The United States Food and Drug Administration recently approved a newly developed heart pump tested in a clinical trial at the University of Wisconsin.

The approval of the new Ventricular Assist Device by the FDA will make therapy aimed at patients waiting for a heart transplant available to a much larger group of patients, according to UW professor of cardiothoracic surgery Takushi Kohmoto.

“It’s a milestone that this new device has been approved as a destination therapy to those who are not candidates for transplants. It’s a major advantage to these patients,” Kohmoto said.

The device, known as the HeartMate II, circulates the blood continuously and pumps the blood throughout the body in heart failure patients, Kohmoto said, adding the device pumps blood when the heart is too weak to do so.

The patients who took part in the trial were diagnosed with advanced heart failure, meaning they did not have much time to live — less than a year in many cases, Nancy Sweitzer, assistant professor in the Department of Cardiovascular Medicine, said.

After being implanted with the device for two years, 47 percent of the patients went without a stroke or a device failure, meeting the goal of the trial, according to a UW release.

It added only 11 percent of the patients implanted with the HeartMate XVE — an older, larger pump — showed the same results.

An estimated 60,000 to 150,000 U.S. patients experience advanced heart failure, in addition to the 2,100 patients who actually receive heart transplants every year, according to the release.

The HeartMate II is expected to keep patients with severe heart disease alive for two to five years, Sweitzer said. Kohmoto added it could keep patients alive for more than five years.

“The HeartMate XVE works much differently than the HeartMate II,” Sweitzer said. “Typically, after about 12 to 24 months, the HeartMate XVE will break down and stop working. The HeartMate II doesn’t have that 12 to 24 month failure.”

One of the major improvements of the HeartMate II from the earlier model is its decrease in size. The older HeartMate XVE measured to be about 1 inch thick and was about the size of a standard CD case, Kohmoto said.

He added the HeartMate II is about a quarter of the size of the HeartMate XVE.

Because of its large size, the HeartMate XVE needed to be implanted in the abdomen. This made it far more difficult to implant and remove than the much smaller HeartMate II, which is about the size of a C battery and is implanted in the chest, the release said.

Both researchers said they were very optimistic about the results of the trial.

“The HeartMate II can do the job of a heart that’s failing,” Sweitzer said. “Some patients have even felt well enough to play tennis with their kids. These pumps really do help the patients feel so much better.”