Saturday, April 7, 2012

How Canada Does Chest Pain

Vancouver, Canada, to be specific.  The 37th most expensive city in the world to live in (ahead of New York and Los Angeles), a jewel on the coast of British Columbia, with breathtaking scenery, evergreens, rugged coasts, and mountains.

This is an observational series of their chest pain algorithm, and it falls into the category of "we do this and we like it" types of articles.  So, they do this, and they like it, and I can see why.

And the first thing you notice is that it is nothing like the United States.  Of the 1,116 patients they enrolled for this follow-up, they send home 25% of their potentially cardiac chest pain after an EKG and a single troponin.  These are patients whose mean age is 43 years old, and have TIMI scores of 0 or 1.  No outpatient stress test is arranged.  None of them had ACS within 30 days.

Another 20% had a negative 2-hour troponin and EKG and were sent home without outpatient stress testing, average age 49 years old and TIMI scores mostly 0 and 1.  None of them had ACS within 30 days.

Finally, at six hours, they were left with a group of 60 year old folks, 30% of their cohort, whose TIMI scores were >1.  They sent them all home, 25% of without an outpatient stress test and 75% with - and none of the no-stress cohort had ACS within 30 days.

Essentially, they send home over half their patients, aged 40 to 60 years old, and a couple cardiac risk factors - and they do fine.  We don't really know what sort of coronary disease the patients discharged without a follow-up stress test had, and it means they probably have some false negatives in their outcomes at 30 days simply because they don't receive any sort of additional diagnostic testing.  But, none of them had an unprovoked adverse coronary event, which counts for something.

About 20% of their patients referred for outpatient stress failed, and about half of those ultimately received a diagnosis of ACS - so, even then, in the patients they were most concerned about after negative ED testing, only 10% had ACS.  Seems like there's room to improve here, as well.

It's not crazy, it's Canada.

"Safety and Efficiency of a Chest Pain Diagnostic Algorithm With Selective Outpatient Stress Testing for Emergency Department Patients With Potential Ischemic Chest Pain"
www.ncbi.nlm.nih.gov/pubmed/22221842

1 comment:

  1. The cheque is in the mail for the lovely first paragraph.

    As a Vancouver emerg guy (in a different hospital) I will endorse that a minimal testing strategy for low risk test pain patients is something that myself and many of my colleagues practice. This pathway is not a zero risk prospect for emerg docs, because although the litigation risk is lower in Canada, chest pain is the single most litigated emergency room case. With that in mind, there are certainly emerg docs on both sides of the border who indiscriminately dump all chest patients into test heavy care pathways because of fear of missing unlikely disease and litigation.

    When you look at this study I think what you see is that once they skim away the patients they think are high risk they are left with a group of patients who they thought were low risk and indeed it turns out that they are low risk. A patient who is clinically low risk, with a low risk ECG and a negative biomarker remains low risk.
    I think this study should be re-titled; 'Low risk chest patients are likely low risk' because that's what it suggests. And, although it seems silly to suggest this in a study, it is clearly necessary because of the inane and expensive work-ups that get initiated in both Canada and the US for patients whose pre-test probability of disease approaches zero.

    Cheers,
    Aaron

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