The transcatheter aortic valve CoreValve Evolut R (Fig. 8.1a) available in sizes 23, 26, and 29 is constituted by a porcine pericardium valve with flaps engineered, obtained by suturing the three valve flaps (obtained from a single sheet of pericardium) to the support with the addition of a “skirt” which facilitates the closure and is shaped to obtain a better fluid dynamics. Support is nitinol self-expanding and is radiopaque. The valve is reduced to an extent of 18 Fr for its positioning, and then, once in place, it is re-expanded to a size between 18 and 20 mm for valve 23, 20 and 23 mm for valve 26, 23 mm for valve 3, and 26 mm for valve 29. The stent is a self-expandable nitinol with cells of diamond in shape and its radiopacity allows the correct positioning of the bioprosthesis; it is designed to have three levels of radial force; in particular in the stretch of inner flow, the radial force is such as to allow the valve to comply native annulus of the patient, to reduce losses paravalvular, and to prevent migration of the prosthesis. The two hooks positioned in the upper portion of the stent allow the loading of the valve. The valve CoreValve Evolut R is designed to be recaptured and repositioned during implant, for a maximum of two times. You can recapture the valve up to 80 % of release. The valve design also allows a radial force constant regardless of the size of the native annulus patient, to mitigate any paravalvular regurgitation. The release system with system EnVeo with introducer InLine is necessary for the percutaneous insertion of the bioprosthesis and is formed by a catheter with an outer diameter of 18 Fr and 15 Fr in the distal part in the central part of the shaft, where the stability layer Accutrak is present. Along the proximal part of the delivery, the introducer InLine is present, with a diameter of 18 outer Fr, which allows to implant the valve without further introducers. The distal part of the device has an atraumatic tip radiopaque. A protective sheath covers in nitinol and maintains bioprosthesis closed. Such sheathing also allows the valve to recapture most twice during implant by turning in the opposite part of the handpiece used to issue the same. This is possible up to 80 % of the opening. Evolut R is available since the fourth quarter of 2014, and very few clinical data are available until now. In CE study of 60 patients, Evolut R showed excellent procedural and 30-day outcomes and strong safety profile (0 % mortality rate) [1].

The Edwards Sapien 3 transcatheter heart valve model (Fig. 8.1b) is the last evolution of balloon-expandable EVS valves. Available from the first quarter of 2014, it combines a stent in chromium-cobalt expandable with a radiopaque balloon, a pericardial three flaps of tissue valve, and an inner and outer skirt made of polyethylene terephthalate (PET). The heart valve Sapien 3 (S3) is available in three sizes (23, 26, and 29), but 20 mm will soon be ready. The valve is assembled with three strips of bovine pericardium. The Edwards Sapien 3 transcatheter heart valve can be implanted with three different approaches: transfemoral, transapical, and transaortic. Before implantation, the bioprosthesis is mounted on the delivery system balloon Commander, using a special compression device (crimper). The bioprosthesis is positioned and released at the site of the native aortic valve stenosis through inflating the balloon of the delivery system, which is subsequently removed. Expandable introducer Edwards eSheath 14 F for the valves 23 and 26 mm or 16 F for the valve 29 mm is used for femoral access, allowing a reduction of sheath size compared to Sapien XT. The release system is constituted by a catheter flexible carrier within which a balloon catheter is assembled. The balloon expands the bioprosthesis through a controlled volume of the mixture of contrast medium and saline. The flexible, load-bearing catheter Commander allows the alignment of the valve with the annulus plane through a controlled rotation of the handle and consequent flexion of the distal end. An important new feature of this valve is the presence of a skirt surrounding the distal part of the stent frame on the purpose to reduce the paravalvular leaks with a better contact with calcifications. First-in-man publication done in 2013 showed from the beginning that the S3 and delivery system might facilitate fully percutaneous implantation in a broader range of patients with the potential for more accurate positioning and less paravalvular regurgitation [2]. Recently, at ACC meeting held in San Diego on March 2015, S Kodali presented 30-day results of S3 implant in high- and intermediate-risk patients. Mortality rate and stroke rate were very low in both populations (cardiovascular mortality rate 1.4 % in high-risk and 0.9 % in intermediate-risk, stroke rate 0.9 in high-risk and 1.0 % in intermediate-risk patients) [3]. PARTNER 2 randomized trial is enrolling, and it will compare S3 results versus surgical results in intermediate-risk profile.

The device Lotus™ (Fig. 8.1c) is a transcatheter valve system designed to be released retrogradely through a guide 0035″ available in three sizes 23, 25, and 27. This system consists of two main components: a bioprosthetic aortic valve premounted on a delivery system consisting of a catheter for the introduction and the valve itself. Such valve is premounted on the delivery system during the production phase. The valve Lotus™ in size from 23 mm is compatible with the introducer 18 Fr, while the same valve in sizes from 25 to 27 mm are compatible with the introducer 20 Fr. This valve consists of three flaps of bovine pericardium, supported by a structure realized by a single wire braided nitinol, which ends exactly in the central part with a tube crimped in tantalum, which assures a radiopaque marker on implantation. The three flaps are cut by patches of bovine pericardium fixed with glutaraldehyde and subsequently sutured together. The woven structure is drawn so as to shorten longitudinally and to expand radially at the time of deployment, and therefore, it is locked in this position by means of a safety mechanism. This mechanism allows the physician to lock the valve in position, unlock to recapture, release it again and reposition, or even withdraw it completely. The maximum height for all sizes of valves, at the time of complete release, is 19 mm. An outer coating of polyurethane-polycarbonate, called Adaptive Seal™, is designed to minimize paravalvular aortic regurgitation. The delivery system of the valve consists of three main components: an inner catheter (described as a multi-lumen catheter) which is connected to the valve, an external catheter (described as an external introducer), and a handpiece which is used to control the positioning and release of the valve itself. The major advantages of this system are the possibility of a complete resheathing until the valve is released and the presence of the outer adaptive membrane facilitating the contact with the native valve, compensating the anatomical variations, and minimizing the paravalvular leak. The still bulky delivery system is the major disadvantage of Lotus, but in the fourth quarter of 2015, the new trackable and lower profile delivery system would be available. The procedure of Lotus valve is shown in Fig. 8.2. Commercial use of BSI Lotus started in 2014, and results available until now are really encouraging especially in terms of reduction of paravalvular leaks compared to competitors [4, 5]. In REPRISE II CE-Mark Study designed to test safety and performance in extreme/high-risk patients, the device success (correct positioning of one valve in proper position without periprocedural mortality) was 99.2 %. Six months of mortality rate was 8.4 % and pacemaker rate 29.4 %. In this study, only 1 % of patients had more than mild paravalvular regurgitation, and no severe aortic regurgitation was reported. At EuroPCR 2015, Van Mieghem presented the first 250 interim analyses of RESPOND post-market safety and performance study. This single-arm registry is designed to enroll 1,000 patients in the real-world population with 23, 25, and 27 mm valve sizes. All-cause mortality was 2.0 %, stroke was 3.3 %, and no moderate or severe aortic regurgitation was reported. Even in this trial, the PM rate rises to 33.7 % but with large difference among centers, and only one-third of patients are still PM dependent at 30 days [6].