Some experts say the debate about the failure rate of a critical and widely used Medtronic heart device has set off a debate among researchers who want to understand the discrepancies and the implications for patient care. But some experts say that debate would not be occurring if federal officials, medical device manufacturers and more doctors had thrown their weight more fully behind efforts to develop a national database of patients who get heart devices.
Medtronic The Obama administration has announced plans to pour hundreds of millions of dollars into studies to compare the effectiveness of competing medical treatments and equipments. Monitoring patients’ outcomes through registries could be part of that process. But setting up such registries in this country has proved difficult so far.
Back in 2004, Medicare required the creation of a national registry for defibrillators — equipments that send out an electrical jolt to interrupt a potentially deadly heart rhythm.
Medicare officials made the registry a condition for approving payments for defibrillators for a new class of heart patients, despite equivocal evidence that they needed the device. The purpose of the registry was to track how many of those patients would really benefit from the devices, which can cost $25,000 or more.
Despite requiring the registry, Medicare has never put any money into supporting it, said Stephen Hammill, a cardiologist at the Mayo Clinic who has headed the defibrillator effort.
And while defibrillator manufacturers did help support the $3 million annual cost of operating the registry in its first year, they have since cut back that financing — even though the Medicare ruling permitted them to sell tens of thousands of additional defibrillators a year.
Alan Kadish of Northwestern University, who is also involved in the registry, said he did not think that manufacturers believed that they would “be fulfilling their fiduciary obligations to shareholders by funding” studies that compare the effectiveness of their devices to those of competitors.
The database, which took several years to set up, is being run by two professional groups, the American College of Cardiology and the Heart Rhythm Society. In recent years, information on more than 340,000 people who have received defibrillators — their age, medical condition and the equipment they received — has been entered into it.
Hospitals are now paying for the effort. In return, they are receiving reports about how their own patients’ short-term complication rates against nationwide rates.
But the limited financial support, as well as technical problems that make it hard to merge registry information with Medicare records, have undermined the registry’s utility. Researchers, for instance, cannot compile data about patients’ longer term results — information that is critical in determining the effectiveness and reliability of defibrillators.
The potential value of even a small registry in detecting device problems was shown in the case of Medtronic’s troubled product, an electrical cable known as the Sprint Fidelis lead that connects a defibrillator to a patient’s heart.
Using a small registry of patients receiving defibrillators at the Minneapolis Heart Institute and a few other facilities, Robert G. Hauser, a cardiologist there, was the first to detect problems with the Sprint Fidelis. Further research by him indicated that the cables seemed to be failing in an unusually high number of patients, causing the defibrillator either to go off for no reason or to fail to deliver a shock when required.
By early 2007, Hauser brought his concerns to Medtronic, which agreed to investigate. But the company did not recall the Sprint Fidelis until that October. During the intervening months, thousands of additional patients received the devices. The company said when it recalled the unit that five deaths might have linked to its problems.
This week, Hauser and a cardiologist at the Mayo Clinic, David L. Hayes, released a RESEARCHstudy based on defibrillator patients at their two institutions, which indicated that the Sprint Fidelis was failing at a far higher rate in patients who still had the device than Medtronic had reported. The company defended its findings, which are based on its monitoring of about 20,000 patients. And the debate ensued.
Kadish of Northwestern University said that a well-run national registry could easily resolve such disputes because it could look at far more patients than either the Hauser-Hayes study or Medtronic. And had such a registry been in operation, he said, it could have detected the Sprint Fidelis flaw much earlier.
“It would have popped up, and it would have been easy to estimate the magnitude of the problem,” he Stated.
The defibrillator database is now being revised so it can monitor the reliability of devices, Hammill said. And last year, the Food and Drug Administration asked that the database be expanded to track the performance of leads like the Fidelis.
Researchers said they planned to test those revisions shortly, although it might take a year or more to gather enough information about device performance to make that data useful.
“These registries can have an enormous role in quality and surveillance,” Hammill said.