Potential Separation of Interconnect Wires (2009)
Kappa 600/700/900 and Sigma 100/200/300 Pacemakers
Original Date of Advisory:
A specific subset of Kappa and Sigma series pacemakers may fail due to separation of interconnect wires from the hybrid circuit. You may use the "Search for Information by Serial Number" tool on this web page to determine if a specific device is affected. The Physician Letter is available at http://www.medtronic.com/kappasigma/physician.html
Specific subsets of Kappa and Sigma series pacemakers may fail at a higher than expected rate due to separation of wires that connect the electronic circuit to other pacemaker components (e.g., battery, connector). This may present clinically as loss of rate response, premature battery depletion, loss of telemetry, or no output.
Some patients, whose devices experience a wire separation resulting in a loss of pacing output, will experience a return of bradycardia symptoms (e.g., fainting or lightheadedness). In rare cases involving pacemaker dependent patients, loss of pacing output may result in death or serious injury.
Since 1997, there have been over 1.7 million Kappa and Sigma devices implanted worldwide. . At the time of the original advisory communication, an estimated 15,200 Kappa and 6,100 Sigma devices affected by the advisory remained implanted and active. These devices were manufactured primarily between November 2000 and November 2002. Most of these devices have been implanted in patients for five years or longer and may be nearing normal elective replacement time.
There is no provocative testing that can predict which specific devices may fail, and no device programming can mitigate this issue if it occurs.
Patient Management Recommendations
We realize that each patient requires unique clinical consideration and we support your judgment in caring for your patients. After consultation with Medtronic’s Independent Physician Quality Panel, Medtronic offers the following recommendations for patients:
- Physicians should advise their patients to seek medical attention immediately if they experience symptoms (e.g., fainting or lightheadedness).
- Physicians should consider device replacement for patients who are both pacemaker dependent and who have been implanted with a device in the affected subsets. Medtronic will offer a supplemental device warranty if the device is not already at elective replacement time.
- Physicians should continue routine follow-up in accordance with standard practice for those patients who are not pacemaker dependent.
Patient management recommendations remain unchanged. As of July 31, 2014, Medtronic has observed 459 Kappa devices and 306 Sigma devices with this failure mechanism from the Kappa and new Sigma device subsets. This represents 0.79% (Kappa) and 2% (Sigma) of the original affected implant population.
Four hundred twenty-two (422) of the Kappa devices (0.72%) and 238 of the Sigma devices (1.59%) were returned with information indicating a problem with the patient’s pacing system prior to explant. The remaining 37 Kappa devices (0.06%) and 68 Sigma devices (0.45%) were returned with no information indicating a potential malfunction while implanted or with insufficient information to determine the state of the device at explant. Lacking definite information indicating proper operation until explant, these remaining devices are conservatively categorized as having experienced interconnect wire separation while implanted.
As of May 2009, our modeling predicts failure rates due to this issue of 1.1% (Kappa) and 4.8% (Sigma) over the remaining lifetime of those pacemakers still in service at that time.
Out of the initial advisory population of 58,300 Kappa devices and 14,900 Sigma devices worldwide, less than 100 Kappa devices remain implanted worldwide. Approximately 800 Sigma devices remain implanted worldwide. Of these, 200 Sigma devices are in the United States.
Included in the advisory communication was information about an additional subset of Kappa devices where we have observed a much lower rate of occurrence of this issue. We estimate that none of these devices remain active.
|Initial Affected Population||Number of Confirmed Advisory Related Events||Estimated Remaining Active Population||Current Malfunction Rate (confirmed malfunctions over total population)||Predicted Malfunction Rate Over the Remaining Life of the Devices Still Implanted|
58,300 Implanted Worldwide (est.) (17,600 United States)
422 Worldwide (223 United States) with information indicating a clinical presentation. An additional 37 worldwide (25 US) without information indicating a clinical presentation or with insufficent information to determine the state of the device at explant.
<100 Worldwide (<100 United States)
0.79% Worldwide (1.40% United States)
|14,900 Implanted Worldwide (est.) (3,700 United States)||238 Worldwide (46 United States) with information indicating a clinical presentation. An additional 68 worldwide (15 US) without information indicating a clinical presentation or with insufficent information to determine the state of the device at explant.||
800 Worldwide (200 United States)
|2% Worldwide (1.6% United States)||4.8%|