Medicare will soon cover implants of Medtronic's tiny new pacemaker, the Micra, when the device is implanted as part of a long-term clinical study.

The device received U.S. Food and Drug Administration approval last April, to much industry fanfare. But financial analysts say it's often insurance coverage decisions that determine whether a novel technology succeeds financially, and Medicare is the nation's largest health insurer.

"Reimbursement by insurance companies has increasingly been the gating factor for a new product's financial success. For Micra, the [Medicare] decision is particularly impactful since pacemakers trend more toward an elderly, i.e. Medicare, population," retired Minneapolis med-tech industry analyst Thomas Gunderson said via e-mail.

Developed in Minnesota, the Micra Transcatheter Pacemaker System is less than 10 percent the size of a traditional pacemaker, allowing it be implanted directly inside the heart's right ventricle without open-chest surgery. It was designed with a slim profile so the doctor can thread it into the heart from a small puncture in a blood vessel in the groin.

The Centers for Medicare and Medicaid Services' (CMS) decision to cover Micra implants hinges on Medtronic using well-designed — and potentially expensive — studies to collect clinical evidence over a long period of time. Medicare will begin covering the devices as soon as CMS approves the studies.

Although Micra pacemakers have batteries that could last eight to 12 years, no patient has had one long enough to deplete the battery. The devices can be retrieved if necessary, but Medtronic says they are designed to stay in the heart after the battery depletes. Additional devices can be placed alongside the depleted ones, if needed.

"Medtronic is pleased with the CMS decision to cover leadless pacemakers, which will allow broad patient access to this novel, minimally invasive pacemaker technology," Dr. John Liddicoat, president of Medtronic's cardiac-rhythm device division, said in a statement.

Pacemakers regulate a slow or irregular heartbeat by sending electric pulses that cause the heart rate to increase. There are many different styles and programming settings for pacemakers, depending on the complexity of the patient's condition. About 200,000 pacemakers are implanted in the U.S. annually in patients with a slow heart beat, according to the American College of Cardiology.

The Micra is a simple single-chamber pacemaker approved to treat the slow heartbeat called bradycardia, as well as more complex conditions in patients for which placement of leads in the heart's upper chambers is considered unneeded or too risky.

The device has no electrical leads and does not require the creation of a surgical "pocket" under the skin, thus avoiding the two biggest sources of complications with traditional pacemakers. In public comments, doctors and medical experts told CMS that leadless pacemakers represent "the future of pacing."

"We feel leadless pacemakers have a small but very important role in patient care, and expect it to grow over time with improvements in the devices," experts with Minneapolis-based Allina Health wrote in a Dec. 14 public comment. "Leadless pacemakers offer significant advantages over existing pacemakers in some circumstances."

At an FDA hearing last year, some medical experts wondered whether the devices could introduce new risks. For example, since leadless pacemakers attach directly to the heart, doctors could potentially damage the tissue during implantation, especially early on when they're still learning how to implant the new type of device.

A study published in the New England Journal of Medicine last year found that 96 percent of 725 Micra patients in a nonrandomized clinical trial had no major complications six months after the implant. That compared favorably to a historical control population, in which more than 7 percent of 2,667 patients had major complications six months after implants of traditional devices.

The Micra is the only device of its kind approved in the U.S. St. Jude Medical, now part of Abbott Laboratories, opted to stop implants of its leadless pacemaker, the Nanostim, late last year. An Abbott spokesman said Thursday that the company is working with regulators to resume implants sometime in the second half of 2017.

Boston Scientific and Biotronik are also developing a leadless pacemaker.

Although Medtronic doesn't publish the sticker prices that hospitals pay for Micra devices, Medicare will pay hospitals higher fees to implant the Micra than traditional pacemakers.

A company spokesman said Medicare's 2017 fee schedule shows the government will pay roughly $14,500 for an outpatient Micra implant vs. $9,200 for a traditional unit. For inpatient procedures, Medicare will pay between $27,700 and $41,000 for a Micra implant vs. $12,500 to $21,600 for a traditional unit.

Medtronic shares closed at $74.04 Thursday, down 45 cents for the day.

Joe Carlson • 612-673-4779