This is further supporting evidence for how important high-sensitivity troponin is as a prognostic factor. There’s a whole raft of areas.
There was a study from Sweden that went into a clinic with patients with CAD who were perfectly stable who had high-sensitivity troponin measured. There was a moderate group who were asymptomatic that had elevated troponin. Over the next couple of years, these patients did badly and had events. Even when you talk to someone who says they feel perfect, if they have an elevated troponin, it’s not a good sign.
We see the same thing in medical intensive care units. When patients have moderate troponin elevation along with their other illness abnormalities, it says they have a bad prognostic sign.
There are further data that say when you come to the ED and you’re having some symptoms like chest pain, if your troponin is normal, you’ll do fine and even in follow-up, you’ll do fine. There have been other reports of this as well.
Often in Europe, when a patient with chest pain comes in, clinicians will watch them for 1 hour with the troponin and if it’s negative, they send them home. We’re a little more reluctant to do it in 1 hour in the U.S. Many of our patients don’t have typical chest pain, and the European studies are done in patients with chest pain. Sometimes MIs present with shortness of breath, fainting or even confusion in elderly patients. Our EDs measure troponin left, right and center. It’s not as focused. We usually take 3 hours to decide MI or no MI, but even so, the high-sensitivity troponin is going to be very helpful as a screening test in the ED and it tells you that it’s not good to have an elevated troponin no matter what the setting is.
We need more U.S. data because the patients we’re seeing in the ED are different than what has been seen in European studies, where they only screen patients with chest pain. I expect studies conducted in the U.S. to be similar with some minor variations, but it will still say if you have an elevated troponin, it’s not good, and if you have a normal troponin, you’re pretty safe.
There are also a couple of articles with data that point out that if you combine troponin with B-type natriuretic peptide or one of the other atrial natriuretic factor measurements, you get a closer approximation as to how much trouble we’re going to have with the patient down the road when they’re admitted. It is not good to have both an elevated atrial natriuretic factor as well as troponin.
This is a very important marker. Just about a year ago, the high-sensitivity test was finally approved in the U.S. and now we have a couple of them, one that measures troponin T and one that measures troponin I.
We’re in an era of biomarkers, and troponin is one of the very best biomarkers. There are many others being offered, but the thing is with troponin is that it’s been standardized. We understand a lot about how it’s used.
I’m collaborating with one of our hospitals up in Phoenix who have an early high-sensitivity troponin program. They find the length of stay in the ED is shorter, and fewer patients are admitted to the hospital. There’s some cost saving in this, and in our current health care system, any cost saving is great.
Joseph S. Alpert, MD
Cardiology Today Editorial Board Member
University of Arizona Sarver Heart Center
Disclosures: Alpert reports no relevant financial disclosures.