Man clutching chest with pain

A new study has found that protocols implemented across New Zealand’s emergency departments are helping rule out a heart attack in patients, a lot sooner.

The study funded by the Health Research Council of New Zealand (HRC) has been published in the journal Circulation, and co-author Dr Martin Than was invited to present the findings as late-breaking news at the American Heart Association’s annual Scientific Sessions in California last week.

Dr Than, Emergency Medicine Specialist at the Canterbury District Health Board, and study co-author Dr John Pickering, Associate Professor in the Department of Medicine at the University of Otago, say their findings suggest that globally many millions of patients with chest pain could be discharged early – freeing up health resources for the care of other patients.

"Suspected heart attacks are one of the most common reasons for presenting to ED. Of all those who come in with chest pain, only about 10 to 15 per cent are actually having heart attacks," says Dr Pickering. "That's why it's very important to rule out those who aren't having one."

‘Clinical pathways’ for assessing chest pain and heart attack risk are now being used in emergency departments nationwide. New Zealand was the first country to have a nationwide implementation of these pathways (since the Ministry of Health in 2014 instructed hospitals to use them), and this study is the first to measure the impact of that programme.

Clinical pathways are an evidence-based set of actions that should be followed within a certain time-frame. The pathways/protocols developed and trialled by Dr Than over the past 10 years feature an ‘accelerated diagnostic protocol’ (ADP) designed to assess patients at risk of a heart attack, faster, and send them home earlier.

The protocol is made up of three key elements: conducting an electrocardiogram (ECG) early; taking two blood tests to measure troponin levels – when the patient first comes into the ED and then two hours later; and assessing the patient’s risk score – based on their medical history, demographics and the nature of pain they’re experiencing.

The study, which included seven hospitals and 31,332 patients, found that prior to implementing a clinical pathway/protocol, 8 per cent of patients who came to ED with suspected cardiac chest pain were sent home within six hours. After implementing the protocol, 18 per cent of patients were sent home within six hours. 

Patient safety was also assessed by identifying any major adverse cardiac events in the 30 days after discharge. It was found that no adverse event occurred when clinical pathways were correctly followed.

The study also found patients reduced their hospital stay by a median of 2.9 hours.

That means, after implementation of clinical pathways across all the acute care hospitals in New Zealand, patients would spend a total of 165,000 hours less in hospital per annum, says Dr Pickering.

It’s a win for both patients and hospitals. "For New Zealanders, it means you're being assessed with some of the best evidence-based tools available, and if you're low-risk, you're much less likely to be hospitalised unnecessarily,” he says.

"There are thousands of patients being reassured a lot earlier that they're not having a heart attack. This is an accelerated process, different to anything else that's been done before. All the work is being done in ED and the decision about risk and discharge is being made nice and early.”

The HRC’s Chief Executive, Professor Kath McPherson, says early and accurate diagnosis is crucial for patients, and the health system.

“It means more rapid and appropriate treatment for those who need it and earlier reassurance for those who have not had a heart attack. It is also really pleasing to see this New Zealand health research leading the world.”

Dr Pickering says it's due to HRC funding that this evaluation could be done. "I'm thrilled we were able to monitor this change. If you don't get grant funding, you don't get to do these things.

"It feels fantastic to be involved with something you actually see makes a difference. I'm privileged to be at the pointy end of the pyramid, to actually see things implemented.”

Some hospitals around the world have implemented a similar pathway, but the study’s authors hope we're getting close to the situation where all countries are going to mandate some kind of diagnostic protocol. 

"The point is that people have accepted and recognised that there needs to be a systematic approach to assessing patients for heart attacks. And, everywhere a clinical pathway is being used, it's getting patients home efficiently and safely,” says Dr Pickering.