Disclosures
Micra™ AV and Micra™ AV2 leadless pacemakers have not been approved by FDA for concomitant use with an active transvenous pacemaker providing atrial pacing and the safety and effectiveness of concomitant use of Micra™ AV and Micra™ AV2 leadless pacemakers with an active transvenous pacemaker providing atrial pacing has not been established.
The FDA approved use for Micra™ AV and Micra™ AV2 leadless pacemakers are as follows:
The Micra™ AV Model MC1AVR1 is indicated for use in patients who have experienced one or more of the following conditions:
- Paroxysmal or permanent high-grade AV block in the presence of AF
- Paroxysmal or permanent high-grade AV block in the absence of AF, as an alternative to dual chamber pacing, when a dual chamber transvenous pacing system is considered difficult, high risk, or not deemed necessary for effective therapy
- Symptomatic bradycardia-tachycardia syndrome or sinus node dysfunction (sinus bradycardia or sinus pauses), as an alternative to atrial or dual chamber pacing, when a dual chamber transvenous pacing system is considered difficult, high risk, or not deemed necessary for effective therapy
The device is also indicated for VDD pacing in patients with adequate sinus rates who may benefit from maintenance of AV synchrony. The Micra™ AV leadless pacemaker provides AV synchronous ventricular pacing similar to a transvenous VDD system. The implanted device depends on the appropriate sensing of atrial mechanical signals to achieve AV synchrony. The level of AV synchrony may vary in individual patients and may not be predictable prior to implant. Rate-responsive pacing is indicated to provide increased heart rate appropriate to increasing levels of activity.
The device is designed to be used only in the right ventricle.
Micra™ AV2 Model MC2AVR1 is indicated for VDD pacing in patients when a dual chamber transvenous pacing system is considered a poor option or not deemed necessary for effective therapy, and when a right ventricular transcatheter pacing system promoting atrioventricular synchrony at rest is acceptable. Conditions when a patient is considered a poor candidate for transvenous pacing may include, but are not limited to, tortuous anatomy, a need to preserve venous access, or increased risk of infection. The device provides atrioventricular synchrony at rest and rate responsive (VVIR) pacing during periods of high patient activity. Device-mediated atrioventricular synchrony can vary depending on patient condition and activity levels, and it can be limited at high sinus rates. During periods of intermittent atrioventricular synchrony, the device will provide ventricular pacing support with an increased potential for pacing rate variability. The Micra™ AV2 leadless pacemaker is indicated for use in patients who have experienced one of the following:
- Paroxysmal or permanent high-grade AV block in the absence of AF
- Paroxysmal or permanent high-grade AV block in the presence of paroxysmal AF
- Paroxysmal or permanent high-grade AV block in the presence of persistent AF when attempts at restoring sinus rhythm are still planned
The device is designed to be used only in the right ventricle.
Pre-implant considerations
The Micra™ AV and Micra™ AV2 leadless pacemakers are intended to provide AV synchrony at rest and VVIR pacing during periods of high patient activity. Synchronous ventricular pacing using sensing of atrial mechanical contraction may not provide continuous AV synchrony. Device-mediated AV synchrony can vary depending on patient condition and activity levels, and it can be limited at high sinus rates. During periods of intermittent AV synchrony, the device will provide ventricular pacing support with increased potential for pacing rate variability.
The decision to implant the Micra™ AV or Micra™ AV2 leadless pacemaker should consider the benefits of leadless pacing versus the patient’s need for continuous AV synchrony.
Some patients will not benefit from the AV synchronous (VDD) mode. Patients with the following conditions should be considered for a dual chamber transvenous pacing system:
- Sinus node dysfunction
- High sinus rates requiring atrial tracking
- Weak atrial contraction
- Symptoms during loss of AV synchrony
- Frequent premature atrial or ventricular contractions where atrial tracking is required immediately after the premature beat
Patient evaluation for the implant of the Micra™ AV Model MC1AVR1 or Micra™ AV2 Model MC2AVR1 should include that the leadless pacemaker may be fully encapsulated prior to the End of Service (EOS) condition.
