Planning preclinical confirmatory multicenter trials to strengthen translation from basic to clinical research – a multi-stakeholder workshop report

Clinical translation from bench to bedside often remains challenging even despite promising preclinical evidence. Among many drivers like biological complexity or poorly understood disease pathology, preclinical evidence often lacks desired robustness. Reasons include low sample sizes, selective reporting, publication bias, and consequently inflated effect sizes. In this context, there is growing consensus that confirmatory multicenter studies -by weeding out false positives- represent an important step in strengthening and generating preclinical evidence before moving on to clinical research. However, there is little guidance on what such a preclinical confirmatory study entails and when it should be conducted in the research trajectory. To close this gap, we organized a workshop to bring together statisticians, clinicians, preclinical scientists, and meta-researcher to discuss and develop recommendations that are solutionoriented and feasible for practitioners. Herein, we summarize and review current approaches and outline strategies that provide decision-critical guidance on when to start and subsequently how to plan a confirmatory study. We define a set of minimum criteria and strategies to strengthen validity before engaging in a confirmatory preclinical trial, including sample size considerations that take the inherent uncertainty of initial (exploratory) studies into account. Beyond this specific guidance, we highlight knowledge gaps that require further research and discuss the role of confirmatory studies in translational biomedical research. In conclusion, this workshop report highlights the need for close interaction and open and honest debate between statisticians, preclinical scientists, meta-researchers (that conduct research on research), and clinicians already at an early stage of a given preclinical research trajectory

Comparative effectiveness of initial computed tomography and invasive coronary angiography in women and men with stable chest pain and suspected coronary artery disease: multicentre randomised trial

To assess the comparative effectiveness of computed tomography and invasive coronary angiography in women and men with stable chest pain suspected to be caused by coronary artery disease

Treatment of post-biopsy arteriovenous fistula of a renal graft by selective embolization

The development of an arteriovenous fistula (AVF) after renal graft biopsy is a rare complication, it is associated in most cases with spontaneous resolution. However, interventional therapies are required in some cases, to prevent graft loss. Selective embolization has been described as an alternative treatment. In the present study, we describes our experience on AVF after biopsy in kidney transplant patients, which was managed with selective embolization. From 2005 to 2015, a total of 452 kidney transplant biopsies were performed, 12 had an AVF requiring embolization. In 92% of cases, this was successful. Beforehand, mean serum creatinine levels were 2.45 mg/dL, after the procedure, that increased to 3.05, however, 3 months later, mean creatinine levels dropped to 1.85 mg/dL. Graft survival after 2 follow-up years was 72%. Our experience demonstrates that selective embolization of the AVF after kidney transplant biopsy is a safe procedure, and that transplant function can be maintained in patients with this complication

Plasmaféresis en rechazo agudo del injerto renal mediado por anticuerpos: Estudio realizado en el Hospital Pablo Tobón Uribe, Medellín, Colombia. Año 2005-2015

Introducción: el rechazo agudo mediado por anticuerpos es una complicación que se presenta luego del trasplante renal y es una causa importante de pérdida del injerto. La plasmaféresis es una de las terapias utilizadas para su tratamiento, algunos estudios sugieren mejor supervivencia del injerto renal con el uso de plasmaféresis; sin embargo su evidencia es débil. Objetivo: este estudio tiene como objetivo describir la experiencia del uso de plasmaféresis en el rechazo agudo mediado por anticuerpos. Materiales y Métodos: estudio descriptivo retrospectivo realizado en el Hospital Pablo Tobón Uribe entre agosto de 2005 y junio de 2015 en pacientes con diagnóstico de rechazo agudo mediado por anticuerpos, quienes recibieron entre tres y nueve sesiones de plasmaféresis. Resultados: se realizaron un total de 769 trasplantes renales; de los cuales 26 pacientes presentaron rechazo agudo mediado por anticuerpos y recibieron plasmaféresis como parte del tratamiento. Todos los pacientes recibieron terapia de inducción al momento del trasplante y en el 80,8% la terapia de mantenimiento utilizada fue tacrolimus-micofenolato-prednisolona. El rechazo mediado por anticuerpos se presentó en forma temprana en el 61,5% de los pacientes. A seis y doce meses el 44% y 53,8% de los pacientes respectivamente presentaron pérdida del injerto renal; las complicaciones se presentaron en el 53,8%  de los pacientes, las cuales fueron hipocalcemia, hipotensión y anailaxia. Conclusión: en esta cohorte el uso de plasmaféresis en el rechazo agudo mediado por anticuerpos no logró evitar la pérdida del injerto renal en el 50% de los pacientes; se sugiere adicionar a esta terapia otras alternativas de tratamiento entre ellas, la inmunoglobulinas intravenosas, rituximab, eculizumab y bortezomib

Medición del NGAL urinario en el donante para detectar función retardada del injerto renal en el receptor

