Figure 1. VitaFlow LibertyTM aortic valve.

Figure 2. VitaFlow LibertyTM delivery system.

Table 1. Baseline demographic characteristics.

Figure 3. Case report showing heavy calcification in the aortic arch (A), aorta abdominal aorta, and...

Table 2. Technical characteristics of the procedures.

Figure 4. Change to the valvular area, and pre- y post-TAVI gradients. The mean hospitalization time...

Figure 5. Paravalvular leak (PVL) at 30 days as seen in different clinical trials. Modified from van...

Table 3. Results and complications.

Introduction

Aortic stenosis (AS) is the most common valvular heart disease. Calcium deposit related degenerative etiology is the most prevalent of all. AS related symptom onset is associated with a lower life expectancy. One out of every 8 people over 75 years will develop moderate or severe aortic valvular stenosis in their lifetime.1 With the ageing of the population this tendency has been growing and now we find elderly patients who are frailer and of a higher surgical risk.2

Transcatheter aortic valve implantation (TAVI) is a new therapeutic much less invasive alternative that prevents the use of extracorporeal circulation and the occurrence of cardiac arrest.

Since it first appeared back in 2002,3 TAVI has revolutionized the management of severe aortic stenosis and become the standard of choice for inoperable or high-surgical risk patients. As a matter of fact, it is the treatment preferred by many elderly intermediate-and-low risk patients.4,5 Over time, several state-of-the-art transcatheter heart valves have been developed—both balloon-expandable and self-expanding—with characteristics aimed at minimizing complications and/or the associated procedural limitations to improve clinical outcomes and expand its indications.6

This is our early experience with the VitaFlow and VitaFlow Liberty valves (Microport Inc, Shanghai, China) in Argentina and Latin America.

Material and methods

A total of 28 consecutive patients with severe aortic valve disease and an indication for TAVI were treated between August 2021 and July 2022. Cases were performed by the same proctoring heart team in Argentina and/or with great experience performing TAVIs. The study group inclusion criteria were the presence of symptomatic severe aortic stenosis and the heart team decision to go with the transcatheter procedure as the best therapeutic option available.

All the group patients were treated with the VitaFlow and VitaFlow Liberty devices. The VitaFlow is a self-expanding valve that consists of a nitinol stent on which 3 bovine pericardial leaflets with anti-calcification properties are mounted plus a PET skirt for better sealing of the landing zone (Figure 1).

There are 4 different sizes available: 21 mm, 24 mm, 27 mm, and 30 mm to cover an aortic valve annulus perimeter between 17 mm and 29 mm, and an area between 229.9 mm2 and 660.2 mm2.

These are the main characteristics of the VitaFlow valve:

• Self-expanding valve for supra-annular implantation.
• Bovine pericardial leaflets with anti-calcification properties.
• PET skirt for better sealing of the landing zone to reduce paravalvular leak.
• Nitinol valve with 2 different sections: one annular section with a high-density cells and high radial strength for better anchoring and sealing plus an aortic section with low-density cells—open cells—and less radial strength for better alignment with the axis of the aorta. Low-density cells and high amplitude allow potential posterior percutaneous coronary accesses to coronary arteries and minimize the chances of coronary ostia obstruction during implantation.
• Fully retrievable valve up to 75%. It can be repositioned up to 3 times.

  VitaFlow is a low-profile 16-Fr-17-Fr easy-to-maneuver, highly flexible, motorized delivery system that can be bent 360 degrees. In addition, it is very precise during valve deployment and comes with a manual back-up system (Figure 2).

  All patients were treated with an echocardiogram, coronary angiography, CCTA, and analyzed using Horos software.

  Sedoanalgesia was used in 100% of the patients based on our routine protocol. Access route was transfemoral via percutaneous or surgical approach. Heparin was administered to achieve an ACT > 300 seconds. Afterwards, a pigtail catheter was introduced via right radial or contralateral femoral access with respect to the valve access route until it reached the non-coronary sinus. Rapid pacing wires were placed in patients except for those with right bundle branch block (RBBB).

  An aortogram was performed through the pigtail catheter in the right caudal oblique position to verify the early work view using the cusp overlapping technique. Afterwards, the femoral artery was punctured, and a 7-Fr introducer-sheath was inserted. A curved guidewire was then passed towards the aortic root on which an AL 1 or JR catheter was mounted. This curved guidewire was exchanged for a flexible tip straight guidewire, and the native aortic valve was crossed. Once the guidewire has been passed, the catheter is advanced until it reaches the inside of the left ventricle. Afterwards, the straight guidewire was exchanged for a Safari™ Extra-Small support guidewire (Boston Scientific, Marlborough, MA, United Sates) until it was properly placed into the left ventricular chamber. Then, the 7-Fr introducer sheath was removed, and through the support guidewire a different 14-Fr introducer sheath or the valve delivery system was advanced.

  Afterwards, a balloon valvuloplasty was performed in cases of severe aortic stenosis for a short period of over-pacing. The size of the balloon picked matched the minimum diameter of the aortic annulus as measured on the CCTA. No valvuloplasty was performed in cases of poorly calcified valves.

