In a first, Minnesota medical device maker CVRx presented data at an influential medical meeting over the weekend showing that its implantable Barostim Neo electric-stimulation device benefits some patients with advanced heart failure, following years of work designing and testing the therapy.

Elsewhere at the 2019 Heart Rhythm Society meeting last week in San Francisco, Medtronic touted promising first-in-human clinical results from a small study of its new implantable defibrillator that doesn't touch the heart. And competitor Boston Scientific said a large study of its commercially approved defibrillator that doesn't touch the heart had a low complication rate in a diverse population.

Regarding the CVRx therapy, researchers presented clinical data showing that mild electric stimulation applied to natural blood-pressure sensors in the carotid artery in the neck can lead to better quality of life and significantly lower levels of an enzyme fragment that can be used to tell if the heart is under stress.

The data have been submitted to the Food and Drug Administration to get U.S. sales approval to treat heart failure with the Barostim Neo system. The FDA gave the device "expedited access pathway" status in 2015, accelerating the pivotal clinical trial, because the device is intended to treat a life-threatening condition for which no other treatment alternative is available.

Data from the CVRx BeAT-HF trial found that levels of the enzyme component NT-proBNP in the blood decreased 21% after 6 months in patients who got Barostim Neo therapy, compared with a 3% increase in the measurements seen in control patients who didn't get the therapy. NT-proBNP is a natural enzyme component that becomes more common in the blood when the heart's left ventricle is stretched, indicating the heart may be working hard and having trouble meeting the body's demands, according to Lab Tests Online.

The lower NT-proBNP levels were found in a group of 162 active-treatment patients who were already in Class III heart failure, but whose NT-proBNP levels were lower than 1,600. Past studies suggested that heart-failure treatments worked better in patients who were symptomatic, but not yet in Class IV or late-stage Class III heart failure with levels about 1,600. (Barostim patients kept taking their heart drugs during the trial.)

The 162 active Barostim patients self-reported an average 20-point improvement in quality of life, captured on Minnesota Living With Heart Failure questionnaires, compared with a six-point improvement in the control arm. Looking at bodily function, patients who received the therapy also had a 49-point average improvement in the Six-Minute Hall Walk test, compared with control-arm patients who had an eight-point drop.

"To our knowledge, this is the first successful pivotal trial of a device-based therapy targeting the brain or the nervous system to treat a cardiovascular condition," CVRx CEO Nadim Yared said Monday.

CVRx was founded in 2001, and has been trying to commercialize a medical treatment in which a pacemaker-like device implanted under the skin delivers electric current to natural receptors in the neck that sense blood pressure. Although the company originally envisioned it as a treatment for high blood pressure, CVRx pivoted to using the device for the related but separate condition of heart failure, which is the gradual weakening of the heart.

The Brooklyn Park-based company has more than 60 U.S. patents, and major investments from New Enterprise Associates and the Johnson & Johnson venture capital subsidiary JJDC, both of which have seats on CVRx's board.

In other conference news, Medtronic, which is run from offices in Fridley, unveiled the results of its first-in-human trial for its EV-ICD device, which is an implantable defibrillator the same size as a normal ICD that doesn't need wires to physically touch the heart or enter blood vessels.

The results were strong enough that Medtronic said it plans to continue developing and testing the device, which is the product of internal R&D rather than acquisition. The experimental device is not approved for sale in any country.

One of the key functions of any implantable ICD is to detect a heart beating too fast and administer shocks to bring it to a healthy rhythm. Medtronic's EV-ICD successfully detected and treated an episode of ventricular tachycardia in one patient outside of the hospital during the study period. And in controlled conditions during the pilot study, 17 of 19 implanted devices successfully treated ventricular events that were induced in the hospital — a success rate that Medtronic said was consistent with existing ICDs.

Meanwhile, Boston Scientific, which designs and partly manufactures heart devices in Arden Hills, offered a look at partial findings from its ongoing large-scale clinical trial of its S-ICD system, called the Emblem, which also does not directly touch the heart with leads. The device, which was approved for U.S. sales in 2015, was implanted in 1,103 patients who had more than 30 days of follow-up time between 2015 and 2018 as part of the Untouched study.

Although the primary outcome of the study is to examine rates of inappropriate shocks, which will be announced later, the early results announced at HRS said that after 30 days, nearly 96% of the patients were free of complications, and 99% successfully converted a dangerous rhythm during testing. Boston Scientific said both rates were comparable to rates seen in previous studies.