NEW ORLEANS — People with a type of heart failure for which there are no treatments saw their symptoms improve using a heart device to improve blood flow to the body, a new study suggests.

About half of heart failure patients have a type called heart failure with preserved ejection fraction, in which the heart can’t normally fill with blood because the muscle is stiff or thickened. This can lead to lung congestion and difficulty breathing, even during simple everyday activities.

In the new study, researchers tested Corvia Medical’s InterAtrial Shunt Device. The flower-shaped wire device is used to create a pencil-sized hole between the heart’s upper chambers to improve blood flow and prevent further weakening of the heart muscle. Surgeons place the device using a noninvasive procedure that involves threading a catheter up to the heart through an artery in the leg.

The 64 patients in the study, called REDUCE LAP-HF, reported fewer symptoms, better quality of life and increased exercise capacity at both six months and one year after receiving the device. There were no safety alarms among patients.

The study was presented Wednesday at the American Heart Association’s Scientific Sessions and published online in the AHA’s journal Circulation: Heart Failure.

A randomized clinical trial expected to be completed early next year is testing how well the device works in patients with the device compared with those without, said the study’s lead investigator David Kaye, Ph.D., a heart failure researcher at Baker IDI Heart and Diabetes Institute in Melbourne, Australia.

Although the study results represent good news for heart failure patients, cardiologist Javed Butler, M.D., cautioned that the trial was relatively short and there isn’t much information about the long-term pros and cons of a procedure that requires doctors to puncture the heart.

Butler, who is chief of cardiology at Stony Brook University in Long Island, New York, was also concerned about the potential cost of the procedure.

Still, Butler recognizes there’s no adequate treatment for the pumping problem and said “every therapy that comes out would be welcome.”

According to the American Heart Association, about 5.7 million U.S. adults have heart failure, and nearly half of patients die within five years of diagnosis. In 2013, heart failure killed more than 65,000 Americans, data from the Centers for Disease Control and Prevention show.

Three patients in the study died before the annual visit, and one did not report for it. One of the deaths was caused by a stroke and another died from renal failure and pneumonia. The cause of death for the third was undetermined.

Tewksbury, Massachusetts-based Corvia Medical funded the study.