Jason, a reader, yesterday raised the following question about door to balloon times:
So I read something interesting a while back and unfortunately I’m not going to be able to site a source but it said this. A door to ballon time (d2b) of < 90 mins was immensely beneficial in decreasing m&m in STEMI pt's. We all know that now. It said a d2b < 75 mins added a little more benefit in reducing m&m. But I think at about d2b of about 60 mins we start to approach the limit. That is in decreasing d2b below 60 mins we realize no additional benefit.
Can anyone site the study?
There are many studies out there. Most of what I have read suggests the shorter the door-to-balloon time the better. Here is the study I use in some of my presentations.Association of door-to-balloon time and mortality in patients admitted to hospital with ST elevation myocardial infarction: national cohort study. It was published in the British Medical Journal in 2009.
Here was the conclusion:
“Any delay in primary percutaneous coronary intervention after a patient arrives at hospital is associated with higher mortality in hospital in those admitted with ST elevation myocardial infarction. Time to treatment should be as short as possible, even in centres currently providing primary percutaneous coronary intervention within 90 minutes.”
Here is a graph from that article illustrating the impact of decreasing door-to-balloon times on mortality.
A new study, also in the British Medical Journal (May 2012), Association of onset to balloon and door to balloon time with long term clinical outcome in patients with ST elevation acute myocardial infarction having primary percutaneous coronary intervention: observational study, suggests that what really matters is presentation to balloon time. And that in those patients who present early, the shortest possible door-to-balloon time improves outcomes.
Here is their summary:
What is already known on this topic:
Results from previous studies are quite inconsistent regarding the relation of symptom onset to balloon time and clinical outcomes in patients with ST segment elevation myocardial infarction.
The time to evaluate endpoints varied widely between these different studies.
Little is known about the relation of onset to balloon time with long term clinical outcomes in actual clinical practice.
What this study adds:
A clear association has been shown between a short onset to balloon time of less than three hours and better long term (three year) clinical outcomes.
The benefit of short door to balloon time was limited to patients who presented early.
Further improvement in the outcome of patients with ST segment elevation myocardial infarction could be achieved by reducing the total ischaemic time with various efforts.
The bottom line for paramedics is do everything we can to contribute to the safe shortening of door-to-balloon times in STEMI patients. The best way we can do that is through early activation.