FDA approves Micra Transcatheter Pacing System, first leadless heart pacemaker.- Medtronic

The FDA has approved the world's smallest pacemaker which does not require the use of wired leads to provide an electrical connection between the pulse-generating device and the heart. While the Micra Transcatheter Pacing System from Medtronic, works like other pacemakers to regulate heart rate, the self-contained, inch-long device is implanted directly in the right ventricle chamber of the heart.

Pacemakers are surgically implanted medical devices that generate electrical impulses to treat irregular or stalled heart beats, and nearly 1 million people worldwide are implanted with pacemakers each year. The leads in a traditional single chamber pacemaker run from the pacemaker, implanted under the skin near the collarbone, through a vein directly into the heart’s right ventricle; the leads deliver electric pulses from the generator to the right ventricle and help coordinate timing of the chamber’s contractions. Micra eliminates these leads, which can sometimes malfunction or cause problems when infections develop in the surrounding tissue, requiring a surgical procedure to replace the device.

The FDA evaluated data from a clinical trial of 719 patients implanted with the Micra device, which found that 98 percent of patients in the trial 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 attack.

Comment: The Micra TPS has received a CE Mark in 2015. Its competitor is the Nanostim from St.Jude which is in clinical trials.

Comment: Micra TPS patients can undergo body scans in 1.5- and 3-tesla MRI machines due to its small size and the absence of leads. The Micra design also incorporates a retrieval feature to enable retrieval when possible; however, the device is designed to be left in the body. For patients who need more than one device, the miniaturized Micra TPS was designed with a unique feature that enables it to be permanently turned off so it can remain in the body and a new device can be implanted without risk of electrical interaction.