Patient evaluation for the implant of the Micra™ AV Model MC1AVR1 or Micra™ AV2 Model MC2AVR1 should include the following consideration about a concomitant implant with a neurostimulator:
Concomitant neurostimulator and cardiac device implants – Some patients have medical conditions that require the implant of both a neurostimulator and a cardiac device (for example, a pacemaker, a defibrillator, or a monitor). In this case, physicians (for example, a neurologist, a neurosurgeon, a cardiologist, and a cardiac surgeon) involved with either device should contact Medtronic Technical Services or their Medtronic representative before implanting the patient with the second device. Based on the particular devices that the physicians have prescribed, Medtronic can provide the necessary precautions and warnings related to the implant procedure. For information about how to contact Medtronic, see the telephone numbers and addresses provided on the back cover of this manual.
The FDA-required labeling contains the following Warnings, Precautions and Cautions about this off-label use of Micra™ AV and Micra™ AV2 leadless pacemakers:
Concomitant neurostimulator and cardiac device implants – Some patients have medical conditions that require the implant of both a neurostimulator and a cardiac device (for example, a pacemaker, a defibrillator, or a monitor). In this case, physicians (for example, a neurologist, a neurosurgeon, a cardiologist, and a cardiac surgeon) involved with either device should contact Medtronic Technical Services or their Medtronic representative before implanting the patient with the second device. Based on the particular devices that the physicians have prescribed, Medtronic can provide the necessary precautions and warnings related to the implant procedure. For information about how to contact Medtronic, see the telephone numbers and addresses provided on the back cover of this manual.
Multiple devices – The use of deactivated Micra™ AV and Micra™ AV2 leadless pacemakers in situ and an active Micra™ AV or Micra™ AV2 leadless pacemaker, or an active transvenous pacemaker or defibrillator, has not been clinically tested to determine whether EMI or physical interaction is clinically significant. Bench testing supports that implantation of an active Micra™ AV or Micra™ AV2 leadless pacemaker, or an active transvenous pacemaker or 14 defibrillator, next to an inactivated Micra™ AV or Micra™ AV2 leadless pacemaker is unlikely to cause EMI or physical interaction. Post-approval studies are planned to characterize risks of co-implanted, deactivated Micra™ AV and Micra™ AV2 leadless pacemakers. Currently recommended end of device life care for a Micra™ AV or Micra™ AV2 leadless pacemaker may include the addition of a replacement device with or without explantation of the Micra™ AV or Micra™ AV2 leadless pacemaker, which should be turned off.
Patient’s age and medical condition – The patient’s age and medical condition should be considered by physicians and patients as they select the pacing system, mode of operation, and implant technique best suited to the individual.
Prosthetic tricuspid valve – Use caution when implanting a Micra™ AV or Micra™ AV2 leadless pacemaker in a patient with a prosthetic tricuspid valve to avoid valve damage. During device implant, visualizing the prosthetic valve using the LAO fluoroscopic view can aid in limiting interaction with the valve leaflets.
End of Service (EOS) – Neither the Micra™ AV nor Micra™ AV2 leadless pacemaker is intended to be removed following the End of Service (EOS) condition. Note: Removal of the Micra™ AV or Micra™ AV2 leadless pacemaker may be difficult because of its deeper implant site in the heart and the development of fibrotic tissue. If removal of the device is required, refer the patient to a medical center that has expertise in the removal of implanted leads (particularly with cardiac surgery backup) or call a Medtronic representative for more information.
Potential Adverse events
The following are known potential adverse events associated with the use of the Micra™ AV leadless pacemaker.
Note: Implant and usage of this product may result in adverse events, which may lead to injury, death, or other serious adverse reactions.