(Bloomberg) -- Two new studies found that for patients with damaged aortic valves, it may be safer and more effective to thread a replacement valve into the body with a catheter rather than cracking open the chest for open-heart surgery.

For decades, surgeons have repaired leaky aortic valves with one of medicine’s most dramatic procedures, splitting the sternum and stopping the heart to sew a new valve in place while the patient is kept alive by machines. The new valves from Edwards Lifesciences Corp. and Medtronic Plc can be inserted through an incision in the leg, threaded up to the heart, and then fixed in place far less invasively.

The new valves are already used in the about 20 percent of patients who are too sick to withstand open-heart surgery or may have complications from the operation. The latest company-sponsored findings, presented at the American College of Cardiology meeting in New Orleans, suggest Edwards’s and Medtronic’s valves should be used in almost all patients.

The heart procedures make up 61 percent of Edwards’s revenues, and expanding use of the devices is a key part of Wall Street’s optimistic view about the company. In the U.S., there are about 90,000 diagnosed, low-risk patients, said Jason McGorman, an analyst with Bloomberg Intelligence. He called the expanded use a $2.5 billion opportunity.

Patients given Edwards’s Sapien 3 valve were almost half as likely to die, suffer a stroke or need to be hospitalized again within the first year of treatment as those who underwent a traditional operation. A study of Medtronic’s Evolut yielded similar benefits after one year and found that the procedure wasn’t inferior to surgery after two years, the primary goal of the study.

“The default until now has been surgical valves, unless you are in one of these high-risk groups,” said Joseph Cleveland, professor of cardiothoracic surgery at the University of Colorado Anschutz Medical Campus. “Surgery will be only for cases where TAVR won’t work. This is a game-changer.” TAVR stands for transcatheter aortic valve replacement.

Cleveland wasn’t involved in the trials; he reviewed the results for the cardiology society.

More Questions

As the valves are used in younger and healthier patients, it’s not clear how they’ll hold up over the long term compared with surgically implanted valves that have a much longer track record.

The Edwards study followed 1,000 healthier, lower-risk patients, finding that 8.5 percent who got Edwards’s Sapien 3 valve died, had a stroke or were rehospitalized in the first year, compared with 15.1 percent of surgery patients.

In the Medtronic trial of 1,468 patients who got the company’s Evolut device, 5.6 percent of patients died, had a disabling stroke or were hospitalized for heart failure in the first year, compared with 10.2 percent of surgery patients.

After two years, the patients who got the less-invasive procedure did just as well as surgery patients on death and disabling stroke, though Evolut patients were more likely to have blood flowing backward into the heart or need a pacemaker after treatment.

To contact the reporter on this story: Michelle Fay Cortez in Minneapolis at mcortez@bloomberg.net

To contact the editors responsible for this story: Drew Armstrong at darmstrong17@bloomberg.net, Mark Schoifet

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