Methods for non-proportional hazards in clinical trials: A systematic review

For the analysis of time-to-event data, frequently used methods such as the log-rank test or the Cox proportional hazards model are based on the proportional hazards assumption, which is often debatable. Although a wide range of parametric and non-parametric methods for non-proportional hazards has been proposed, there is no consensus on the best approaches. To close this gap, we conducted a systematic literature search to identify statistical methods and software appropriate under non-proportional hazard. Our literature search identified 907 abstracts, out of which we included 211 articles, mostly methodological ones. Review articles and applications were less frequently identified. The articles discuss effect measures, effect estimation and regression approaches, hypothesis tests, and sample size calculation approaches, which are often tailored to specific non-proportional hazard situations. Using a unified notation, we provide an overview of methods available. Furthermore, we derive some guidance from the identified articles.

Virtual reality cricothyrotomy - a case-control study on gamification in emergency education

BACKGROUND

Cricothyrotomy is an invasive and rare emergency intervention to secure the airway in a "cannot intubate, cannot ventilate" situation. This leads to lack of routine. Cricothyrotomy is performed only hesitantly. Therefore, we aim to improve teaching by including a virtual reality (VR) cricothyrotomy as a learning tool.

METHODS

We programmed the VR cricothyrotomy in the C# programming language on the open-source Unity platform. We could include 149 students that we randomly assigned to either a study group (VR cricothyrotomy) or control group (educational video). We asked the study group to subjectively rate the VR cricothyrotomy. To evaluate our intervention (VR cricothyrotomy) we took the time participants needed to perform a cricothyrotomy on a plastic model of a trachea and evaluated the correct procedural steps.

RESULTS

The majority of students that performed the VR simulation agreed that they improved in speed (81%) and procedural steps (92%). All participants completed the cricothyrotomy in 47s ± 16s and reached a total score of 8.7 ± 0.7 of 9 possible points. We saw no significant difference in time needed to perform a cricothyrotomy between study and control group (p > 0.05). However, the total score of correct procedural steps was significantly higher in the study group than in the control group (p < 0.05).

CONCLUSIONS

Virtual reality is an innovative learning tool to improve teaching of emergency procedures. The VR cricothyrotomy subjectively and objectively improved correct procedural steps. Digitized education fills an educational gap between pure haptic experience and theoretical knowledge. This is of great value when focusing on extension of factual knowledge.

TRIAL REGISTRATION

DRKS00031736, registered on the 20th April 2023.

Clinical course and follow-up of pediatric patients with COVID-19 vaccine-associated myocarditis compared to non-vaccine-associated myocarditis within the prospective multicenter registry-"MYKKE"

BACKGROUND

Since the onset of widespread COVID-19 vaccination, increased incidence of COVID-19 vaccine-associated myocarditis (VA-myocarditis) has been noted, particularly in male adolescents.

METHODS

Patients <18 years with suspected myocarditis following COVID-19 vaccination within 21 days were enrolled in the PedMYCVAC cohort, a substudy within the prospective multicenter registry for pediatric myocarditis "MYKKE." Clinical data at initial admission, 3- and 9-months follow-up were monitored and compared to pediatric patients with confirmed non-vaccine-associated myocarditis (NVA-myocarditis) adjusting for various baseline characteristics.

RESULTS

From July 2021 to December 2022, 56 patients with VA-myocarditis across 15 centers were enrolled (median age 16.3 years, 91% male). Initially, 11 patients (20%) had mildly reduced left ventricular ejection fraction (LVEF; 45%-54%). No incidents of severe heart failure, transplantation or death were observed. Of 49 patients at 3-months follow-up (median (IQR) 94 (63-118) days), residual symptoms were registered in 14 patients (29%), most commonly atypical intermittent chest pain and fatigue. Diagnostic abnormalities remained in 23 patients (47%). Of 21 patients at 9-months follow-up (259 (218-319) days), all were free of symptoms and diagnostic abnormalities remained in 9 patients (43%). These residuals were mostly residual late gadolinium enhancement in magnetic resonance imaging. Patients with NVA-myocarditis (n=108) more often had symptoms of heart failure (P = .003), arrhythmias (P = .031), left ventricular dilatation (P = .045), lower LVEF (P < .001) and major cardiac adverse events (P = .102).

CONCLUSIONS

Course of COVID-19 vaccine-associated myocarditis in pediatric patients seems to be mild and differs from non-vaccine-associated myocarditis. Due to a considerable number of residual symptoms and diagnostic abnormalities at follow-up, further studies are needed to define its long-term implications.

Development and validation of explainable machine learning models for risk of mortality in transcatheter aortic valve implantation: TAVI risk machine scores

Aims

Identification of high-risk patients and individualized decision support based on objective criteria for rapid discharge after transcatheter aortic valve implantation (TAVI) are key requirements in the context of contemporary TAVI treatment. This study aimed to predict 30-day mortality following TAVI based on machine learning (ML) using data from the German Aortic Valve Registry.

