While most of the biggest headlines in cardiovascular news last year, and so far this year, have been focused on the rhythm management space of cardiovascular devices – pacemakers and implantable cardioverter defibrillators (ICDs) and the problems with those devices – the cardio sector making the most clinical noise probably has been that of ventricular assist devices (VADs). Pushing forward are several companies making these devices, with their recent developments all packaged as some sort of “first,” if only of the intra-company type.

While still in its earliest stages, this space tends to focus on the most urgent need: end-stage heart failure patients who are in the long line of those seeking heart transplants. But the variety of devices being developed will eventually be used to address a wide range of patient conditions and patient types, and extend backwards for treating the heart failure continuum at earlier stages of heart disease.

A developmental company attempting to position itself in the sector to offer a variety of VADs rather than depending on one tech offering is WorldHeart (San Diego). The company last month reported the first human implant, earlier this month, of its VAD using a rotary platform rather than a pulsatile (pulsing or beating) platform, at St. Luke’s Hospital (Thessaloniki, Greece). The procedure marked the start of the company’s first-in-man feasibility study of this advanced-generation device. (And an example, perhaps, of Europe’s openness to many of the most advanced trials in med-tech).

Going rotary

The rotary type of VAD was added to the WorldHeart portfolio last August with its acquisition of MedQuest Products (Salt Lake City), developer of the HeartQuestVAD. The acquisition expanded the company’s breadth of systems since its primary products, the Novacor LVAS and HeartSaver VAD systems, are pulsatile, the slight beating activity the result of a pump system revealing the activity of bearings.

When it purchased MedQuest, WorldHeart president and CEO Jal Jassawalla noted the company’s stretch to this platform, saying, “Our industry needs both pulsatile and rotary pumps to treat the full spectrum of clinical needs of end- and late-stage heart failure patients.”

The surgical team members that implanted the device were trained at WorldHeart’s Salt Lake City facility in February. Then the initial implantation was into a 67-year-old man with advanced congestive heart failure, in conjunction with an operation that included heart valve repair as well as a coronary artery bypass graft.

In late April, WorldHeart reported that he first human implanted with its advanced rotary VAD continues to do well after six weeks of support on the device.

WorldHeart says that this VAD device is the only bearingless, fully magnetically levitated implantable centrifugal rotary pump in clinical trials. Its continuous-flow pump uses magnetic levitation to fully suspend a spinning rotor, its only moving part, inside a compact housing. The pump’s levitation technology employs a combination of passive magnetic suspension and single-axis active control. In this description, the term “bearingless” is key, specifically in terms of the device’s compatibility with blood and the ability to avoid thrombosis and clotting that may be caused by the contact between blood and mechanical bearings.

Bearingless crucial

“This is absolutely crucial,” Jassawalla told Cardiovascular Device Update. “We’re not just talking about standard biocompatibility. The system has been designed to be the best ever for hemocompatibility, for its flow characteristics, with magnetic suspension – a bearing-free unobstructed blood pathway across the widest range of operation possible.”

The unobstructed flow of blood around a magnetically levitated rotor, “translates, we hope,” Jassawalla said, “to extreme gentleness to red cells and white cells.” This, in turn, will result in the ability to use “anti-platelet therapy only and minimal anticoagulation therapy” following implantation, he said.

Dr. Antonis Pitsis, cardiac surgeon and director of the Thessaloniki Heart Institute at St. Luke’s Hospital, and principal clinical investigator of the feasibility trial, said, “The WorldHeart Rotary VAD has performed well, meeting all of our expectations to date. The patient has been mobile for the last four weeks, is now exercising regularly by walking indoors and outdoors and climbing stairs, and is enjoying interacting with his family. He has also been outside the hospital to have meals with his family at a local restaurant.”

Gathering information on safety

The first-in-man trial will enroll five patients, with a focus on demonstrating safety. “The idea,” Jassawalla said, “is to get critical information on how [the device] interacts with physiology controls systems, blood compatibility and the blood flow pathway.” The feasibility study then will be followed by other European trials, sometime by the end of 2006 or early 2007, to support application for CE marking.

The first-in-man trial is focused on use of the rotary device as bridge to transplant, with the patient being very high risk, but the study researchers also are hoping for some degree of heart function recovery in this patient.

Dr. James Long, cardiac surgeon and director of the Utah Artificial Heart Program – and one of the physicians assisting in the first implantation – called the focus on recovery “extremely important” in terms of the possible opportunity to take very sick Class III/IV patients back to Class II – a functional state.

