Micra safety benefits sustained beyond six months


New results from the Medtronic Micra Transcatheter Pacing System (TPS) global clinical trial have been presented in a late-breaking trial session at CARDIOSTIM / EHRA EUROPACE (8-11 June; Nice, France).

The follow-up data presented by Gabor Duray (head of Clinical Electrophysiology and Pacing, State Health Center, Budapest, Hungary) found only 3.7% of patients (27 of 726; Kaplan-Meier estimate) experiencing a major complication, and no patients experiencing a device dislodgement, at 7.7 months of follow-up.

Additionally, the risk for major complications with Micra was shown to be significantly lower (52%) than the risk associated with conventional pacing systems (hazard ratio: 0.48; 95% CI, 0.32 to 0.72; P<0.001). Moreover, the risk for major complications was lower for the Micra TPS relative to conventional systems across all patient sub-groups, whether measured by age, sex or comorbidity (all hazard ratios <1).

“Clinicians are extremely pleased that the evidence continues to demonstrate the strong safety profile of the Micra for all patient groups,” said Duray. “These data provide the largest sample and the longest follow-up reported for this technology to date.”

At 7.7 months, Micra TPS continued to provide low and stable pacing thresholds, yielding projected average longevity for the device of more than 12 years based on device use conditions through six-months on 590 patients.

In November 2015, preliminary results from the trial were published in the New England Journal of Medicine and presented at the American Heart Association Scientific Sessions. Data showed the Micra TPS was successfully implanted in 99.2% of patients, and the system met its safety and effectiveness endpoints with wide margins.

Micra’s design incorporates a retrieval feature designed 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 miniaturised Micra TPS was designed with the ability to be permanently turned off, so it can remain in the body and a new device can be implanted without risk of electrical interaction.

The Micra TPS was awarded CE mark in April 2015 and US Food and Drug Administration (FDA) approval in April 2016. It is intended for use in patients who need a single-chamber pacemaker. Micra is the first and only leadless pacing system to be approved for both 1.5 and 3 Tesla full-body magnetic resonance imaging (MRI) scans, providing patients with access to the most advanced imaging diagnostic procedures available. The device was designed to allow patients to be followed by their physicians and send data remotely via the Medtronic CareLink Network; remote monitoring of Micra devices is expected to be available later this year.