GP access to cardiac tests under debate

Ruby Prosser Scully reports from the CSANZ conference in Adelaide

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Should stress ECG be a gatekeeper for stress echocardiographs? Ruby Prosser Scully reports from the CSANZ conference in Adelaide

Restricting GP access to stress echocardiography and myocardial perfusion studies are two of the issues being debated as part of the government’s review into MBS item numbers, according to the chair of the review’s cardiac committee.

The group is debating whether to tighten the descriptors for these studies in the hopes of curbing increasing spending on the tests, Professor Richard Harper told the 64th Annual Scientific Meeting of Cardiac Society of Australia conference.

Rates of echo cardiographs had increased “dramatically” and there was immense variation in testing relating to Medicare Local regions, he said.

Quite a few of these tests were likely to be unnecessary, and the question was “extremely important”, Monash University’s emeritus director of cardiology said.

“You can see that 65% of the expenditure is on echo, and that stress echo is also a big component,” he said.
More than half of all echocardiography tests were referred by GPs, and GP referrals made up 70% of all stress echocardiographs on the MBS, he added.

This suggested GPs were bypassing exercise ECG tests which were half the cost, for the obvious reason that
stress echocardiography had a higher sensitivity and specificity, Professor Harper said.

“But what is sometimes forgotten is the negative predictive value of an ordinary ECG test.”

Stress ECG tests had a negative predictive value of outcomes over a four-year period of 99.3%, according to one large study of general practice patients who had vague symptoms and a low-to-intermediate probability of coronary disease.

So one controversial argument is that stress ECG should be a gatekeeper test for stress echocardiographs or stress nuclear studies.

This would mean that only if a stress ECG came back as equivocal or concerning, could a clinician order a
stress echocardiograph.

“But because [echocardiograph] is such a useful test and because it has so many indications, it’s extremely difficult to write any meaningful descriptor,” he said.

“In fact, it’s almost impossible. So it’s going to be very difficult to stop.”

The group was also looking at the appropriate frequency for cardiographs and whether a repeat test should attract a lower MBS rebate because most of the yield was from the initial test, he said.

Stress myocardial perfusion scans, which accounted for only 6% of services but incur around 20% of the costs, was singled out.

“So it’s still a significant issue as to when nuclear stress tests should be done in comparison to stress echo,” he said, especially considering the diagnostic accuracy was virtually identical but a nuclear stress test was two and a half times the cost and had a radiation burden.

There is also a debate about whether GPs should have access to CT coronary angiogram testing to assess patients with low or intermediate risk.

A CTCA actually provided more information than stress tests, Professor Harper said.

But the CTCA item descriptor should also be tightened to patients with known coronary disease, and limited to once every five years, he said.