Introducción: en el trasplante renal de donante fallecido es importante tener marcadores tempranos que ayuden a predecir la funcionalidad adecuada del injerto renal. La medición de creatinina continúa siendo el marcador de elección para definir si los riñones de un posible donante son aptos para ser trasplantados. La lipocalina asociada a la gelatinasa delneutrófilo urinaria (NGALu) es un biomarcador que ha sido utilizado para el diagnóstico temprano de lesión renal aguda, pero su comportamiento es incierto en el donante fallecido. Este estudio tiene como objetivo determinar si los niveles de NGALu del donante pueden predecir la función retardada del injerto (FRI) en los receptores. Metodología: cohorte prospectiva en la que se evaluaron los niveles de NGALu del donante al momentode la extracción renal; se aplicó estadística descriptiva y pruebasno paramétricas. Se exploró el comportamiento de este  biomarcador en el donante del injerto renal para determinar si es un factor predictivo de función retardada del injerto. Resultados: se evaluaron 27 donantes de criterios óptimos; el 74,1 % eran hombres, la edad tuvo una mediana de 27 años (rango: 18,8-43,3); la principal causa de muerte fue trauma encefalocraneano, seguido por el accidente cerebrovascular. La creatinina tuvo una mediana de 0,8 mg/dl y los valores de NGALu tuvieron una mediana de 11,1ng/ml (4,2-33,6). En total se realizaron 46 trasplantes, de los cuales el 15,2 % presentaron función retardada del injerto y dos pacientes necesitaron terapia de reemplazo renal en la primera semana luego del trasplante.Los valores de NGALu agrupados de acuerdo a presencia o no de función retardada del injerto fueron de 11,1 ng/ml (3-17,3) en los pacientes sin función retardada del injerto y 11,2 ng/ml en los pacientes con dicha función (7,7-39,4) (p=0,40). En el análisis multivariado no se encontró ningún factor asociado al desarrollo de función retardada del injerto. Conclusión: en este estudio la medición de uNGAL en donantes fallecidos de criteriosóptimos no predijo función retardada del injerto

Development and internal validation of the Comprehensive ALPPS Preoperative Risk Assessment (CAPRA) score: is the patient suitable for Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS)?

Background Preoperative patient selection in Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) is not always reliable with currently available scores, particularly in patients with primary liver tumor. This study aims to (I) to determine whether comorbidities and patients characteristics are a risk factor in ALPPS and (II) to create a score predicting 90-day mortality preoperatively. Methods Thirteen high-volume centers participated in this retrospective multicentric study. A risk analysis based on patient characteristics, underlying disease and procedure type was performed to identify risk factors and model the Comprehensive ALPPS Preoperative Risk Assessment (CAPRA) score. A nonparametric receiver operating characteristic analysis was performed to estimate the predictive ability of our score against the Charlson Comorbidity Index (CCI), the age-adjusted CCI (aCCI), the ALPPS risk score before Stage 1 (ALPPS-RS1) and Stage 2 (ALPPS-RS2). The model was internally validated applying bootstrapping. Results A total of 451 patients were included. Mortality was 14.4%. The CAPRA score is calculated based on the following formula: (0.1 × age) - (2 × BSA) + 1 (in the presence of primary liver tumor) + 1 (in the presence of severe cardiovascular disease) + 2 (in the presence of moderate or severe diabetes) + 2 (in the presence of renal disease) + 2 (if classic ALPPS is planned). The predictive ability was 0.837 for the CAPRA score, 0.443 for CCI, 0.519 for aCCI, 0.693 for ALPPS-RS1 and 0.807 for ALPPS-RS2. After 1,000 cycles of bootstrapping the C statistic was 0.793. The accuracy plot revealed a cut-off for optimal prediction of postoperative mortality of 4.70. Conclusions Comorbidities play an important role in ALPPS and should be carefully considered when planning the procedure. By assessing the patient's preoperative condition in relation to ALPPS, the CAPRA score has a very good ability to predict postoperative mortality

Additional file 1 of Planning preclinical confirmatory multicenter trials to strengthen translation from basic to clinical research – a multi-stakeholder workshop report

Additional file 1: Figure S 1. Composition of workshop participants as per field of expertise. The organizing team mainly consists of meta-researchers with a clinical or preclinical background. Other refers to e.g., stakeholders from funding agencies that also attended the workshop. Methods S1. Multi-stakeholder workshop method-Workshop design. Glossary. Glossary of terms

Computed Tomography Versus Invasive Coronary Angiography in Patients With Diabetes and Suspected Coronary Artery Disease

