The Medtronic Revo MRI SureScan™ pacemaker is out, and the natural question arises: who should get it? Up until now, pacemakers have not coexisted well with MRI scanners. Problems including inductive heating of the leads, spurious reprogramming, and various malfunctions have been reported. Up until now, patients getting pacemakers have been told that they could not ever get MRI scans, and that’s that. Now that there is an MRI compatible pacemaker, should all new pacemaker candidates get one?
I’m sure Medtronic would be happy if the answer to this question is yes. The new pacemaker and leads are more expensive than their other pacemakers, and, given the ugly morass that is the U.S. Patent Office, where a company like Microsoft can patent double-clicking with a mouse, I’m sure Medtronic holds a bunch of patents on MRI compatible pacemakers that will suppress any healthy competition from other companies, or at least result in hefty licensing fees that other companies will pass on to the consumer. So the cost will stay high, though I doubt this kind of pacemaker is any more difficult to make than any other pacemaker. So the question becomes: is it worth the added cost of this pacing system just to ensure that sometime in the future a patient may be able to get an MRI scan? I might add that, in addition to the added cost, the system uses larger caliber leads, and the Revo generator has an upper tracking rate of only 150 bpm, making it less attractive for use in younger patients who might be more likely to need an MRI scan over the course of their lifetime.
Medtronic states on their website that 75% of pacemaker patients will have an indication for an MRI scan during the lifetime of their device. I think this statistic needs to be taken with a grain of salt. There is evidence that MRI scans (as well as CT scans) are overused. In the past, we have told pacemaker patients that they would have to settle for CT scans instead of MRI scans, and I can remember only a few instances where not being able to do the MRI scan was a real problem. So are we now to believe that, even though we have somehow survived the inability to do MRI scans in these patients since MRI scanning was invented, this is now a feature that we can’t live without?
If you read the fine print in the Revo Technical Manual, you see that the device is listed as MRI-Compatible, which is not necessarily the same as MRI-Safe. There are still warnings listed in the manual that there can be heating of the leads and other adverse effects on the device. You still cannot do MRI scanning of the chest region. I’m not sure one can take away the message that it is totally safe to do MRI scanning in patients with these devices. I might still lean towards doing CT scanning instead in a patient who is pacemaker dependent. I’m sure it is only a matter of time before someone reports a patient who has a device complication from MRI scanning, and it only takes one lawsuit to temper one’s enthusiasm for new technology.
I do think that an MRI-Compatible pacemaker is an advance, and hope that MRI-Compatible ICDs are coming as well. Certainly in patients that already have indications or potential indications for MRI scanning these devices are the way to go. I cannot accept that these devices are necessary for all pacemaker candidates. In a health care system that is on the verge of bankruptcy we don’t have the luxury to increase our costs further without getting a significant benefit. I’m just not convinced that we should pay more just for the possibility that a patient might develop an indication for an MRI scan at some point in the future.