New Heart Valves: Third-Generation, Sutureless and Polymer

New heart valves attack the two weaknesses of the old ones. Third-generation tissue valves resist calcification and are built so that a failed valve can later be replaced through a catheter (valve-in-valve). Sutureless valves are implanted without stitches, shortening the operation. Polymer valves such as the Foldax Tria are designed not to degenerate and to need no lifelong anticoagulation.

Dr. Z S Meharwal, Chairman & Head- Adult Cardiac Surgery, Fortis Escorts, New Delhi, India, closed the technical part of his October 2025 masterclass with these developments. They matter because they change the basic bargain of valve replacement described in mechanical vs tissue heart valves: how to choose: a mechanical valve that lasts but needs blood thinners for life, or a tissue valve that spares the patient blood thinners but wears out. The full overview of the masterclass is in the complete guide to advances in heart valve surgery.

Why tissue valves are now used more often

Tissue valves are now used more and more commonly compared with mechanical valves. One of the main reasons, in Dr. Meharwal's account, is that currently available tissue valves are expected to last longer and to degenerate more slowly than earlier generations. The so-called third-generation valves, from several international manufacturers and one Indian manufacturer, are now in common use.

Why tissue heart valves degenerate

Tissue valves degenerate mainly through calcification. A great deal of research has gone into why they fail, and the commonest cause of structural valve degeneration is calcification of the tissue: calcium deposits build up in the valve leaflets, which stiffen, stop opening and closing properly, and eventually leak or narrow.

Many factors influence calcification. One of them is the way the tissue is preserved. Valve tissue is fixed in glutaraldehyde, a chemical that stabilises the animal tissue and makes it suitable for implantation, and exposure to the aldehyde was itself one of the factors that promoted calcification. Most manufacturers have therefore focused on anti-calcification treatment of the tissue, so that calcification, and with it degeneration, is minimised. In Dr. Meharwal's summary of the field, anti-calcification tissue treatment was developed from the 1980s to make tissue valves last longer.

Valve-in-valve: designing for the next procedure

A valve-in-valve procedure places a new valve inside a failed surgical tissue valve through a catheter, without reopening the chest, and new surgical valves are built to make it easier. That procedure is the second area of focus for manufacturers. Sooner or later most tissue valves will degenerate, and the patient will need either a redo open operation or an alternative. Technology now allows that alternative: valve-in-valve is an application of transcatheter aortic valve implantation (TAVI), which is examined in depth in Dr. Subhash Chandra's guide to TAVI and minimally invasive heart interventions.

Manufacturers are now designing surgical valves to make that future procedure easier. Dr. Meharwal described two examples.

Visible size markers and an expansion zone

One third-generation tissue valve incorporates two technologies aimed at valve-in-valve:

• Fluoroscopically visible markers. The size of the implanted valve can be read on fluoroscopy, the live X-ray imaging used in the catheter laboratory. Years later, the team planning a valve-in-valve procedure can see exactly what size of valve is already in place.
• An expansion zone. Part of the sewing ring is designed to expand when a valve-in-valve procedure is performed. That allows a larger transcatheter valve to be implanted in the second procedure than the original surgical valve would otherwise accommodate.

Size matters because a transcatheter valve placed inside a surgical valve narrows the opening further. A larger second valve means better blood flow through it and a better result for the patient.

Radiopaque markers on the Abbott Epic valve

Abbott's Epic valve takes a similar approach. The company has placed radiopaque markers, visible under fluoroscopy, both in the sewing ring at the valve's base (the annulus) and in the stent posts. These again help the team perform a valve-in-valve procedure in future.

Sutureless heart valves

Sutureless valves, as the name suggests, are implanted without surgical sutures. In a conventional valve replacement the surgeon places sutures through the valve's sewing ring and the patient's annulus and then ties the valve down. A sutureless valve needs none of these sutures.

