FDA Approved ‘Micra Transcatheter Pacing System’ (New Pacemaker)

Micra Transcatheter Pacing System (TPS) contains a one inch-long, self-contained pacemaker that is implanted directly in the right ventricle chamber of the heart. It works like other pacemakers to control the heartbeat. Unlike other pacemakers, the Micra TPS does not have leads. The Micra TPS is a single-chamber pacing system – it paces only the right ventricle of the heart.

How does it work? The Micra TPS is implanted directly into the heart via the femoral vein (in the leg) using a catheter delivery system. It is attached to the right ventricle with four small prongs (tines), which contain steroids to reduce inflammation at the implantation site. After the pacemaker is implanted, a physician tests and programs the device.

Picture of the device.

Like other pacemakers, the Micra TPS generates electrical impulses that cause the heart to contract or beat. Once in place, the pacemaker monitors the heart rate and adjusts therapy in response to the patient’s activity level.

When is it used? The Micra TPS is indicated to be used in patients who have slow or irregular heart rhythms and who may benefit from a single chamber pacemaker system or when placement of a traditional system is difficult.

What will it accomplish? The Micra TPS has been shown to provide pacing when a patient’s heart is too slow. It responds to patient activity levels and has a low rate of complications.

The FDA evaluated data from a clinical trial of 719 patients implanted with the Micra TPS. In this study, 98 percent of patients had adequate heart pacing (known as pacing capture threshold) six months after the device was implanted. Complications occurred in fewer than 7 percent of participants in the clinical trials and included prolonged hospitalizations, blood clots in the legs (deep vein thrombosis) and lungs (pulmonary embolism), heart injury, device dislocation and heart attacks.

The clinical trial will continue to follow patients for at least 12 months to further evaluate long-term performance of the device.

When should it not be used? There are no known contraindications for the use of pacing as a therapy to control heart rate. The patient’s age and medical condition may influence the selection of the pacing system, the mode of operation, and the implant technique used by the physician.

The Micra TPS device is contraindicated in patients with the following:

  • an implanted inferior vena cava (IVC) filter
  • a mechanical tricuspid valve
  • another pacemaker or implantable defibrillator that might interfere with the sensing performance of the Micra device
  • femoral venous anatomy unable to accommodate a 7.8 mm (23 French) introducer sheath or implant on the right side of the heart
  • obesity that prevents a telemeter device on the patient’s chest to come within 12.5 cm (4.9 in) of the device
  • intolerance to the materials in the device
  • intolerance to heparin
  • sensitivity to contrast media that cannot be adequately premedicated
  • inability to tolerate a single dose of 1.0 mg dexamethasone acetate (steroid)

Credit :FDA