Medical Device Advisories Regarding Certain Boston Scientific Pacemakers
Boston Scientific (BSC) recently announced two distinct, unrelated medical device advisories related to certain pacemakers and cardiac resynchronization therapy pacemakers (CRT-Ps). This communication summarizes the 2 alerts and BSC recommendations.
Hydrogen-Induced Accelerated Battery Depletion in subset of ACCOLADE Pacemakers and CRT-Ps
Boston Scientific is expanding its September 2018 advisory regarding premature battery depletion in ACCOLADE, PROPONENT, ESSENTIO, and ALTRUA 2 pacemakers, and VISIONIST and VALITUDE CRT-Ps due to premature battery depletion events occurring in devices not included in the original advisory device population. The root cause of the battery depletion is a release of small amounts of hydrogen which compromises the low voltage capacitor used in these devices made before November 2017. Pacemakers and CRT-Ps manufactured after November 2017 have not exhibited this accelerated battery depletion behavior. For the 2018 advisory subset the observed malfunction rate is 11.0% at 5 years, with an observed malfunction rate of 1.3% at 5 years for the expanded 2021 advisory subset.
Patients should be enrolled in LATITUDE remote monitoring whenever feasible. Continue to follow patients either in person or with remote interrogations at least annually and then every 3 months when the battery has one year of longevity remaining. At each follow up, note the pacemaker's "Approximate Time to Explant" and compare it to the prior follow up value to assess if the change in estimated longevity is appropriate or whether it may reflect accelerated depletion. For example, at an annual clinic visit, if the estimated longevity is reported as 2 years but at the prior visit one year ago, it was reported to be 5 years, this may reflect accelerated depletion since only 1 year, not 3, has passed. Any device with accelerated depletion should be replaced within 90 days of the explant battery status indicator. Prophylactic generator replacement is not recommended in devices exhibiting normal battery consumption.
Safety Mode in INGENIO family Extended Life (EL) pacemakers and CRT-Ps
Dual chamber INGENIO EL pacemakers and CRT-Ps may enter Safety Mode several years after implant prior to reaching the 'Explant Battery Indicator'. As the device ages, battery impedance increases based upon usage and time. A higher battery impedance can cause a device to exhibit transient voltage decreases during periods of high power consumption associated with telemetry communication with a programmer or a LATITUDE communicator making the device more susceptible to a system reset.
Once a device has three system resets within 48 hours, the device will automatically go into Safety Mode. Once in Safety Mode, device replacement is necessary.
Safety Mode is readily detected; Device interrogation will display a warning screen on the programmer screen and for patients followed remotely, LATITUDE will issue a red alert. Safety Mode consists of pacing in VVI mode at 72.5 bpm at 5.0 V at 1.0 ms, with sensitivity at 0.25mV, and unipolar sensing/pacing configuration which some patients may not tolerate due to myopotential oversensing resulting in pacing inhibition, loss of AV synchrony or extracardiac stimulation.
There are approximately 48,000 active INGENIO devices affected by this advisory and approximately one third or more of them will experience a Safety Mode occurrence over the device lifetime. Affected pacemaker models include a subset of ADVANTIO DR EL, INGENIO DR EL, VITALIO DR EL, and INVIVE, INTUA, and INLIVEN CRT-Ps.
Continue to follow patients either in person or with remote interrogations at least annually and then every 3 months when the battery has one year of longevity remaining. Assess each individual patient carefully including their ability to tolerate Safety Mode pacing or possible loss of pacing due to myopotential oversensing. Routine prophylactic generator replacement is not recommended; however, it may be reasonable to have a shared decision-making discussion in select patients who are felt to be at higher risk in order to discuss the benefits and risks of device replacement. If device replacement is being considered, Boston Scientific recommends device replacement for EL pacemakers when the estimated longevity is 4 years and for CRT-Ps when the estimated longevity is 3 years.
A device look-up tool to check for affected devices is available online.
Adverse reactions or quality problems experienced with the use either of these products should be reported to Boston Scientific or to the FDA MedWatch Safety Information and Adverse Event Reporting Program either online, by regular mail or by fax.