Transcatheter aortic valve implantation (TAVI) in patients with aortic regurgitation

Transcatheter aortic valve implantation (TAVI) has become the standard of care for elderly high-risk patients presenting severe and symptomatic aortic valve stenosis, while surgical aortic valve replacement (sAVR) is still considered as the treatment of choice for younger patients and patients with low and intermediate risk profiles (1,2). With more than 100,000 implants worldwide, TAVI has changed the paradigm in the treatment of aortic valve stenosis. The principle concept of TAVI is based on implanting a balloon- or self-expandable transcatheter heart valve into the calcified native aortic annulus (3). Therefore, a certain amount of aortic annulus and/or valve calcification is presumably essential to anchor the valve-mounted stent-frame into the annulus. This follows from the fact that, pure, severe aortic regurgitation has been considered as a relative contraindication to TAVI due to the absence of aortic calcification. This is also reflected by the instructions for use of all commercial TAVI systems. On the other hand, there is clearly an unmet clinical need for TAVI as high-risk patients frequently present with a combined aortic valve disease with predominant regurgitation without a reasonable amount of calcium or even pure aortic regurgitation without any aortic valve calcification. Up to now, those patients were mostly treated by sAVR. More recent experiences with TAVI in patients with aortic regurgitation has been reported in several case reports and small clinical studies. The first successful cases were reported as ‘off-label’ procedures by using the CoreValve？ (Medtronic, Minneapolis, Minnesota, USA) as well as the Edwards Sapien THV system (Edwards Lifesciences LLC, Irvine, CA, USA) (4-6). Since then, the only approved valve system to be used in pure aortic regurgitation is the JenaValve？ prosthesis (JenaValve Technology GmbH, Munich, Germany) (7,8). The J-valve？ system (JC Medical, Inc. Burlingame, CA, USA and Suzhou, China), a recently introduced new, also self-expandable TAVI-system has also been used in pure aortic regurgitation (9) and just recently, the Lotus？ valve system (Boston Scientific, Marlborough, MA, USA) was reported to be used successfully for treatment of patients with pure aortic regurgitation. Another interesting concept of a self-expandable transcatheter valve, the Symetis ACURATE TA？ device (Symetis S.A., Ecublens, Switzerland) has been introduced firstly for pure aortic regurgitation by our Essen TAVI group (10), being the largest single-center study published so far