[Recent and upcoming randomized trials for left atrial appendage occlusion : Need for a definite assessment of the situation]

The DZHK research platform: maximisation of scientific value by enabling access to health data and biological samples collected in cardiovascular clinical studies

The German Centre for Cardiovascular Research (DZHK) is one of the German Centres for Health Research and aims to conduct early and guideline-relevant studies to develop new therapies and diagnostics that impact the lives of people with cardiovascular disease. Therefore, DZHK members designed a collaboratively organised and integrated research platform connecting all sites and partners. The overarching objectives of the research platform are the standardisation of prospective data and biological sample collections among all studies and the development of a sustainable centrally standardised storage in compliance with general legal regulations and the FAIR principles. The main elements of the DZHK infrastructure are web-based and central units for data management, LIMS, IDMS, and transfer office, embedded in a framework consisting of the DZHK Use and Access Policy, and the Ethics and Data Protection Concept. This framework is characterised by a modular design allowing a high standardisation across all studies. For studies that require even tighter criteria additional quality levels are defined. In addition, the Public Open Data strategy is an important focus of DZHK. The DZHK operates as one legal entity holding all rights of data and biological sample usage, according to the DZHK Use and Access Policy. All DZHK studies collect a basic set of data and biosamples, accompanied by specific clinical and imaging data and biobanking. The DZHK infrastructure was constructed by scientists with the focus on the needs of scientists conducting clinical studies. Through this, the DZHK enables the interdisciplinary and multiple use of data and biological samples by scientists inside and outside the DZHK. So far, 27 DZHK studies recruited well over 11,200 participants suffering from major cardiovascular disorders such as myocardial infarction or heart failure. Currently, data and samples of five DZHK studies of the DZHK Heart Bank can be applied for.

[Left atrial appendage occlusion in patients with nonvalvular atrial fibrillation : Present evidence, ongoing studies, open questions]

About every fifth ischemic stroke is caused by atrial fibrillation. Oral anticoagulation is highly effective in secondary stroke prevention, but a relevant portion of patients with atrial fibrillation is not (permanently) anticoagulated for a variety of reasons. Based on present evidence, no general recommendation can be given for left atrial appendage occlusion in patients with nonvalvular atrial fibrillation. However, left atrial appendage occlusion is a treatment option after severe anticoagulation-related bleeding, if the cause of bleeding is not treatable. Left atrial appendage occlusion is critical in patients with a relative contraindication for oral anticoagulation or lack of adherence to given medication. It seems to be important that further randomized studies confirm a benefit of left atrial appendage occlusion in selected patients with nonvalvular atrial fibrillation. In addition, it is vital to clarify whether discontinuation of antiplatelets is feasible after catheter-based left atrial appendage occlusion, as antiplatelets are associated with a risk of bleeding. Within this review article, we discuss present evidence, gaps of knowledge and provide an overview on ongoing clinical studies. In addition, we summarize the design of the CLOSURE-AF study. This randomized multicenter study will start recruitment soon and is funded by the German Center for Cardiovascular Research e. V.