With more self-contained models potentially on their way to patients, the FDA is taking steps to remind healthcare providers of certain risks posed by leadless pacemakers, including the possibility of puncturing the heart wall during implantation.
While the overall chance of a leadless system causing a cardiac perforation is rare and appears similar to that of traditional pacemakers the agency said that when these cases do happen, the consequences tend to be more severe. With traditional pacemakers, the device is placed in a pocket under the collarbone and wired to the heart using small electrodes, while leadless pacemakers are miniaturized implants that are housed within the heart itself
Regardless of the type of device, perforations happen in about 1% of cases and typically during the implantation procedure, the FDA said. However, these punctures can also occur in the days and even months that follow, causing leakages that can pool fluid around the outside of the heart and strain the muscle’s ability to function. Draining those fluids with a needle or emergency surgery can be a life-saving procedure.
In 2016, the FDA approved the first leadless pacemaker, Medtronic’s transcatheter Micra implant for patients with atrial fibrillation and other irregular heartbeats. A newer version, the Micra AV, was approved in January 2020.
But the market could expand in the near future. The agency is reviewing Abbott’s retrievable Aveir system for approval, which recently cleared a global clinical study. Both are placed inside the base of the right ventricle and rely on small tines to anchor themselves to the heart muscle wall.
In its letter to healthcare providers, the FDA said that premarket studies and real-world data from Micra implants suggested that “major complications related to cardiac perforation appeared to be more severe for patients who received a leadless pacing system compared to patients who received a transvenous pacemaker.”
The agency said it received over 300 medical device safety reports for the Micra describing a perforation, with over 90 detailing a perforation that resulted in death. The FDA’s letter urged physicians to inform the agency and the manufacturer of any cases and reminded surgeons to have emergency equipment on hand during an implantation procedure.
In a company statement, Medtronic said it supports “the important reminders provided in the letter” as well as studies to evaluate the safety and efficacy of its devices. The medtech giant noted that the company’s clinical research has included more than 17,000 patients who received a Micra device, with implantation success rates above 99%, and that the frequency of major complications have remained stable over time.
Earlier this year, Medtronic presented real-world data at the annual congress of the European Society of Cardiology showing that its leadless pacemakers led to fewer complications compared to traditional pacing systems over a period of two years.
Medicare claims the data showed a 38% drop in the need for reinterventions such as less frequent system revisions, device removals and fewer cases where patients needed to be upgraded to cardiac resynchronization therapy. There was also a 31% reduction in chronic side effects.