FDA Advisors Recommend Comprehensive, Long-Term Study of Leadless Pacemakers

Concerned with the unknown long-term risks of leadless cardiac pacemakers, the FDA tasked its Circulatory System Devices Panel yesterday to make recommendations for how manufacturers of these pioneering devices should plan to study them going forward.

Both the Micra (Medtronic) and Nanostim (St. Jude Medical) leadless pacemakers have excited the field with small profiles and direct implantation, but they have also left uncertainty related to tissue damage and limited battery lives. For example, Micra exceeded its 6-month safety performance goal compared with historical controls in a presentation at the American Heart Association 2015 Scientific Sessions, but was associated with a 1.6% cardiac perforation rate deemed “somewhat high” by trial discussant Sanjay Dixit, MD, of the University of Pennsylvania (Philadelphia, PA).

This technology is “a major step forward… but with it comes challenges that we’re not sure about,” FDA panel member E. Magnus Ohman, MD, of Duke University Medical Center (Durham, NC), told TCTMD.

Both Micra and Nanostim are approved for use in Europe, and are awaiting FDA approval. Boston Scientific and Biotronik are also developing similar devices.

Follow Them Until the Batteries Die

In its preparatory materials, the FDA advocated for post-approval studies of leadless pacemakers to follow patients out to at least 5 years to bridge the knowledge gap in long-term performance.

“The current paradigm does not capture data when the lead reaches its end-of-life, but is expected to capture intermediate and long-term failures that may occur around or after 5 years,” according to the FDA’s executive summary. “While this paradigm is applicable and beneficial to cardiac leads, FDA envisions the [post-approval study] for the leadless pacemaker devices to be used to gain understanding of [end-of-life] issues, extraction risks/success rates, and risks of co-implantation.”

Ohman said the committee’s discussion yesterday did not specify an exact number of years for which a post-approval study should be planned, but said both patients who receive new devices and those who already have these pacemakers should be followed beyond the point of battery expiration—typically 6-12 years.

Additional issues studies will be tasked to solve include how and when these devices can be removed, what is the clinical significance of increased cardiac perforations, and which patients, if any, should not be considered for leadless pacemaker implantation.

“Here is a real opportunity to collectively learn,” said Ohman, referring not only to physicians but also industry partners.

In addition, the panel also focused on proper training procedures for operators—should manufacturers train physicians directly or teach a cohort of physicians to train the rest? Ohman said each manufacturer attending the meeting presented slightly different, yet comprehensive and “impressive,” plans.

Overall, the tone of the day was generally positive and productive, according to Ohman, who was satisfied with how the meeting unfolded. “Panels tend to have a lot of drama to them, but this was one of the more benign ones,” he said.

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Source: 
FDA executive summary memorandum: general issues: leadless pacemaker devices. http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/MedicalDevices/MedicalDevicesAdvisoryCommittee/CirculatorySystemDevicesPanel/UCM485093.pdf.

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