Methods and results

Mortality risk was determined using a random forest ML model that was condensed in the newly developed TAVI Risk Machine (TRIM) scores, designed to represent clinically meaningful risk modelling before (TRIMpre) and in particular after (TRIMpost) TAVI. Algorithm was trained and cross-validated on data of 22 283 patients (729 died within 30 days post-TAVI) and generalisation was examined on data of 5864 patients (146 died). TRIMpost demonstrated significantly better performance than traditional scores [C-statistics value, 0.79; 95% confidence interval (CI)] [0.74; 0.83] compared to Society of Thoracic Surgeons (STS) with C-statistics value 0.69; 95%-CI [0.65; 0.74]). An abridged (aTRIMpost) score comprising 25 features (calculated using a web interface) exhibited significantly higher performance than traditional scores (C-statistics value, 0.74; 95%-CI [0.70; 0.78]). Validation on external data of 6693 patients (205 died within 30 days post-TAVI) of the Swiss TAVI Registry confirmed significantly better performance for the TRIMpost (C-statistics value 0.75, 95%-CI [0.72; 0.79]) compared to STS (C-statistics value 0.67, CI [0.63; 0.70]).

Conclusion

TRIM scores demonstrate good performance for risk estimation before and after TAVI. Together with clinical judgement, they may support standardised and objective decision-making before and after TAVI.

In-situ alignment of 3D printed anisotropic hard magnets

Within this work, we demonstrate in-situ alignment of the easy axis single-crystal magnetic particles inside a polymer matrix using fused filament fabrication. Two different magnetic materials are investigated: (i) Strontium hexaferrite inside a PA6 matrix, fill grade: 49 vol% and (ii) Samarium iron nitride inside a PA12 matrix, fill grade: 44 vol%. In the presence of the external alignment field, the strontium hexaferrite particles inside the PA6 matrix can be well aligned with a ratio of remnant magnetization to saturation magnetization in an easy axis of 0.7. No significant alignment for samarium iron nitride could be achieved. The results show the feasibility to fabricate magnets with arbitrary and locally defined easy axis using fused filament fabrication since the permanent magnets (or alternatively an electromagnet) can be mounted on a rotatable platform.

Effect of Minocycline on Depressive Symptoms in Patients With Treatment-Resistant Depression: A Randomized Clinical Trial

IMPORTANCE

Insufficient treatment response and resulting chronicity constitute a major problem in depressive disorders. Remission rates range as low as 15% to 40% and treatment-resistant depression (TRD) is associated with low-grade inflammation, suggesting anti-inflammatory interventions as a rational treatment strategy. Minocycline, which inhibits microglial activation, represents a promising repurposing candidate in the treatment of TRD.

OBJECTIVE

To determine whether 6 weeks of minocycline as add-on to antidepressant treatment as usual can significantly reduce depressive symptoms in patients with TRD.

DESIGN, SETTING, AND PARTICIPANTS

The study was conducted in Germany and designed as a multicenter double-blind randomized clinical trial (RCT) of 200 mg/d minocycline treatment over a course of 6 weeks with a 6-month follow-up. Participants were recruited from January 2016 to August 2020 at 9 university hospitals that served as study sites. Key inclusion criteria were a diagnosis of major depressive disorder (according to Diagnostic and Statistical Manual of Mental Disorders [Fifth Edition] criteria), severity of depressive symptoms on the Hamilton Depression Rating Scale (HAMD-17) greater than or equal to 16 points, aged 18 to 75 years, body mass index 18 to 40, Clinical Global Impression Scale (CGI-S) greater than or equal to 4, failure to adequately respond to an initial antidepressant standard medication as per Massachusetts General Hospital Antidepressant Treatment History Questionnaire, and stable medication for at least 2 weeks. A total of 258 patients were screened, of whom 173 were randomized and 168 were included into the intention-to-treat population. Statistical analysis was performed from April to November 2020.

INTERVENTIONS

Participants were randomized (1:1) to receive adjunct minocycline (200 mg/d) or placebo for 6 weeks.

MAIN OUTCOMES AND MEASURES

Primary outcome measure was the change in Montgomery-Åsberg Depression Rating Scale (MADRS) score from baseline to week 6 analyzed by intention-to-treat mixed model repeated measures. Secondary outcome measures were response, remission, and various other clinical rating scales.

RESULTS

Of 173 eligible and randomized participants (84 randomized to minocycline and 89 randomized to placebo), 168 formed the intention-to-treat sample (79 [47.0%] were women, 89 [53.0%] were men, 159 [94.6%] were White, 9 [6.4%] were of other race and ethnicity, including Asian and unknown ethnicity), with 81 in the minocycline group and 87 in the placebo group. The mean (SD) age was 46.1 (13.1) years, and the mean (SD) MADRS score at baseline was 26.5 (5.0). There was no difference in rates of completion between the minocycline (83.3% [70 of 81]) and the placebo group (83.1% [74 of 87]). Minocycline treatment did not alter the course of depression severity compared with placebo as assessed by a decrease in MADRS scores over 6 weeks of treatment (1.46 [-1.04 to 3.96], P = .25). Minocycline treatment also exhibited no statistically significant effect on secondary outcomes.

CONCLUSIONS AND RELEVANCE

In this large randomized clinical trial with minocycline at a dose of 200 mg/d added to antidepressant treatment as usual for 6 weeks, minocycline was well tolerated but not superior to placebo in reducing depressive symptoms in patients with TRD. The results of this RCT emphasize the unmet need for therapeutic approaches and predictive biomarkers in TRD.

TRIAL REGISTRATION

EU Clinical Trials Register Number: EudraCT 2015-001456-29.

Pulmonary vein isolation with high power, short duration ablation leads to shorter procedure times associated with high success rates: a Prospective Randomized Trial

Funding Acknowledgements

Type of funding sources: None.

