New diagnostic tool cuts hospital admissions for chest pain
7 October 2013
New fast-track diagnostic tool cuts hospital admissions for chest pain
A new fast-track cardiac diagnostic tool trialled at Christchurch Hospital is already cutting down the number of unnecessary hospital admissions involving people presenting with chest pain.
The Accelerated Diagnostic Pathway (ADP), developed by Dr Martin Than and a cross-speciality team at Christchurch Hospital, was designed to speed up the diagnostic process without compromising patient safety. It was put to the test in a two-year randomised control trial funded by the Health Research Council of New Zealand (HRC).
"The results showed that we could double the number of patients that were discharged early from 10 per cent to about 20 per cent. Effectively one in five patients could be discharged within two hours," says Dr Than.
A paper on the study will be released online today in the Journal of the American Medical Association (JAMA).
The usual process for ruling out a heart attack is quite time consuming, and only about 10 to 20 per cent of patients with chest pain will actually have a heart attack as the cause of their pain. The assessment process typically involves a blood test for cardiac troponin when the patient comes in, then a later follow-up troponin test about six hours later. This later test means that patients usually have to be admitted or put in observation wards.
"Potentially there is not only a huge burden on the system, there is a lot of worry for the patient and their family for something that’s not as serious as feared."
Building on their earlier accelerated pathways studies at Christchurch Hospital, Dr Than and his colleagues made use of modern troponin assays in the trial, which involved 544 patients.
Those patients in the experimental group underwent serial troponin tests and an ECG, as well as undergoing risk assessment using the Thrombolysis In Myocardial Infarction score (TIMI). The TIMI score was designed to predict the risk of people coming into hospital with a cardiac problem, and the risk of them coming to harm over the next 30 days.
Dr Than's group hypothesised that if your TIMI score was zero and you had two negative troponin tests and an ECG in the first two hours then you were at less than 1 per cent risk of having a heart attack. You could therefore go home and be followed up as an outpatient, or proceed more quickly to the next inpatient investigations – also saving time.
Doctors in the emergency department were not forced to follow the pathway and there were a further 15 per cent of people that doctors admitted for investigation even though they were categorised as low risk by the diagnostic pathway. None of these patients turned out to have heart disease.
"Potentially we could have seen 35 per cent of patients discharged early, but as the pathway becomes more accepted over time those are gains that will also hopefully be picked up."
The study team was confident in the data and implemented the pathway immediately at Christchurch Public Hospital in mid-2012.
"We’ve been auditing it and it’s been a very successful pathway. We're not aware of any adverse events and we are turning people around quickly."
The pathway has been implemented at Nambour Hospital on Australia’s Sunshine Coast in Queensland without any adverse events, and the Director General of Health in Queensland wants to adopt it for the whole state. It has also been implemented at a hospital in Hong Kong.
Chest pain of suspected cardiac origin is one of the most common presenting complaints in hospitals in the western world and represents up to 25 per cent of admissions. In the United States it leads to about 8 million visits per year at a cost of $20 billion annually.
"That sort of volume of patients puts a lot of strain on a health system because one of the biggest challenges in the modern era is the issue of available beds and overcrowding in the emergency department," says Dr Than.