Each year, 200,000 patients with pacemakers in the US have to skip MRI scans, possibly forgoing the early detection and treatment of many serious medical conditions.
The Food and Drug Administration just approved Medtronic’s Revo MRI SureScan pacing system (pictured) – the first and only pacemaker in the country specifically designed to be safely used during magnetic resonance imaging exams.
For people with irregular or slowed heart beats, pacemakers help restore and regulate heart rhythms using electrical impulses.
MRI scans allow doctors to see bones and soft tissues like internal organs, blood vessels, and tumors – helping them diagnose stroke, cancer, and neurologic and orthopedic conditions. Sometimes these kinds of information can't be seen with X-rays, ultrasounds, or CT scans.
Until now, this imaging procedure has been contraindicated for patients with implanted pacemakers because of potentially serious complications.
Exposure to the magnetic fields generated by MRI machines (as much as 30,000 times more powerful than Earth’s magnetic field), could disrupt pacemaker settings and overheat wires – causing unintended heart stimulation, device electrical failure, or tissue damage.
Approximately 5 million patients worldwide are currently implanted with a pacemaker or cardioverter-defibrillator, according to Medtronic. And at the same time, the use of MRI as a diagnostic tool is increasing, with approximately 30 million scans annually.
Up to 75% of patients with electronic cardiac devices will likely need an MRI over their device’s lifetime.
Along with hardware redesigns, the 21.5 g Revo MRI can be programmed into SureScan mode before an MRI procedure, reducing or eliminating hazards.
In a clinical trial, none of the 211 patients who underwent an MRI experienced an MRI-related complication.
However, according to the FDA, the Revo's use in MRIs is limited to certain patients, certain parts of the body, and certain scanning parameters. And as Bloomberg points out, many patients who qualify for a Revo can’t get MRIs because they have other metal devices such as replacement hips implanted in their bodies.
Additionally, the agency issued a warning letter in 2009 regarding quality issues. But according to the FDA, the product's release was approved despite the warning because the device "meets a significant public health need," so its availability should not be delayed.
Shipments of Revo MRI will begin immediately.
Image: Medtronic Revo MRI