Background

The single procedure success rates of durable pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) varies between 85 and 90 %.

This prospective, randomized study investigated the efficacy of high power, short duration ablation in a temperature-controlled mode versus standard power settings in terms of single-procedure arrhythmia-free outcome, safety and procedural time.

Methods and results

A total number of 176 patients undergoing de-novo catheter ablation for paroxysmal AF were randomized to two different treatment arms. In group-A patients, PVI was performed with RF-energy with standard power settings of 30 Watts in a temperature-controlled mode.

The ablation procedure in group B was performed with RF-energy with higher power settings of 45 Watts. In both groups the ablation was performed with ablation index (AI) and following the CLOSE protocol (Biosense Webster Thermocool STSF).

A total of 88 patients were randomized into each group without significant differences in baseline characteristics.

During a mean follow-up of 12 ± 4 months after a single procedure, 79 (90%) patients of group A were free of arrhythmia recurrence versus 82 (93 %) patients in group B (p=ns).

With regard to the procedural data, the procedure time was significantly shorter in group B (115.35 ± 15.38 versus 96.45 ± 17.19; p&lt;0.01), the flouroscopy time and dose area were also significantly lower in Group B (9.66 ± 3.86 vs 5.45 ± 2.35; 330.84 ± 150.36 vs 202.51 ± 135.23) and total ablation times were significantly shorter in group B ((Table 1). Both procedures were performed with a low number of complications, no pericardial effusion was seen in either group, in both groups two patients had a significant hematoma of the groin with the need of surgical repair.

Conclusions

RF-ablation with high power (45 Watts) in combination with ablation index and following the CLOSE protocol leads to shorter procedure times, a lower total ablation time and a good safety profile.

Predicted Global Spread of SARS-CoV-2 Alpha Variant of Concern via Air Travel

Purpose

To predict the global spread of SARS-CoV-2 Alpha Variant of Concern (VoC) from England via air travel and compare against observed importation.

Methods & Materials

Risk models were used to estimate a country's likelihood of importing at least one traveller infected with the Alpha VoC from England by January 19, 2021.

First, the prior 60-day incidence of Alpha VoC associated with each English airport was estimated using cumulative Alpha VoC cases reported by Public Health England between September 20, 2020 – January 4, 2021 proportionately allocated to each airport. Each airport's catchment population was derived from a probabilistic Huff model. Next, the prevalence of the Alpha VoC for each airport was derived from the estimated incidence to represent the probability that at least one departing traveller was infected with the Alpha VoC for each English airport. The prevalence and forecasted flight volumes were used to estimate the likelihood of each destination airport receiving at least one infected traveller from England. Forecasted flight volumes were based on historical passenger volumes data from the International Air Transport Association and prospective flight schedules from CIRIUM. All airport-level likelihoods were aggregated to the country-level.

Each country's predicted likelihood was compared against observed cases of Alpha VoC by January 25, 2021, collected by cov-lineages.org and a manual search of online sources.

Results

Among 211 countries, the median likelihood was 1.6% (interquartile range: 17.5%) and the mean was 13.9% (SD: 23.5%). In total, 28.9% (n=55) of countries had observed importation of the Alpha VoC by January 25^th. Fifteen of 16 countries with a predicted likelihood of importation greater than 50% had reported at least one case (kappa = 0.88), while 31 of 39 countries with a predicted likelihood lower than 1% did not detect a case (kappa = 0.92).

Conclusion

Risk models based on air travel to inform public health preparedness accurately identified most potential destinations at highest risk of importing the SARS-CoV-2 Alpha VoC.

Classification of Companion Diagnostics: A New Framework for Biomarker-Driven Patient Selection

Background

Modern personalized medicine strategies builds on therapy companion diagnostics to stratify patients into subgroups with differential benefit/risk. In general, stratification for drug response implies a treatment-by-subgroup interaction. This interaction is usually suggested by the drug’s mechanism of action and investigated in pharmacological research or in clinical studies. In these candidate genes or pathway approaches, either biological reasons for a differential benefit/risk or statistical interaction regarding a pharmacological or clinical endpoint or both may be given. For successful drug approval, demonstration of a positive benefit/risk balance in the intended patient population is required. This also applies to situations with biomarker-selected populations. However, further regulatory considerations relate to the usefulness and plausibility of the selected patients and benefit/risk extrapolations or alternative therapy options in biomarker-negative populations.

Methods

To facilitate the specification of regulatory requirements and support the design of clinical development programmes, a systematic classification of biomarker-drug pairs is needed, in particular with regard to the expected underlying molecular mechanism and the clinical evidence.

Results

A classification of five biomarker-drug categories is proposed related to increasing evidence on the biomarker’s predictive value in relation to a specific drug. We classified biomarkers into five ascending categories with increasing evidence on the predictive nature of the biomarker in relation to a specific drug according to the comparative pharmacological and clinical evidence.

Conclusions

The proposed classification will facilitate regulatory decision-making and support drug development with respect to biomarker-related subgrouping, both, during clinical programme and at the time of marketing authorization application, since the grade of evidence on the differential power of the biomarker can be considered as an indicator for the usefulness of a biomarker-related subgrouping.

