The MANTRA study: a new umbrella concept prospectively applied to assess implantable medical devices for heart valve procedures.

Background: Clinical evidence is commonly obtained through individual trials that are time-, cost- and resource-consuming, and which often leave unanswered clinically relevant questions. Umbrella studies have been developed to address the need for more efficient and flexible trial structures, predominantly for cancer treatments. The umbrella concept foresees data collection within a unifying trial structure, to which one or more substudies may be added at any time to address product- or therapy-specific questions.