New research from the University of Leicester in the United Kingdom suggests that a test to check if patients with aortic stenosis need open heart surgery could be sending twice as many people into an unnecessary procedure, which can be costly and dangerous.

The study, led by Gerry McCann, MD, a professor of cardiac imaging and an honorary consultant cardiologist from the University of Leicester, was conducted as part of a National Institute for Health Research (NIHR) fellowship. Findings on the test, approved in 2012, were published in the European Heart Journal.

Results showed that the test could have resulted in many unnecessary surgeries. Furthermore, according to the study, the test only has a 60 percent accuracy rate.

"Our findings showed that this exercise test, which has been approved by the American Heart Association, American College of Cardiology and the European Society of Cardiology, was highly inaccurate as almost twice the number of people who became breathless during the test did not develop symptoms within a year,” McCann said in a statement.

During the test, if participants become breathless, the test guidelines recommend they undergo valve replacement therapy.

"There is no doubt that valve replacement therapy is highly effective for patients with symptoms, however there are risks involved,” McCann said. “It's a major operation and there's a 1 percent chance of people dying or having a stroke during or after. There's also the chance they could develop an infection.”

Developing a better way to determine if a patient needs open heart surgery could save thousands of dollars and between seven and 10 days in the hospital per patient. McCann wants to conduct more research in the future to find a better method of assessing a patient’s condition.

"It can often take six months to recover, but if they survive they tend to do very well afterwards,” McCann said. “However, if we know a patient has aortic stenosis and no symptoms and we do nothing, there's also a one percent chance they will die so there's a fine line between whether we should intervene or not.”