Refined prediction and validation of individual risk using machine learning in transcatheter aortic valve implantation: TAVI Risk Machine (TRIM) scores

Background

Given the recent option for treatment using TAVI irrespective of surgical risk, general surgical risk scores have become less relevant, while TAVI-specific scores require refinement. Additionally, post-TAVI risk models are lacking; however, such risk models can support decision between post-TAVI treatment approaches, such as early discharge or close surveillance.

Purpose

This study aimed to predict 30-day mortality following transcatheter aortic valve implantation (TAVI) based on machine learning (ML) using data from the German Aortic Valve Registry.

Methods

Mortality risk was determined using a random forest ML model that was condensed in the newly developed TAVI Risk Machine (TRIM) scores, designed to represent clinically meaningful risk modelling before (TRIMpre) and after (TRIMpost) TAVI. Algorithm was trained and cross-validated on data of 24,452 patients and generalisation was examined on data of 5,889 patients.

Results

TRIMpost demonstrated significantly better performance than traditional scores (C-statistics value, 0.79; 95% confidence interval [CI] [0.74; 0.83]). An abridged TRIMpost score comprising 25 features (calculated using a web interface) exhibited significantly higher performance than traditional scores (C-statistics value, 0.74; 95% CI [0.70; 0.78]).

Conclusion

TRIM scores have high performance for risk estimation before and after TAVI. Together with clinical judgement, they may support standardised and objective decision-making before and after TAVI.

Funding Acknowledgement

Type of funding sources: None.

Applications of artificial intelligence/machine learning approaches in cardiovascular medicine: a systematic review with recommendations

Aims

Artificial intelligence (AI) and machine learning (ML) promise vast advances in medicine. The current state of AI/ML applications in cardiovascular medicine is largely unknown. This systematic review aims to close this gap and provides recommendations for future applications.

Methods and results

Pubmed and EMBASE were searched for applied publications using AI/ML approaches in cardiovascular medicine without limitations regarding study design or study population. The PRISMA statement was followed in this review. A total of 215 studies were identified and included in the final analysis. The majority (87%) of methods applied belong to the context of supervised learning. Within this group, tree-based methods were most commonly used, followed by network and regression analyses as well as boosting approaches. Concerning the areas of application, the most common disease context was coronary artery disease followed by heart failure and heart rhythm disorders. Often, different input types such as electronic health records and images were combined in one AI/ML application. Only a minority of publications investigated reproducibility and generalizability or provided a clinical trial registration.

Conclusions

A major finding is that methodology may overlap even with similar data. Since we observed marked variation in quality, reporting of the evaluation and transparency of data and methods urgently need to be improved.

Pad, psychiatry and stigma

In 2018, the Swiss Academy of Medical Sciences (SAMW) published a new guideline on physician-assisted dying (PAD). In line with the SAMW guideline published in 2004, the patients’ ability to judge, their self-determination, careful consideration and permanence of their wish to die as well as the lack of therapeutic options were set as necessary conditions. However, while the previous wording considered assisted suicide to be ethically justifiable if the patient’s condition is terminal, the new guideline requires that it is unbearable. This difference has been the subject of intense discussion in Swiss healthcare professionals and the population alike. This controversy is particularly important for those affected by mental illness who have a persistent desire to die. This is because mental disorders cannot usually be classified as terminal illnesses, but they can certainly lead to suffering that is perceived as unbearable. Furthermore, it is known that persons with mental illness are subject to stigmatization. It is therefore likely that there is a connection between the stigmatization of mentally ill people and the position on PAD for this group. This talk provides theoretical background on this discusion and proposes a study protocol to investigate the acceptance of PAD in relation to the type of illness as well as the factors of unbearable suffering and terminality. It will furthermore look into the criteria of the 2004 and 2018 guidelines and will explore if there is a connection between stigmatization and the assessment of whether a person should be granted access to assisted suicide.

FAST: a randomised phase II study of zolbetuximab (IMAB362) plus EOX versus EOX alone for first-line treatment of advanced CLDN18.2-positive gastric and gastro-oesophageal adenocarcinoma

BACKGROUND

Claudin 18.2 (CLDN18.2) is contained within normal gastric mucosa epithelial tight junctions; upon malignant transformation, CLDN18.2 epitopes become exposed. Zolbetuximab, a chimeric monoclonal antibody, mediates specific killing of CLDN18.2-positive cells through immune effector mechanisms.

PATIENTS AND METHODS

The FAST study enrolled advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients (aged ≥18 years) with moderate-to-strong CLDN18.2 expression in ≥40% tumour cells. Patients received first-line epirubicin + oxaliplatin + capecitabine (EOX, arm 1, n = 84) every 3 weeks (Q3W), or zolbetuximab + EOX (loading dose, 800 mg/m² then 600 mg/m² Q3W) (arm 2, n = 77). Arm 3 (exploratory) was added after enrolment initiation (zolbetuximab + EOX 1000 mg/m² Q3W, n = 85). The primary endpoint was progression-free survival (PFS) and overall survival (OS) was a secondary endpoint.