Two companies make sutureless valves. The one available in India is the Perceval valve from Corcym. It is a bovine pericardial valve mounted on a nitinol frame. Nitinol is a nickel-titanium alloy that returns to its set shape at body temperature, which makes the valve self-expanding: it is implanted in a manner similar to a transcatheter aortic valve, expanding to anchor itself in the annulus.

Advantages of sutureless valves

Dr. Meharwal set out three advantages:

1. Shorter operating time. Without sutures, the surgical time is shorter. So are the two intervals that matter most for outcome: the cardiopulmonary bypass time, during which the heart-lung machine supports the circulation, and the aortic cross-clamp time, during which the heart is stopped and receives no blood supply. Both affect how well the patient recovers.
2. Better haemodynamics. Because there is no sewing ring, the orifice area of the valve, the opening through which blood flows, is larger. Blood flow across the valve is better than with sutured valves.
3. Easier minimally invasive surgery. Because no sutures need to be placed, sutureless valves facilitate minimally invasive aortic valve replacement through a small incision, the approaches described in the complete guide.

Like any valve, sutureless valves involve trade-offs. Published series report a higher rate of permanent pacemaker implantation after sutureless valves than after conventional sutured valves, because the frame sits close to the heart's conduction system, the specialised tissue that carries the electrical signal for each heartbeat.

The polymer heart valve: Foldax Tria

The polymer heart valve is the newest valve design Dr. Meharwal described: made of a biopolymer, it is intended to last like a mechanical valve without lifelong anticoagulation. The company Foldax researched and developed the Foldax Tria valve. A clinical study was conducted about two years before the masterclass, its results were published the following year, and the valve was introduced commercially in India shortly before the session in October 2025. Dr. Meharwal's team has used the valve and was part of its clinical trial.

What the polymer valve is designed to do

The Tria valve is made of a biopolymer rather than animal tissue or metal. Its design rests on three properties:

• Calcification resistance. The biopolymer resists calcification, so the valve is not expected to degenerate as a tissue valve does.
• Durability under stress. It is designed to withstand the repeated stresses and strains of opening and closing without failure. Like a mechanical valve, it is meant not to wear out.
• Thromboresistance. It is expected to resist thrombosis and thromboembolism, so anticoagulants should not be needed for the patient's life.

Anticoagulants may still be required for a few months after implantation. How long exactly is not yet known: Dr. Meharwal was clear that longer follow-up is needed to establish it.

Why it could change valve surgery

If the polymer valve performs as designed, it would remove the trade-off that has defined valve replacement since the 1970s. It would last the patient's lifetime like a mechanical valve, without the lifelong anticoagulation, and without the degeneration that limits a tissue valve. Dr. Meharwal described this, if it is borne out, as a potential game changer in valve design and in the surgical management of valve disease.

The qualification matters. The case for the polymer valve rests on its design and on early clinical results. Lifetime durability and freedom from anticoagulation are expectations that only long-term follow-up can confirm.

What new heart valves mean for the mechanical vs tissue choice

Each of these technologies shifts the balance of the mechanical versus tissue choice in a specific way:

• Third-generation tissue valves slow degeneration, so a tissue valve is more likely to last longer before it needs attention.
• Valve-in-valve-ready designs mean that when a tissue valve does fail, the next step can be a catheter procedure rather than a second open operation. The availability of valve-in-valve treatment is one reason tissue valves are increasingly considered for younger patients.
• Sutureless valves shorten the operation and make minimally invasive aortic valve replacement easier.
• Polymer valves aim to remove the trade-off altogether, pending long-term data.

They also affect cost. Mechanical valves remain significantly cheaper than tissue valves, and third-generation tissue valves cost more than second-generation ones, so the valve chosen is one of the two main drivers of the cost of surgery. Indicative figures for aortic valve replacement are on Jivo Healthcare's treatment-cost pages. Doctors' questions to Dr. Meharwal on cost, referral and recovery are recorded on the Live Discussion page for the masterclass.