How Cardiac Dimensions developed the Carillon Mitral Contour System — and makes the nitinol implant in-house

The Cardiac Dimensions Carillon Mitral Contour System is a minimally invasive treatment for mitral valve regurgitation that would not be possible without nitinol and advanced catheter technology.

Cardiac Dimensions has European approval and reimbursement for the system and is conducting a pivotal trial for U.S. approval.

“We never would have been able to do what we can without nitinol. … The catheter technology coupled with the nitinol metal technology are the two things that really drive the device,” said Cardiac Dimensions President and CEO Rick Wypych.

In an interview with Medical Design & Outsourcing, Wypych discussed how the Carillon Mitral Contour System works, how it was developed, and how it’s manufactured.

How the Cardiac Dimensions Carillon Mitral Contour System treats mitral regurgitation

The Carillon system uses a catheter-delivered heart implant to treat mitral regurgitation by remodeling the mitral valve’s geometry without actually touching the valve leaflets. Instead, the implant uses nitinol’s shape memory and superelastic properties to compress down for delivery via a specialized steerable catheter.

That catheter keeps the implant compressed as it’s introduced through the jugular vein and placed in the coronary sinus, where the implant expands and cinches the mitral valve annulus to allow the leaflets to fully touch when the valve closes, restoring normal blood flow.

The Carillon implant is designed to lock into place in a rigid form within the coronary sinus, using the device’s radial force to maintain its position in the vein but also allowing it to unlock if the physician needs to retrieve it. The implant has two anchors connected by a bridge, with lockbumps at each anchor.

“The anchors create the hoop shape, and at end of one anchor there’s an eyelet — a spinned wire where it creates a circle that’s smaller than that bump — and we push the circle over the bump to keep it locked in place to have that radial force maintained within the vein,” Wypych said. “Then it holds when we pull to cinch the device, and we do it in a similar way on the proximal anchor. Once we get the tension in the location that we want, we can lock it with that in place and the device is held in place with radial force, as it will be for the rest of the life of the patient.”

The device has not yet needed to be explanted from a patient because the procedure includes checking for safety and efficacy at the time of the deployment and the device is designed to be easily recapturable, he said.

“If we don’t like what we see because it’s not as efficacious as we want or there’s a safety issue in that we’ve created a perfusion problem in an artery, we simply recapture the device and reinstall a different device in a different location or a different size or under different tension to optimize it for the patient,” Wypych said.

The procedure takes 15 or 20 minutes and typically doesn’t require a stay in the intensive care unit. (A video showing the Carillon implantation procedure is at the end of this post.) A transcatheter mitral valve repair (TMVR) clip implantation, for comparison, takes a few hours in the cath lab and one or two days in the ICU because TMVR requires a transeptal puncture.

Related: Nitinol grips prevent slips in Abbott’s heart valve clips

Developing the Carillon implant

Cardiac Dimensions was founded in 2000 by Scout Medical Technologies, with a mission from the now-defunct incubator of finding an invasive surgical procedure with a large market that was ripe for a minimally invasive solution.

When Wypych joined the company in 2003, it had already identified mitral regurgitation as a target condition.

“We had some ideas on a whiteboard and a lot of R&D thought behind a million different ideas;” he said. “… That’s where the Carillon device popped out: make it very minimally invasive, make it very small so it fits in a 10 Fr catheter, make it recapturable so if we don’t see the efficacy or the safety we like, we can recapture the device and it’s no harm, no foul to the patient, and make it extremely easy to use so you don’t have the top 1% of users able to successfully use it, you have 99% of the users successfully using it.”

One early challenge was how to anchor the implant in the coronary sinus — which is just outside the heart next to the mitral valve annulus — but to allow for recapturing, which you can’t do with stents or tethers.

“We looked at oversizing the device for the vein [and] found the veins are very compliant, and therefore we could use a pretty significant amount of radial force to hold it in place and not have to use sutures or barbs or anything more invasive or more creative to get the device to hold in place while we cinch tension,” Wypych said.

