By OMAR FORD
CD&D Staff Writer
The broad range and wide variety of new cardiovascular products under development can amaze even those of us who report on the sector as a normal matter of course. Let's look at three such devices that have come to our attention over the past month.
Terumo Heart (Ann Arbor, Michigan) reported as June was coming to a close that it was one step closer in the quest to release its DuraHeart Left Ventricular Assist System on the market, after the Institutional Review Board of the University of Michigan (also Ann Arbor) voted to move forward with the device's pivotal trial for a bridge-to-transplant indication.
The DuraHeart LVAS Pivotal Trial, for which FDA gave its approval in March, is a multi-center, prospective, non-randomized study of 140 patients. It will include up to 40 centers and will last for 2-1/2 years, according to the company.
The DuraHeart LVAS is a third-generation circulatory support device intended to provide cardiac support for patients who are at risk of death due to end-stage left ventricular failure. An LVAS assists the left side of the heart in pumping blood throughout the body.
"Development of the device started in the mid-1990s," Marketing Manager Mark White told Cardiovascular Devices & Drugs. "It works off the principle of centripetal force. The pump itself is shaped like a hockey puck. Fluid enters the center of the pump and flows out in a radial formation."
White said it is the only CE-marked implantable LVAS combining a centrifugal pump with magnetic levitation of the impeller, providing exceptional reliability and minimizing the potential for blood damage and thrombus.
"That's what makes the device unique the magnetic levitation of the impeller this allows the piece of the pump that does the work not to touch the cell. Typically when you use a pump to move blood there are a lot of issues to deal with. You just cannot have a device that ruptures cells."
Here's how it works.
The DuraHeart helps the left ventricle pump oxygenated blood throughout the body. Since a failing heart cannot pump enough blood to the body, the DuraHeart takes over the additional work.
With an implanted DuraHeart LVAS, blood flows from the left ventricle along two paths. Blood flows along its normal route, from the left ventricle directly to the body. At the same time, the DuraHeart Pump assists the heart by pushing blood from the bottom of the left ventricle to the aorta.
DuraHeart consists of seven main parts.
• The primary component is the pump, which is implanted in the abdomen and is about the diameter of a hockey puck.
• The Inflow conduit is a small titanium tube which connects the pump to the heart.
• An outflow conduit comprised of Vaskuteck Gelweave is sewn to the aorta.
• A small controller serves as the brain of DuraHeart and is worn or carried by the patient. It connects to the pump cable and is powered by batteries.
• The batteries provide energy for the pump for a little more than three hours.
• A battery charger provides power to the device and charges it while it remains inactive.
• Finally, there is the hospital console, which allows doctors and hospital staff to monitor and have a degree of control over the pump.
The device is implanted in a preperitoneal pocket in the left upper abdomen. An apical cuff is sutured to the apical hole in the left ventricular apex with 12 mattress sutures of 3-0 Prolene pledgeted with Dacron felt.
In the first six mattress sutures, the needle is exited from the apical hole after a full-thickness bite of myocardium, and in six additional mattress sutures, the needle is exited from the epicardial edge of the apical hole. Next, a double purse-string suture with 3-0 Prolene is placed on the Dacron pledgets around the apical hole.
After the inflow conduit has been connected to the inlet port of the blood pump, the inflow conduit is secured to the apical cuff. The graft portion of the outflow conduit, which was connected to the blood pump beforehand, is sewn end-to-side to the ascending aorta with a 4-0 Prolene suture. Gentle suture connection of the apical cuff to the left ventricular apex and optimal alignment of the inflow conduit, which is bent by 60 , are crucial in the surgical procedure.
Ultimately Terumo Heart is looking toward getting a designation of permanent use for the device. To accomplish this designation the company plans to have another pivotal trial to be started about a year or so into the current bridge-to-transplant trial.
"We're going to have over 200 patients in (the permanent trial)," White said.
As to when the device might be available on the market with "permanent" labeling, he added that "designation is a little bit harder to peg" than the bridge-to-transplant indication.
Terumo Heart is a business unit of Terumo Medical (Somerset, New Jersey) and develops cardiovascular devices.
CryoCath reports Arctic Front results
CryoCath Technologies (Montreal) reported in the latter part of July that an Arctic Front is one step closer to coming on the U.S. horizon. No, not the typical arctic front with extreme temperatures and ice, but rather a cryoablation balloon catheter which allows for physicians to isolate all four pulmonary veins for paroxysmal atrial fibrillation (PAF).
CryoCath designed the device and released results from three European study centers using the Arctic Front in the July 22 edition of the Journal of the American College of Cardiology (JACC).
The peer-reviewed article titled, "Circumferential Pulmonary Vein Isolation with the Cryoballoon Technique," discusses the three-center trial in which 74% of the 293 paroxysmal AFib patients enrolled were AFib free and off anti-arrhythmic drugs (AADs) after only one procedure with Arctic Front upon a median follow-up time of 12 months.
"It is quite standard in the medical profession, right now for patients to go through [numerous] AFib procedures before the procedure is successful," JeanPierre Desmarais, chief scientific officer of CryoCath, told CD&D. "The Artific Frony is boasting no repeat procedures."
