Medtronic announced yesterday that it received FDA approval for the world's smallest pacemaker, the Mica Transcatheter Pacing System (TPS). It's a leadless pacemaker that was designed to be cosmetically invisible and small enough to be implanted directly into the heart with a catheter.
"We believe Micra TPS is the future of pacing technology — a transition to a new paradigm for cardiac devices, and Micra is the first major step for patients in the U.S.," Mike Hess, VP of the bradycardia R&D, cardiac rhythm and heart failure division of Medtronic, told HCB News.
The Micra TPS is about the size of a large vitamin and it attaches to the heart with small tines that deliver electrical impulses and pace the heart through an electrode at the end of the device. Unlike conventional pacemakers, this one doesn't require leads or a surgical "pocket" under the skin.
In addition to being the smallest pacemaker, it's also the first and only transcatheter pacing system that is approved for both 1.5 and 3 T full-body MR exams.
Two of the biggest challenges the development team encountered centered around battery longevity due to electrical current drain and fixation mechanisms. The team was able to get the battery to last for 12 years by deploying advanced microelectronic designs and reducing the drain of the integrated circuit.
The team didn't think that the fixation approach of pacing leads was appropriate for the Micra TPS, so they developed a novel approach where the device could extend small tines to hold it securely to the heart.
"From a material perspective, we brought nitinol (nickel-titanium alloy) into the pacemaker product line for the first time," said Hess. "The team of engineers were able to apply the nitinol expertise and usage experience from Medtronic’s other cardiac business units — particularly its shape memory and temperature-controlled properties — to the tines we designed that hold the Micra in place."
In November, data was published in the New England Journal of Medicine and presented at the American Heart Association Scientific Sessions that found that Micra TPS was successfully implanted in 99.2 percent of patients. In addition, there were no dislodgments and it met its safety and effectiveness endpoints with wide margins.