RESULTS

In the overall population, both PFS [hazard ratio (HR) = 0.44; 95% confidence interval (CI), 0.29-0.67; P < 0.0005] and OS (HR = 0.55; 95% CI, 0.39-0.77; P < 0.0005) were significantly improved with zolbetuximab + EOX (arm 2) compared with EOX alone (arm 1). This significant PFS benefit was retained in patients with moderate-to-strong CLDN18.2 expression in ≥70% of tumour cells (HR = 0.38; 95% CI, 0.23-0.62; P < 0.0005). Significant improvement in PFS was also reported in the overall population of arm 3 versus arm 1 (HR = 0.58; 95% CI, 0.39-0.85; P = 0.0114) but not in high CLDN18.2-expressing patients; no significant improvement in OS was observed in either population. Most adverse events (AEs) related to zolbetuximab + EOX (nausea, vomiting, neutropenia, anaemia) were grade 1-2. Grade ≥3 AEs showed no substantial increases overall (zolbetuximab + EOX versus EOX alone).

CONCLUSIONS

In advanced gastric/gastro-oesophageal junction and oesophageal adenocarcinoma patients expressing CLDN18.2, adding zolbetuximab to first-line EOX provided longer PFS and OS versus EOX alone. Zolbetuximab + EOX was generally tolerated and AEs were manageable. Zolbetuximab 800/600 mg/m² is being evaluated in phase III studies based on clinical benefit observed in the overall population and in patients with moderate-to-strong CLDN18.2 expression in ≥70% of tumour cells.

Age-related clinical and hemodynamic outcome following transcatheter aortic valve replacement: a swiss TAVI registry analysis

Background

Transcatheter aortic valve implantation (TA) is the preferred treatment modality for patients with severe aortic valve disease at high surgical risk and is expanding into lower risk populations. Therefore age range of treated patients is increasing.

Purpose

The aim of this study is to analyze age-related clinical and hemodynamic outcome of patients following TAVI in a nationwide, prospective, multicentre cohort (Swiss TAVI registry).

Methods

We retrospectively analyzed prospectively collected data from all patients included in the Swiss TAVI registry between February 2011 and December 2018. In an adjusted analysis, in-hospital, 30-days and 1-year outcome between four age groups were compared.

Results

Overall, 7097 patients underwent TAVI (&lt;70 years: n=324, 70–79 years: n=1913, 80–89 years: n=4353, 90–100 years n=507). Median STS risk score for mortality was 5.23±4.13% and differed significantly between age groups (3.46±4.10%, 3.97±3.73%, 5.57±3.97%, 8.22±4.74%; p=0.001). Valve predilatation was more often performed in older patients (54.3% vs. 54.3% vs. 60.7% vs. 69.6%; p≤0.001). Difference in hospital stay was statistically sigificant between age groups, numerically however not relevant (10.01±7.56 days vs. 9.25±6.38 days vs. 9.55±5.70 days vs 10.03±5.77 days; p=0.02). Post-procedural acute kidney injury stage 3 was highest in the youngest age group (3.4% vs. 1.6% vs. 1.1% vs. 1.0%; RR [95% CI] 0.65 (0.48–0.87); p=0,004) and rate of new pacemakers for conduction abnormalities increased significantly with age (10.2% vs. 13.7% vs. 17.1% vs. 18.7%; RR [95% CI] 1.22 (1.12–1.32); p&lt;0.001). There was no significant difference in life threatening/major bleeding (p=0.288/0.197) or major vascular complications (p=0.083).

All-cause mortality and cardiovascular mortality in hospital, at 30 days and at 1 year were highest in nonagenarians and higher in the patients &lt;70 years compared to patients of 70–79 years: in hospital all-cause mortality 2.2% vs. 1.6% vs. 2.9% vs. 5.5% (RR [95% CI] 1.64 (1.28–2.10), p&lt;0.001); 30 day all-cause mortality 3.1% vs. 2.0% vs. 3.7% vs. 6.7%; (HR [95% CI] 1.59 (1.30–1.96); p&lt;0.0001); 1-year all-cause mortality 10.9% vs. 10.4% vs. 12% vs. 19.5% (HR [95% CI] 1.27 (1.14–1.41); p&lt;0.001); in hospital cardiovascular mortality 1.5% vs. 1.5% vs. 2.6% vs. 5.1% (RR [95% CI] 1.70 (1.31–2.20), p&lt;0.001); 30 day cardiovascular mortality 2.2% vs. 1.9% vs. 3.3% vs. 6.3%; (HR [95% CI] 1.68 (1.35–2.09); p&lt;0.001); 1-year cardiovascular mortality 7.2% vs. 6.9% vs. 8.3% vs. 15.3% (HR [95% CI] 1.36 (1.19–1.55); p&lt;0.001). This held true, when hazard ratio was corrected for STS PROM score, femoral access vs other access and year of procedure.

Conclusion

In-hospital, 30-day and 1-year clinical outcome of nonagenarians undergoing TAVI are less favorable compared to lower age groups. Interestingly, clinical outcome of the patients group 70–79 years was the most favorable.

Mortality at 30 according to age

Funding Acknowledgement

Type of funding source: None

A comparison of subgroup identification methods in clinical drug development: Simulation study and regulatory considerations

With advancement of technologies such as genomic sequencing, predictive biomarkers have become a useful tool for the development of personalized medicine. Predictive biomarkers can be used to select subsets of patients, which are most likely to benefit from a treatment. A number of approaches for subgroup identification were proposed over the last years. Although overviews of subgroup identification methods are available, systematic comparisons of their performance in simulation studies are rare. Interaction trees (IT), model-based recursive partitioning, subgroup identification based on differential effect, simultaneous threshold interaction modeling algorithm (STIMA), and adaptive refinement by directed peeling were proposed for subgroup identification. We compared these methods in a simulation study using a structured approach. In order to identify a target population for subsequent trials, a selection of the identified subgroups is needed. Therefore, we propose a subgroup criterion leading to a target subgroup consisting of the identified subgroups with an estimated treatment difference no less than a pre-specified threshold. In our simulation study, we evaluated these methods by considering measures for binary classification, like sensitivity and specificity. In settings with large effects or huge sample sizes, most methods perform well. For more realistic settings in drug development involving data from a single trial only, however, none of the methods seems suitable for selecting a target population. Using the subgroup criterion as alternative to the proposed pruning procedures, STIMA and IT can improve their performance in some settings. The methods and the subgroup criterion are illustrated by an application in amyotrophic lateral sclerosis.

