Medical device maker Boston Scientific Corp. plans to pay more than $200 million to buy the remaining stake in a device company called Cryterion Medical, which owns an invention that uses a burst of cold to the heart to treat atrial fibrillation.

Boston Scientific, a Massachusetts company that employs thousands of Minnesotans who design and make heart devices, announced Thursday that it would make an upfront cash payment of $202 million to acquire the roughly 65 percent stake in Southern California’s Cryterion Medical that it didn’t already own.

Boston Scientific has been an investor in Cryterion Medical since 2016, when the company was founded, the deal announcement said. Cryterion Medical is also the owner of a contract-manufacturer based in County Wexford, Ireland, called Cryterion Balloons.

So far Cryterion Medical’s “single-shot” cryoablation balloon technology hasn’t been approved for use in any country. Cryterion is running a clinical study in Europe to support a 2019 application for CE Mark approval there. Cryterion also expects to begin enrollment next year for a clinical study to support future regulatory approval from the U.S. Food and Drug Administration.

“Initial clinical study results demonstrate that our system has a promising safety profile as well as acute efficacy,” Keegan Harper, CEO of Cryterion Medical, said in the deal announcement. “We look forward to bringing this advanced cryoablation system to market with the support of Boston Scientific.”

Atrial fibrillation, an erratic heartbeat linked to problems including stroke, is a relatively common heart problem affecting about 9 percent of people aged 65 or older, according to the Centers for Disease Control and Prevention.

“Afib” is often treated with prescription drugs, but medical device therapies exist for difficult-to-treat cases. The goal of Afib “ablation” treatments is to precisely apply energy to the heart muscle to alter the irregular electric signals in the tissue that trigger the problem. Radio-frequency (RF) energy, which produces heat, as well as cryothermal therapy, which applies cold, have both been tested as Afib treatments.

Cryterion is developing a single-shot “cryoablation” system that includes a next-generation balloon catheter that can be threaded into the heart and expanded to apply cold energy to the ablation target. The system is being developed with an advanced mapping catheter that helps monitor therapy effectiveness, as well as a steerable sheath that guides it into place. It’s designed to improve the workflow in a cryoablation procedure, especially cases involving challenging cardiac anatomy.

Once the deal to acquire Cryterion Medical is complete, Boston Scientific will have balloon-based ablation devices for RF and cryothermal energy in its portfolio.

The deal for Cryterion Medical “enhances our AF ablation procedure offerings, allowing physicians to select a therapeutic option based on clinical preference and specific patient needs,” Dr. Kenneth Stein, chief medical officer for rhythm management at Boston Scientific, said in the news release.

Within the $5 billion global market for electrophysiology devices, single-shot ablation therapies are among the fastest-growing market segments, with double-digit sales growth that will trend toward $1 billion in annual sales within “the next few years,” Boston Scientific said.

One May 2017 systematic review of past studies on ablation concluded that the single-shot cryoablation appeared to be a promising and effective alternative to traditional point-by-point ablation of heart tissue using RF devices. Another systematic review, published the same month in a different journal, found that cryoablation is characterized by shorter learning curves and procedure times than RF ablation for intermittent Afib.