Medtronic (Minneapolis) in mid-June received FDA approval of its Attain StarFix OTW (over-the-wire) lead. The company said it's the first active fixation left-heart lead for cardiac resynchronization therapy (CRT) and that the lead has demonstrated a 0% chronic (meaning more than one day post-implant) dislodgement rate.
Overall, including the acute dislodgements at one day post-implant, the lead has a low 0.7% dislodgement rate. These dislodgement rates are supported by one of the industry's largest and longest-running left-heart lead clinical studies, involving 385 implants followed for up to four years, according to Medtronic.
Traditional passive fixation left-heart leads, where there is no active mechanism to fix the lead in place, show average dislodgement rates of 2% to 8% based on several published clinical studies.
David Jones, a product manager for Medtronic, told Cardiovascular Devices & Drugs that the company identified a number of what he called "key failure modes" associated with traditional left-heart leads and decided the dislodgement rate was the first problem it wanted to tackle. The Attain StarFix lead is Medtronic's solution to that problem.
"Since there is no real active mechanism keeping the leads in place they can become dislodged chronically, post-operatively," Jones said.
Dislodgements have serious impacts for both the physician and the patient, Jones said, including longer operations and even the possibility of another surgery to replace the lead. "Every anatomy is different," Jones said. "There are small veins and huge hearts and large veins. With traditional leads implanters would just kind of wedge them down wherever they fit and hope they stayed put."
The Attain StarFix lead provides physicians with a new solution for achieving successful placement and stability of the left-heart lead in heart failure patients receiving a CRT device, Medtronic said. A patient's vein size or configuration can make it difficult to secure a left-heart lead in the optimal location. Therefore, stable fixation of the left-heart lead is critical to a successful CRT implantation. Dislodgement of the left-heart lead may require additional surgeries, which could increase the risk of infection, the company noted.
The Medtronic Attain StarFix steroid-eluting unipolar lead has a 5 Fr diameter and is available in 78 cm, 88 cm and 103 cm lengths. The Attain StarFix's design includes three soft, polyurethane lobes near the lead tip that, when expanded, enable stable lead placement in the target location. The soft, pliable lobes, which can be deployed to up to a 24 Fr diameter about one-quarter inch can be relaxed multiple times to allow for acute repositioning of the lead as necessary. Once deployed, the electrode is securely fixed in place, reducing the potential for dislodgement.
The Attain StarFix lead, which will be commercially available nationwide later this summer, is designed to complement the Attain Model 4193 and Model 4194 over-the-wire leads. The Attain catheters along with the Attain Hybrid guide wires are used to deliver leads for precise placement in a wide variety of coronary anatomies.
It can be used with any Medtronic CRT-defibrillator (CRT-D), including those within the company's new Vision 3D portfolio. The Vision 3D wireless ICD and CRT-D portfolio offers "unparalleled depth and breadth of unique clinical options that are built on our industry leading pacing and ICD exclusives," according to Medtronic.
"With the Attain StarFix's unique active fixation mechanism, physicians have a left-heart lead that can be safely placed in a wide variety of veins regardless of location and diameter," said Stuart Adler, MD, clinical cardiac electrophysiologist at St. Paul Heart Clinic (St. Paul, Minnesota). "This lead helps to ensure successful placement of CRT therapy in even the most difficult cases, which ultimately results in better management of my patients' cardiac disease."
Jones said Medtronic is working toward developing left-heart leads that would address other key obstacles, such as how to sub-select the right vein deep inside the coronary anatomy, and how to ensure that both the catheter and the lead can track very well into place. He said Medtronic would continue to introduce products over the next several years based on what the company has learned through its market research.
"Providing physicians the technology and tools they need to better treat their patients is at the core of Medtronic's mission to alleviate pain, restore health and extend life," said Pat Mackin, president of the company's Cardiac Rhythm Disease Management business. "This product launch, backed with the support of strong clinical data, is part of our overall commitment and long-term investment in left-heart leads and delivery systems."
Chronic heart failure occurs when the heart is unable to pump enough blood to sustain adequate circulation in the body's tissues; it affects more than 5 million Americans and 22 million people worldwide. Roughly one-third of these patients have dysynchronous beating of the left and right ventricles (lower chambers of the heart) that interferes with the heart's ability to pump adequate blood supply throughout the body.