ABCD3 – Better, But Good Enough?

The ABCD2 score for the prediction of stroke after TIA was initially touted as a possible risk-stratification tool geared towards determining which patients could undergo delayed evaluation for modifiable risk factors.  Unfortunately, the “low risk” cohort generated by the ABCD2 score still has an unacceptably high risk of stroke at 7 days, with poor predictive and discriminative power.

These authors try to take it to the next level – the ABCD3 score and the ABCD3-I score.  Derived retrospectively from the Kyoto Stroke Registry, the third element of D3 is “Dual TIA” – which is having had another TIA within the prior 7 days.  Then, the “I” is dependent upon having a positive MRI DWI lesion associated with concurrent ipsilateral carotid artery stenosis.

In their retrospective application of ABCD2, ABCD3, and ABCD3-I, as expected, the ABCD2 score showed minimal utility for the outcome of interest for the Emergency Department – the 7 day risk of stroke in the low-risk cohort was ~6%.  The low-risk ABCD3 and ABCD3-I cohort, however, had a ~1 to 2% risk at 7 days.  If verified prospectively, this begins to approach reliable utility for discharge decision-making in the ED.  Given the ABCD2 score’s checkered past, I would certainly wait for the next bit of evidence.

“ABCD3 and ABCD3-I Scores Are Superior to ABCD2 Score in the Prediction of Short- and Long-Term Risks of Stroke After Transient Ischemic Attack”
http://stroke.ahajournals.org/content/45/2/418.full

2 thoughts on “ABCD3 – Better, But Good Enough?”

  1. I have always been troubled by the ABCD2 score. Not necessarily because some studies have failed to show it works (i.e. failed external validation) But rather it asks us to adopt a less aggressive approach at working up young healthy people who present with TIA's. I would be philosophically much more likely to want to be aggressive in this cohort.

    But let's face it… the reason why the tool probably works is because the patients identified as low risk probably never had a TIA in the first place. Quite a quandary.

    Brian

    Brian Doyle, MD FACEM FACEP

  2. My TIA experience..

    I'm a 48 male, fairly healthy, not overweight, a naturally athletic/muscular type body.

    When I went to the ER after experiencing what I thought at the time was a stroke (and am now convinced was a TIA), i.e. sudden intense numbness in my hand that quickly (within seconds) traveled up my arm and to the side of my face.. and lasted less than a minute. Let me tell you this was an extremely scary experience, which cannot be properly described unless you've gone through it yourself. The point is, you just KNOW it's something serious and not a "pinched nerve" as the ER doctor suggested. Your body and common sense has a way of letting you know this is not run-of-the-mill stuff.

    After talking to me for literally all of 3 minutes or so the ER doctor was somewhat dismissive, almost as if he thought I was some hypochondriac (this was my first visit to an ER in probably 20 years or so) wasting his time and told me I had a choice, that he could either send me home and instruct me to take aspirin or he could start running tests, but that he was sure everything was going to come back negative. The nurse told me she couldn't believe he was willing to send me home, considering my symptoms, without insisting on tests first. I asked him to advise, he after all was the doctor. He shrugged his shoulders and said "it's up to you", lol. I opted for some testing (blood work, EKG, CAT) Of course it all came back negative.. the doctor was almost smug in giving me the "good" news telling me "I told you", what bedside manners. He sent me on my way and told me to take an aspirin every morning.

    Of course I understand that a TIA is fairly hard to correctly diagnose, due to there being no damage, to begin with, but everything I read says my symptoms were a textbook sign of a TIA.

    According to ABCD2 score of 2 (Unilateral Weakness was the only relevant choice for me) I have a low risk of a stroke overall. Of course this does little to reassure me after reading more about it's usefulness. I'm by no means totally consumed with fear, but it's always in the back of my mind. The experience was surreal in that it's like nothing I've ever experienced before and well, extremely scary. The though that this could possibly be a precursor to a full-on stroke, where things could be much worse, is to say the least, unsettling. Being relatively young, a non-smoker (5 years now) and negative blood work I'm just hoping this was a bump in the road and I'll be sticking around for a while and doing so stroke free..

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