“That would be a significant plus for the field, an advancement of an area we know will be extremely promising,” he told CDU.

”Future trials in the U.S., Jassawalla indicated, will likely focus on using the rotary VAD system to support patients “for multiple years.”

“What we brought to the party,” he said – the party being the VAD sector – “is a relatively mature quality system, an infrastructure, a small team in Europe and a robust qualification unit. It was very much taking what was already developed [by HeartQuest] to the clinical stage and adding our experience and final testing.” He acknowledged that development of the rotary VAD for longer term support “will take a few years” but that ultimately the device could address a worldwide population of from 50,000 to 100,000 and be a financial opportunity of from $3.5 billion to $7 billion.

A clear positive, he noted, is current reimbursement in place for bridge-to-transplant use of the device and support of clinical trials. An additional need, he said, is “to get the cardiologist to support the field. It’s happening at a slower rate . . . but more and more of our surgical colleagues are cooperating.”

HeartWare in the hunt

Also in March a 48-year-old male patient suffering New York Heart Association Class IV heart failure became the first recipient of the HeartWare ventricular assist device (HVAD) from HeartWare (Sydney, Australia). The implant was conducted at the Vienna General Hospital, and the surgical team was led by Georg Wieselthaler, MD, clinical director of Mechanical Circulatory Support at the University of Vienna. HeartWare said the implant marked the start of its clinical study to support CE-marking.

The trial goal is to enroll 20 patients suffering advanced heart failure. The implants are to be conducted at the Vienna General Hospital, the Royal Perth Hospital (Australia), the Hannover Medical Centre (Germany) and Harefield Hospital (UK). HeartWare said it expects to complete enrollment by the end of 2006.

Wieselthaler said: “Our first clinical experience of the HVAD was extremely positive. The procedure was completed quickly and without incident, and our patient’s early post-operative recovery has been excellent.”

The device features a small size and configuration that facilitated fast implant, and the procedure took just 85 minutes, “significantly less than the time typically required to implant other devices,” according to HeartWare. “The patient was moved from the operating theatre into the post-operative recovery area, conscious and off ventilation within seven hours. He continues to recover quickly and has met with his family. We are very pleased with these results.”

An Aussie competitor

HeartWare has a feisty Australian competitor in this sector, VentraCor (Sydney, Australia), with the two in heated competition to win the country’s banner for being the first to commercialize an Aussie VAD product. The company is developing the VentrAssist Left Ventricular Assist System and reported the first implant of the device in the U.S. last July.

The VentrAssist is a centrifugal blood pump designed to provide permanent left heart support. Powered by a set of wearable batteries, the device uses a hydrodynamically suspended rotor and has no valves, seals, shafts or bearings.

Ventracor has released no clinical updates recently but in early Aprilit did announce a variety of management appointments that it said were intended to expand its global reach and prepare for the anticipated market launch of the VentrAssist in Europe.

Success in the East

A regional "first" in the space was posted by SynCardia Systems (Tucson, Arizona), last month. It reported that a cardiac surgery team at the Pauley Heart Center of Virginia Commonwealth University (VCU; Richmond, Virginia) performed the first artificial heart implant on the East Coast using its CardioWest temporary total artificial heart.

SynCardia is really a major annex to the space since it can claim its assist product as "a total artificial heart," not just a VAD. Its CardioWest heart support system works to replace the entire heart. Calling it a TAH-t system - for Temporary Total Artificial Heart - the heart's "temporary" tag reveals its main initial purpose, for heart support until a transplant can be found. The company won the FDA approval for use in bridge to transplant in late 2004.

The patient, a man in his late 50s from Virginia, had been critically ill suffering from end-stage heart failure and thus hopes to soon receive a transplant.

The TAH-t is a modern version of the Jarvik-7 artificial heart, developed by Robert Jarvik, MD, in the 1980s. Since Jarvik's initial efforts, survival rates have increased dramatically because of major therapeutic advancements to reduce the occurrence of strokes and life threatening bleeding. The TAH-t is the only total artificial heart approved by the FDA, Health Canada and the European Union.

Sheldon Retchin, MD, CEO of the VCU Health System and vice president for Health Sciences, said, "As a national leader in treating heart failure and in heart transplantation, we are excited to be among the first to introduce this new technology to the nation."