THE successful Australian trial of a new emergency department (ED) strategy that cut 20 minutes off door-to-balloon (DTB) times in cases of suspected myocardial infarction (MI) has prompted calls for the approach to be widely adopted.
The strategy involves ED doctors activating the cardiac catheterisation laboratory (CCL) and immediately transferring patients with suspected ST-elevation myocardial infarction (STEMI), bypassing time-consuming consultation with the cardiology team.
Trial results favourable
The 2-year trial included 234 patients who underwent emergency coronary angiography for suspected STEMI at Perth’s Sir Charles Gairdner Hospital.
The median DTB time for patients who subsequently required percutaneous coronary intervention (PCI) was cut from 97 to 77 minutes.
The proportion of patients treated within the recommended DTB time of less than 90 minutes almost doubled, from 41% to 77%, and there was no change in false-positive CCL activation rates.
The authors said every 30-minute delay in PCI increased the absolute risk of the patient dying in hospital by 1%.
Co-author Associate Professor David Mountain, ED physician at Sir Charles Gairdner Hospital, said that since the trial ended in 2009, DTB time had been cut by a further 10-15 minutes.
About 80% of patients were now treated in less than 90 minutes, he told InSight.
Ambulances bypass ED when MI suspected
DTB times were also cut by an initiative where skilled ambulance staff notified the ED of suspected MI cases and headed straight to the CCL.
“It should be a worldwide standard that the first doctor qualified to read ECGs that the [patient] meets calls the lab – it shouldn’t be a delayed multi-layered system,” Professor Mountain said.
The approach is also cost-effective because it involves fewer medical staff, he said.
Addressing delays critical
Professor Richard Harper, emeritus director of cardiology at MonashHeart, Monash Medical Centre in Melbourne, said some emergency departments needed ‘a shake-up’ and should introduce the new pathway, or a variation of it, that ensured a DTB time of less than 90 minutes for patients presenting at a PCI-capable hospital.
National Heart Foundation chief medical adviser, Professor James Tatoulis, said delays from the time of dialling 000 to arrival at a PCI centre also needed addressing.
A Danish study published in JAMA last week (August 18) of more than 6000 patients with STEMI found the longer the system delay from the time of contact with the ambulance service to arrival at the PCI centre, the higher the death rate.
Professor Tatoulis said early data from the Monash Medical Centre and the Royal Melbourne Hospital, both trialling the direct transport of STEMI patients from the ambulance to the CCL, indicated a reduction in DTB time of 50%.
Professor Mountain said he believed some other major hospitals in Australia were already using the new pathway.
Posted 23 August, 2010