A multicentre, phase IIa study of zolbetuximab as a single agent in patients with recurrent or refractory advanced adenocarcinoma of the stomach or lower oesophagus: the MONO study

BACKGROUND

Claudin 18.2 (CLDN18.2) is physiologically confined to gastric mucosa tight junctions; however, upon malignant transformation, perturbations in cell polarity lead to CLDN18.2 epitopes being exposed on the cancer cell surface. The first-in-class monoclonal antibody, zolbetuximab (formerly known as IMAB362), binds to CLDN18.2 and can induce immune-mediated lysis of CLDN18.2-positive cells.

PATIENTS AND METHODS

Patients with advanced gastric, gastro-oesophageal junction (GEJ) or oesophageal adenocarcinomas with moderate-to-strong CLDN18.2 expression in ≥50% of tumour cells received zolbetuximab intravenously every 2 weeks for five planned infusions. At least three patients were enrolled in two sequential cohorts (cohort 1300 mg/m2; cohort 2600 mg/m2); additional patients were enrolled into a dose-expansion cohort (cohort 3600 mg/m2). The primary end point was the objective response rate [ORR: complete and partial response (PR)]; secondary end points included clinical benefit [ORR+stable disease (SD)], progression-free survival, safety/tolerability, and zolbetuximab pharmacokinetic profile.

RESULTS

From September 2010 to September 2012, 54 patients were enrolled (cohort 1, n = 4; cohort 2, n = 6; cohort 3, n = 44). Three patients in cohort 1 and 25 patients in cohorts 2/3 received at least 5 infusions. Antitumour activity data were available for 43 patients, of whom 4 achieved PR (ORR 9%) and 6 (14%) had SD for a clinical benefit rate of 23%. In a subgroup of patients with moderate-to-high CLDN18.2 expression in ≥70% of tumour cells, ORR was 14% (n = 4/29). Treatment-related adverse events occurred in 81.5% (n = 44/54) patients; nausea (61%), vomiting (50%), and fatigue (22%) were the most frequent.

CONCLUSIONS

Zolbetuximab monotherapy was well tolerated and exhibited antitumour activity in patients with CLDN18.2-positive advanced gastric or GEJ adenocarcinomas, with response rates similar to those reported for single-agent targeted agents in gastric/GEJ cancer trials.

CLINICALTRIALS.GOV NUMBER

NCT01197885.

The Danish STR sequence database: duplicate typing of 363 Danes with the ForenSeq™ DNA Signature Prep Kit

Some STR loci have internal sequence variations, which are not revealed by the standard STR typing methods used in forensic genetics (PCR and fragment length analysis by capillary electrophoresis (CE)). Typing of STRs with next-generation sequencing (NGS) uncovers the sequence variation in the repeat region and in the flanking regions. In this study, 363 Danish individuals were typed for 56 STRs (26 autosomal STRs, 24 Y-STRs, and 6 X-STRs) using the ForenSeq™ DNA Signature Prep Kit to establish a Danish STR sequence database. Increased allelic diversity was observed in 34 STRs by the PCR-NGS assay. The largest increases were found in DYS389II and D12S391, where the numbers of sequenced alleles were around four times larger than the numbers of alleles determined by repeat length alone. Thirteen SNPs and one InDel were identified in the flanking regions of 12 STRs. Furthermore, 36 single positions and five longer stretches in the STR flanking regions were found to have dubious genotyping quality. The combined match probability of the 26 autosomal STRs was 10,000 times larger using the PCR-NGS assay than by using PCR-CE. The typical paternity indices for trios and duos were 500 and 100 times larger, respectively, than those obtained with PCR-CE. The assay also amplified 94 SNPs selected for human identification. Eleven of these loci were not in Hardy-Weinberg equilibrium in the Danish population, most likely because the minimum threshold for allele calling (30 reads) in the ForenSeq™ Universal Analysis Software was too low and frequent allele dropouts were not detected.

Redirecting public oral health fluoride varnish intervention to low socio-economic status children in Alberta

SETTING

Dental decay is most prevalent among low socio-economic status (SES) groups where cost limits access to dental care. To address inequities in oral health outcomes, Alberta Health Services (AHS) Oral Health Action Plan encompasses a population health approach that redirects fluoride varnish (FV) applications to low SES children. Using low SES measures to establish the eligibility criteria is fundamental to the delivery of FV applications to the target population.

INTERVENTION

A series of four FV applications over two years is directed to children age 12-35 months and two applications per year to children in Kindergarten and grades 1 and 2, using low SES measures for eligibility criteria. The provincial objective for children receiving the first FV application is 10%-20% of the population age. Additional objectives are set for rates of subsequent FV applications for each population group.