  Afterwards, the delivery system mounted on the Safari™ support guidewire was advanced under radiological control until it was placed in the landing zone as confirmed by the angiography. Valve was slowly deployed, and implantation depth was corrected through small variations of the cusp overlapping view. Valve was deployed up to 75% of its full capacity under rapid pacing (moment when the valve opens and shuts) to check the left oblique position once again, and slowly complete the deployment. When in doubt, the valve was retrieved and repositioned uneventfully. After implantation, the delivery system was removed. The final outcome was confirmed on the angiography and, if necessary, on the transthoracic echocardiogram.

  In cases with unacceptable residual paravalvular leak, postdilatation was performed with a smaller balloon compared to the maximum aortic valve annulus diameter.

  After successful implantation, all guidewires and catheters were removed. The introducer sheath was removed too, and the femoral artery was percutaneously or surgically closed.

  Afterwards, patients were referred to the coronary care unit (CCU) and remained there under 24-hour monitoring.

  The in-hospital and 30-day mortality rates were collected. Intra- and postoperative complications were reported based on the consensus definitions established in the guidelines published by the Valve Academic Research Consortium, and the Valve Academic Research Consortium-2.7 Demographic and clinical variables, and echocardiographic data were collected too. In addition, hospitalization stay (in days) and complications at discharge were collected as well. Thirty-day clinical and echocardiographic follow-up was conducted.

  Results

  The VitaFlow (13; 47%) and VitaFlow Liberty (15; 53%) transcatheter heart valves were implanted in all the patients. Mean age was 79.5 ± 8.2 years and 44% were men. The median risk scores obtained in the EuroSCORE II and STS scores were 5.3 (4.3-6.7) and 5.5 (4-6.7), respectively. Valve-in-valve procedure was performed in 1 case only (Table 1).

  Only 1 valve was implanted in each patient (100% implantation success rate).

  Access route was transfemoral in 28 patients (100%). In 50% of the patients with percutaneous access 2 Abbott’s Perclose ProGlide™ vascular closure devices were used.

  Balloon valvuloplasty was performed in 26 patients (93%). After implantation, 5 patients (20%) required balloon postdilatation.

  No in-hospital or overall deaths were reported at the early 30-day follow-up.

  In all the cases, the implantation system navigability was good even in anatomies with tortuous iliofemoral axes or more horizontal aortas. In cases of severe aortic calcification including the aortic arch (as seen on Figures 3 A and B) 2 support guidewires were used: the aforementioned Safari plus a high-support Lunderquist guidewire (Cook Cop, IN, United States). A pigtail catheter was advanced for better movement of the valve through the aortic arch avoiding difficult maneuvers while crossing the arch or the snare technique that is much more complicated. The 2 support guidewires helped cross this difficult aortic arch and successfully implant the valve as seen on Figures 3 C, D, E, and F.

  Implantation was successful on the 1st attempt in 18 cases (64%) with need for partial recapture in 9 (32%) and full recapture in 7 (28%). Both the valve and the delivery system were removed completely uneventfully (Table 2).

  After successful valve implantation, residual paravalvular leak was considered non-existent/trivial and mild in 78.6% (22) and 21.4%, respectively. (6) No moderate of severe paravalvular leak was reported. The mean transvalvular gradient was 6.86 ± 3.2 mmHg in the native valves with a median effective orifice area of 2.04 mmHg (1.8-2.2) (Figure 4).

  Definitive pacemaker implantation was required in 1 patient (3.5%) due to the presence of BAV type 3 (table 3).

  Discussion

  TAVI has become an unquestionable therapeutic reality that has gained popularity to treat lower-risk patients. In our early experience reported here, the clinical success rate—both immediate and at 30-days—was 100%. The valve proved effective and safe to treat this population group of mostly moderate-to-high risk patients for conventional surgery.

  The lack of major intraoperative complications and at 30 days can be explained by the fact that the operator group is experienced performing this type of transcatheter implantation procedures. However, we believe that some questions regarding the valve specific design should be mentioned.

  The low rate of permanent pacemaker implantation at 30-days was only 3.5%. In this series, this rate is lower than the one recently reported by us regarding self-expanding valves (12.5% and 9.4%).8,9 Also, this rate of 3.5% is similar to the one reported in the latest designs for balloon-expandable valves in low-and-intermediate risk patients.10-17

  The rate of permanent pacemaker implantation is a crucial element when indicating TAVI for young and low or intermediate risk patients. Although permanent pacemaker implantation has not been associated with a higher mortality rate in the first studies published, it is obvious that the high numbers reported jeopardize the quality of life of young patients treated with TAVI.15

  The valve design with its electronic delivery device makes it extraordinarily precise and is probably a pivotal factor that explains the low rate of permanent pacemaker implantation reported and the lack of paravalvular leak > 2 in this series, which is inidicative of a highly competitive valve compared to other balloon-expandable valves as shown on Figure 5.10

  Also, we think that other technical factors involved like implantation using the cusp overlapping technique were important. There is no doubt that these factors were very useful and lowered the rate of permanent pacemaker implantation after TAVI.

