comment on the RESPOND study

J Thorac Dis 2017;9(10):3587-3589 jtd.amegroups.com It was a real pleasure to write an Editorial comment for this issue of the Journal of Thoracic Disease. We read with great interest the paper of Volkmar Falk, submitted to the European Heart Journal describing the safety and efficacy of the transcatheter Lotus valve (Boston Scientific Corporation, Marlborough, Massachusetts, USA) (1). In Essen, we had the great opportunity to be involved within the early and first-in-man implantation of the predecessor of the Lotus valve, the SadraTM TAVI (transcatheter aortic valve implantation) system, in collaboration with Raimund Erbel and Eberhard Grube in 2007. The abovementioned paper summarized the results of a prospective, mult i-centre, open-label and s ingle-arm registry (RESPOND: Repositionable Lotus Valve System-Post Market Evaluation of Real World Clinical Outcomes) from 41 centres in Europe, New Zealand and Latin America in a total of 1,014 patients. In general, the Lotus device represents a secondgeneration TAVI device, which consists of a pre-loaded, stent-mounted tissue valve prosthesis and catheter delivery system. The frame consists of braided nitinol wires with three bovine pericardial leaflets. The idea of this concept was that this new device offers the possibility to reposition or retrieve the device if it is not perfectly placed. The valve is illustrated in Figure 1. Moreover, the valve is surrounded by an adaptive seal (polymer membrane) to act against paravalvular leakage (PVL). By the way, especially this feature has meanwhile created a landmark legal battle between different medical companies. An aortic diameter of ≥20 to ≤27 mm could be covered by the LotusTM valve. Generally speaking, the concept of this device can be quite vividly explained by the so called Chinese finger trap. The paper what we refer to, aimed to describe for the first time, the use of the LotusTM device in a large and “allcomer” patient population and to evaluate 30-day mortality and VARC-2 criteria (2). The paper comes with several new, positive, but also debatable aspects in the field of TAVI. In regard to the obtained results, it should be mentioned at first, that an independent echo core-lab was used to assess postoperative valve function. It should be mentioned, that the overall “intention-to-treat” population consisted of a total of 1,014 patients, but in 18 patients, no LotusTM valve was implanted, which corresponds to 1.8%. Therefore, only 996 patients received a LotusTM valve with a rate of 99.7% correct positioning. An ideal valve should cover all pathologies and should be suitable for every TAVI patient. The reasons for not implanting a LotusTM valve were inability to track through the anatomy/device complication (n=10), procedural complication (n=6), incorrect sizing (n=1) or one unknown reason. On the other side however, it must be highlighted, that 11.7% of the “as-treated” group showed moderate to severe aortic regurgitation as the underlying pathology. In this respect, the LotusTM device will definitively create new possibilities to treat also patients with aortic regurgitation, which has been also published so far (3). The major innovation of the LotusTM valve is based on the possible repositioning and retrievability of the device. This feature has been attempted in 296 (29.2%) of Editorial