OUTCOMES

From 2015 to 2016, the rate of first FV applications for eligible target populations is below the provincial objective for children age 12-35 months (5%) and within the objective for children in Kindergarten and grades 1 and 2 (16%). Rates of subsequent FV applications in the school setting are being met.

IMPLICATIONS

Encompassing a population health approach to deliver standardized fluoride varnish applications to low SES children better targets inequities in oral health outcomes in Alberta. Challenges of redirecting the FV intervention include creating the eligibility criteria and engaging the target population, particularly for the preschool population. Achieving population objectives are challenged by unequal distribution of resources across the province.

Chondrodysplasia with multiple dislocations: comprehensive study of a series of 30 cases

The group of chondrodysplasia with multiple dislocations includes several entities, characterized by short stature, dislocation of large joints, hand and/or vertebral anomalies. Other features, such as epiphyseal or metaphyseal changes, cleft palate, intellectual disability are also often part of the phenotype. In addition, several conditions with overlapping features are related to this group and broaden the spectrum. The majority of these disorders have been linked to pathogenic variants in genes encoding proteins implicated in the synthesis or sulfation of proteoglycans (PG). In a series of 30 patients with multiple dislocations, we have performed exome sequencing and subsequent targeted analysis of 15 genes, implicated in chondrodysplasia with multiple dislocations, and related conditions. We have identified causative pathogenic variants in 60% of patients (18/30); when a clinical diagnosis was suspected, this was molecularly confirmed in 53% of cases. Forty percent of patients remain without molecular etiology. Pathogenic variants in genes implicated in PG synthesis are of major importance in chondrodysplasia with multiple dislocations and related conditions. The combination of hand features, growth failure severity, radiological aspects of long bones and of vertebrae allowed discrimination among the different conditions. We propose key diagnostic clues to the clinician.

Status of hormones and painkillers in wastewater effluents across several European states-considerations for the EU watch list concerning estradiols and diclofenac

Present technologies for wastewater treatment do not sufficiently address the increasing pollution situation of receiving water bodies, especially with the growing use of personal care products and pharmaceuticals (PPCP) in the private household and health sector. The relevance of addressing this problem of organic pollutants was taken into account by the Directive 2013/39/EU that introduced (i) the quality evaluation of aquatic compartments, (ii) the polluter pays principle, (iii) the need for innovative and affordable wastewater treatment technologies, and (iv) the identification of pollution causes including a list of principal compounds to be monitored. In addition, a watch list of 10 other substances was recently defined by Decision 2015/495 on March 20, 2015. This list contains, among several recalcitrant chemicals, the painkiller diclofenac and the hormones 17β-estradiol and 17α-ethinylestradiol. Although some modern approaches for their removal exist, such as advanced oxidation processes (AOPs), retrofitting most wastewater treatment plants with AOPs will not be acceptable as consistent investment at reasonable operational cost. Additionally, by-product and transformation product formation has to be considered. The same is true for membrane-based technologies (nanofiltration, reversed osmosis) despite of the incredible progress that has been made during recent years, because these systems lead to higher operation costs (mainly due to higher energy consumption) so that the majority of communities will not easily accept them. Advanced technologies in wastewater treatment like membrane bioreactors (MBR) that integrate biological degradation of organic matter with membrane filtration have proven a more complete elimination of emerging pollutants in a rather cost- and labor-intensive technology. Still, most of the presently applied methods are incapable of removing critical compounds completely. In this opinion paper, the state of the art of European WWTPs is reflected, and capacities of single methods are described. Furthermore, the need for analytical standards, risk assessment, and economic planning is stressed. The survey results in the conclusion that combinations of different conventional and advanced technologies including biological and plant-based strategies seem to be most promising to solve the burning problem of polluting our environment with hazardous emerging xenobiotics.

Influence of the substrate material on the knife-edge based profiling of tightly focused light beams

The performance of the knife-edge method as a beam profiling technique for tightly focused light beams depends on several parameters, such as the material and height of the knife-pad as well as the polarization and wavelength of the focused light beam under study. Here we demonstrate that the choice of the substrate the knife-pads are fabricated on has a crucial influence on the reconstructed beam projections as well. We employ an analytical model for the interaction of the knife-pad with the beam and report good agreement between our numerical and experimental results. Moreover, we simplify the analytical model and demonstrate, in which way the underlying physical effects lead to the apparent polarization dependent beam shifts and changes of the beamwidth for different substrate materials and heights of the knife-pad.

Bubble accumulation and its role in the evolution of magma reservoirs in the upper crust

Volcanic eruptions transfer huge amounts of gas to the atmosphere. In particular, the sulfur released during large silicic explosive eruptions can induce global cooling. A fundamental goal in volcanology, therefore, is to assess the potential for eruption of the large volumes of crystal-poor, silicic magma that are stored at shallow depths in the crust, and to obtain theoretical bounds for the amount of volatiles that can be released during these eruptions. It is puzzling that highly evolved, crystal-poor silicic magmas are more likely to generate volcanic rocks than plutonic rocks. This observation suggests that such magmas are more prone to erupting than are their crystal-rich counterparts. Moreover, well studied examples of largely crystal-poor eruptions (for example, Katmai, Taupo and Minoan) often exhibit a release of sulfur that is 10 to 20 times higher than the amount of sulfur estimated to be stored in the melt. Here we argue that these two observations rest on how the magmatic volatile phase (MVP) behaves as it rises buoyantly in zoned magma reservoirs. By investigating the fluid dynamics that controls the transport of the MVP in crystal-rich and crystal-poor magmas, we show how the interplay between capillary stresses and the viscosity contrast between the MVP and the host melt results in a counterintuitive dynamics, whereby the MVP tends to migrate efficiently in crystal-rich parts of a magma reservoir and accumulate in crystal-poor regions. The accumulation of low-density bubbles of MVP in crystal-poor magmas has implications for the eruptive potential of such magmas, and is the likely source of the excess sulfur released during explosive eruptions.

