An FDA advisory panel yesterday recommended deep, long-term surveillance of the leadless pacemakers being developed by the 4 leading companies in the cardiac rhythm management space.
Medtronic (NYSE:MDT), St. Jude Medical (NYSE:STJ), Boston Scientific (NYSE:BSX) and Biotronik are all developing versions of a leadless pacemaker designed to be implanted directly into the heart’s right ventricle, eschewing the need for the leads used in conventional pacers.
Both Medtronic and St. Jude are on the market in Europe with their leadless pacers; St. Jude acquired Nanstim and its device back in October 2013, shortly after EU approval, and Medtronic’s Micra device won CE Mark approval there last April.
Boston Scientific (NYSE:BSX), which put its S-ICD subcutaneous-lead pacemaker on the U.S. market in September 2012, is also working on a truly leadless pacing implant designed to work on its own or in conjunction with the S-ICD device. Germany’s Biotronik also has a leadless device in development. The FDA has yet to approve a leadless pacemaker for the U.S. market.
Although they noted the potentially groundbreaking nature of the leadless technology, panelists on the FDA’s Circulatory System Devices committee were particularly concerned yesterday about reports of cardiac tissue perforation and whether the leadless pacemakers can be explanted after their batteries die.
“Cardiac perforation is a big deal to me, because it is potentially lethal,” Dr. Jeffrey Borer said, according to the Minneapolis Star-Tribune. “It looks as if there are about 50% more perforations with the leadless pacemaker.”
“I think this is a very disruptive technology and it is at the beginning of a long career that we can’t predict,” Dr. David Slotwiner added, the newspaper reported.
Dr. Ken Stein, chief medical officer for cardiac rhythm management at Boston Scientific, told MassDevice.com this morning that the panelists’ concerns are right on target.
“They really did a very nice job of discussing both the long-range, longer-term promises of this kind of technology but also how you balance that against some of the safety issues that have been evident in the 1st-generation devices,” Stein told us.
As for the perforation issue, Boston Scientific took it as a fundamental design principle that its leadless device must have complication rates that are comparable to those of traditional intravenous pacemakers, he said.
“We designed the device with a fixation mechanism that uses nitinol metallic talons at the end to grab onto the heart tissue, rather than a screw-based mechanism,” Stein said. “That was a very deliberate decision, to minimize the risk of perforation.”
Stein said the battery is also important, noting that Boston assumes that the 10- or 12-year battery life on its device likely means that the pacemaker will become encapsulated by heart tissue. Boston’s strategy is to deactivate the initial device and implant a new device alongside it, he said.
“One of the things we really went to great pains to talk about in our [panel] presentation is that patients and doctors think about that issue at the time of initial device implantation,” Stein said. “Folks need to discuss that and not push it off.”
On the subject of long-term post-approval monitoring, Stein said the FDA’s total product life cycle approach “makes a huge amount of sense overall and in particular for this kind of device.”
“We agree completely that this [kind of device] requires longer trials and longer duration of follow-up than traditional pacemakers,” he told us, noting that Boston Scientific plans to present pre-clinical data at the April meeting of the American College of Cardiology in Chicago.
Dr. Mark Carlson, global clinical affairs vice president chief medical officer at St. Jude Medical, said the Nanostim device offers the least invasive and smallest delivery system of any leadless pacemaker.
“Leadless pacing technology is a critical advancement for patients in need of a single-chamber ventricular pacemaker, and we are optimistic that today’s discussion is an important step toward offering patients leadless pacing technology in the U.S.,” Carlson said. “We’re highly appreciative of the FDA’s proactive effort to gain more insight and understanding around leadless pacing technology, and for the opportunity to participate in the dialogue that will help ensure that leadless technology is adopted with patient safety in mind and with successful clinical outcomes as a top priority.”
“Medtronic commends the FDA for bringing together an expert panel to look in-depth at the latest clinical data for these novel medical technologies, which have the potential to transform cardiac care,” Dr. David Steinhaus, medical director for Medtronic’s cardiac rhythm & heart failure division, said in prepared remarks. “Results from our large-scale, multi-center clinical trial of transcatheter pacing patients – spanning 19 countries and 5 continents – demonstrate the safety and effectiveness profile of the Micra TPS in a broad, real-world patient population. We are committed to ensuring patient safety and device effectiveness over the long term with ongoing monitoring of the Micra TPS using a comprehensive post-approval study, a proprietary post-market surveillance program and a rigorous implanter training program, all of which are fully aligned with today’s panel discussions.”