Medtronic offers positive stress test data on newly approved leadless pacemaker

Micra Transcatheter Pacing System--Courtesy of Medtronic

Medtronic ($MDT) has presented data on its leadless pacemaker, Micra, showing consistent safety and efficacy at months after implant--even under extreme conditions. Micra was just approved by the FDA last month and is the first leadless, transcatheter pacemaker to be approved in the U.S.

The data came at the Heart Rhythm Society Conference in San Francisco, CA, and showed that even under maximal exertion treadmill tests, the pacemakers offered appropriate rate-responsive pacing in a 20-patient study at three months and again at 6 months after the implant.

"Many patients with bradycardia require rate-responsive pacing so that their heart rates increase during exercise," said Dr. Razali Omar, senior consultant cardiologist at the National Heart Institute in Kuala Lumpur, Malaysia, in a statement. "Conventional pacemakers use various sensors outside the heart to detect patient activity, but even these sensors can have difficulty detecting moderate physical activity.

As data presented today show, the Micra accurately responds to patients' activity levels by adjusting therapy when needed using a sensor within the heart."

The Micra Transcatheter Pacing System (TPS) is less than one-tenth the size of traditional pacemakers; it's about the size of a vitamin pill. It responds to patient activity levels by using an accelerometer sensor positioned within the heart to adjust therapy.

Pivotal data published in November in The New England Journal of Medicine showed that Micra TPS was successfully implanted in 99.2% of patients.

Data on another leadless pacemaker were also presented at the Heart Rhythm Society conference this week. This time from startup EBR Systems for its novel Wireless Stimulation of the Endocardium (WISE) System. European data for its pacemaker in patients who had failed on another pacemaker found that in the 39-patient study, 34 patients successfully achieved bi-valvular pacing.

EBR's leadless cardiac resynchronization therapy is placed in the left ventricle, unlike systems from Medtronic and St. Jude Medical ($STJ), which go in the right ventricle.

"This multicentre experience has demonstrated the feasibility of direct, wireless endocardial LV pacing to achieve CRT in patients with a previous CRT failure or previously unsuitable for CRT," the researchers said.

- here is the Medtronic announcement
- and the EBR data