[Short-Term Cryotherapy--Putting Dynamic Foot and Ankle Stability at Risk?]

BACKGROUND

The application of ice or other forms of cooling represent a common method to treat acute musculoskeletal injuries during sporting events in order to reduce pain. Often athletes return to competition immediately after cooling. It is not known if short-term cryotherapy in the form of ice spray has an influence on the joint's dynamic stability. The aim of this study was to investigate if application of ice spray to the ankle has an effect on the dynamic stability of the joint in healthy participants.

METHODS

A randomized controlled single-blind pilot study with crossover-design was conducted. 22 healthy athletic participants (15 women, 7 men, mean age 31.8 years ± 5.7) were included. Time-to-stability (TTS) was used to investigate the effect of the interventions, ice spray and water spray, applied on the lateral ankle. TTS was assessed in medio-lateral (ML) and antero-posterior (AP) direction on a force plate with two different tests (side step down and 1-leg jump). Collected co-variables were age, gender, height, weight, previous ankle injuries, Tegner activity scale and leg dominance.

RESULTS

There were no significant differences between the two tests (side step down and 1-leg jump) in TTS after the application of ice spray or a water spray compared to the baseline (p > 0.05). There was no significant difference between the two interventions. The testing of the co-variable "previous ankle injury" showed a significant influence on the TTS in medio-lateral direction in the 1-leg jump test of the non-dominant leg after application of ice spray (p = 0.027). On the dominant leg same tendency could be found (p = 0.062).

CONCLUSION

The application of ice spray to the lateral ankle does not have an effect on dynamic stability in healthy participants. In participants with a previous ankle injury a significant decrease in dynamic stability after application of ice spray could be shown. Whether further factors affecting stability such as fatigue and the influence of an opponent player or the application of ice spray on adjacent muscles may augment this effect should be subject to future investigations.

Mafic magma replenishment, unrest and eruption in a caldera setting: insights from the 2006 eruption of Rabaul (Papua New Guinea)

Understanding the magmatic processes that drive unrest at silicic calderas remains a major goal in Volcanology. Rabaul in Papua New Guinea is an exceptional location because after two decades of unrest and a peak in seismicity and deformation in 1983–85, eruptive activity began in 1994 and is still ongoing. A particularly large sub-Plinian eruption occurred from Tavurvur in October 2006. Whole-rock compositions are andesitic and reflect mixing/mingling between basaltic and dacitic magmas from the same system. The magmas that fed the 2006 eruption were stored at about 930°C, with 1–3 wt% H2O, 25–520 ppm CO2, and 50–2500 ppm SO2 in the melt. Melt inclusions hosted in pyroxene, and plagioclase phenocrysts record fractional crystallization at ≤200 MPa under relatively dry and poorly oxidizing conditions. Magma mixing/mingling is expressed as heterogeneous glass compositions, strongly zoned phenocrysts, and mafic crystal aggregates. A textural maturation from fine, acicular to large, blocky crystal clots implies different relative ages of formation. Modelling the chemical zoning of plagioclase shows that mafic–silicic interactions started a couple of decades prior to the 2006 eruption and continued until days to weeks prior to eruption. Basaltic replenishments have been driving unrest and eruption at the Rabaul caldera since the 1970s.

Supplementary material:

Tables and figures reporting the composition of the Tavurvur 2006, Kombiu and 1.4 ka BP caldera samples and showing thermodynamic modelling with MELTS are available at http://www.geolsoc.org.uk/SUP18816

Myopic astigmatism as a substitute for accommodation in pseudophakia

Pseudophacic eyes can be made nearly spectacle-independent by increasing the depth of focus of the uncorrected implanted eye. When the postoperative ametropia is a simple myopic astigmatism the uncorrected visual acuity can be above 0.4 from far to near. The quasi-constant visual acuity in different distances is due to the slow change in the dimension of the blurred retinal image when a point source comes nearer to a myopic astigmatic eye. The intersection of Sturm's conoid and the retina (i.e. the blur spot) changes mainly in form but its size changes much less than in a sperical ametropia. To obtain such a refraction the dioptric change in corneal power induced by surgery must be included in the calculation of the intraocular lens. The induced corneal ametropia is a mixed astigmatism with no equivalent power. The optical principles and the clinical results obtained with iridocapsular Binkhorst lenses are discussed.

Three ophthalmological instruments: the rotating contact glass holder, the cutying forceps and the diamond cystotome

Three new ophthalmological instruments are described: a rotating contact glass holder for easier control of the three-mirror Goldmann or other diagnostic contact lens which must be rotated on the eye; a suture-tying forceps combined with a sapphire blade, combining the tying and cutting functions in one instrument and a diamond cystotome for anterior capsulectomy with a cutting edge of unequalled sharpness.