Powerful magnetic fields created during an MRI scan were thought to play havoc with some pacemakers, but a new study says these scans are safe for people with the heart devices.
Investigative researchers have tested the safety of MRIs on over 1,500 people who had older pacemakers or implantable defibrillators — called legacy devices — that the U.S. Food and Drug Administration does not consider safe for MRIs. The result: No long-term adverse effects were found.
“Many patients have implanted pacemakers or defibrillators that were not designed to be used with MRI scans,” said senior study author Dr. Henry Halperin. He’s a professor of medicine and co-director of the Johns Hopkins Imaging Institute of Excellence in Baltimore.
A majority of people who have these devices will need an MRI at some point, he noted. The study results show that “it’s really safe to do MRIs in these patients,” he added.
When MRIs were first used, issues with scanning those patients with implanted devices did exist, according to Halperin.
“There were some real issues, like the devices would stop working, and there were 13 to 15 deaths reported,” he said. Based on those reports, the FDA said that people with these devices should not have MRIs.
Since 2000, devices have been modified to make them safe during an MRI. But many people still have legacy devices that the FDA does not consider MRI-safe.MRIs are also safe for people who have wires that connect the devices to the heart — called leads — left in place after new leads were implanted, Halperin added.
In reference to Dr. Byron Lee, a professor of medicine and director of electrophysiology laboratories and clinics at the University of California, San Francisco, “This is important research that affects patient care immediately.” Lee was not involved with the new study but was familiar with the findings.
“Contrary to the official word from the device manufacturers and many doctors, almost all patients with pacemakers and defibrillators, and even those with older-generation devices, can get MRIs,” Lee said.