Objective: To compare cardiac computed tomography (CT) with invasive coronary angiography (ICA) as the initial strategy in patients with diabetes and stable chest pain. Research design and methods: This prespecified analysis of the multicenter DISCHARGE trial in 16 European countries was performed in patients with stable chest pain and intermediate pretest probability of coronary artery disease. The primary end point was a major adverse cardiac event (MACE) (cardiovascular death, nonfatal myocardial infarction, or stroke), and the secondary end point was expanded MACE (including transient ischemic attacks and major procedure-related complications). Results: Follow-up at a median of 3.5 years was available in 3,541 patients of whom 557 (CT group n = 263 vs. ICA group n = 294) had diabetes and 2,984 (CT group n = 1,536 vs. ICA group n = 1,448) did not. No statistically significant diabetes interaction was found for MACE (P = 0.45), expanded MACE (P = 0.35), or major procedure-related complications (P = 0.49). In both patients with and without diabetes, the rate of MACE did not differ between CT and ICA groups. In patients with diabetes, the expanded MACE end point occurred less frequently in the CT group than in the ICA group (3.8% [10 of 263] vs. 8.2% [24 of 294], hazard ratio [HR] 0.45 [95% CI 0.22-0.95]), as did the major procedure-related complication rate (0.4% [1 of 263] vs. 2.7% [8 of 294], HR 0.30 [95% CI 0.13 - 0.63]). Conclusions: In patients with diabetes referred for ICA for the investigation of stable chest pain, a CT-first strategy compared with an ICA-first strategy showed no difference in MACE and may potentially be associated with a lower rate of expanded MACE and major procedure-related complications

CT or invasive coronary angiography in stable chest pain

Background: In the diagnosis of obstructive coronary artery disease (CAD), computed tomography (CT) is an accurate, noninvasive alternative to invasive coronary angiography (ICA). However, the comparative effectiveness of CT and ICA in the management of CAD to reduce the frequency of major adverse cardiovascular events is uncertain. Methods: We conducted a pragmatic, randomized trial comparing CT with ICA as initial diagnostic imaging strategies for guiding the treatment of patients with stable chest pain who had an intermediate pretest probability of obstructive CAD and were referred for ICA at one of 26 European centers. The primary outcome was major adverse cardiovascular events (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke) over 3.5 years. Key secondary outcomes were procedure-related complications and angina pectoris. Results: Among 3561 patients (56.2% of whom were women), follow-up was complete for 3523 (98.9%). Major adverse cardiovascular events occurred in 38 of 1808 patients (2.1%) in the CT group and in 52 of 1753 (3.0%) in the ICA group (hazard ratio, 0.70; 95% confidence interval [CI], 0.46 to 1.07; P=0.10). Major procedure-related complications occurred in 9 patients (0.5%) in the CT group and in 33 (1.9%) in the ICA group (hazard ratio, 0.26; 95% CI, 0.13 to 0.55). Angina during the final 4 weeks of follow-up was reported in 8.8% of the patients in the CT group and in 7.5% of those in the ICA group (odds ratio, 1.17; 95% CI, 0.92 to 1.48). Conclusions: Among patients referred for ICA because of stable chest pain and intermediate pretest probability of CAD, the risk of major adverse cardiovascular events was similar in the CT group and the ICA group. The frequency of major procedure-related complications was lower with an initial CT strategy. (Funded by the European Union Seventh Framework Program and others; DISCHARGE ClinicalTrials.gov number, NCT02400229

Impact of smoking in patients with suspected coronary artery disease in the randomised DISCHARGE trial

Objectives: To investigate if the effect of cardiac computed tomography (CT) vs. invasive coronary angiography (ICA) on cardiovascular events differs based on smoking status. Materials and methods: This pre-specified subgroup analysis of the pragmatic, prospective, multicentre, randomised DISCHARGE trial (NCT02400229) involved 3561 patients with suspected coronary artery disease (CAD). The primary endpoint was major adverse cardiovascular events (MACE: cardiovascular death, non-fatal myocardial infarction, or stroke). Secondary endpoints included an expanded MACE composite (MACE, transient ischaemic attack, or major procedure-related complications). Results: Of 3445 randomised patients with smoking data (mean age 59.1 years + / - 9.7, 1151 men), at 3.5-year follow-up, the effect of CT vs. ICA on MACE was consistent across smoking groups (p for interaction = 0.98). The percutaneous coronary intervention rate was significantly lower with a CT-first strategy in smokers and former smokers (p = 0.01 for both). A CT-first strategy reduced the hazard of major procedure-related complications (HR: 0.21, 95% CI: 0.03, 0.81; p = 0.045) across smoking groups. In current smokers, the expanded MACE composite was lower in the CT- compared to the ICA-first strategy (2.3% (8) vs 6.0% (18), HR: 0.38; 95% CI: 0.17, 0.88). The rate of non-obstructive CAD was significantly higher in all three smoking groups in the CT-first strategy. Conclusion: For patients with stable chest pain referred for ICA, the clinical outcomes of CT were consistent across smoking status. The CT-first approach led to a higher detection rate of non-obstructive CAD and fewer major procedure-related complications in smokers. Clinical relevance statement: This pre-specified sub-analysis of the DISCHARGE trial confirms that a CT-first strategy in patients with stable chest pain referred for invasive coronary angiography with an intermediate pre-test probability of coronary artery disease is as effective as and safer than invasive coronary angiography, irrespective of smoking status. Trial registration: ClinicalTrials.gov NCT02400229. Key points: • No randomised studies have assessed smoking status on CT effectiveness in symptomatic patients referred for invasive coronary angiography. • A CT-first strategy results in comparable adverse events, fewer complications, and increased coronary artery disease detection, irrespective of smoking status. • A CT-first strategy is safe and effective for stable chest pain patients with intermediate pre-test probability for CAD, including never smokers