*2.1.1 CoreValve/evolut family*

First, the SEV 'CoreValve' was initially presented by Medtronic. In CoreValve US Pivotal Trial, TAVR showed higher survival rates compared to SAVR at 1 year [6]. The main disadvantages of this system were large size of delivery system, increased postprocedure permanent pacing rate, increased rate of paravalvular leak (PVL) and relatively increased stroke rates [7–10]. After the CoreValve system, Evolut R, Pro and Pro+ were designed by Medtronic (**Figure 1**). All models contain tri-leaflet porcine pericardial tissue on a Nitinol frame and work in a supra-annular position. Evolut R system has favorable outcomes compared to the CoreValve system, especially on paravalvular leak. Evolut Pro kept all features of Evolut R, is recapturable and repositionable to assist in optimal deployment. Also, this system has an extra porcine pericardial wrap over first 1.5 cells to reduce PVL [11, 12]. Evolut Pro+ platform can treat an even larger annulus range up to 30 mm diameter. Evolut FX valve was recently developed with enhanced visualization capabilities [13]. Platforms use transvascular ways. Evolut R and Evolut Pro+ have four annular diameter sizes. The size of 23 mm is suitable for 18–20 mm aortic valve annuli, 26 mm for annuli 20–23 mm, 29 mm for annuli 23–26 mm and 34 mm for annuli 26–29 mm. Evolut R platform uses 14 French (Fr) equivalent sheath. But 34 mm Evolut R and Evolut Pro platform use 16 Fr sheath. Evolut Pro+ platform uses 14 Fr sheath (18 Fr sheath is necessary for a 34 mm valve). Generally before implantation, predilatation is recommended. Usually rapid pacing is

**Figure 1.** *CoreValve/evolut valve design.* *Transcatheter Aortic Valve Replacement Technique and Current Approaches DOI: http://dx.doi.org/10.5772/intechopen.111904*


#### **Table 1.**

*Comparison of self-expandable valves' basic features.*

not necessary but in aortic regurgitation and high annuli diameter, controlled pacing (90–130 rates/min) can be used (**Table 1**).

#### *2.1.2 Portico and Navitor*

Portico is the first resheathable and repositionable SEV. Its intra-annular design provides early valve function and reduces hemodynamic interaction during the procedure. Portico has large frame cells that enhance coronary access. Available sizes are 23 mm, 25 mm, 27 mm and 29 mm. Both platforms use transvascular ways. The 14 Fr sheath is suitable for 23–25 mm valves and the 15 Fr sheath is suitable for 27–29 mm valves [14, 15]. Navitor is a new generation of Portico valves (**Figure 2**). It has an external cuff to reduce PVL. Abbott published 30-day results. All-cause mortality 0%, permanent pacemaker 15%, major vascular complications 0.8% and mean gradient 7.4 mmHg, higher than minimal PVL 0%, were observed. Highlighted potential risk is associated with increased rates of permanent pacemaker implantation [16].

#### *2.1.3 Acurate TA and Acurate NEO*

Acurate TA is used for transapical access and Acurate Neo is used for transvascular access. Unlike other SEVs, Acurate cannot be repositioned. It has a supra-annular design with three stabilization arches that help bioprosthetic valve alignment. Implantation has two steps from 'up to down'. First aortic side releases then subannular side releases. Because of this unique opening style, the platform protects

**Figure 2.** *Portico/Navitor valve design.*

hemodynamics, allows blood flow and decreases embolization risk. Acurate Neo is especially suitable for low coronary distances and horizontal aorta (**Figure 3**). Acurate Neo has the lowest permanent pace ratio in all SEVs. This is a consequence of lower radial force. Due to lower radial force, conduction system trauma reduces. But this low radial force makes necessary predilatation and postdilatation. Acurate Neo has three sizes (23 mm, 25 mm and 27 mm) [17].