Of the 346 patients enrolled in the study, 293 were predominantly paroxysmal AFib sufferers, with a small group of persistent AFib patients numbering 53.
Of the 1,403 pulmonary veins treated, 1,360 (or 97%) were ablated with Arctic Front or Arctic Front in combination with CryoCath's Freezor MAX catheter demonstrating the broad applicability of Arctic Front cryoablation.
The median number of applications per vein was 2.8 and the median total procedure time was 170 minutes, which CryoCath said confirms the ease of use and speed with which physicians are able to use Arctic Front compared with other ablation technologies.
The safety data reported in the article confirms the strong safety profile Arctic Front has demonstrated to date. There were no observed reports of atrio esophageal fistula, stroke, death or peri-interventional complications. Phrenic nerve palsies were reported in 7.5% of patients treated; in some instances these were resolved prior to the end of the procedure or hospital discharge and all cases were resolved by the 12-month follow up visit.
Here's how the device works.
A balloon is inserted via a catheter through a vein, usually in the groin. The balloon is then frozen to around -60 C, using compressed nitrous oxide gas. The gas can achieve a temperature as low as -92 C.
The device causes cells to malfunction so that they can no longer hinder electrical impulses that control the heart's rhythm.
"Our biggest differing factor is the use of cryo," Jeff Silver, Cryocath market manager, told MDD. "Other techniques use ultrasound or microwaveable energy ... so heat is involved."
He emphasized the difference by describing the radical changes in temperature of a sponge.
"If you use heat, then you burn the sponge," Silver said. "You may get it in the shape of a crater or it might shrink. But, if you use a cooling technique, the structure remains intact. Currently there is no gold standard to treating PAF, but we believe [Artic Fox] will become that standard."
Pending FDA approval, the company is looking to launch the product in the U.S. in late 2009.
So far more than 2,600 patients have been treated with the device in more than 45 centers across Europe.
Welch Allyn launches new BP cuff
Navigating the waters of having a safe blood pressure cuff is problematic for most medical practioners. The problems stem from the same cuff being used on multiple patients, which leads to the spread of disease; different connection points for blood pressure cuffs; and multiple cuffs being used in each department, which have a hand in jacking up supply costs.
Studies show that more than 99,000 deaths occur each year in the U.S. that are a result from infections garnered from the hospital.
The major way to eliminate this problem: create a cuff that would stay with the patient from admission to omission, thus eliminating the spread of harmful bacteria or general confusion clinicians might have over which cuff to use, according to Lisa Riggs, a clinical nurse specialist at St. Luke's Hospital (Chesterfield, Missouri).
Welch Allyn (Skaneateles Falls, New York) introduced such a solution through its FlexiPort blood pressure cuffs to its U.S. market what it calls the first cuffs designed to work with devices in any patient care area. The nearly century-old-company held a press conference to discuss the device and how it could revolutionize the way hospitals use blood pressure cuffs in the future.
"The real problem is that there are compatibility issues and practioners are forced to make it work," said Sean Karla, global category manager of Welch Allen, during a press briefing touting the devices. What we've developed is a unique fitting that will go under the device tube ... so that the cuff can stay with the patient throughout their [stay in the hospital]."
FlexiPort cuffs connect to virtually any manual or electronic blood pressure device, so patients can be freely moved from room to room, floor to floor and department to department without forcing clinicians to find new cuffs for each different device.
"FlexiPort cuffs make finding, ordering and using cuffs as simple as it should be," Karla said. "There is currently incredible variability with all the different tube, connector, and cuff styles out there, which causes a tremendous amount of caregiver confusion and leads to excess inventory. By providing a single common connection point between the device and cuff, FlexiPort cuffs can eliminate much of that variability."
Facility standardization with FlexiPort blood pressure cuffs can reduce the typical hospital's cuff part numbers by up to 60%. The reduced part numbers mean a reduction in inventory levels so blood pressure cuffs are easier to find for clinicians and easier to order for purchasing managers.
"If hospitals were to simply open new cuffs every time they used one on a parient, then they would significantly run up costs," Karla said during the conference.
The FlexiPort connection is built into every new FlexiPort cuff. When a facility standardizes with FlexiPort cuffs, it attaches FlexiPort fittings to every device tube it has in-house. The fittings, which vaguely resemble extenstion cord endings, can then snap directly into the FlexiPort connection to eliminate traditional tubes and connectors from their cuffs, while making every cuff work like a one- or a two-tube cuff.
"Clinicians face enough challenges when they're at work, so we designed a cuff option that actually makes caregivers' lives easier," Karla said. "FlexiPort removes one of the many problems caregivers face on a daily basis so they can focus on what matters most their patients."
FlexiPort also helps cut down the risk of spreading infectious diseases through cuffs by enabling a single cuff to be used on multiple devices. Assigning a FlexiPort cuff to a patient when he or she is admitted to the hospital allows the patient to move freely throughout the facility without having the cuff changed every time the patient is hooked up to a new device, which reduces waste as well as exposure to other hospital-borne illness, the company said.
The FlexiPort feature was available for both reusable and disposable cuffs and approved for sale throughout Europe and the Middle East in November 2007. The feature is now approved for sale and available in the U.S.