After many years of various studies of moderate size looking at the diagnostic performance of high-sensitivity troponin assays, now we have a new entry: the Calculation of Myocardial Infarction Risk Probabilities to Manage Patients with Suspicion of Myocardial Infarction (COMPASS-MI) project.
This is not new data, but rather the power team of Roche and Abbott pooling the results of 15 prior studies to describe the diagnostic performance of their Elecsys and Architect high-sensitivity platforms. Then, there are really two parts of this article. There is an initial analysis looking at the performance characteristics of differing combinations of initial and serial sampling of each. After that, these authors pull in several age- and comorbidity-matched comparison populations and describe the long-term 1- and 2- year outcomes of patients with differing levels of troponin concentrations.
The main product of their work, however, boils down to a set of mildly confusing wheels of data regarding the negative predictive value of various combinations of initial troponin level and serial troponin change, divided up based on whether repeat sampling was performed early or late. These cut-offs are further divided on the wheel regarding the proportion of the population with a certain risk level for 30-ay MI or death.
The end result, combined with the various massive supplementary appendicies, are massive amounts of data to help systems using these assays tailor their practice patterns to their desired level of sensitivity and specificity. The authors are not specifically prescriptive in any one cut-off, but rather try to provide as much data as possible. Prevalence of nSTEMI in their population was about 14%, meaning the negative predictive values are only generalizable to to similar patient demographics.
If you’re using these assays, this is quite important work to help assist in interpretation. If not, considering there’s no comparative data to conventional assays, it seems to have limited utility.
It should finally be noted virtually all the listed authors of this work receive some financial support from the manufacturers of these assays.
“Application of High-Sensitivity Troponin in Suspected Myocardial Infarction”
https://www.nejm.org/doi/full/10.1056/NEJMoa1803377