One moving part. That's one of the advantages that WorldHeart (Salt Lake City) is banking on as it launches into a study of its fourth-generation Levacor VAD (ventricular assist device) for heart failure. The Levacor VAD Bridge-to-Transplant Study has just been approved by the Institutional Review Board (IRB) at Integris Baptist Medical Center (Oklahoma City) and a study of the company's only product is underway.
Early VADs have had high complication rates including stroke and infection. "Most manufacturers have been working to reduce complication risks and device size," Alex Martin, WorldHeart president/CEO, told Medical Device Daily. "That's what we've worked on over the past several years. The advantage of having a magnetically levitated device is that there's only one moving part. It reduces friction or wear and it improves durability."
The Levacor VAD is a rotary blood pump intended for adults who suffer from late-stage heart failure and are awaiting a transplant. Early generation rotary pumps had mechanical or blood-lubricated bearings. But the Levacor VAD is a compact, centrifugal pump with an impeller that is magnetically levitated, which eliminates wear mechanisms during operation of the pump. It also permits greater clearances and more optimized blood flow around the impeller while eliminating dependence on the patient's blood for suspension, according to the company.
The 160-patient study will start at 10 centers and later it will expand to 25-30 centers once data is submitted to the FDA on the first round of patients. The primary endpoint is survival to six months or successful transplant.
Douglas Horstmansh, MD, is the program director of the Integris Baptist Heart Failure Institute and the center's principal investigator for the Levacor trial. James Long, MD, is the study's co-investigator and the director of Integris Advanced Cardiac Care, which is the only ventricular assist device program in Oklahoma.
This trial is many years in coming since WorldHeart received the first ever FDA approval of a device like this via its predecessor company Novacor Medical. In 1984, the Novacor LVAS (left ventricular assist device) was used in the world's first successful bridge-to-transplant operation. It received FDA approval in 1994. Sales of that device were discontinued last year with the advent of improved technology.
At the heart of the newer technology, Levacor VAD, is magnetic levitation, which uses passive, permanent magnet support in all of these axes but one. The combination of passive and active magnetic control design, with only a single axis of active control, yields a simpler system that's reliable and efficient.
Full magnetic levitation eliminates dependence on blood properties for rotor suspension, as well as wear within the pump.
In addition to that technological advance, Martin said WorldHeart has made the device more comfortable with a power device that's half the size of the earlier model. It's about the size of a hockey puck and is implanted in the rib cage. The power unit and controller worn by the patient totals about two pounds.
The current generation Levacor VAD has also been reconfigured to allow for easier implantation and removal. The older generation device called for complete removal if any parts needed to be replaced. But the new version is modularized so that various parts can be disconnected without replacing the entire assembly.
If all goes well with the current study, data will be ready in 2011. WorldHeart will then endeavor to seek approval to use the device as a permanent destination therapy in addition to the current bridge-to-transplant indication.
Last year WorldHeart suffered a string of financial challenges (MDD, Jan. 12, 2009), but the future looks brighter now.
"We've recapitalized to the tune of $30 million," Martin said, adding that the company has also retained a strategic partner in Abiomed (Danvers, Massachusetts) (MDD, Aug. 5, 2008).
Martin said WorldHeart has enough cash to last "several more months" and then it will seek to raise more funds. "It was always anticipated that we'll need a couple more raises."
Lynn Yoffee, 770-361-4789;