception until September 2010 (including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, PsycINFO, EMBASE, The Cochrane Library), internet resources were used to identify guidelines on the treatment of depression, and the bibliographies of relevant reviews, guidelines and included studies were scrutinised.

REVIEW METHODS

Two reviewers independently screened titles and abstracts; data were extracted independently by one reviewer using a standardised data extraction form and checked by another. Discrepancies were resolved by consensus, with involvement of a third reviewer when necessary. The inclusion criteria were population - adults or adolescents who had received treatment for depression; intervention - part A, low-intensity interventions, specifically any unsupported psychological/psychosocial interventions or any supported interventions that did not involve highly qualified mental health professionals, and, part B, interventions carried out by qualified mental health professionals that involved < 6 hours of contact per patient; comparator - any, including no treatment, placebo, psychological or pharmacological interventions; outcomes - relapse or recurrence, other outcomes (e.g. social function, quality of life) were recorded where reported; and study design - for clinical effectiveness, randomised, quasi-randomised and non-randomised studies with concurrent control patients. For cost-effectiveness, full economic evaluations that compared two or more treatment options and considered both costs and consequences. No studies met the main part A inclusion criteria.

RESULTS

For the clinical effectiveness review, 17 studies (14 completed, three ongoing), reported in 27 publications, met the part B inclusion criteria. These studies were clinically and methodologically diverse, and reported differing degrees of efficacy for the evaluated interventions. One randomised controlled trial (RCT), which evaluated a collaborative care-type programme, was potentially relevant to part A; this study reported no difference between patients receiving the intervention and those receiving usual care in terms of relapse of depression over 12 months. For the cost-effectiveness review, two studies met the criteria for part B. One of these was an economic evaluation of the RCT above, which was potentially relevant to part A. This evaluation found that the intervention may be a cost-effective use of resources when compared with usual care; however, it was unclear how valid these estimates were for the NHS.

LIMITATIONS

Although any definition of 'brief' is likely to be somewhat arbitrary, an inclusion threshold of 6 hours contact per patient was used to select brief high-intensity intervention studies. Most excluded studies evaluated clearly resource-intensive interventions, though occasionally, studies were excluded on the basis of having only slightly more than 6 hours contact per patient.

CONCLUSIONS

There is inadequate evidence to determine the clinical effectiveness or cost-effectiveness of low-intensity interventions for the prevention of relapse or recurrence of depression. A scoping review of brief high-intensity therapies indicates that some approaches have shown promise in some studies, but findings have not been consistent. Many uncertainties remain and further primary research is required. Careful consideration should be given to the scope of such research; it is important to evaluate the broader patient pathway accounting for the heterogeneous patient groups of interest. Future RCTs conducted in a UK primary care setting should include adult participants in remission or recovery from depression, and evaluate the quality of the intervention and consistency of delivery across practitioners where appropriate. The occurrence of relapse or recurrence should be measured using established methods, and functional outcomes as well as symptoms should be measured; data on quality of life using a generic instrument, such as the European Quality of Life-5 Dimensions (EQ-5D), should be collected.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The effectiveness of interventions in the management of patients with primary frozen shoulder

There are many types of treatment used to manage the frozen shoulder, but there is no consensus on how best to manage patients with this painful and debilitating condition. We conducted a review of the evidence of the effectiveness of interventions used to manage primary frozen shoulder using the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Physiotherapy Evidence Database, MEDLINE and EMBASE without language or date restrictions up to April 2009. Two authors independently applied selection criteria and assessed the quality of systematic reviews using the Assessment of Multiple Systematic Reviews (AMSTAR) tool. Data were synthesised narratively, with emphasis placed on assessing the quality of evidence. In total, 758 titles and abstracts were identified and screened, which resulted in the inclusion of 11 systematic reviews. Although these met most of the AMSTAR quality criteria, there was insufficient evidence to draw firm conclusions about the effectiveness of treatments commonly used to manage a frozen shoulder. This was mostly due to poor methodological quality and small sample size in primary studies included in the reviews. We found no reviews evaluating surgical interventions. More rigorous randomised trials are needed to evaluate the treatments used for frozen shoulder.

Non-contingent positive and negative reinforcement schedules of superstitious behaviors

The role of schedules of reinforcement on the development of superstitious conditioning was investigated in a college age population. Participants were randomly assigned to one of eight operant schedules and instructed to remove (escape), prevent and/or remove (avoidance and escape) or produce (positive) the appearance of a computer generated stimulus using a response pad. Results from the experiment indicate that concomitant (escape and avoidance) schedules of reinforcement are most effective in facilitating acquisition of superstitious behavior as measured by self-reports of participants.

Psychobiological effects of carbohydrates

The authors studied whether the fatiguing effects of eating lunch are greater for carbohydrate-rich meals than for other meals, and related the time course of behavioral change to plasma glucose, insulin, and amino acids. On different occasions, in counterbalanced order, normal women (N = 7) fasted overnight, ate a standard breakfast, and at lunch either continued to fast or ate a high-carbohydrate, low-protein meal; a hedonically similar meal containing both carbohydrate and protein; or a high-protein, low-carbohydrate meal. Meals were isocaloric and equated for fat content. Only the carbohydrate meal significantly increased fatigue, which could not be attributed to hypoglycemia because plasma glucose remained elevated. Fatigue began approximately, when the carbohydrate meal elevated the plasma tryptophan ratio but ended even though the ratio remained elevated. Fatigue after a high-carbohydrate lunch could not be explained by reactive hypoglycemia or sweet taste, and could partially be explained by the hypothesis that fatigue parallels an elevation of the tryptophan ratio.

Compliance of insulin-dependent diabetics with a low-fat diet

Compliance with medical therapy is widely researched yet unpredictable. When counseled by a dietitian to begin a low-fat (25%) diabetic diet, subjects significantly decreased fat intake but did not achieve the prescribed 25% fat level. The significantly lower fat intake after instruction identified the registered dietitian as an effective behavioral change agent. Six compliance predictors obtained at an initial interview accounted for 77% of the variance in compliance.