Medtronic and the FDA were both aware of battery and wire connection defects in a now-recalled heart failure pacemaker for over a year before patients developed serious side effects, according to a report published in JAMA Internal Medicine.
When the FDA did issue a recall, the report found, the agency’s information was incomplete and underestimated the severity of the pacemaker’s defects.
Jay Sengupta, MD, and colleagues at the Minneapolis Heart Institute said in JAMA that while medical device safety is framed as a major public concern in the U.S., there’s little data concerning what patients experience before and after a device is recalled. For their study, the researchers focused on 90 patients who were implanted with Medtronic’s InSyncIII model 8042 cardiac resynchronization therapy pacemaker (CRT-P) between May 2003 and January 2011. In 2015, the pacemaker was formally recalled.
Recall reports stated that the InSyncIII CRT-P might fail unexpectedly because a buildup of resistive film on the pacemaker’s cathode current collector could trigger high internal battery impedance, which decreases current flow from the battery and can cut pacing off altogether. Medtronic estimated the risk of failure for the 9,300 or so pacemakers still implanted at the time was between 0.16% and 0.6%; per-patient mortality risk was estimated to be between 0.007% and 0.02%.
“The FDA classified this recall as class II, meaning the device could cause temporary or medically reversible health consequences but that the probability of serious adverse health consequences was remote,” Sengupta et al. wrote. “The recall notification did not mention any other product performance issues.”
Five of 90 patients observed prior to the recall in 2015 experienced syncope when their pacemakers stopped working, either due to battery or wire connection defects. An analysis of MAUDE (Manufacturer and User Facility Device Experience) data revealed that battery failures prior to the recall were linked to serious adverse events, including one death, one cardiac arrest, five syncopal attacks and six heart failure exacerbations. Another three pre-recall syncopal events could be attributed to wire connection defects.
Sengupta and co-authors said that, according to MAUDE and FDA data, both Medtronic and the FDA were aware of battery and wire connection defects for 19 months before issuing a recall. Even when the recall did go live, the FDA didn’t include information about the wire connection issues and physicians weren’t informed that interrogating the CRT-P could result in a loss of pacing.
“The report demonstrates considerable deficits in both the swiftness and the appropriateness of the response,” editorialists James W. Salazar, MD, MAS, and Rita F. Redberg, MD, MSc, wrote in a comment for JAMA, noting the class II status suggested the problem was more minor than it actually was. “This long, unexplained delay before the recall and the inappropriate recall classification raise concerns about patient harms that could have been prevented by speedier and stronger regulatory actions.”
Salazar and Redberg called it “appalling” that the U.S. “lacks even a rudimentary means to track medical devices,” and said the progress in medical device safety will lag until the FDA makes data collection and transparency a priority. It’s also important, they said, to take prompt regulatory action when manufacturers identify any kind of safety problem.
“There is no question that the current medical device surveillance system, which is based on the voluntary reporting of adverse events, requires substantial improvement to prevent avoidable serious illnesses and deaths,” the pair wrote. “Patients deserve a robust medical device surveillance system that invariably puts patient safety first.”