Transcatheter aortic valve replacement (TAVR)

The Repositionable 3rd-Generation Trinity TAVI System: A Case Report and Interview

Cath Lab Digest talks with Christian Hengstenberg, MD, German Heart Center, Munich, Germany.

Cath Lab Digest talks with Christian Hengstenberg, MD, German Heart Center, Munich, Germany.

Disclosure: Dr. Hengstenberg reports no financial interest, arrangement or affiliation with Transcatheter Technologies. 

Dr. Christian Hengstenberg can be contacted at christian.hengstenberg@gmail.com.

What is unique about the Trinity valve?

One of the Trinity valve’s most important features is its repositionability and ease of positioning. For transcatheter aortic valve implantation (TAVI) (or ‘replacement’, TAVR) procedures in general, there are probably two critical moments. One is the positioning of the valve, and the second is how the system leaves the body. Valve position is, of course, crucial. During the last three years or so, we have learned that if there is an ideal valve position, there is an ideal clinical result. If you have a suboptimal positioning and consecutive regurgitation, then you also have a suboptimal clinical result. Trinity’s major advance is that the operator can evaluate the positioning and functioning of the valve during the procedure. If you are happy, then fine. If you are not happy, it is very easy to correct the valve position. It can be closed slightly or folded, you can move the Trinity valve up or down according to your wish, and then open it again. It is very easy to do and very atraumatic.

What steps do you take if you would like reposition the Trinity valve?

With the Trinity system, the operator holds a handle. By turning a wheel for one quarter, the valve is unfolded. When turning the wheel in the opposite direction, the valve is slightly folded, and can then be moved up or down. When the operator is happy with the valve position, the valve is opened again with a turn of the handle. It is very easy.

Once you are committed to a particular position, is there anything you do to ensure that the valve doesn’t close on its own or remains ‘open’ to being further repositioned?

There are strings wrapped around the nitinol frame, and it is important that you pull back these strings very carefully. Pulling too hard might close the valve slightly. We practiced this maneuver quite a lot in animals and have done it in humans also. When done carefully and slowly, with the current system, it is very well feasible.

What have you seen regarding patient outcomes thus far?

We have Trinity permanently implanted in three patients. One patient died after 30 postoperative days because of non-cardiac or valve related reasons. The remaining two patients have had a very good outcome. The procedural result is very good and we are expecting the one-year follow-up soon. For the procedural result, we saw no regurgitation at all — which was a surprise in view of the severe calcification of the valves. We had not considered that the result would be so good, but it is probably due to the structure of Trinity’s nitinol frame, which aligns very nicely to the anatomical structure. Additionally, the valve has a porcine pericardial tissue wrapped around the lower frame portion in order to help to avoid paravalvular leakage.

What is the current status of the Trinity TAVI system?

We are still at first-in-man. All cases have been done in South America. Transcatheter Technologies is working on developing more sizes of the frame, which is currently only available in a 20 mm valve annulus size. The company plans to add two or three other necessary sizes. Once this is complete, Trinity will go into clinical trial, apply for CE mark, and eventually develop a transfemoral system.

What access is currently used to deliver the valve?

Transapical.

What is the size of the Trinity system?

Currently, the system is 31 French delivery, which is relatively large. However, if you compare it to the initial transapical systems from other companies on the European market, they are all about the same size, about 28 or 30 French or so. It doesn’t make much of a difference. 

How difficult is preparation of the valve?

The introduction system is made of two parts. One is the tip, with the Trinity valve pre-mounted. The other is a handle and a short introducer system. The two are connected together in the operating room. The valve itself is not crushed, which is important, because crushing might affect durability. The tip of the introducer system is connected with the rest of the system, then the valve is folded, in a “garage”, and the valve can be introduced into the apex. In our experience so far, it has been relatively easy.

Can you talk more about the durability of the Trinity valve and how it is affected by folding versus crimping?

This is one of the valve’s special features. At this time, most of the systems on the market are crimped together very tightly. It is important for these systems to be as small as possible, and in order to achieve a small size, the valves are crimped very hard. In the past, at open surgery, all cardiac surgeons were very reluctant to squeeze or even touch the valves, because they were afraid of harming the valve tissue with less optimal results for their durability. If this is true, then it would be an advantage to avoid crushing the valve, and instead fold it together, and this is what the Trinity valve does. Systems that crimp the valves come with a crimping machine, which uses brute force to crimp tightly the valve onto the balloon to avoid any slipping of the valve and to make it very small. Therefore, we think that it is advantageous to avoid the firm crimping of valve leaflets in Trinity. Especially in the possible development in TAVI towards intermediate-risk individuals, this might be of of great importance. Intermediate or even lower risk patients might be not like today, 75 years or older, but maybe around 70 years old. The necessity of a valve with a longer durability as compared to those currently on the market might be crucial. Trinity’s folding rather than crimping could be advantageous in this context. We do not have any long-term results at this point, but in theory, this should be true.

Can you share your own history with structural heart disease treatment?

Until about two years ago, I was senior cardiologist at the University Hospital in Regensburg, Germany. Together with the cardiac surgeons, we started a program with the CoreValve (Medtronic), and expanded into the use of Edwards Sapien, both transapical and transfemoral access. Over two and a half years, we had about 500 valve implantations. I then moved to the German Heart Center in Munich, where the program was continued. In our heart team with the cardiac surgeons, we have all of the currently available and CE-marked systems. Our workhorse is the Edwards Sapien 3. In the German Heart Center, we have performed more than 1,500 TAVI procedures. Only this year, we have implanted over 200 valves, and about 130 Edwards Sapien 3 valves. 

Any final thoughts?

Positioning a valve can be quite difficult, particularly for operators with less experience. A system that is more forgiving, offering repositionability, is truly an advantage. Achieving an optimal valve position means achieving an optimal clinical outcome. Then, durability is certainly of great importance. The Trinity valve offers the first and may offer the second. All the rest is nice to have.

Dr. Christian Hengstenberg will be presenting “Trinity Valve: Technology Review, Clinical Results, and Case Examples” at the TCT meeting on September 15, 2014, at 4:25pm in the session “Didactic Symposia: AORTIC VALVE THERAPIES – Today and Tomorrow III” Room: Level 2, Room 202A/B.

View the Trinity Valve case report.

Reference

  1. Hengstenberg C, Condado J, Garcia D, Martinez MM, La Forgia G, Ebner A, Gallo S, Silva E, Holzamer A, Husser O, Hilker M. TRINITY heart valve prosthesis — a novel repositionable and retrievable transapical transcatheter aortic valve system. EuroIntervention. 2014 Jul 16. pii: 20131221-02. doi: 10.4244/EIJY14M07_08.