  The experience of the operator group is also important since all procedures were performed via transfemoral access even to treat hostile and highly calcified aortic territories as it was the case with 2 patients from this series.

  Study limitations

  The study limitations have to do with its small sample size mainly, the short follow-up period involved, and the fact that procedures were performed by 2 operators with great expertise performing TAVI procedures. However, we don’t know if these numbers will be the same in larger samples with more patients or what evolution will this device have in the mid- and long-term.

  Conclusions

  Our early experience with VitaFlow and VitaFlow Liberty demonstrated that this valve safety profile is good. Also, that the 30-day hemodynamic status was excellent as the low rate of permanent pacemaker implantation and 30-day paravalvular leak > 2 proved.

1. Nkomo VT, Gardin JM, Skelton TN, Gottdiener JS, Scott CG, Enríquez-Sarano E. Burden of valvular heart diseases: A population-based study. Lancet 2006;368:1005-11.

2. Iung B, Baron G, Tornos P, Gohlke-Bärwolf C, Burchart EG, Vahaninan A. Valvular heart disease in the community: A European experience. Curr Probl Cardiol 2007;32:609-61. http://dx.doi.org/10.1016/j.cpcardiol.2007.07.002.

3. Cribier A, Eltchaninoff H, Bash A, et al. Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: First human case description. Circulation 2002;106:3006-8. http://dx.doi.org/10.1161/01.cir.0000047200.36165.b8.

4. Baumgartner H, Falk V, Bax JJ, et al. 2017 ESC/EACTS guidelines for the management of valvular heart disease. Eur Heart J 2017;38:2739-91.

5. Cahill TJ, Chen M, Hayashida K, et al. Transcatheter aortic valve implantation: Current status and future perspectives. Eur Heart J 2018;39:2625-34.

6. Tchetche D, Van Mieghem NM. New-generation TAVI devices: Description and specifications. EuroIntervention 2014;10 Suppl U:U90-U100.

7. Kappetein AP, Head SJ, Genereux P, et al. Updated standardized endpoint definitions for transcatheter aortic valve implantation: The Valve Academic Research Consortium-2 consensus document. J Thorac Cardiovasc Surg 2013;145:6-23.

8. Sztejfman M, Giuliani CM, Peralta S, Zaidel EJ, Sztejfman LC, Bettinotti MO. Impacto de la técnica de Cusp-Overlap en el requerimiento de marcapasos luego de un implante valvular aórtico percutáneo. Rev Argent Cardiol. [online]. 2021;89(2):140-144.

9. Fernández-Pereira C, Mieres J, Pavlovsky H, et al, Experiencia con el implante valvular aórtico con la válvula autoexpandible Portico: resultados hospitalarios, a 30 días y en el seguimiento alejado de una serie consecutiva de pacientes. Revista Argentina de Cardioangiología Intervencionista 2021;(04):0213-0217 | Doi: 10.30567/RACI/202104/0213-021.

10. van Gils L, Van Mieghem NM. Transcatheter aortic valve replacement with the Lotus Valve. Interv Cardiol Clin 2019;8(4):393-402.

11. Waksman R, Rogers T, Torguson R, et al. Transcatheter aortic valve replacement in low-risk patients with symptomatic severe aortic stenosis. J Am Coll Cardiol 2018;72:2095-105. doi: 10.1016/j.jacc.2018.08.1033.

12. Sondergaard L, Costa G. Transcatheter aortic valve replacement in patients with aortic stenosis and low surgical risk. J Am Coll Cardiol 2019;74:1541-2. doi: 10.1016/j.jacc.2019.07.067.

13. Reardon M, Van Mieghem N, Popma J, et al. Surgical or transcatheter aortic-valve replacement in intermediate-risk patients. N Engl J Med 2017;376:1321-31.

14. Leon M, Smith C, Mack M, et al. transcatheter or surgical aortic-valve replacement in intermediate-risk patients. New Eng J Med 2016;374:1609-20.

15. Kolte D, Vlahakes GJ, Palacios IF, et al. Transcatheter versus surgical aortic valve replacement in low-risk patients. J Am Coll Cardiol 2019;74:1532-40. doi: 10.1016/j. jacc.2019.06.076.

16. Mack MJ, Leon MB, Thourani VH, et al, Transcatheter aortic-valve replacement with a balloon-expandable valve in low-risk patients. N Engl J Med 2019;380:1695-705. doi: 10.1056/NEJMoa1814052.

17. Popma JJ, Deeb GM, Yakubov SJ, et al,. Transcatheter aortic-valve replacement with a self-expanding valve in low-risk patients. N Engl J Med 2019;380:1706-15. doi: 10.1056/NEJMoa1816885.

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Early experience in Argentina and Latin America with aortic valve transcatheter implantation with the VitaFlow self-expanding transcatheter heart valve

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