Aortic stenosis exercise test ‘inaccurate’

An established test used to see if people need open heart surgery could be leading to too many patients undergoing the procedure, it is claimed.

A study, led by Professor Gerry McCann, professor of cardiac imaging and honorary consultant cardiologist from the University of Leicester’s Department of Cardiovascular Sciences, has claimed that the exercise test, which involves cycling on a stationary bike, has only a 60% accuracy rate.

It means that almost twice as many people with aortic stenosis undergo surgery than actually need to, costing the NHS millions of pounds.

“There is no doubt that valve replacement therapy is highly effective for patients with symptoms, however there are risks involved,” said Professor McCann, whose study is published in the European Heart Journal.

“It’s a major operation and there’s a 1% chance of people dying or having a stroke during or after. There’s also the chance they could develop an infection.

“It can often take six months to recover, but if they survive they tend to do very well afterwards. However, if we know a patient has AS and no symptoms and we do nothing there’s also a 1% chance they will die so there’s a fine line between whether we should intervene or not.

“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.”

Professor McCann said further research is needed to establish if there is a more accurate way for doctors to determine if patients should wait for symptoms to develop or to intervene beforehand.

Singh A et al. Comparison of exercise testing and CMR measured myocardial perfusion reserve for predicting outcome in asymptomatic aortic stenosis: the Prognostic Importance of Microvascular Dysfunction in Aortic Stenosis (PRIMID AS) Study. European Heart Journal 13 February 2017; doi: 10.1093/eurheartj/ehx001 [abstract]