That method of anchoring and cinching — and retrieval, if needed — called for a delivery catheter that could not only get to the target site, but withstand the compression force needed to lock the anchor for placement or to recapture the device.

“The end of the catheter opens up large enough to recapture the device and gobble it back up to get it back in the system without perforating the vein or anything else,” he said.

Cardiac Dimensions outsourced the manufacturing of the delivery catheter, but it makes the implants in-house. Building that nitinol expertise took “a lot of trial-and-error” and work with metallurgists and nitinol suppliers all the way back to the raw ingots from which the nitinol wire was extruded.

“We needed to see, for example, how how much in the way of carbon inclusions in the wire could be allowed without degrading the strength of the wire, [what] the best way was to shape the wire and how much can you bend it in one set versus two sets or three sets? Sometimes with nitinol, you can’t just bend it in a circle. You’ve got to bend it in half a circle, and then three-quarters of a circle and then one circle. Instead of a single process, you have three.”

“We’ve had a pretty stable team within R&D and manufacturing where they’re at 10, 15, 20 years with us,” he later continued. “So we have a lot of in-house, nitinol experience, and they know the device better than anybody in the world. I would put a lot of the people here up against just about anybody in the world as far as nitinol experience and knowledge.”

A key design engineering challenge was material selection for the crimp tubes that hold the nitinol wire anchors to the nitinol wire bridge. Early attempts to use stainless steel for those tubes resulted in problems with wear.

“Part of it might have been the way that we were crimping and putting the wires in, and part of it might have been the different types of metal,” Wypych said. “Stainless is very rigid and hard, and nitinol tends to be a little bit softer.”

Seeing that wear and considering the potential addition of another component to the device or another material like tungsten that could cause biocompatibility issues, the team solved the wear problems by using titanium (one of the metals used to make nitinol) for the crimp tubes.

“Titanium was a complimentary metal and strong enough to hold the device together and crimp but didn’t cause us other problems along the way,” Wypych said. “… It solved the wear problems and everything else. It was a good solution all around.”

The science and art of Carillon implant manufacturing

Much of the in-house manufacturing of the Cardiac Dimensions nitinol implant is manual, with Wypych describing it as both art and science.

“The science is the actual metal,” he said. “The art is forming it.”

Cardiac dimensions shape sets the nitinol wire by bending it over a tool and then submerging it in a 500°C molten salt bath. That first step takes “a few minutes … depending on the length of the wire and the bend in the wire and things like that.”

With the shape set, the device is dipped in acid to eliminate microcracks in the nitinol wire arches and bends.

“If you don’t eliminate those cracks, that’s an ideal place for a fatigue fracture to form in the device,” he said. “… Given it’s a Class III permanent heart implant, it’s pretty important that everything is absolutely top notch and cutting edge and done exactly right, because it doesn’t take more than one mistake to have a big, huge problem with this type of device.”

What’s next for Cardiac Dimensions

Cardiac Dimensions raised $53 million in March, which Wypych said should be the last funding round the company will need. He hopes to fully enroll the Empower pivotal trial in late 2026 or early 2027 and submit an application for FDA premarket approval (PMA) around the end of 2027.

The Empower trial is the company’s top priority, he said, followed by commercial sales growth in Europe, where the system has reimbursement.

Cardiac Dimensions has a strategic investor that Wypych declined to name, only saying it’s a “multibillion-dollar market cap, well-known, interventional-based type of company.” But Cardiac Dimensions could also go public given the proof of commercial viability from Europe, or grow on its own after U.S. approval.

“My goal and my job is to provide options for our investors,” he said. “We don’t fund or run the company toward an IPO or a possible sale of the company or other acquisitions within the space that are complementary or use nitinol, for example, as a device or a method to solve for a problem. My job is to make sure that we do everything right as a company, maximizing Carillon and getting Carillon as established as possible. … The focus is to do what’s right for the company and the device and the patient, and the doors will open from there.”